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Diffstat (limited to 'lib')
| -rw-r--r-- | lib/system/gc2.nim | 749 |
1 files changed, 0 insertions, 749 deletions
diff --git a/lib/system/gc2.nim b/lib/system/gc2.nim deleted file mode 100644 index ed046b5fd..000000000 --- a/lib/system/gc2.nim +++ /dev/null @@ -1,749 +0,0 @@ -# -# -# Nim's Runtime Library -# (c) Copyright 2017 Andreas Rumpf -# -# See the file "copying.txt", included in this -# distribution, for details about the copyright. -# - -# xxx deadcode, consider removing unless something could be reused. - - -# Garbage Collector -# -# The basic algorithm is an incremental mark -# and sweep GC to free cycles. It is hard realtime in that if you play -# according to its rules, no deadline will ever be missed. -# Since this kind of collector is very bad at recycling dead objects -# early, Nim's codegen emits ``nimEscape`` calls at strategic -# places. For this to work even 'unsureAsgnRef' needs to mark things -# so that only return values need to be considered in ``nimEscape``. - -{.push profiler:off.} - -const - CycleIncrease = 2 # is a multiplicative increase - InitialCycleThreshold = 512*1024 # start collecting after 500KB - 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 declared(getTicks): - include "system/timers" -when defined(memProfiler): - proc nimProfile(requestedSize: int) {.benign.} - -when hasThreadSupport: - include sharedlist - -type - ObjectSpaceIter = object - state: range[-1..0] - -iterToProc(allObjects, ptr ObjectSpaceIter, allObjectsAsProc) - -const - escapedBit = 0b1000 # so that lowest 3 bits are not touched - rcBlackOrig = 0b000 - rcWhiteOrig = 0b001 - rcGrey = 0b010 # traditional color for incremental mark&sweep - rcUnused = 0b011 - colorMask = 0b011 -type - WalkOp = enum - waMarkGlobal, # part of the backup mark&sweep - waMarkGrey, - waZctDecRef, - waDebug - - Phase {.pure.} = enum - None, Marking, Sweeping - Finalizer {.compilerproc.} = proc (self: pointer) {.nimcall, benign.} - # A ref type can have a finalizer that is called before the object's - # storage is freed. - - GcStat = object - stackScans: int # number of performed stack scans (for statistics) - completedCollections: 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 - - GcStack {.final, pure.} = object - when nimCoroutines: - prev: ptr GcStack - next: ptr GcStack - maxStackSize: int # Used to track statistics because we can not use - # GcStat.maxStackSize when multiple stacks exist. - bottom: pointer - - when withRealTime or nimCoroutines: - pos: pointer # Used with `withRealTime` only for code clarity, see GC_Step(). - when withRealTime: - bottomSaved: pointer - - GcHeap = object # this contains the zero count and - # non-zero count table - black, red: int # either 0 or 1. - stack: GcStack - when nimCoroutines: - activeStack: ptr GcStack # current executing coroutine stack. - phase: Phase - cycleThreshold: int - when useCellIds: - idGenerator: int - greyStack: CellSeq - recGcLock: int # prevent recursion via finalizers; no thread lock - when withRealTime: - maxPause: Nanos # max allowed pause in nanoseconds; active if > 0 - region: MemRegion # garbage collected region - stat: GcStat - additionalRoots: CellSeq # explicit roots for GC_ref/unref - spaceIter: ObjectSpaceIter - pDumpHeapFile: pointer # File that is used for GC_dumpHeap - when hasThreadSupport: - toDispose: SharedList[pointer] - gcThreadId: int - -var - gch {.rtlThreadVar.