diff options
Diffstat (limited to 'lib')
| -rwxr-xr-x | lib/nimbase.h | 11 | ||||
| -rwxr-xr-x | lib/pure/streams.nim | 8 | ||||
| -rwxr-xr-x | lib/system.nim | 20 | ||||
| -rwxr-xr-x | lib/system/cellsets.nim | 6 | ||||
| -rwxr-xr-x | lib/system/gc.nim | 1034 | ||||
| -rwxr-xr-x | lib/system/hti.nim | 43 | ||||
| -rwxr-xr-x | lib/system/mmdisp.nim | 6 | ||||
| -rw-r--r-- | lib/system/oldgc.nim | 1044 | ||||
| -rwxr-xr-x | lib/system/sysstr.nim | 15 | ||||
| -rw-r--r-- | lib/system/timers.nim | 7 | ||||
| -rwxr-xr-x | lib/wrappers/openssl.nim | 6 |
11 files changed, 1883 insertions, 317 deletions
diff --git a/lib/nimbase.h b/lib/nimbase.h index 7fb70a60c..573ad16f7 100755 --- a/lib/nimbase.h +++ b/lib/nimbase.h @@ -436,6 +436,17 @@ struct TFrame { NI len; }; +#define nimfr(proc, file) \ + volatile TFrame F; \ + F.procname = proc; F.filename = file; F.line = 0; F.len = 0; pushFrame(&F); + +#define nimfrs(proc, file, slots) \ + volatile struct {TFrame* prev;NCSTRING procname;NI line;NCSTRING filename; NI len; TVarSlot s[slots];} F; \ + F.procname = proc; F.filename = file; F.line = 0; F.len = slots; pushFrame((TFrame*)&F); + +#define nimln(n, file) \ + F.line = n; F.filename = file; + #define NIM_POSIX_INIT __attribute__((constructor)) #if defined(_MSCVER) && defined(__i386__) diff --git a/lib/pure/streams.nim b/lib/pure/streams.nim index 212aab493..232205ebd 100755 --- a/lib/pure/streams.nim +++ b/lib/pure/streams.nim @@ -180,8 +180,12 @@ proc readLine*(s: PStream): TaintedString = if c == '\c': c = readChar(s) break - elif c == '\L' or c == '\0': break - result.string.add(c) + if c == '\b': + result.string.setLen(result.len - 1) + elif c == '\L' or c == '\0': + break + else: + result.string.add(c) type PStringStream* = ref TStringStream ## a stream that encapsulates a string diff --git a/lib/system.nim b/lib/system.nim index 892f4f8c5..b4c265f62 100755 --- a/lib/system.nim +++ b/lib/system.nim @@ -186,9 +186,9 @@ when not defined(niminheritable): when not defined(EcmaScript) and not defined(NimrodVM): type - TGenericSeq {.compilerproc, pure, inheritable.} = object + TGenericSeq* {.compilerproc, pure, inheritable.} = object len, reserved: int - PGenericSeq {.exportc.} = ptr TGenericSeq + PGenericSeq* {.exportc.} = ptr TGenericSeq # len and space without counting the terminating zero: NimStringDesc {.compilerproc, final.} = object of TGenericSeq data: array[0..100_000_000, char] @@ -565,7 +565,7 @@ proc abs*(x: int64): int64 {.magic: "AbsI64", noSideEffect.} ## checking is turned on). type - IntMax32 = int|int8|int16|int32 + IntMax32 = bool|int|int8|int16|int32 proc `+%` *(x, y: IntMax32): IntMax32 {.magic: "AddU", noSideEffect.} proc `+%` *(x, y: Int64): Int64 {.magic: "AddU", noSideEffect.} @@ -2486,3 +2486,17 @@ proc compiles*(x: expr): bool {.magic: "Compiles", noSideEffect.} = when defined(initDebugger): initDebugger() + +# XXX: make these the default (or implement the NilObject optimization) +proc safeAdd*[T](x: var seq[T], y: T) {.noSideEffect.} = + if x == nil: x = @[y] + else: x.add(y) + +proc safeAdd*(x: var string, y: char) = + if x == nil: x = "" + x.add(y) + +proc safeAdd*(x: var string, y: string) = + if x == nil: x = y + else: x.add(y) + diff --git a/lib/system/cellsets.nim b/lib/system/cellsets.nim index b860ef38c..5de4ca811 100755 --- a/lib/system/cellsets.nim +++ b/lib/system/cellsets.nim @@ -10,10 +10,12 @@ # Efficient set of pointers for the GC (and repr) type + TRefCount = int + TCell {.pure.} = object - refcount: int # the refcount and some flags + refcount: TRefCount # the refcount and some flags typ: PNimType - when leakDetector: + when trackAllocationSource: filename: cstring line: int diff --git a/lib/system/gc.nim b/lib/system/gc.nim index ec656e0ef..bc3474adf 100755 --- a/lib/system/gc.nim +++ b/lib/system/gc.nim @@ -32,20 +32,73 @@ when defined(memProfiler): proc nimProfile(requestedSize: int) const - rcIncrement = 0b1000 # so that lowest 3 bits are not touched - # NOTE: Most colors are currently unused - rcBlack = 0b000 # cell is colored black; in use or free - rcGray = 0b001 # possible member of a cycle - rcWhite = 0b010 # member of a garbage cycle - rcPurple = 0b011 # possible root of a cycle - rcZct = 0b100 # in ZCT - rcRed = 0b101 # Candidate cycle undergoing sigma-computation - rcOrange = 0b110 # Candidate cycle awaiting epoch boundary - rcShift = 3 # shift by rcShift to get the reference counter - colorMask = 0b111 + rcShift = 6 # the reference count is shifted so we can use + # the least significat bits for additinal flags: + + rcAlive = 0b00000 # object is reachable. + # color *black* in the original paper + + rcCycleCandidate = 0b00001 # possible root of a cycle. *purple* + + rcDecRefApplied = 0b00010 # the first dec-ref phase of the + # collector was already applied to this + # object. *gray* + + rcMaybeDead = 0b00011 # this object is a candidate for deletion + # during the collect cycles algorithm. + # *white*. + + rcReallyDead = 0b00100 # this is proved to be garbage + + rcRetiredBuffer = 0b00101 # this is a seq or string buffer that + # was replaced by a resize operation. + # see growObj for details + + rcColorMask = TRefCount(0b00111) + + rcZct = 0b01000 # already added to ZCT + rcInCycleRoots = 0b10000 # already buffered as cycle candidate + rcHasStackRef = 0b100000 # the object had a stack ref in the last + # cycle collection + + rcMarkBit = rcHasStackRef # this is currently used for leak detection + # when traceGC is on + + rcBufferedAnywhere = rcZct or rcInCycleRoots + + rcIncrement = 1 shl rcShift # don't touch the color bits + +const + NewObjectsAreCycleRoots = true + # the alternative is to use the old strategy of adding cycle roots + # in incRef (in the compiler itself, this doesn't change much) + + IncRefRemovesCandidates = false + # this is safe only if we can reliably track the fact that the object + # has stack references. This could be easily done by adding another bit + # to the refcount field and setting it up in unmarkStackAndRegisters. + # The bit must also be set for new objects that are not rc1 and it must be + # examined in the decref loop in collectCycles. + # XXX: not implemented yet as tests didn't show any improvement from this + + MarkingSkipsAcyclicObjects = false + # Acyclic objects can be safely ignored in the mark and scan phases, + # because they cannot contribute to the internal count. + # XXX: if we generate specialized `markCyclic` and `markAcyclic` + # procs we can further optimize this as there won't be need for any + # checks in the code + + MinimumStackMarking = false + # Try to scan only the user stack and ignore the part of the stack + # belonging to the GC itself. see setStackTop for further info. + # XXX: still has problems in release mode in the compiler itself. + # investigate how it affects growObj + + CollectCyclesStats = false + type TWalkOp = enum - waZctDecRef, waPush, waCycleDecRef + waPush TFinalizer {.compilerproc.} = proc (self: pointer) {.nimcall.} # A ref type can have a finalizer that is called before the object's @@ -63,19 +116,28 @@ type TGcHeap {.final, pure.} = object # this contains the zero count and # non-zero count table stackBottom: pointer + stackTop: pointer cycleThreshold: int zct: TCellSeq # the zero count table decStack: TCellSeq # cells in the stack that are to decref again - cycleRoots: TCellSet + cycleRoots: TCellSeq tempStack: TCellSeq # temporary stack for recursion elimination + freeStack: TCellSeq # objects ready to be freed recGcLock: int # prevent recursion via finalizers; no thread lock + cycleRootsTrimIdx: int # Trimming is a light-weight collection of the + # cycle roots table that uses a cheap linear scan + # to find only possitively dead objects. + # One strategy is to perform it only for new objects + # allocated between the invocations of CollectZCT. + # This index indicates the start of the range of + # such new objects within the table. when withRealTime: maxPause: TNanos # max allowed pause in nanoseconds; active if > 0 region: TMemRegion # garbage collected region stat: TGcStat var - gch {.rtlThreadVar.}: TGcHeap + gch* {.rtlThreadVar.}: TGcHeap when not defined(useNimRtl): InstantiateForRegion(gch.region) @@ -88,16 +150,92 @@ template release(gch: TGcHeap) = when hasThreadSupport and hasSharedHeap: releaseSys(HeapLock) -proc addZCT(s: var TCellSeq, c: PCell) {.noinline.} = - if (c.refcount and rcZct) == 0: - c.refcount = c.refcount and not colorMask or rcZct - add(s, c) +template setColor(c: PCell, color) = + c.refcount = (c.refcount and not rcColorMask) or color + +template color(c: PCell): expr = + c.refcount and rcColorMask + +template isBitDown(c: PCell, bit): expr = + (c.refcount and bit) == 0 + +template isBitUp(c: PCell, bit): expr = + (c.refcount and bit) != 0 + +template setBit(c: PCell, bit): expr = + c.refcount = c.refcount or bit + +template isDead(c: Pcell): expr = + c.isBitUp(rcReallyDead) # also covers rcRetiredBuffer + +template clearBit(c: PCell, bit): expr = + c.refcount = c.refcount and (not TRefCount(bit)) + +when debugGC: + var gcCollectionIdx = 0 + + proc colorStr(c: PCell): cstring = + let color = c.color + case color + of rcAlive: return "alive" + of rcMaybeDead: return "maybedead" + of rcCycleCandidate: return "candidate" + of rcDecRefApplied: return "marked" + of rcRetiredBuffer: return "retired" + of rcReallyDead: return "dead" + else: return "unknown?" + + proc inCycleRootsStr(c: PCell): cstring = + if c.isBitUp(rcInCycleRoots): result = "cycleroot" + else: result = "" + + proc inZctStr(c: PCell): cstring = + if c.isBitUp(rcZct): result = "zct" + else: result = "" + + proc writeCell*(msg: CString, c: PCell, force = false) = + var kind = -1 + if c.typ != nil: kind = ord(c.typ.kind) + when trackAllocationSource: + c_fprintf(c_stdout, "[GC %d] %s: %p %d rc=%ld %s %s %s from %s(%ld)\n", + gcCollectionIdx, + msg, c, kind, c.refcount shr rcShift, + c.colorStr, c.inCycleRootsStr, c.inZctStr, + c.filename, c.line) + else: + c_fprintf(c_stdout, "[GC] %s: %p %d rc=%ld\n", + msg, c, kind, c.refcount shr rcShift) + +proc addZCT(zct: var TCellSeq, c: PCell) {.noinline.} = + if c.isBitDown(rcZct): + c.setBit rcZct + zct.add c + +template setStackTop(gch) = + # This must be called immediately after we enter the GC code + # to minimize the size of the scanned stack. The stack consumed + # by the GC procs may amount to 200-400 bytes depending on the + # build settings and this contributes to false-positives + # in the conservative stack marking + when MinimumStackMarking: + var stackTop {.volatile.}: pointer + gch.stackTop = addr(stackTop) + +template addCycleRoot(cycleRoots: var TCellSeq, c: PCell) = + if c.color != rcCycleCandidate: + c.setColor rcCycleCandidate + + # the object may be buffered already. for example, consider: + # decref; incref; decref + if c.isBitDown(rcInCycleRoots): + c.setBit rcInCycleRoots + cycleRoots.add c proc cellToUsr(cell: PCell): pointer {.inline.} = # convert object (=pointer to refcount) to pointer to userdata result = cast[pointer](cast[TAddress](cell)+%TAddress(sizeof(TCell))) -proc usrToCell(usr: pointer): PCell {.inline.} = +proc usrToCell*(usr: pointer): PCell {.inline.} = # convert pointer to userdata to object (=pointer to refcount) result = cast[PCell](cast[TAddress](usr)-%TAddress(sizeof(TCell))) @@ -115,22 +253,30 @@ proc internRefcount(p: pointer): int {.exportc: "getRefcount".} = when BitsPerPage mod (sizeof(int)*8) != 0: {.error: "(BitsPerPage mod BitsPerUnit) should be zero!".} -when debugGC: - proc writeCell(msg: CString, c: PCell) = - var kind = -1 - if c.typ != nil: kind = ord(c.typ.kind) - when leakDetector: - c_fprintf(c_stdout, "[GC] %s: %p %d rc=%ld from %s(%ld)\n", - msg, c, kind, c.refcount shr rcShift, c.filename, c.line) - else: - c_fprintf(c_stdout, "[GC] %s: %p %d rc=%ld\n", - msg, c, kind, c.refcount shr rcShift) +# forward declarations: +proc collectCT(gch: var TGcHeap) +proc IsOnStack*(p: pointer): bool {.noinline.} +proc forAllChildren(cell: PCell, op: TWalkOp) +proc doOperation(p: pointer, op: TWalkOp) +proc forAllChildrenAux(dest: Pointer, mt: PNimType, op: TWalkOp) +# we need the prototype here for debugging purposes + +proc prepareDealloc(cell: PCell) = + if cell.typ.finalizer != nil: + # the finalizer could invoke something that + # allocates memory; this could trigger a garbage + # collection. Since we are already collecting we + # prevend recursive entering here by a lock. + # XXX: we should set the cell's children to nil! + inc(gch.recGcLock) + (cast[TFinalizer](cell.typ.finalizer))(cellToUsr(cell)) + dec(gch.recGcLock) when traceGC: # traceGC is a special switch to enable extensive debugging type TCellState = enum - csAllocated, csZctFreed, csCycFreed + csAllocated, csFreed var states: array[TCellState, TCellSet] @@ -140,155 +286,197 @@ when traceGC: if c in states[csAllocated]: writeCell("attempt to alloc an already allocated cell", c) sysAssert(false, "traceCell 1") - excl(states[csCycFreed], c) - excl(states[csZctFreed], c) - of csZctFreed: - if c in states[csZctFreed]: - writeCell("attempt to free zct cell twice", c) + excl(states[csFreed], c) + # writecell("allocated", c) + of csFreed: + if c in states[csFreed]: + writeCell("attempt to free a cell twice", c) sysAssert(false, "traceCell 2") - if c in states[csCycFreed]: - writeCell("attempt to free with zct, but already freed with cyc", c) - sysAssert(false, "traceCell 3") if c notin states[csAllocated]: writeCell("attempt to free not an allocated cell", c) - sysAssert(false, "traceCell 4") - excl(states[csAllocated], c) - of csCycFreed: - if c notin states[csAllocated]: - writeCell("attempt to free a not allocated cell", c) - sysAssert(false, "traceCell 5") - if c in states[csCycFreed]: - writeCell("attempt to free cyc cell twice", c) - sysAssert(false, "traceCell 6") - if c in states[csZctFreed]: - writeCell("attempt to free with cyc, but already freed with zct", c) - sysAssert(false, "traceCell 7") + sysAssert(false, "traceCell 3") excl(states[csAllocated], c) + # writecell("freed", c) incl(states[state], c) - proc writeLeakage() = - var z = 0 - var y = 0 - var e = 0 + proc computeCellWeight(c: PCell): int = + var x: TCellSet + x.init + + let startLen = gch.tempStack.len + c.forAllChildren waPush + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if c in states[csFreed]: continue + inc result + if c notin x: + x.incl c + c.forAllChildren waPush + + template markChildrenRec(cell) = + let startLen = gch.tempStack.len + cell.forAllChildren waPush + let isMarked = cell.isBitUp(rcMarkBit) + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if c in states[csFreed]: continue + if c.isBitDown(rcMarkBit): + c.setBit rcMarkBit + c.forAllChildren waPush + if c.isBitUp(rcMarkBit) and not isMarked: + writecell("cyclic cell", cell) + cprintf "Weight %d\n", cell.computeCellWeight + + proc writeLeakage(onlyRoots: bool) = + if onlyRoots: + for c in elements(states[csAllocated]): + if c notin states[csFreed]: + markChildrenRec(c) + var f = 0 + var a = 0 for c in elements(states[csAllocated]): - inc(e) - if c in states[csZctFreed]: inc(z) - elif c in states[csCycFreed]: inc(y) - else: writeCell("leak", c) - cfprintf(cstdout, "Allocations: %ld; ZCT freed: %ld; CYC freed: %ld\n", - e, z, y) + inc a + if c in states[csFreed]: inc f + elif c.isBitDown(rcMarkBit): + writeCell("leak", c) + cprintf "Weight %d\n", c.computeCellWeight + cfprintf(cstdout, "Allocations: %ld; freed: %ld\n", a, f) template gcTrace(cell, state: expr): stmt {.immediate.} = + when logGC: writeCell($state, cell) when traceGC: traceCell(cell, state) -# forward declarations: -proc collectCT(gch: var TGcHeap) -proc IsOnStack*(p: pointer): bool {.noinline.} -proc forAllChildren(cell: PCell, op: TWalkOp) -proc doOperation(p: pointer, op: TWalkOp) -proc forAllChildrenAux(dest: Pointer, mt: PNimType, op: TWalkOp) -# we need the prototype here for debugging purposes - -when hasThreadSupport and hasSharedHeap: - template `--`(x: expr): expr = atomicDec(x, rcIncrement) <% rcIncrement - template `++`(x: expr): stmt = discard atomicInc(x, rcIncrement) -else: - template `--`(x: expr): expr = - Dec(x, rcIncrement) - x <% rcIncrement - template `++`(x: expr): stmt = Inc(x, rcIncrement) - -proc prepareDealloc(cell: PCell) = - if cell.typ.finalizer != nil: - # the finalizer could invoke something that - # allocates memory; this could trigger a garbage - # collection. Since we are already collecting we - # prevend recursive entering here by a lock. - # XXX: we should set the cell's children to nil! - inc(gch.recGcLock) - (cast[TFinalizer](cell.typ.finalizer))(cellToUsr(cell)) - dec(gch.recGcLock) +template WithHeapLock(blk: stmt): stmt = + when hasThreadSupport and hasSharedHeap: AcquireSys(HeapLock) + blk + when hasThreadSupport and hasSharedHeap: ReleaseSys(HeapLock) proc rtlAddCycleRoot(c: PCell) {.rtl, inl.} = # we MUST access gch as a global here, because this crosses DLL boundaries! - when hasThreadSupport and hasSharedHeap: - AcquireSys(HeapLock) - incl(gch.cycleRoots, c) - when hasThreadSupport and hasSharedHeap: - ReleaseSys(HeapLock) + WithHeapLock: addCycleRoot(gch.cycleRoots, c) proc rtlAddZCT(c: PCell) {.rtl, inl.} = # we MUST access gch as a global here, because this crosses DLL boundaries! - when hasThreadSupport and hasSharedHeap: - AcquireSys(HeapLock) - addZCT(gch.zct, c) - when hasThreadSupport and hasSharedHeap: - ReleaseSys(HeapLock) + WithHeapLock: addZCT(gch.zct, c) + +type + TCyclicMode = enum + Cyclic, + Acyclic, + MaybeCyclic + + TReleaseType = enum + AddToZTC + FreeImmediately + + THeapType = enum + LocalHeap + SharedHeap + +template `++` (rc: TRefCount, heapType: THeapType): stmt = + when heapType == SharedHeap: + discard atomicInc(rc, rcIncrement) + else: + inc rc, rcIncrement -proc decRef(c: PCell) {.inline.} = +template `--`(rc: TRefCount): expr = + dec rc, rcIncrement + rc <% rcIncrement + +template `--` (rc: TRefCount, heapType: THeapType): expr = + (when heapType == SharedHeap: atomicDec(rc, rcIncrement) <% rcIncrement + else: --rc) + +template doDecRef(cc: PCell, + heapType = LocalHeap, + cycleFlag = MaybeCyclic): stmt = + var c = cc sysAssert(isAllocatedPtr(gch.region, c), "decRef: interiorPtr") + # XXX: move this elesewhere + sysAssert(c.refcount >=% rcIncrement, "decRef") - if --c.refcount: + if c.refcount--(heapType): + # this is the last reference from the heap + # add to a zero-count-table that will be matched against stack pointers rtlAddZCT(c) - elif canBeCycleRoot(c): - # unfortunately this is necessary here too, because a cycle might just - # have been broken up and we could recycle it. - rtlAddCycleRoot(c) - -proc incRef(c: PCell) {.inline.} = - sysAssert(isAllocatedPtr(gch.region, c), "incRef: interiorPtr") - ++c.refcount - if canBeCycleRoot(c): - rtlAddCycleRoot(c) - -proc nimGCref(p: pointer) {.compilerProc, inline.} = incRef(usrToCell(p)) -proc nimGCunref(p: pointer) {.compilerProc, inline.} = decRef(usrToCell(p)) + else: + when cycleFlag != Acyclic: + if cycleFlag == Cyclic or canBeCycleRoot(c): + # a cycle may have been broken + rtlAddCycleRoot(c) + +template doIncRef(cc: PCell, + heapType = LocalHeap, + cycleFlag = MaybeCyclic): stmt = + var c = cc + c.refcount++(heapType) + when cycleFlag != Acyclic: + when NewObjectsAreCycleRoots: + if canbeCycleRoot(c): + addCycleRoot(gch.cycleRoots, c) + elif IncRefRemovesCandidates: + c.setColor rcAlive + # XXX: this is not really atomic enough! + +proc nimGCref(p: pointer) {.compilerProc, inline.} = doIncRef(usrToCell(p)) +proc nimGCunref(p: pointer) {.compilerProc, inline.} = doDecRef(usrToCell(p)) proc nimGCunrefNoCycle(p: pointer) {.compilerProc, inline.} = sysAssert(allocInv(gch.region), "begin nimGCunrefNoCycle") var c = usrToCell(p) sysAssert(isAllocatedPtr(gch.region, c), "nimGCunrefNoCycle: isAllocatedPtr") - if --c.refcount: + if c.refcount--(LocalHeap): rtlAddZCT(c) sysAssert(allocInv(gch.region), "end nimGCunrefNoCycle 2") sysAssert(allocInv(gch.region), "end nimGCunrefNoCycle 5") -proc asgnRef(dest: ppointer, src: pointer) {.compilerProc, inline.} = - # the code generator calls this proc! +template doAsgnRef(dest: ppointer, src: pointer, + heapType = LocalHeap, cycleFlag = MaybeCyclic): stmt = sysAssert(not isOnStack(dest), "asgnRef") # BUGFIX: first incRef then decRef! - if src != nil: incRef(usrToCell(src)) - if dest[] != nil: decRef(usrToCell(dest[])) + if src != nil: doIncRef(usrToCell(src), heapType, cycleFlag) + if dest[] != nil: doDecRef(usrToCell(dest[]), heapType, cycleFlag) dest[] = src +proc asgnRef(dest: ppointer, src: pointer) {.compilerProc, inline.} = + # the code generator calls this proc! + doAsgnRef(dest, src, LocalHeap, MaybeCyclic) + proc asgnRefNoCycle(dest: ppointer, src: pointer) {.compilerProc, inline.} = # the code generator calls this proc if it is known at compile time that no # cycle is possible. - if src != nil: - var c = usrToCell(src) - ++c.refcount - if dest[] != nil: - var c = usrToCell(dest[]) - if --c.refcount: - rtlAddZCT(c) - dest[] = src + doAsgnRef(dest, src, LocalHeap, Acyclic) proc unsureAsgnRef(dest: ppointer, src: pointer) {.compilerProc.} = # unsureAsgnRef updates the reference counters only if dest is not on the # stack. It is used by the code generator if it cannot decide wether a # reference is in the stack or not (this can happen for var parameters). if not IsOnStack(dest): - if src != nil: incRef(usrToCell(src)) + if src != nil: doIncRef(usrToCell(src)) + # XXX we must detect a shared heap here + # better idea may be to just eliminate the need for unsureAsgnRef + # # XXX finally use assembler for the stack checking instead! # the test for '!= nil' is correct, but I got tired of the segfaults # resulting from the crappy stack checking: - if cast[int](dest[]) >=% PageSize: decRef(usrToCell(dest[])) + if cast[int](dest[]) >=% PageSize: doDecRef(usrToCell(dest[])) else: # can't be an interior pointer if it's a stack location! - sysAssert(interiorAllocatedPtr(gch.region, dest)==nil, + sysAssert(interiorAllocatedPtr(gch.region, dest)==nil, "stack loc AND interior pointer") dest[] = src +when hasThreadSupport and hasSharedHeap: + # shared heap version of the above procs + proc asgnRefSh(dest: ppointer, src: pointer) {.compilerProc, inline.