}: GcHeap - -when not defined(useNimRtl): - instantiateForRegion(gch.region) - -# Which color to use for new objects is tricky: When we're marking, -# they have to be *white* so that everything is marked that is only -# reachable from them. However, when we are sweeping, they have to -# be black, so that we don't free them prematuredly. In order to save -# a comparison gch.phase == Phase.Marking, we use the pseudo-color -# 'red' for new objects. -template allocColor(): untyped = gch.red - -template gcAssert(cond: bool, msg: string) = - when defined(useGcAssert): - if not cond: - echo "[GCASSERT] ", msg - GC_disable() - writeStackTrace() - rawQuit 1 - -proc cellToUsr(cell: PCell): pointer {.inline.} = - # convert object (=pointer to refcount) to pointer to userdata - result = cast[pointer](cast[int](cell)+%ByteAddress(sizeof(Cell))) - -proc usrToCell(usr: pointer): PCell {.inline.} = - # convert pointer to userdata to object (=pointer to refcount) - result = cast[PCell](cast[int](usr)-%ByteAddress(sizeof(Cell))) - -proc extGetCellType(c: pointer): PNimType {.compilerproc.} = - # used for code generation concerning debugging - result = usrToCell(c).typ - -proc internRefcount(p: pointer): int {.exportc: "getRefcount".} = - result = 0 - -# 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!".} - -template color(c): untyped = c.refCount and colorMask -template setColor(c, col) = - c.refcount = c.refcount and not colorMask or col - -template markAsEscaped(c: PCell) = - c.refcount = c.refcount or escapedBit - -template didEscape(c: PCell): bool = - (c.refCount and escapedBit) != 0 - -proc writeCell(file: File; msg: cstring, c: PCell) = - var kind = -1 - if c.typ != nil: kind = ord(c.typ.kind) - let col = if c.color == rcGrey: 'g' - elif c.color == gch.black: 'b' - else: 'w' - when useCellIds: - let id = c.id - else: - let id = c - when defined(nimTypeNames): - c_fprintf(file, "%s %p %d escaped=%ld color=%c of type %s\n", - msg, id, kind, didEscape(c), col, c.typ.name) - elif leakDetector: - c_fprintf(file, "%s %p %d escaped=%ld color=%c from %s(%ld)\n", - msg, id, kind, didEscape(c), col, c.filename, c.line) - else: - c_fprintf(file, "%s %p %d escaped=%ld color=%c\n", - msg, id, kind, didEscape(c), col) - -proc writeCell(msg: cstring, c: PCell) = - stdout.writeCell(msg, c) - -proc myastToStr[T](x: T): string {.magic: "AstToStr", noSideEffect.} - -template gcTrace(cell, state: untyped) = - when traceGC: writeCell(myastToStr(state), cell) - -# forward declarations: -proc collectCT(gch: var GcHeap) {.benign.} -proc isOnStack(p: pointer): bool {.noinline, benign.} -proc forAllChildren(cell: PCell, op: WalkOp) {.benign.} -proc doOperation(p: pointer, op: WalkOp) {.benign.} -proc forAllChildrenAux(dest: pointer, mt: PNimType, op: WalkOp) {.benign.} -# we need the prototype here for debugging purposes - -proc nimGCref(p: pointer) {.compilerproc.} = - let cell = usrToCell(p) - markAsEscaped(cell) - add(gch.additionalRoots, cell) - -proc nimGCunref(p: pointer) {.compilerproc.} = - let cell = usrToCell(p) - var L = gch.additionalRoots.len-1 - var i = L - let d = gch.additionalRoots.d - while i >= 0: - if d[i] == cell: - d[i] = d[L] - dec gch.additionalRoots.len - break - dec(i) - -proc nimGCunrefNoCycle(p: pointer) {.compilerproc, inline.} = - discard "can we do some freeing here?" - -proc nimGCunrefRC1(p: pointer) {.compilerproc, inline.} = - discard "can we do some freeing here?" - -template markGrey(x: PCell) = - if x.color != 1-gch.black and gch.phase == Phase.Marking: - if not isAllocatedPtr(gch.region, x): - c_fprintf(stdout, "[GC] markGrey proc: %p\n", x) - #GC_dumpHeap() - sysAssert(false, "wtf") - x.setColor(rcGrey) - add(gch.greyStack, x) - -proc asgnRef(dest: PPointer, src: pointer) {.compilerproc, inline.