} = + doAsgnRef(dest, src, SharedHeap, MaybeCyclic) + + proc asgnRefNoCycleSh(dest: ppointer, src: pointer) {.compilerProc, inline.} = + doAsgnRef(dest, src, SharedHeap, Acyclic) + proc initGC() = when not defined(useNimRtl): when traceGC: @@ -303,6 +491,7 @@ proc initGC() = # init the rt init(gch.zct) init(gch.tempStack) + init(gch.freeStack) Init(gch.cycleRoots) Init(gch.decStack) @@ -355,9 +544,10 @@ proc forAllChildren(cell: PCell, op: TWalkOp) = var d = cast[TAddress](cellToUsr(cell)) var s = cast[PGenericSeq](d) if s != nil: + let baseAddr = d +% GenericSeqSize for i in 0..s.len-1: - forAllChildrenAux(cast[pointer](d +% i *% cell.typ.base.size +% - GenericSeqSize), cell.typ.base, op) + forAllChildrenAux(cast[pointer](baseAddr +% i *% cell.typ.base.size), + cell.typ.base, op) else: nil proc addNewObjToZCT(res: PCell, gch: var TGcHeap) {.inline.} = @@ -378,7 +568,7 @@ proc addNewObjToZCT(res: PCell, gch: var TGcHeap) {.inline.} = template replaceZctEntry(i: expr) = c = d[i] if c.refcount >=% rcIncrement: - c.refcount = c.refcount and not colorMask + c.clearBit(rcZct) d[i] = res return if L > 8: @@ -399,84 +589,108 @@ proc addNewObjToZCT(res: PCell, gch: var TGcHeap) {.inline.} = for i in countdown(L-1, max(0, L-8)): var c = d[i] if c.refcount >=% rcIncrement: - c.refcount = c.refcount and not colorMask + c.clearBit(rcZct) d[i] = res return add(gch.zct, res) -proc rawNewObj(typ: PNimType, size: int, gch: var TGcHeap): pointer = +proc rawNewObj(typ: PNimType, size: int, gch: var TGcHeap, rc1: bool): pointer = # generates a new object and sets its reference counter to 0 acquire(gch) + sysAssert(allocInv(gch.region), "rawNewObj begin") sysAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1") + collectCT(gch) - sysAssert(allocInv(gch.region), "rawNewObj begin") + sysAssert(allocInv(gch.region), "rawNewObj after collect") + var res = cast[PCell](rawAlloc(gch.region, size + sizeof(TCell))) + sysAssert(allocInv(gch.region), "rawNewObj after rawAlloc") + sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "newObj: 2") - # now it is buffered in the ZCT + res.typ = typ - when leakDetector and not hasThreadSupport: - if framePtr != nil and framePtr.prev != nil: - res.filename = framePtr.prev.filename - res.line = framePtr.prev.line - res.refcount = rcZct # refcount is zero, but mark it to be in the ZCT + + when trackAllocationSource and not hasThreadSupport: + if framePtr != nil and framePtr.prev != nil and framePtr.prev.prev != nil: + res.filename = framePtr.prev.prev.filename + res.line = framePtr.prev.prev.line + else: + res.filename = "nofile" + + if rc1: + res.refcount = rcIncrement # refcount is 1 + else: + # its refcount is zero, so add it to the ZCT: + res.refcount = rcZct + addNewObjToZCT(res, gch) + + if NewObjectsAreCycleRoots and canBeCycleRoot(res): + res.setBit(rcInCycleRoots) + res.setColor rcCycleCandidate + gch.cycleRoots.add res + sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3") - # its refcount is zero, so add it to the ZCT: - addNewObjToZCT(res, gch) + when logGC: writeCell("new cell", res) gcTrace(res, csAllocated) release(gch) result = cellToUsr(res) + zeroMem(result, size) + when defined(memProfiler): nimProfile(size) sysAssert(allocInv(gch.region), "rawNewObj end") {.pop.} -proc newObj(typ: PNimType, size: int): pointer {.compilerRtl.} = - result = rawNewObj(typ, size, gch) - zeroMem(result, size) - when defined(memProfiler): nimProfile(size) +proc freeCell(gch: var TGcHeap, c: PCell) = + # prepareDealloc(c) + gcTrace(c, csFreed) + + when reallyDealloc: rawDealloc(gch.region, c) + else: + sysAssert(c.typ != nil, "collectCycles") + zeroMem(c, sizeof(TCell)) + +template eraseAt(cells: var TCellSeq, at: int): stmt = + cells.d[at] = cells.d[cells.len - 1] + dec cells.len + +template trimAt(roots: var TCellSeq, at: int): stmt = + # This will remove a cycle root candidate during trimming. + # a candidate is removed either because it received a refup and + # it's no longer a candidate or because it received further refdowns + # and now it's dead for sure. + let c = roots.d[at] + c.clearBit(rcInCycleRoots) + roots.eraseAt(at) + if c.isBitUp(rcReallyDead) and c.refcount <% rcIncrement: + # This case covers both dead objects and retired buffers + # That's why we must also check the refcount (it may be + # kept possitive by stack references). + freeCell(gch, c) +proc newObj(typ: PNimType, size: int): pointer {.compilerRtl.} = + setStackTop(gch) + result = rawNewObj(typ, size, gch, false) + proc newSeq(typ: PNimType, len: int): pointer {.compilerRtl.} = - # `newObj` already uses locks, so no need for them here. + setStackTop(gch) + # `rawNewObj` already uses locks, so no need for them here. let size = addInt(mulInt(len, typ.base.size), GenericSeqSize) - result = newObj(typ, size) + result = rawNewObj(typ, size, gch, false) cast[PGenericSeq](result).len = len cast[PGenericSeq](result).reserved = len - when defined(memProfiler): nimProfile(size) proc newObjRC1(typ: PNimType, size: int): pointer {.compilerRtl.} = - # generates a new object and sets its reference counter to 1 - sysAssert(allocInv(gch.region), "newObjRC1 begin") - acquire(gch) - sysAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1") - collectCT(gch) - sysAssert(allocInv(gch.region), "newObjRC1 after collectCT") - - var res = cast[PCell](rawAlloc(gch.region, size + sizeof(TCell))) - sysAssert(allocInv(gch.region), "newObjRC1 after rawAlloc") - sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "newObj: 2") - # now it is buffered in the ZCT - res.typ = typ - when leakDetector and not hasThreadSupport: - if framePtr != nil and framePtr.prev != nil: - res.filename = framePtr.prev.filename - res.line = framePtr.prev.line - res.refcount = rcIncrement # refcount is 1 - sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3") - when logGC: writeCell("new cell", res) - gcTrace(res, csAllocated) - release(gch) - result = cellToUsr(res) - zeroMem(result, size) - sysAssert(allocInv(gch.region), "newObjRC1 end") - when defined(memProfiler): nimProfile(size) + setStackTop(gch) + result = rawNewObj(typ, size, gch, true) proc newSeqRC1(typ: PNimType, len: int): pointer {.compilerRtl.} = + setStackTop(gch) let size = addInt(mulInt(len, typ.base.size), GenericSeqSize) - result = newObjRC1(typ, size) + result = rawNewObj(typ, size, gch, true) cast[PGenericSeq](result).len = len cast[PGenericSeq](result).reserved = len - when defined(memProfiler): nimProfile(size) - + proc growObj(old: pointer, newsize: int, gch: var TGcHeap): pointer = acquire(gch) collectCT(gch) @@ -486,43 +700,73 @@ proc growObj(old: pointer, newsize: int, gch: var TGcHeap): pointer = sysAssert(allocInv(gch.region), "growObj begin") var res = cast[PCell](rawAlloc(gch.region, newsize + sizeof(TCell))) - var elemSize = 1 - if ol.typ.kind != tyString: elemSize = ol.typ.base.size + var elemSize = if ol.typ.kind != tyString: ol.typ.base.size + else: 1 var oldsize = cast[PGenericSeq](old).len*elemSize + GenericSeqSize + + # XXX: This should happen outside + # call user-defined move code + # call user-defined default constructor copyMem(res, ol, oldsize + sizeof(TCell)) zeroMem(cast[pointer](cast[TAddress](res)+% oldsize +% sizeof(TCell)), newsize-oldsize) + sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "growObj: 3") sysAssert(res.refcount shr rcShift <=% 1, "growObj: 4") - #if res.refcount <% rcIncrement: - # add(gch.zct, res) - #else: # XXX: what to do here? - # decRef(ol) - if (ol.refcount and colorMask) == rcZct: - var j = gch.zct.len-1 - var d = gch.zct.d - while j >= 0: - if d[j] == ol: - d[j] = res - break - dec(j) - if canBeCycleRoot(ol): excl(gch.cycleRoots, ol) - when logGC: - writeCell("growObj old cell", ol) - writeCell("growObj new cell", res) - gcTrace(ol, csZctFreed) - gcTrace(res, csAllocated) - when reallyDealloc: rawDealloc(gch.region, ol) + + when false: + if ol.isBitUp(rcZct): + var j = gch.zct.len-1 + var d = gch.zct.d + while j >= 0: + if d[j] == ol: + d[j] = res + break + dec(j) + + if ol.isBitUp(rcInCycleRoots): + for i in 0 .. <gch.cycleRoots.len: + if gch.cycleRoots.d[i] == ol: + eraseAt(gch.cycleRoots, i) + + freeCell(gch, ol) + else: - sysAssert(ol.typ != nil, "growObj: 5") - zeroMem(ol, sizeof(TCell)) + # the new buffer inherits the GC state of the old one + if res.isBitUp(rcZct): gch.zct.add res + if res.isBitUp(rcInCycleRoots): gch.cycleRoots.add res + + # Pay attention to what's going on here! We're not releasing the old memory. + # This is because at this point there may be an interior pointer pointing + # into this buffer somewhere on the stack (due to `var` parameters now and + # and `let` and `var:var` stack locations in the future). + # We'll release the memory in the next GC cycle. If we release it here, + # we cannot guarantee that no memory will be corrupted when only safe + # language features are used. Accessing the memory after the seq/string + # has been invalidated may still result in logic errors in the user code. + # We may improve on that by protecting the page in debug builds or + # by providing a warning when we detect a stack pointer into it. + let bufferFlags = ol.refcount and rcBufferedAnywhere + if bufferFlags == 0: + # we need this in order to collect it safely later + ol.refcount = rcRetiredBuffer or rcZct + gch.zct.add ol + else: + ol.refcount = rcRetiredBuffer or bufferFlags + + when logGC: + writeCell("growObj old cell", ol) + writeCell("growObj new cell", res) + + gcTrace(res, csAllocated) release(gch) result = cellToUsr(res) sysAssert(allocInv(gch.region), "growObj end") when defined(memProfiler): nimProfile(newsize-oldsize) proc growObj(old: pointer, newsize: int): pointer {.rtl.} = + setStackTop(gch) result = growObj(old, newsize, gch) {.push profiler:off.} @@ -533,70 +777,214 @@ proc doOperation(p: pointer, op: TWalkOp) = if p == nil: return var c: PCell = usrToCell(p) sysAssert(c != nil, "doOperation: 1") - case op # faster than function pointers because of easy prediction - of waZctDecRef: - #if not isAllocatedPtr(gch.region, c): - # return - # c_fprintf(c_stdout, "[GC] decref bug: %p", c) - sysAssert(isAllocatedPtr(gch.region, c), "decRef: waZctDecRef") - sysAssert(c.refcount >=% rcIncrement, "doOperation 2") - c.refcount = c.refcount -% rcIncrement - when logGC: writeCell("decref (from doOperation)", c) - if c.refcount <% rcIncrement: addZCT(gch.zct, c) - of waPush: - add(gch.tempStack, c) - of waCycleDecRef: - sysAssert(c.refcount >=% rcIncrement, "doOperation 3") - c.refcount = c.refcount -% rcIncrement - + gch.tempStack.add c + proc nimGCvisit(d: pointer, op: int) {.compilerRtl.} = doOperation(d, TWalkOp(op)) +type + TRecursionType = enum + FromChildren, + FromRoot + +proc CollectZCT(gch: var TGcHeap): bool + +template pseudoRecursion(typ: TRecursionType, body: stmt): stmt = + # + +proc trimCycleRoots(gch: var TGcHeap, startIdx = gch.cycleRootsTrimIdx) = + var i = startIdx + while i < gch.cycleRoots.len: + if gch.cycleRoots.d[i].color != rcCycleCandidate: + gch.cycleRoots.trimAt i + else: + inc i + + gch.cycleRootsTrimIdx = gch.cycleRoots.len + # we now use a much simpler and non-recursive algorithm for cycle removal proc collectCycles(gch: var TGcHeap) = - var tabSize = 0 - for c in elements(gch.cycleRoots): - inc(tabSize) - forallChildren(c, waCycleDecRef) - if tabSize == 0: return - gch.stat.cycleTableSize = max(gch.stat.cycleTableSize, tabSize) - - # restore reference counts (a depth-first traversal is needed): - var marker: TCellSet - Init(marker) - for c in elements(gch.cycleRoots): - if c.refcount >=% rcIncrement: - if not containsOrIncl(marker, c): - gch.tempStack.len = 0 - forAllChildren(c, waPush) - while gch.tempStack.len > 0: - dec(gch.tempStack.len) - var d = gch.tempStack.d[gch.tempStack.len] - d.refcount = d.refcount +% rcIncrement - if d in gch.cycleRoots and not containsOrIncl(marker, d): - forAllChildren(d, waPush) - # remove cycles: - for c in elements(gch.cycleRoots): - if c.refcount <% rcIncrement: - gch.tempStack.len = 0 - forAllChildren(c, waPush) - while gch.tempStack.len > 0: - dec(gch.tempStack.len) - var d = gch.tempStack.d[gch.tempStack.len] - if d.refcount <% rcIncrement: - if d notin gch.cycleRoots: # d is leaf of c and not part of cycle - addZCT(gch.zct, d) - when logGC: writeCell("add to ZCT (from cycle collector)", d) - prepareDealloc(c) - gcTrace(c, csCycFreed) - when logGC: writeCell("cycle collector dealloc cell", c) - when reallyDealloc: rawDealloc(gch.region, c) + if gch.cycleRoots.len == 0: return + gch.stat.cycleTableSize = max(gch.stat.cycleTableSize, gch.cycleRoots.len) + + when CollectCyclesStats: + let l0 = gch.cycleRoots.len + let tStart = getTicks() + + var + decrefs = 0 + increfs = 0 + collected = 0 + maybedeads = 0 + + template ignoreObject(c: PCell): expr = + # This controls which objects will be ignored in the mark and scan stages + (when MarkingSkipsAcyclicObjects: not canbeCycleRoot(c) else: false) + # not canbeCycleRoot(c) + # false + # c.isBitUp(rcHasStackRef) + + template earlyMarkAliveRec(cell) = + let startLen = gch.tempStack.len + cell.setColor rcAlive + cell.forAllChildren waPush + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if c.color != rcAlive: + c.setColor rcAlive + c.forAllChildren waPush + + template earlyMarkAlive(stackRoots) = + # This marks all objects reachable from the stack as alive before any + # of the other stages is executed. Such objects cannot be garbage and + # they don't need to participate in the recursive decref/incref. + for i in 0 .. <stackRoots.len: + var c = stackRoots.d[i] + # c.setBit rcHasStackRef + earlyMarkAliveRec(c) + + earlyMarkAlive(gch.decStack) + + when CollectCyclesStats: + let tAfterEarlyMarkAlive = getTicks() + + template recursiveDecRef(cell) = + let startLen = gch.tempStack.len + cell.setColor rcDecRefApplied + cell.forAllChildren waPush + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if ignoreObject(c): continue + + sysAssert(c.refcount >=% rcIncrement, "recursive dec ref") + dec c.refcount, rcIncrement + inc decrefs + if c.color != rcDecRefApplied: + c.setColor rcDecRefApplied + c.forAllChildren waPush + + template markRoots(roots) = + var i = 0 + while i < roots.len: + if roots.d[i].color == rcCycleCandidate: + recursiveDecRef(roots.d[i]) + inc i else: - sysAssert(c.typ != nil, "collectCycles") - zeroMem(c, sizeof(TCell)) + roots.trimAt i + + markRoots(gch.cycleRoots) + + when CollectCyclesStats: + let tAfterMark = getTicks() + c_printf "COLLECT CYCLES %d: %d/%d\n", gcCollectionIdx, gch.cycleRoots.len, l0 + + template recursiveMarkAlive(cell) = + let startLen = gch.tempStack.len + cell.setColor rcAlive + cell.forAllChildren waPush + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if ignoreObject(c): continue + inc c.refcount, rcIncrement + inc increfs + + if c.color != rcAlive: + c.setColor rcAlive + c.forAllChildren waPush + + template scanRoots(roots) = + for i in 0 .. <roots.len: + let startLen = gch.tempStack.len + gch.tempStack.add roots.d[i] + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + if ignoreObject(c): continue + if c.color == rcDecRefApplied: + if c.refcount >=% rcIncrement: + recursiveMarkAlive(c) + else: + # note that this is not necessarily the ultimate + # destiny of the object. we may still mark it alive + # later if we encounter another node from where it's + # reachable. + c.setColor rcMaybeDead + inc maybedeads + c.forAllChildren waPush + + scanRoots(gch.cycleRoots) + + when CollectCyclesStats: + let tAfterScan = getTicks() + + template collectDead(roots) = + for i in 0 .. <roots.len: + var c = roots.d[i] + c.clearBit(rcInCycleRoots) + + let startLen = gch.tempStack.len + gch.tempStack.add c + + while startLen != gch.tempStack.len: + dec gch.tempStack.len + var c = gch.tempStack.d[gch.tempStack.len] + when MarkingSkipsAcyclicObjects: + if not canbeCycleRoot(c): + # This is an acyclic object reachable from a dead cyclic object + # We must do a normal decref here that may add the acyclic object + # to the ZCT + doDecRef(c, LocalHeap, Cyclic) + continue + if c.color == rcMaybeDead and not c.isBitUp(rcInCycleRoots): + c.setColor(rcReallyDead) + inc collected + c.forAllChildren waPush + # we need to postpone the actual deallocation in order to allow + # the finalizers to run while the data structures are still intact + gch.freeStack.add c + prepareDealloc(c) + + for i in 0 .. <gch.freeStack.len: + freeCell(gch, gch.freeStack.d[i]) + + collectDead(gch.cycleRoots) + + when CollectCyclesStats: + let tFinal = getTicks() + cprintf "times:\n early mark alive: %d ms\n mark: %d ms\n scan: %d ms\n collect: %d ms\n decrefs: %d\n increfs: %d\n marked dead: %d\n collected: %d\n", + (tAfterEarlyMarkAlive - tStart) div 1_000_000, + (tAfterMark - tAfterEarlyMarkAlive) div 1_000_000, + (tAfterScan - tAfterMark) div 1_000_000, + (tFinal - tAfterScan) div 1_000_000, + decrefs, + increfs, + maybedeads, + collected + Deinit(gch.cycleRoots) Init(gch.cycleRoots) + Deinit(gch.freeStack) + Init(gch.freeStack) + + when MarkingSkipsAcyclicObjects: + # Collect the acyclic objects that became unreachable due to collected + # cyclic objects. + discard CollectZCT(gch) + # CollectZCT may add new cycle candidates and we may decide to loop here + # if gch.cycleRoots.len > 0: repeat + +var gcDebugging* = false + +var seqdbg* : proc (s: PGenericSeq) {.cdecl.} + proc gcMark(gch: var TGcHeap, p: pointer) {.inline.} = # the addresses are not as cells on the stack, so turn them to cells: sysAssert(allocInv(gch.region), "gcMark begin") @@ -607,13 +995,26 @@ proc gcMark(gch: var TGcHeap, p: pointer) {.inline.} = var objStart = cast[PCell](interiorAllocatedPtr(gch.region, cell)) if objStart != nil: # mark the cell: - objStart.refcount = objStart.refcount +% rcIncrement - add(gch.decStack, objStart) + if objStart.color != rcReallyDead: + if gcDebugging: + # writeCell("marking ", objStart) + else: + inc objStart.refcount, rcIncrement + gch.decStack.add objStart + else: + # With incremental clean-up, objects spend some time + # in various lists before being deallocated. + # We just found a reference on the stack to an object, + # which we have previously labeled as unreachable. + # This is either a bug in the GC or a pure accidental + # coincidence due to the conservative stack marking. + when debugGC: + # writeCell("marking dead object", objStart) when false: if isAllocatedPtr(gch.region, cell): sysAssert false, "allocated pointer but not interior?" # mark the cell: - cell.refcount = cell.refcount +% rcIncrement + inc cell.refcount, rcIncrement add(gch.decStack, cell) sysAssert(allocInv(gch.region), "gcMark end") @@ -664,6 +1065,11 @@ proc stackSize(): int {.noinline.} = var stackTop {.volatile.}: pointer result = abs(cast[int](addr(stackTop)) - cast[int](gch.stackBottom)) +var + jmpbufSize {.importc: "sizeof(jmp_buf)", nodecl.}: int + # a little hack to get the size of a TJmpBuf in the generated C code + # in a platform independant way + when defined(sparc): # For SPARC architecture. proc isOnStack(p: pointer): bool = var stackTop {.volatile.}: pointer @@ -703,12 +1109,7 @@ elif stackIncreases: var b = cast[TAddress](stackTop) var x = cast[TAddress](p) result = a <=% x and x <=% b - - var - jmpbufSize {.importc: "sizeof(jmp_buf)", nodecl.}: int - # a little hack to get the size of a TJmpBuf in the generated C code - # in a platform independant way - + proc markStackAndRegisters(gch: var TGcHeap) {.noinline, cdecl.} = var registers: C_JmpBuf if c_setjmp(registers) == 0'i32: # To fill the C stack with registers. @@ -739,8 +1140,20 @@ else: type PStackSlice = ptr array [0..7, pointer] var registers: C_JmpBuf if c_setjmp(registers) == 0'i32: # To fill the C stack with registers. + when MinimumStackMarking: + # mark the registers + var jmpbufPtr = cast[TAddress](addr(registers)) + var jmpbufEnd = jmpbufPtr +% jmpbufSize + + while jmpbufPtr <=% jmpbufEnd: + gcMark(gch, cast[ppointer](jmpbufPtr)[]) + jmpbufPtr = jmpbufPtr +% sizeof(pointer) + + var sp = cast[TAddress](gch.stackTop) + else: + var sp = cast[TAddress](addr(registers)) + # mark the user stack var max = cast[TAddress](gch.stackBottom) - var sp = cast[TAddress](addr(registers)) # loop unrolled: while sp <% max - 8*sizeof(pointer): gcMark(gch, cast[PStackSlice](sp)[0]) @@ -761,11 +1174,36 @@ else: # end of non-portable code # ---------------------------------------------------------------------------- +proc releaseCell(gch: var TGcHeap, cell: PCell) = + if cell.color != rcReallyDead: + prepareDealloc(cell) + cell.setColor rcReallyDead + + let l1 = gch.tempStack.len + cell.forAllChildren waPush + let l2 = gch.tempStack.len + for i in l1 .. <l2: + var cc = gch.tempStack.d[i] + if cc.refcount--(LocalHeap): + releaseCell(gch, cc) + else: + if canbeCycleRoot(cc): + addCycleRoot(gch.cycleRoots, cc) + + gch.tempStack.len = l1 + + if cell.isBitDown(rcBufferedAnywhere): + freeCell(gch, cell) + # else: + # This object is either buffered in the cycleRoots list and we'll leave + # it there to be collected in the next collectCycles or it's pending in + # the ZCT: + # (e.g. we are now cleaning the 15th object, but this one is 18th in the + # list. Note that this can happen only if we reached this point by the + # recursion). + # We can ignore it now as the ZCT cleaner will reach it soon. + proc CollectZCT(gch: var TGcHeap): bool = - # Note: Freeing may add child objects to the ZCT! So essentially we do - # deep freeing, which is bad for incremental operation. In order to - # avoid a deep stack, we move objects to keep the ZCT small. - # This is performance critical! const workPackage = 100 var L = addr(gch.zct.len) @@ -773,35 +1211,30 @@ proc CollectZCT(gch: var TGcHeap): bool = var steps = workPackage var t0: TTicks if gch.maxPause > 0: t0 = getticks() + while L[] > 0: var c = gch.zct.d[0] + sysAssert c.isBitUp(rcZct), "CollectZCT: rcZct missing!" sysAssert(isAllocatedPtr(gch.region, c), "CollectZCT: isAllocatedPtr") - # remove from ZCT: - sysAssert((c.refcount and rcZct) == rcZct, "collectZCT") - c.refcount = c.refcount and not colorMask + # remove from ZCT: + c.clearBit(rcZct) gch.zct.d[0] = gch.zct.d[L[] - 1] dec(L[]) when withRealtime: dec steps - if c.refcount <% rcIncrement: + if c.refcount <% rcIncrement: # It may have a RC > 0, if it is in the hardware stack or # it has not been removed yet from the ZCT. This is because # ``incref`` does not bother to remove the cell from the ZCT # as this might be too slow. # In any case, it should be removed from the ZCT. But not # freed. **KEEP THIS IN MIND WHEN MAKING THIS INCREMENTAL!