} = - # the code generator calls this proc! - gcAssert(not isOnStack(dest), "asgnRef") - # BUGFIX: first incRef then decRef! - if src != nil: - let s = usrToCell(src) - markAsEscaped(s) - markGrey(s) - dest[] = src - -proc asgnRefNoCycle(dest: PPointer, src: pointer) {.compilerproc, inline, - deprecated: "old compiler compat".} = asgnRef(dest, src) - -proc unsureAsgnRef(dest: PPointer, src: pointer) {.compilerproc.} = - # unsureAsgnRef marks 'src' as grey only if dest is not on the - # stack. It is used by the code generator if it cannot decide whether a - # reference is in the stack or not (this can happen for var parameters). - if src != nil: - let s = usrToCell(src) - markAsEscaped(s) - if not isOnStack(dest): markGrey(s) - dest[] = src - -proc forAllSlotsAux(dest: pointer, n: ptr TNimNode, op: WalkOp) {.benign.} = - var d = cast[int](dest) - case n.kind - of nkSlot: forAllChildrenAux(cast[pointer](d +% n.offset), n.typ, op) - of nkList: - for i in 0..n.len-1: - 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: WalkOp) = - var d = cast[int](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: discard - -proc forAllChildren(cell: PCell, op: WalkOp) = - gcAssert(cell != nil, "forAllChildren: 1") - gcAssert(isAllocatedPtr(gch.region, cell), "forAllChildren: 2") - gcAssert(cell.typ != nil, "forAllChildren: 3") - gcAssert cell.typ.kind in {tyRef, tySequence, tyString}, "forAllChildren: 4" - 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[int](cellToUsr(cell)) - var s = cast[PGenericSeq](d) - if s != nil: - for i in 0..s.len-1: - forAllChildrenAux(cast[pointer](d +% align(GenericSeqSize, cell.typ.base.align) +% i *% cell.typ.base.size), cell.typ.base, op) - else: discard - -{.push stackTrace: off, profiler:off.} -proc gcInvariant*() = - sysAssert(allocInv(gch.region), "injected") - when declared(markForDebug): - markForDebug(gch) -{.pop.} - -include gc_common - -proc initGC() = - when not defined(useNimRtl): - gch.red = (1-gch.black) - gch.cycleThreshold = InitialCycleThreshold - gch.stat.stackScans = 0 - gch.stat.completedCollections = 0 - gch.stat.maxThreshold = 0 - gch.stat.maxStackSize = 0 - gch.stat.maxStackCells = 0 - gch.stat.cycleTableSize = 0 - # init the rt - init(gch.additionalRoots) - init(gch.greyStack) - when hasThreadSupport: - init(gch.toDispose) - gch.gcThreadId = atomicInc(gHeapidGenerator) - 1 - gcAssert(gch.gcThreadId >= 0, "invalid computed thread ID") - -proc rawNewObj(typ: PNimType, size: int, gch: var GcHeap): pointer = - # generates a new object and sets its reference counter to 0 - sysAssert(allocInv(gch.region), "rawNewObj begin") - gcAssert(typ.kind in {tyRef, tyString, tySequence}, "newObj: 1") - collectCT(gch) - var res = cast[PCell](rawAlloc(gch.region, size + sizeof(Cell))) - gcAssert((cast[int](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 - # refcount is zero, color is black, but mark it to be in the ZCT - res.refcount = allocColor() - sysAssert(isAllocatedPtr(gch.region, res), "newObj: 3") - when logGC: writeCell("new cell", res) - gcTrace(res, csAllocated) - when useCellIds: - inc gch.idGenerator - res.id = gch.idGenerator - result = cellToUsr(res) - sysAssert(allocInv(gch.region), "rawNewObj end") - -{.pop.} - -proc newObjNoInit(typ: PNimType, size: int): pointer {.compilerRtl.} = - result = rawNewObj(typ, size, gch) - when defined(memProfiler): nimProfile(size) - -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(align(GenericSeqSize, typ.base.align), mulInt(len, typ.base.size)) - 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.} = - result = newObj(typ, size) - -proc newSeqRC1(typ: PNimType, len: int): pointer {.compilerRtl.