** - if canBeCycleRoot(c): excl(gch.cycleRoots, c) - when logGC: writeCell("zct dealloc cell", c) - gcTrace(c, csZctFreed) - # We are about to free the object, call the finalizer BEFORE its - # children are deleted as well, because otherwise the finalizer may - # access invalid memory. This is done by prepareDealloc(): - prepareDealloc(c) - forAllChildren(c, waZctDecRef) - when reallyDealloc: rawDealloc(gch.region, c) + if c.color == rcRetiredBuffer: + if c.isBitDown(rcInCycleRoots): + freeCell(gch, c) else: - sysAssert(c.typ != nil, "collectZCT 2") - zeroMem(c, sizeof(TCell)) + # if c.color == rcReallyDead: writeCell("ReallyDead in ZCT?", c) + releaseCell(gch, c) when withRealtime: if steps == 0: steps = workPackage @@ -813,22 +1246,40 @@ proc CollectZCT(gch: var TGcHeap): bool = if duration >= gch.maxPause - 50_000: return false result = true + gch.trimCycleRoots + #deInit(gch.zct) + #init(gch.zct) -proc unmarkStackAndRegisters(gch: var TGcHeap) = +proc unmarkStackAndRegisters(gch: var TGcHeap) = var d = gch.decStack.d - for i in 0..gch.decStack.len-1: + for i in 0 .. <gch.decStack.len: sysAssert isAllocatedPtr(gch.region, d[i]), "unmarkStackAndRegisters" - # decRef(d[i]) inlined: cannot create a cycle and must not acquire lock + # XXX: just call doDecRef? var c = d[i] + sysAssert c.typ != nil, "unmarkStackAndRegisters 2" + + if c.color == rcRetiredBuffer: + continue + # XXX no need for an atomic dec here: - if --c.refcount: + if c.refcount--(LocalHeap): + # the object survived only because of a stack reference + # it still doesn't have heap refernces addZCT(gch.zct, c) - sysAssert c.typ != nil, "unmarkStackAndRegisters 2" + + if canbeCycleRoot(c): + # any cyclic object reachable from the stack can be turned into + # a leak if it's orphaned through the stack reference + # that's because the write-barrier won't be executed for stack + # locations + addCycleRoot(gch.cycleRoots, c) + gch.decStack.len = 0 proc collectCTBody(gch: var TGcHeap) = when withRealtime: let t0 = getticks() + when debugGC: inc gcCollectionIdx sysAssert(allocInv(gch.region), "collectCT: begin") gch.stat.maxStackSize = max(gch.stat.maxStackSize, stackSize()) @@ -842,7 +1293,7 @@ proc collectCTBody(gch: var TGcHeap) = when cycleGC: if getOccupiedMem(gch.region) >= gch.cycleThreshold or alwaysCycleGC: collectCycles(gch) - discard collectZCT(gch) + sysAssert gch.zct.len == 0, "zct is not null after collect cycles" inc(gch.stat.cycleCollections) gch.cycleThreshold = max(InitialCycleThreshold, getOccupiedMem() * cycleIncrease) @@ -909,6 +1360,7 @@ when not defined(useNimRtl): # set to the max value to suppress the cycle detector proc GC_fullCollect() = + setStackTop(gch) acquire(gch) var oldThreshold = gch.cycleThreshold gch.cycleThreshold = 0 # forces cycle collection @@ -928,7 +1380,7 @@ when not defined(useNimRtl): "[GC] max cycle table size: " & $gch.stat.cycleTableSize & "\n" & "[GC] max stack size: " & $gch.stat.maxStackSize & "\n" & "[GC] max pause time [ms]: " & $(gch.stat.maxPause div 1000_000) - when traceGC: writeLeakage() + when traceGC: writeLeakage(true) GC_enable() {.pop.} diff --git a/lib/system/hti.nim b/lib/system/hti.nim index 93dc79e3d..a2d132dbf 100755 --- a/lib/system/hti.nim +++ b/lib/system/hti.nim @@ -13,11 +13,19 @@ when defined(NimString): else: {.pragma: codegenType.} -type # This should be he same as ast.TTypeKind - # many enum fields are not used at runtime +type + # This should be he same as ast.TTypeKind + # many enum fields are not used at runtime TNimKind = enum - tyNone, tyBool, tyChar, - tyEmpty, tyArrayConstr, tyNil, tyExpr, tyStmt, tyTypeDesc, + tyNone, + tyBool, + tyChar, + tyEmpty, + tyArrayConstr, + tyNil, + tyExpr, + tyStmt, + tyTypeDesc, tyGenericInvokation, # ``T[a, b]`` for types to invoke tyGenericBody, # ``T[a, b, body]`` last parameter is the body tyGenericInst, # ``T[a, b, realInstance]`` instantiated generic type @@ -30,15 +38,30 @@ type # This should be he same as ast.TTypeKind tyTuple, # WARNING: The compiler uses tyTuple for pure objects! tySet, tyRange, - tyPtr, tyRef, + tyPtr, + tyRef, tyVar, tySequence, tyProc, - tyPointer, tyOpenArray, - tyString, tyCString, tyForward, - tyInt, tyInt8, tyInt16, tyInt32, tyInt64, - tyFloat, tyFloat32, tyFloat64, tyFloat128, - tyUInt, tyUInt8, tyUInt16, tyUInt32, tyUInt64, + tyPointer, + tyOpenArray, + tyString, + tyCString, + tyForward, + tyInt, + tyInt8, + tyInt16, + tyInt32, + tyInt64, + tyFloat, + tyFloat32, + tyFloat64, + tyFloat128, + tyUInt, + tyUInt8, + tyUInt16, + tyUInt32, + tyUInt64, tyBigNum, TNimNodeKind = enum nkNone, nkSlot, nkList, nkCase diff --git a/lib/system/mmdisp.nim b/lib/system/mmdisp.nim index 1abf3fbbf..9bf9c1e67 100755 --- a/lib/system/mmdisp.nim +++ b/lib/system/mmdisp.nim @@ -21,6 +21,7 @@ const alwaysGC = false # collect after every memory allocation (for debugging) leakDetector = false overwriteFree = false + trackAllocationSource = leakDetector cycleGC = true # (de)activate the cycle GC reallyDealloc = true # for debugging purposes this can be set to false @@ -306,7 +307,10 @@ else: include "system/cellsets" when not leakDetector: sysAssert(sizeof(TCell) == sizeof(TFreeCell), "sizeof TFreeCell") - include "system/gc" + when true: + include "system/gc" + else: + include "system/oldgc" {.pop.} diff --git a/lib/system/oldgc.nim b/lib/system/oldgc.nim new file mode 100644 index 000000000..f3b90e6bd --- /dev/null +++ b/lib/system/oldgc.nim @@ -0,0 +1,1044 @@ +# +# +# Nimrod's Runtime Library +# (c) Copyright 2012 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +# Garbage Collector +# +# The basic algorithm is *Deferrent Reference Counting* with cycle detection. +# This is achieved by combining a Deutsch-Bobrow garbage collector +# together with Christoper's partial mark-sweep garbage collector. +# +# Special care has been taken to avoid recursion as far as possible to avoid +# stack overflows when traversing deep datastructures. It is well-suited +# for soft real time applications (like games). +{.push profiler:off.} + +const + CycleIncrease = 2 # is a multiplicative increase + InitialCycleThreshold = 4*1024*1024 # X MB because cycle checking is slow + ZctThreshold = 500 # we collect garbage if the ZCT's size + # reaches this threshold + # this seems to be a good value + withRealTime = defined(useRealtimeGC) + +when withRealTime and not defined(getTicks): + include "system/timers" +when defined(memProfiler): + proc nimProfile(requestedSize: int) + +include "system/timers" + +const + rcIncrement = 0b1000 # so that lowest 3 bits are not touched + # NOTE: Most colors are currently unused + rcBlack = 0b000 # cell is colored black; in use or free + rcGray = 0b001 # possible member of a cycle + rcWhite = 0b010 # member of a garbage cycle + rcPurple = 0b011 # possible root of a cycle + rcZct = 0b100 # in ZCT + rcRed = 0b101 # Candidate cycle undergoing sigma-computation + rcOrange = 0b110 # Candidate cycle awaiting epoch boundary + rcShift = 3 # shift by rcShift to get the reference counter + colorMask = 0b111 +type + TWalkOp = enum + waZctDecRef, waPush, waCycleDecRef + + TFinalizer {.compilerproc.} = proc (self: pointer) {.nimcall.} + # A ref type can have a finalizer that is called before the object's + # storage is freed. + + TGcStat {.final, pure.} = object + stackScans: int # number of performed stack scans (for statistics) + cycleCollections: int # number of performed full collections + maxThreshold: int # max threshold that has been set + maxStackSize: int # max stack size + maxStackCells: int # max stack cells in ``decStack`` + cycleTableSize: int # max entries in cycle table + maxPause: int64 # max measured GC pause in nanoseconds + + TGcHeap {.final, pure.} = object # this contains the zero count and + # non-zero count table + stackBottom: pointer + cycleThreshold: int + zct: TCellSeq # the zero count table + decStack: TCellSeq # cells in the stack that are to decref again + cycleRoots: TCellSet + tempStack: TCellSeq # temporary stack for recursion elimination + recGcLock: int # prevent recursion via finalizers; no thread lock + when withRealTime: + maxPause: TNanos # max allowed pause in nanoseconds; active if > 0 + region: TMemRegion # garbage collected region + stat: TGcStat + +var + gch {.rtlThreadVar.}: TGcHeap + +when not defined(useNimRtl): + InstantiateForRegion(gch.region) + +template acquire(gch: TGcHeap) = + when hasThreadSupport and hasSharedHeap: + AcquireSys(HeapLock) + +template release(gch: TGcHeap) = + when hasThreadSupport and hasSharedHeap: + releaseSys(HeapLock) + +proc addZCT(s: var TCellSeq, c: PCell) {.noinline.} = + if (c.refcount and rcZct) == 0: + c.refcount = c.refcount and not colorMask or rcZct + add(s, c) + +proc cellToUsr(cell: PCell): pointer {.inline.} = + # convert object (=pointer to refcount) to pointer to userdata + result = cast[pointer](cast[TAddress](cell)+%TAddress(sizeof(TCell))) + +proc usrToCell(usr: pointer): PCell {.inline.} = + # convert pointer to userdata to object (=pointer to refcount) + result = cast[PCell](cast[TAddress](usr)-%TAddress(sizeof(TCell))) + +proc canbeCycleRoot(c: PCell): bool {.inline.} = + result = ntfAcyclic notin c.typ.flags + +proc extGetCellType(c: pointer): PNimType {.compilerproc.} = + # used for code generation concerning debugging + result = usrToCell(c).typ + +proc internRefcount(p: pointer): int {.exportc: "getRefcount".} = + result = int(usrToCell(p).refcount) shr rcShift + +# this that has to equals zero, otherwise we have to round up UnitsPerPage: +when BitsPerPage mod (sizeof(int)*8) != 0: + {.error: "(BitsPerPage mod BitsPerUnit) should be zero!".} + +when debugGC: + proc writeCell(msg: CString, c: PCell) = + var kind = -1 + if c.typ != nil: kind = ord(c.typ.kind) + when leakDetector: + c_fprintf(c_stdout, "[GC] %s: %p %d rc=%ld from %s(%ld)\n", + msg, c, kind, c.refcount shr rcShift, c.filename, c.line) + else: + c_fprintf(c_stdout, "[GC] %s: %p %d rc=%ld\n", + msg, c, kind, c.refcount shr rcShift) + +when traceGC: + # traceGC is a special switch to enable extensive debugging + type + TCellState = enum + csAllocated, csZctFreed, csCycFreed + var + states: array[TCellState, TCellSet] + + proc traceCell(c: PCell, state: TCellState) = + case state + of csAllocated: + if c in states[csAllocated]: + writeCell("attempt to alloc an already allocated cell", c) + sysAssert(false, "traceCell 1") + excl(states[csCycFreed], c) + excl(states[csZctFreed], c) + of csZctFreed: + if c in states[csZctFreed]: + writeCell("attempt to free zct cell twice", c) + sysAssert(false, "traceCell 2") + if c in states[csCycFreed]: + writeCell("attempt to free with zct, but already freed with cyc", c) + sysAssert(false, "traceCell 3") + if c notin states[csAllocated]: + writeCell("attempt to free not an allocated cell", c) + sysAssert(false, "traceCell 4") + excl(states[csAllocated], c) + of csCycFreed: + if c notin states[csAllocated]: + writeCell("attempt to free a not allocated cell", c) + sysAssert(false, "traceCell 5") + if c in states[csCycFreed]: + writeCell("attempt to free cyc cell twice", c) + sysAssert(false, "traceCell 6") + if c in states[csZctFreed]: + writeCell("attempt to free with cyc, but already freed with zct", c) + sysAssert(false, "traceCell 7") + excl(states[csAllocated], c) + incl(states[state], c) + + proc writeLeakage() = + var z = 0 + var y = 0 + var e = 0 + for c in elements(states[csAllocated]): + inc(e) + if c in states[csZctFreed]: inc(z) + elif c in states[csCycFreed]: inc(y) + else: writeCell("leak", c) + cfprintf(cstdout, "Allocations: %ld; ZCT freed: %ld; CYC freed: %ld\n", + e, z, y) + +template gcTrace(cell, state: expr): stmt {.immediate.} = + when traceGC: traceCell(cell, state) + +# forward declarations: +proc collectCT(gch: var TGcHeap) +proc IsOnStack*(p: pointer): bool {.noinline.} +proc forAllChildren(cell: PCell, op: TWalkOp) +proc doOperation(p: pointer, op: TWalkOp) +proc forAllChildrenAux(dest: Pointer, mt: PNimType, op: TWalkOp) +# we need the prototype here for debugging purposes + +when hasThreadSupport and hasSharedHeap: + template `--`(x: expr): expr = atomicDec(x, rcIncrement) <% rcIncrement + template `++`(x: expr): stmt = discard atomicInc(x, rcIncrement) +else: + template `--`(x: expr): expr = + Dec(x, rcIncrement) + x <% rcIncrement + template `++`(x: expr): stmt = Inc(x, rcIncrement) + +proc prepareDealloc(cell: PCell) = + if cell.typ.finalizer != nil: + # the finalizer could invoke something that + # allocates memory; this could trigger a garbage + # collection. Since we are already collecting we + # prevend recursive entering here by a lock. + # XXX: we should set the cell's children to nil! + inc(gch.recGcLock) + (cast[TFinalizer](cell.typ.finalizer))(cellToUsr(cell)) + dec(gch.recGcLock) + +proc rtlAddCycleRoot(c: PCell) {.rtl, inl.} = + # we MUST access gch as a global here, because this crosses DLL boundaries! + when hasThreadSupport and hasSharedHeap: + AcquireSys(HeapLock) + incl(gch.cycleRoots, c) + when hasThreadSupport and hasSharedHeap: + ReleaseSys(HeapLock) + +proc rtlAddZCT(c: PCell) {.rtl, inl.} = + # we MUST access gch as a global here, because this crosses DLL boundaries! + when hasThreadSupport and hasSharedHeap: + AcquireSys(HeapLock) + addZCT(gch.zct, c) + when hasThreadSupport and hasSharedHeap: + ReleaseSys(HeapLock) + +proc decRef(c: PCell) {.inline.} = + sysAssert(isAllocatedPtr(gch.region, c), "decRef: interiorPtr") + sysAssert(c.refcount >=% rcIncrement, "decRef") + if --c.refcount: + rtlAddZCT(c) + elif canBeCycleRoot(c): + # unfortunately this is necessary here too, because a cycle might just + # have been broken up and we could recycle it. + rtlAddCycleRoot(c) + +proc incRef(c: PCell) {.inline.} = + sysAssert(isAllocatedPtr(gch.region, c), "incRef: interiorPtr") + ++c.refcount + if canBeCycleRoot(c): + rtlAddCycleRoot(c) + +proc nimGCref(p: pointer) {.compilerProc, inline.} = incRef(usrToCell(p)) +proc nimGCunref(p: pointer) {.compilerProc, inline.} = decRef(usrToCell(p)) + +proc nimGCunrefNoCycle(p: pointer) {.compilerProc, inline.} = + sysAssert(allocInv(gch.region), "begin nimGCunrefNoCycle") + var c = usrToCell(p) + sysAssert(isAllocatedPtr(gch.region, c), "nimGCunrefNoCycle: isAllocatedPtr") + if --c.refcount: + rtlAddZCT(c) + sysAssert(allocInv(gch.region), "end nimGCunrefNoCycle 2") + sysAssert(allocInv(gch.region), "end nimGCunrefNoCycle 5") + +proc asgnRef(dest: ppointer, src: pointer) {.compilerProc, inline.} = + # the code generator calls this proc! + sysAssert(not isOnStack(dest), "asgnRef") + # BUGFIX: first incRef then decRef! + if src != nil: incRef(usrToCell(src)) + if dest[] != nil: decRef(usrToCell(dest[])) + dest[] = src + +proc asgnRefNoCycle(dest: ppointer, src: pointer) {.compilerProc, inline.} = + # the code generator calls this proc if it is known at compile time that no + # cycle is possible. + if src != nil: + var c = usrToCell(src) + ++c.refcount + if dest[] != nil: + var c = usrToCell(dest[]) + if --c.refcount: + rtlAddZCT(c) + dest[] = src + +proc unsureAsgnRef(dest: ppointer, src: pointer) {.compilerProc.} = + # unsureAsgnRef updates the reference counters only if dest is not on the + # stack. It is used by the code generator if it cannot decide wether a + # reference is in the stack or not (this can happen for var parameters). + if not IsOnStack(dest): + if src != nil: incRef(usrToCell(src)) + # XXX finally use assembler for the stack checking instead! + # the test for '!= nil' is correct, but I got tired of the segfaults + # resulting from the crappy stack checking: + if cast[int](dest[]) >=% PageSize: decRef(usrToCell(dest[])) + else: + # can't be an interior pointer if it's a stack location! + sysAssert(interiorAllocatedPtr(gch.region, dest)==nil, + "stack loc AND interior pointer") + dest[] = src + +proc initGC() = + when not defined(useNimRtl): + when traceGC: + for i in low(TCellState)..high(TCellState): Init(states[i]) + gch.cycleThreshold = InitialCycleThreshold + gch.stat.stackScans = 0 + gch.stat.cycleCollections = 0 + gch.stat.maxThreshold = 0 + gch.stat.maxStackSize = 0 + gch.stat.maxStackCells = 0 + gch.stat.cycleTableSize = 0 + # init the rt + init(gch.zct) + init(gch.tempStack) + Init(gch.cycleRoots) + Init(gch.decStack) + +proc forAllSlotsAux(dest: pointer, n: ptr TNimNode, op: TWalkOp) = + var d = cast[TAddress](dest) + case n.kind + of nkSlot: forAllChildrenAux(cast[pointer](d +% n.offset), n.typ, op) + of nkList: + for i in 0..n.len-1: + # inlined for speed + if n.sons[i].kind == nkSlot: + if n.sons[i].typ.kind in {tyRef, tyString, tySequence}: + doOperation(cast[ppointer](d +% n.sons[i].offset)[], op) + else: + forAllChildrenAux(cast[pointer](d +% n.sons[i].offset), + n.sons[i].typ, op) + else: + forAllSlotsAux(dest, n.sons[i], op) + of nkCase: + var m = selectBranch(dest, n) + if m != nil: forAllSlotsAux(dest, m, op) + of nkNone: sysAssert(false, "forAllSlotsAux") + +proc forAllChildrenAux(dest: Pointer, mt: PNimType, op: TWalkOp) = + var d = cast[TAddress](dest) + if dest == nil: return # nothing to do + if ntfNoRefs notin mt.flags: + case mt.Kind + of tyRef, tyString, tySequence: # leaf: + doOperation(cast[ppointer](d)[], op) + of tyObject, tyTuple: + forAllSlotsAux(dest, mt.node, op) + of tyArray, tyArrayConstr, tyOpenArray: + for i in 0..(mt.size div mt.base.size)-1: + forAllChildrenAux(cast[pointer](d +% i *% mt.base.size), mt.base, op) + else: nil + +proc forAllChildren(cell: PCell, op: TWalkOp) = + sysAssert(cell != nil, "forAllChildren: 1") + sysAssert(cell.typ != nil, "forAllChildren: 2") + sysAssert cell.typ.kind in {tyRef, tySequence, tyString}, "forAllChildren: 3" + let marker = cell.typ.marker + if marker != nil: + marker(cellToUsr(cell), op.int) + else: + case cell.typ.Kind + of tyRef: # common case + forAllChildrenAux(cellToUsr(cell), cell.typ.base, op) + of tySequence: + var d = cast[TAddress](cellToUsr(cell)) + var s = cast[PGenericSeq](d) + if s != nil: + let baseAddr = d +% GenericSeqSize + for i in 0..s.len-1: + forAllChildrenAux(cast[pointer](baseAddr +% i *% cell.typ.base.size), + cell.typ.base, op) + else: nil + +proc addNewObjToZCT(res: PCell, gch: var TGcHeap) {.inline.} = + # we check the last 8 entries (cache line) for a slot that could be reused. + # In 63% of all cases we succeed here! But we have to optimize the heck + # out of this small linear search so that ``newObj`` is not slowed down. + # + # Slots to try cache hit + # 1 32% + # 4 59% + # 8 63% + # 16 66% + # all slots 68% + var L = gch.zct.len + var d = gch.zct.d + when true: + # loop unrolled for performance: + template replaceZctEntry(i: expr) = + c = d[i] + if c.refcount >=% rcIncrement: + c.refcount = c.refcount and not colorMask + d[i] = res + return + if L > 8: + var c: PCell + replaceZctEntry(L-1) + replaceZctEntry(L-2) + replaceZctEntry(L-3) + replaceZctEntry(L-4) + replaceZctEntry(L-5) + replaceZctEntry(L-6) + replaceZctEntry(L-7) + replaceZctEntry(L-8) + add(gch.zct, res) + else: + d[L] = res + inc(gch.zct.len) + else: + for i in countdown(L-1, max(0, L-8)): + var c = d[i] + if c.refcount >=% rcIncrement: + c.refcount = c.refcount and not colorMask + d[i] = res + return + add(gch.zct, res) + +proc rawNewObj(typ: PNimType, size: int, gch: var TGcHeap): pointer = + # generates a new object and sets its reference counter to 0 + acquire(gch) + sysAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1") + collectCT(gch) + sysAssert(allocInv(gch.region), "rawNewObj begin") + var res = cast[PCell](rawAlloc(gch.region, size + sizeof(TCell))) + sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "newObj: 2") + # now it is buffered in the ZCT + res.typ = typ + when trackAllocationSource and not hasThreadSupport: + if framePtr != nil and framePtr.prev != nil and framePtr.prev.prev != nil: + res.filename = framePtr.prev.prev.filename + res.line = framePtr.prev.prev.line + else: + res.filename = "nofile" + res.refcount = rcZct # refcount is zero, but mark it to be in the ZCT + sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3") + # its refcount is zero, so add it to the ZCT: + addNewObjToZCT(res, gch) + when logGC: writeCell("new cell", res) + gcTrace(res, csAllocated) + release(gch) + result = cellToUsr(res) + sysAssert(allocInv(gch.region), "rawNewObj end") + +{.pop.} + +proc newObj(typ: PNimType, size: int): pointer {.compilerRtl.} = + result = rawNewObj(typ, size, gch) + zeroMem(result, size) + when defined(memProfiler): nimProfile(size) + +proc newSeq(typ: PNimType, len: int): pointer {.compilerRtl.} = + # `newObj` already uses locks, so no need for them here. + let size = addInt(mulInt(len, typ.base.size), GenericSeqSize) + result = newObj(typ, size) + cast[PGenericSeq](result).len = len + cast[PGenericSeq](result).reserved = len + when defined(memProfiler): nimProfile(size) + +proc newObjRC1(typ: PNimType, size: int): pointer {.compilerRtl.