} = - result = newSeq(typ, len) - -proc growObj(old: pointer, newsize: int, gch: var GcHeap): pointer = - collectCT(gch) - var ol = usrToCell(old) - sysAssert(ol.typ != nil, "growObj: 1") - gcAssert(ol.typ.kind in {tyString, tySequence}, "growObj: 2") - - var res = cast[PCell](rawAlloc(gch.region, newsize + sizeof(Cell))) - var elemSize, elemAlign = 1 - if ol.typ.kind != tyString: - elemSize = ol.typ.base.size - elemAlign = ol.typ.base.align - incTypeSize ol.typ, newsize - - var oldsize = align(GenericSeqSize, elemAlign) + cast[PGenericSeq](old).len*elemSize - copyMem(res, ol, oldsize + sizeof(Cell)) - zeroMem(cast[pointer](cast[int](res)+% oldsize +% sizeof(Cell)), - newsize-oldsize) - sysAssert((cast[int](res) and (MemAlign-1)) == 0, "growObj: 3") - when false: - # this is wrong since seqs can be shared via 'shallow': - when reallyDealloc: rawDealloc(gch.region, ol) - else: - zeroMem(ol, sizeof(Cell)) - when useCellIds: - inc gch.idGenerator - res.id = gch.idGenerator - result = cellToUsr(res) - when defined(memProfiler): nimProfile(newsize-oldsize) - -proc growObj(old: pointer, newsize: int): pointer {.rtl.} = - result = growObj(old, newsize, gch) - -{.push profiler:off.} - - -template takeStartTime(workPackageSize) {.dirty.} = - const workPackage = workPackageSize - var debugticker = 1000 - when withRealTime: - var steps = workPackage - var t0: Ticks - if gch.maxPause > 0: t0 = getticks() - -template takeTime {.dirty.} = - when withRealTime: dec steps - dec debugticker - -template checkTime {.dirty.} = - if debugticker <= 0: - #echo "in loop" - debugticker = 1000 - 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 - # order to miss deadlines less often: - if duration >= gch.maxPause - 50_000: - return false - -# ---------------- dump heap ---------------- - -template dumpHeapFile(gch: var GcHeap): File = - cast[File](gch.pDumpHeapFile) - -proc debugGraph(s: PCell) = - c_fprintf(gch.dumpHeapFile, "child %p\n", s) - -proc dumpRoot(gch: var GcHeap; s: PCell) = - if isAllocatedPtr(gch.region, s): - c_fprintf(gch.dumpHeapFile, "global_root %p\n", s) - else: - c_fprintf(gch.dumpHeapFile, "global_root_invalid %p\n", s) - -proc GC_dumpHeap*(file: File) = - ## Dumps the GCed heap's content to a file. Can be useful for - ## debugging. Produces an undocumented text file format that - ## can be translated into "dot" syntax via the "heapdump2dot" tool. - gch.pDumpHeapFile = file - var spaceIter: ObjectSpaceIter - when false: - var d = gch.decStack.d - for i in 0 .. gch.decStack.len-1: - if isAllocatedPtr(gch.region, d[i]): - c_fprintf(file, "onstack %p\n", d[i]) - else: - c_fprintf(file, "onstack_invalid %p\n", d[i]) - if gch.gcThreadId == 0: - for i in 0 .. globalMarkersLen-1: globalMarkers[i]() - for i in 0 .. threadLocalMarkersLen-1: threadLocalMarkers[i]() - while true: - let x = allObjectsAsProc(gch.region, addr spaceIter) - if spaceIter.state < 0: break - if isCell(x): - # cast to PCell is correct here: - var c = cast[PCell](x) - writeCell(file, "cell ", c) - forAllChildren(c, waDebug) - c_fprintf(file, "end\n") - gch.pDumpHeapFile = nil - -proc GC_dumpHeap() = - var f: File - if open(f, "heap.txt", fmWrite): - GC_dumpHeap(f) - f.close() - else: - c_fprintf(stdout, "cannot write heap.txt") - -# ---------------- cycle collector ------------------------------------------- - -proc freeCyclicCell(gch: var GcHeap, c: PCell) = - gcAssert(isAllocatedPtr(gch.region, c), "freeCyclicCell: freed pointer?") - prepareDealloc(c) - gcTrace(c, csCycFreed) - when logGC: writeCell("cycle collector dealloc cell", c) - when