} = + # generates a new object and sets its reference counter to 1 + sysAssert(allocInv(gch.region), "newObjRC1 begin") + acquire(gch) + sysAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1") + collectCT(gch) + sysAssert(allocInv(gch.region), "newObjRC1 after collectCT") + + var res = cast[PCell](rawAlloc(gch.region, size + sizeof(TCell))) + sysAssert(allocInv(gch.region), "newObjRC1 after rawAlloc") + sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "newObj: 2") + # now it is buffered in the ZCT + res.typ = typ + when trackAllocationSource and not hasThreadSupport: + if framePtr != nil and framePtr.prev != nil and framePtr.prev.prev != nil: + res.filename = framePtr.prev.prev.filename + res.line = framePtr.prev.prev.line + else: + res.filename = "nofile" + res.refcount = rcIncrement # refcount is 1 + sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3") + when logGC: writeCell("new cell", res) + gcTrace(res, csAllocated) + release(gch) + result = cellToUsr(res) + zeroMem(result, size) + sysAssert(allocInv(gch.region), "newObjRC1 end") + when defined(memProfiler): nimProfile(size) + +proc newSeqRC1(typ: PNimType, len: int): pointer {.compilerRtl.} = + let size = addInt(mulInt(len, typ.base.size), GenericSeqSize) + result = newObjRC1(typ, size) + cast[PGenericSeq](result).len = len + cast[PGenericSeq](result).reserved = len + when defined(memProfiler): nimProfile(size) + +proc growObj(old: pointer, newsize: int, gch: var TGcHeap): pointer = + acquire(gch) + collectCT(gch) + var ol = usrToCell(old) + sysAssert(ol.typ != nil, "growObj: 1") + sysAssert(ol.typ.kind in {tyString, tySequence}, "growObj: 2") + sysAssert(allocInv(gch.region), "growObj begin") + + var res = cast[PCell](rawAlloc(gch.region, newsize + sizeof(TCell))) + var elemSize = 1 + if ol.typ.kind != tyString: elemSize = ol.typ.base.size + + var oldsize = cast[PGenericSeq](old).len*elemSize + GenericSeqSize + copyMem(res, ol, oldsize + sizeof(TCell)) + zeroMem(cast[pointer](cast[TAddress](res)+% oldsize +% sizeof(TCell)), + newsize-oldsize) + sysAssert((cast[TAddress](res) and (MemAlign-1)) == 0, "growObj: 3") + sysAssert(res.refcount shr rcShift <=% 1, "growObj: 4") + #if res.refcount <% rcIncrement: + # add(gch.zct, res) + #else: # XXX: what to do here? + # decRef(ol) + if (ol.refcount and colorMask) == rcZct: + var j = gch.zct.len-1 + var d = gch.zct.d + while j >= 0: + if d[j] == ol: + d[j] = res + break + dec(j) + if canBeCycleRoot(ol): excl(gch.cycleRoots, ol) + when logGC: + writeCell("growObj old cell", ol) + writeCell("growObj new cell", res) + gcTrace(ol, csZctFreed) + gcTrace(res, csAllocated) + when reallyDealloc: rawDealloc(gch.region, ol) + else: + sysAssert(ol.typ != nil, "growObj: 5") + zeroMem(ol, sizeof(TCell)) + release(gch) + result = cellToUsr(res) + sysAssert(allocInv(gch.region), "growObj end") + when defined(memProfiler): nimProfile(newsize-oldsize) + +proc growObj(old: pointer, newsize: int): pointer {.rtl.} = + result = growObj(old, newsize, gch) + +{.push profiler:off.} + +# ---------------- cycle collector ------------------------------------------- + +var + decrefs = 0 + increfs = 0 + marked = 0 + collected = 0 + +proc doOperation(p: pointer, op: TWalkOp) = + if p == nil: return + var c: PCell = usrToCell(p) + sysAssert(c != nil, "doOperation: 1") + case op # faster than function pointers because of easy prediction + of waZctDecRef: + #if not isAllocatedPtr(gch.region, c): + # return + # c_fprintf(c_stdout, "[GC] decref bug: %p", c) + sysAssert(isAllocatedPtr(gch.region, c), "decRef: waZctDecRef") + sysAssert(c.refcount >=% rcIncrement, "doOperation 2") + c.refcount = c.refcount -% rcIncrement + when logGC: writeCell("decref (from doOperation)", c) + if c.refcount <% rcIncrement: addZCT(gch.zct, c) + of waPush: + add(gch.tempStack, c) + of waCycleDecRef: + sysAssert(c.refcount >=% rcIncrement, "doOperation 3") + c.refcount = c.refcount -% rcIncrement + inc decrefs + +proc nimGCvisit(d: pointer, op: int) {.compilerRtl.} = + doOperation(d, TWalkOp(op)) + +# we now use a much simpler and non-recursive algorithm for cycle removal +proc collectCycles(gch: var TGcHeap) = + var tabSize = 0 + let tStart = getTicks() + decrefs = 0 + increfs = 0 + marked = 0 + collected = 0 + + # XXX: acyclic cutoff (specialized marker procs) + # short trim cycle roots + # long trim with threshold + # don't add new objects to both ztc and cycleroots? + # leak detector with hash in rawNew / free + # + for c in elements(gch.cycleRoots): + inc(tabSize) + forallChildren(c, waCycleDecRef) + if tabSize == 0: return + gch.stat.cycleTableSize = max(gch.stat.cycleTableSize, tabSize) + + c_printf "COLLECT CYCLES: %d\n", tabSize + let tAfterMark = getTicks() + + # restore reference counts (a depth-first traversal is needed): + var marker: TCellSet + Init(marker) + for c in elements(gch.cycleRoots): + if c.refcount >=% rcIncrement: + inc marked + if not containsOrIncl(marker, c): + gch.tempStack.len = 0 + forAllChildren(c, waPush) + while gch.tempStack.len > 0: + dec(gch.tempStack.len) + var d = gch.tempStack.d[gch.tempStack.len] + d.refcount = d.refcount +% rcIncrement + inc increfs + if d in gch.cycleRoots and not containsOrIncl(marker, d): + forAllChildren(d, waPush) + + let tAfterScan = getTicks() + + # remove cycles: + for c in elements(gch.cycleRoots): + if c.refcount <% rcIncrement: + inc collected + gch.tempStack.len = 0 + forAllChildren(c, waPush) + while gch.tempStack.len > 0: + dec(gch.tempStack.len) + var d = gch.tempStack.d[gch.tempStack.len] + if d.refcount <% rcIncrement: + if d notin gch.cycleRoots: # d is leaf of c and not part of cycle + addZCT(gch.zct, d) + when logGC: writeCell("add to ZCT (from cycle collector)", d) + prepareDealloc(c) + gcTrace(c, csCycFreed) + when logGC: writeCell("cycle collector dealloc cell", c) + when reallyDealloc: rawDealloc(gch.region, c) + else: + sysAssert(c.typ != nil, "collectCycles") + zeroMem(c, sizeof(TCell)) + + let tFinal = getTicks() + + cprintf "times:\n mark: %d ms\n scan: %d ms\n collect: %d ms\n decrefs: %d\n increfs: %d\n marked: %d\n collected: %d\n", + (tAfterMark - tStart) div 1_000_000, + (tAfterScan - tAfterMark) div 1_000_000, + (tFinal - tAfterScan) div 1_000_000, + decrefs, + increfs, + marked, + collected + + Deinit(gch.cycleRoots) + Init(gch.cycleRoots) + +var gcDebugging* = false +var vis*: proc (a: pointer, b: PNimType) + +proc debugNode(n: ptr TNimNode) = + c_fprintf(c_stdout, "node %s\n", n.name) + for i in 0..n.len-1: + debugNode(n.sons[i]) + +proc debugTyp(x: PNimType) = + c_fprintf(c_stdout, "type %d\n", x.kind) + if x.node != nil: + debugNode(x.node) + +var seqdbg* : proc (s: PGenericSeq) {.cdecl.} + +type + TCyclicMode = enum + Cyclic, + Acyclic, + MaybeCyclic + + TReleaseType = enum + AddToZTC + FreeImmediately + + THeapType = enum + LocalHeap + SharedHeap + +template `++` (rc: TRefCount, heapType: THeapType): stmt = + when heapType == SharedHeap: + discard atomicInc(rc, rcIncrement) + else: + inc rc, rcIncrement + +template `--`(rc: TRefCount): expr = + dec rc, rcIncrement + rc <% rcIncrement + +template `--` (rc: TRefCount, heapType: THeapType): expr = + (when heapType == SharedHeap: atomicDec(rc, rcIncrement) <% rcIncrement + else: --rc) + +template doDecRef(cc: PCell, + heapType = LocalHeap, + cycleFlag = MaybeCyclic): stmt = + var c = cc + sysAssert(isAllocatedPtr(gch.region, c), "decRef: interiorPtr") + # XXX: move this elesewhere + + sysAssert(c.refcount >=% rcIncrement, "decRef") + if c.refcount--(heapType): + # this is the last reference from the heap + # add to a zero-count-table that will be matched against stack pointers + rtlAddZCT(c) + # writeCell("decref to 0", c) + else: + when cycleFlag != Acyclic: + if cycleFlag == Cyclic or canBeCycleRoot(c): + # a cycle may have been broken + rtlAddCycleRoot(c) + +proc gcMark(gch: var TGcHeap, p: pointer) {.inline.} = + # the addresses are not as cells on the stack, so turn them to cells: + sysAssert(allocInv(gch.region), "gcMark begin") + var cell = usrToCell(p) + var c = cast[TAddress](cell) + if c >% PageSize: + # fast check: does it look like a cell? + var objStart = cast[PCell](interiorAllocatedPtr(gch.region, cell)) + if objStart != nil: + # mark the cell: + if not gcDebugging: + objStart.refcount = objStart.refcount +% rcIncrement + add(gch.decStack, objStart) + when false: + if isAllocatedPtr(gch.region, cell): + sysAssert false, "allocated pointer but not interior?" + # mark the cell: + cell.refcount = cell.refcount +% rcIncrement + add(gch.decStack, cell) + sysAssert(allocInv(gch.region), "gcMark end") + +proc markThreadStacks(gch: var TGcHeap) = + when hasThreadSupport and hasSharedHeap: + {.error: "not fully implemented".} + var it = threadList + while it != nil: + # mark registers: + for i in 0 .. high(it.registers): gcMark(gch, it.registers[i]) + var sp = cast[TAddress](it.stackBottom) + var max = cast[TAddress](it.stackTop) + # XXX stack direction? + # XXX unroll this loop: + while sp <=% max: + gcMark(gch, cast[ppointer](sp)[]) + sp = sp +% sizeof(pointer) + it = it.next + +# ----------------- stack management -------------------------------------- +# inspired from Smart Eiffel + +when defined(sparc): + const stackIncreases = false +elif defined(hppa) or defined(hp9000) or defined(hp9000s300) or + defined(hp9000s700) or defined(hp9000s800) or defined(hp9000s820): + const stackIncreases = true +else: + const stackIncreases = false + +when not defined(useNimRtl): + {.push stack_trace: off.} + proc setStackBottom(theStackBottom: pointer) = + #c_fprintf(c_stdout, "stack bottom: %p;\n", theStackBottom) + # the first init must be the one that defines the stack bottom: + if gch.stackBottom == nil: gch.stackBottom = theStackBottom + else: + var a = cast[TAddress](theStackBottom) # and not PageMask - PageSize*2 + var b = cast[TAddress](gch.stackBottom) + #c_fprintf(c_stdout, "old: %p new: %p;\n",gch.stackBottom,theStackBottom) + when stackIncreases: + gch.stackBottom = cast[pointer](min(a, b)) + else: + gch.stackBottom = cast[pointer](max(a, b)) + {.pop.} + +proc stackSize(): int {.noinline.} = + var stackTop {.volatile.}: pointer + result = abs(cast[int](addr(stackTop)) - cast[int](gch.stackBottom)) + +when defined(sparc): # For SPARC architecture. + proc isOnStack(p: pointer): bool = + var stackTop {.volatile.}: pointer + stackTop = addr(stackTop) + var b = cast[TAddress](gch.stackBottom) + var a = cast[TAddress](stackTop) + var x = cast[TAddress](p) + result = a <=% x and x <=% b + + proc markStackAndRegisters(gch: var TGcHeap) {.noinline, cdecl.} = + when defined(sparcv9): + asm """"flushw \n" """ + else: + asm """"ta 0x3 ! ST_FLUSH_WINDOWS\n" """ + + var + max = gch.stackBottom + sp: PPointer + stackTop: array[0..1, pointer] + sp = addr(stackTop[0]) + # Addresses decrease as the stack grows. + while sp <= max: + gcMark(gch, sp[]) + sp = cast[ppointer](cast[TAddress](sp) +% sizeof(pointer)) + +elif defined(ELATE): + {.error: "stack marking code is to be written for this architecture".} + +elif stackIncreases: + # --------------------------------------------------------------------------- + # Generic code for architectures where addresses increase as the stack grows. + # --------------------------------------------------------------------------- + proc isOnStack(p: pointer): bool = + var stackTop {.volatile.}: pointer + stackTop = addr(stackTop) + var a = cast[TAddress](gch.stackBottom) + var b = cast[TAddress](stackTop) + var x = cast[TAddress](p) + result = a <=% x and x <=% b + + var + jmpbufSize {.importc: "sizeof(jmp_buf)", nodecl.}: int + # a little hack to get the size of a TJmpBuf in the generated C code + # in a platform independant way + + proc markStackAndRegisters(gch: var TGcHeap) {.noinline, cdecl.} = + var registers: C_JmpBuf + if c_setjmp(registers) == 0'i32: # To fill the C stack with registers. + var max = cast[TAddress](gch.stackBottom) + var sp = cast[TAddress](addr(registers)) +% jmpbufSize -% sizeof(pointer) + # sp will traverse the JMP_BUF as well (jmp_buf size is added, + # otherwise sp would be below the registers structure). + while sp >=% max: + gcMark(gch, cast[ppointer](sp)[]) + sp = sp -% sizeof(pointer) + +else: + # --------------------------------------------------------------------------- + # Generic code for architectures where addresses decrease as the stack grows. + # --------------------------------------------------------------------------- + proc isOnStack(p: pointer): bool = + var stackTop {.volatile.}: pointer + stackTop = addr(stackTop) + var b = cast[TAddress](gch.stackBottom) + var a = cast[TAddress](stackTop) + var x = cast[TAddress](p) + result = a <=% x and x <=% b + + proc markStackAndRegisters(gch: var TGcHeap) {.noinline, cdecl.} = + # We use a jmp_buf buffer that is in the C stack. + # Used to traverse the stack and registers assuming + # that 'setjmp' will save registers in the C stack. + type PStackSlice = ptr array [0..7, pointer] + var registers: C_JmpBuf + if c_setjmp(registers) == 0'i32: # To fill the C stack with registers. + var max = cast[TAddress](gch.stackBottom) + var sp = cast[TAddress](addr(registers)) + # loop unrolled: + while sp <% max - 8*sizeof(pointer): + gcMark(gch, cast[PStackSlice](sp)[0]) + gcMark(gch, cast[PStackSlice](sp)[1]) + gcMark(gch, cast[PStackSlice](sp)[2]) + gcMark(gch, cast[PStackSlice](sp)[3]) + gcMark(gch, cast[PStackSlice](sp)[4]) + gcMark(gch, cast[PStackSlice](sp)[5]) + gcMark(gch, cast[PStackSlice](sp)[6]) + gcMark(gch, cast[PStackSlice](sp)[7]) + sp = sp +% sizeof(pointer)*8 + # last few entries: + while sp <=% max: + gcMark(gch, cast[ppointer](sp)[]) + sp = sp +% sizeof(pointer) + +# ---------------------------------------------------------------------------- +# end of non-portable code +# ---------------------------------------------------------------------------- + +proc CollectZCT(gch: var TGcHeap): bool = + # Note: Freeing may add child objects to the ZCT! So essentially we do + # deep freeing, which is bad for incremental operation. In order to + # avoid a deep stack, we move objects to keep the ZCT small. + # This is performance critical! + const workPackage = 100 + var L = addr(gch.zct.len) + + when withRealtime: + var steps = workPackage + var t0: TTicks + if gch.maxPause > 0: t0 = getticks() + while L[] > 0: + var c = gch.zct.d[0] + sysAssert(isAllocatedPtr(gch.region, c), "CollectZCT: isAllocatedPtr") + # remove from ZCT: + sysAssert((c.refcount and rcZct) == rcZct, "collectZCT") + + c.refcount = c.refcount and not colorMask + gch.zct.d[0] = gch.zct.d[L[] - 1] + dec(L[]) + when withRealtime: dec steps + if c.refcount <% rcIncrement: + # It may have a RC > 0, if it is in the hardware stack or + # it has not been removed yet from the ZCT. This is because + # ``incref`` does not bother to remove the cell from the ZCT + # as this might be too slow. + # In any case, it should be removed from the ZCT. But not + # freed. **KEEP THIS IN MIND WHEN MAKING THIS INCREMENTAL!** + if canBeCycleRoot(c): excl(gch.cycleRoots, c) + when logGC: writeCell("zct dealloc cell", c) + gcTrace(c, csZctFreed) + # We are about to free the object, call the finalizer BEFORE its + # children are deleted as well, because otherwise the finalizer may + # access invalid memory. This is done by prepareDealloc(): + prepareDealloc(c) + forAllChildren(c, waZctDecRef) + when reallyDealloc: rawDealloc(gch.region, c) + else: + sysAssert(c.typ != nil, "collectZCT 2") + zeroMem(c, sizeof(TCell)) + when withRealtime: + if steps == 0: + steps = workPackage + if gch.maxPause > 0: + let duration = getticks() - t0 + # the GC's measuring is not accurate and needs some cleanup actions + # (stack unmarking), so subtract some short amount of time in to + # order to miss deadlines less often: + if duration >= gch.maxPause - 50_000: + return false + result = true + +proc unmarkStackAndRegisters(gch: var TGcHeap) = + var d = gch.decStack.d + for i in 0..gch.decStack.len-1: + sysAssert isAllocatedPtr(gch.region, d[i]), "unmarkStackAndRegisters" + # decRef(d[i]) inlined: cannot create a cycle and must not acquire lock + var c = d[i] + # XXX no need for an atomic dec here: + if --c.refcount: + addZCT(gch.zct, c) + sysAssert c.typ != nil, "unmarkStackAndRegisters 2" + gch.decStack.len = 0 + +proc collectCTBody(gch: var TGcHeap) = + when withRealtime: + let t0 = getticks() + sysAssert(allocInv(gch.region), "collectCT: begin") + + gch.stat.maxStackSize = max(gch.stat.maxStackSize, stackSize()) + sysAssert(gch.decStack.len == 0, "collectCT") + prepareForInteriorPointerChecking(gch.region) + markStackAndRegisters(gch) + markThreadStacks(gch) + gch.stat.maxStackCells = max(gch.stat.maxStackCells, gch.decStack.len) + inc(gch.stat.stackScans) + if collectZCT(gch): + when cycleGC: + if getOccupiedMem(gch.region) >= gch.cycleThreshold or alwaysCycleGC: + collectCycles(gch) + discard collectZCT(gch) + inc(gch.stat.cycleCollections) + gch.cycleThreshold = max(InitialCycleThreshold, getOccupiedMem() * + cycleIncrease) + gch.stat.maxThreshold = max(gch.stat.maxThreshold, gch.cycleThreshold) + unmarkStackAndRegisters(gch) + sysAssert(allocInv(gch.region), "collectCT: end") + + when withRealtime: + let duration = getticks() - t0 + gch.stat.maxPause = max(gch.stat.maxPause, duration) + when defined(reportMissedDeadlines): + if gch.maxPause > 0 and duration > gch.maxPause: + c_fprintf(c_stdout, "[GC] missed deadline: %ld\n", duration) + +proc collectCT(gch: var TGcHeap) = + if (gch.zct.len >= ZctThreshold or (cycleGC and + getOccupiedMem(gch.region)>=gch.cycleThreshold) or alwaysGC) and + gch.recGcLock == 0: + collectCTBody(gch) + +when withRealtime: + proc toNano(x: int): TNanos {.inline.} = + result = x * 1000 + + proc GC_setMaxPause*(MaxPauseInUs: int) = + gch.maxPause = MaxPauseInUs.toNano + + proc GC_step(gch: var TGcHeap, us: int, strongAdvice: bool) = + acquire(gch) + gch.maxPause = us.toNano + if (gch.zct.len >= ZctThreshold or (cycleGC and + getOccupiedMem(gch.region)>=gch.cycleThreshold) or alwaysGC) or + strongAdvice: + collectCTBody(gch) + release(gch) + + proc GC_step*(us: int, strongAdvice = false) = GC_step(gch, us, strongAdvice) + +when not defined(useNimRtl): + proc GC_disable() = + when hasThreadSupport and hasSharedHeap: + discard atomicInc(gch.recGcLock, 1) + else: + inc(gch.recGcLock) + proc GC_enable() = + if gch.recGcLock > 0: + when hasThreadSupport and hasSharedHeap: + discard atomicDec(gch.recGcLock, 1) + else: + dec(gch.recGcLock) + + proc GC_setStrategy(strategy: TGC_Strategy) = + case strategy + of gcThroughput: nil + of gcResponsiveness: nil + of gcOptimizeSpace: nil + of gcOptimizeTime: nil + + proc GC_enableMarkAndSweep() = + gch.cycleThreshold = InitialCycleThreshold + + proc GC_disableMarkAndSweep() = + gch.cycleThreshold = high(gch.cycleThreshold)-1 + # set to the max value to suppress the cycle detector + + proc GC_fullCollect() = + acquire(gch) + var oldThreshold = gch.cycleThreshold + gch.cycleThreshold = 0 # forces cycle collection + collectCT(gch) + gch.cycleThreshold = oldThreshold + release(gch) + + proc GC_getStatistics(): string = + GC_disable() + result = "[GC] total memory: " & $(getTotalMem()) & "\n" & + "[GC] occupied memory: " & $(getOccupiedMem()) & "\n" & + "[GC] stack scans: " & $gch.stat.stackScans & "\n" & + "[GC] stack cells: " & $gch.stat.maxStackCells & "\n" & + "[GC] cycle collections: " & $gch.stat.cycleCollections & "\n" & + "[GC] max threshold: " & $gch.stat.maxThreshold & "\n" & + "[GC] zct capacity: " & $gch.zct.cap & "\n" & + "[GC] max cycle table size: " & $gch.stat.cycleTableSize & "\n" & + "[GC] max stack size: " & $gch.stat.maxStackSize & "\n" & + "[GC] max pause time [ms]: " & $(gch.stat.maxPause div 1000_000) + when traceGC: writeLeakage() + GC_enable() + +{.pop.} diff --git a/lib/system/sysstr.nim b/lib/system/sysstr.nim index 5d2113439..55223d6c6 100755 --- a/lib/system/sysstr.nim +++ b/lib/system/sysstr.nim @@ -204,10 +204,21 @@ proc setLengthSeq(seq: PGenericSeq, elemSize, newLen: int): PGenericSeq {. # we need to decref here, otherwise the GC leaks! when not defined(boehmGC) and not defined(nogc): for i in newLen..result.len-1: + let len0 = gch.tempStack.len forAllChildrenAux(cast[pointer](cast[TAddress](result) +% GenericSeqSize +% (i*%elemSize)), - extGetCellType(result).base, waZctDecRef) - # and set the memory to nil: + extGetCellType(result).base, waPush) + let len1 = gch.tempStack.len + for i in len0 .. <len1: + doDecRef(gch.tempStack.d[i], LocalHeap, MaybeCyclic) + gch.tempStack.len = len0 + + # XXX: zeroing out the memory can still result in crashes if a wiped-out + # cell is aliased by another pointer (ie proc paramter or a let variable). + # This is a tought problem, because even if we don't zeroMem here, in the + # presense of user defined destructors, the user will expect the cell to be + # "destroyed" thus creating the same problem. We can destoy the cell in the + # finalizer of the sequence, but this makes destruction non-deterministic. zeroMem(cast[pointer](cast[TAddress](result) +% GenericSeqSize +% (newLen*%elemSize)), (result.len-%newLen) *% elemSize) result.len = newLen diff --git a/lib/system/timers.nim b/lib/system/timers.nim index 0166c1e3f..fa1a13a5f 100644 --- a/lib/system/timers.nim +++ b/lib/system/timers.nim @@ -44,10 +44,11 @@ elif defined(macosx): proc getTicks(): TTicks {.inline.} = result = TTicks(mach_absolute_time()) - + + var timeBaseInfo: TMachTimebaseInfoData + mach_timebase_info(timeBaseInfo) + proc `-`(a, b: TTicks): TNanos = - var timeBaseInfo: TMachTimebaseInfoData - mach_timebase_info(timeBaseInfo) result = (a.int64 - b.int64) * timeBaseInfo.numer div timeBaseInfo.denom elif defined(posixRealtime): diff --git a/lib/wrappers/openssl.nim b/lib/wrappers/openssl.nim index f692db13a..438774a15 100755 --- a/lib/wrappers/openssl.nim +++ b/lib/wrappers/openssl.nim @@ -49,9 +49,9 @@ else: const versions = "(|.1.0.0|.0.9.9|.0.9.8|.0.9.7|.0.9.6|.0.9.5|.0.9.4)" when defined(macosx): - const - DLLSSLName = "libssl.dylib" & versions - DLLUtilName = "libcrypto.dylib" & versions + const + DLLSSLName = "libssl" & versions & ".dylib" + DLLUtilName = "libcrypto" & versions & ".dylib" else: const DLLSSLName = "libssl.so" & versions |