reallyDealloc: - sysAssert(allocInv(gch.region), "free cyclic cell") - rawDealloc(gch.region, c) - else: - gcAssert(c.typ != nil, "freeCyclicCell") - zeroMem(c, sizeof(Cell)) - -proc sweep(gch: var GcHeap): bool = - takeStartTime(100) - #echo "loop start" - let white = 1-gch.black - #c_fprintf(stdout, "black is %d\n", black) - while true: - let x = allObjectsAsProc(gch.region, addr gch.spaceIter) - if gch.spaceIter.state < 0: break - takeTime() - if isCell(x): - # cast to PCell is correct here: - var c = cast[PCell](x) - gcAssert c.color != rcGrey, "cell is still grey?" - if c.color == white: freeCyclicCell(gch, c) - # Since this is incremental, we MUST not set the object to 'white' here. - # We could set all the remaining objects to white after the 'sweep' - # completed but instead we flip the meaning of black/white to save one - # traversal over the heap! - checkTime() - # prepare for next iteration: - #echo "loop end" - gch.spaceIter = ObjectSpaceIter() - result = true - -proc markRoot(gch: var GcHeap, c: PCell) {.inline.} = - if c.color == 1-gch.black: - c.setColor(rcGrey) - add(gch.greyStack, c) - -proc markIncremental(gch: var GcHeap): bool = - var L = addr(gch.greyStack.len) - takeStartTime(100) - while L[] > 0: - var c = gch.greyStack.d[0] - if not isAllocatedPtr(gch.region, c): - c_fprintf(stdout, "[GC] not allocated anymore: %p\n", c) - #GC_dumpHeap() - sysAssert(false, "wtf") - - #sysAssert(isAllocatedPtr(gch.region, c), "markIncremental: isAllocatedPtr") - gch.greyStack.d[0] = gch.greyStack.d[L[] - 1] - dec(L[]) - takeTime() - if c.color == rcGrey: - c.setColor(gch.black) - forAllChildren(c, waMarkGrey) - elif c.color == (1-gch.black): - gcAssert false, "wtf why are there white objects in the greystack?" - checkTime() - gcAssert gch.greyStack.len == 0, "markIncremental: greystack not empty " - result = true - -proc markGlobals(gch: var GcHeap) = - if gch.gcThreadId == 0: - for i in 0 .. globalMarkersLen-1: globalMarkers[i]() - for i in 0 .. threadLocalMarkersLen-1: threadLocalMarkers[i]() - -proc doOperation(p: pointer, op: WalkOp) = - if p == nil: return - var c: PCell = usrToCell(p) - gcAssert(c != nil, "doOperation: 1") - # the 'case' should be faster than function pointers because of easy - # prediction: - case op - of waZctDecRef: - #if not isAllocatedPtr(gch.region, c): - # c_fprintf(stdout, "[GC] decref bug: %p", c) - gcAssert(isAllocatedPtr(gch.region, c), "decRef: waZctDecRef") - discard "use me for nimEscape?" - of waMarkGlobal: - template handleRoot = - if gch.dumpHeapFile.isNil: - markRoot(gch, c) - else: - dumpRoot(gch, c) - handleRoot() - discard allocInv(gch.region) - of waMarkGrey: - when false: - if not isAllocatedPtr(gch.region, c): - c_fprintf(stdout, "[GC] not allocated anymore: MarkGrey %p\n", c) - #GC_dumpHeap() - sysAssert(false, "wtf") - if c.color == 1-gch.black: - c.setColor(rcGrey) - add(gch.greyStack, c) - of waDebug: debugGraph(c) - -proc nimGCvisit(d: pointer, op: int) {.compilerRtl.} = - doOperation(d, WalkOp(op)) - -proc gcMark(gch: var GcHeap, 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[int](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: - markRoot(gch, objStart) - sysAssert(allocInv(gch.region), "gcMark end") - -proc markStackAndRegisters(gch: var GcHeap) {.noinline, cdecl.} = - forEachStackSlot(gch, gcMark) - -proc collectALittle(gch: var GcHeap): bool = - case gch.phase - of Phase.None: - if getOccupiedMem(gch.region) >= gch.cycleThreshold: - gch.phase = Phase.Marking - markGlobals(gch) - result = collectALittle(gch) - #when false: c_fprintf(stdout, "collectALittle: introduced bug E %ld\n", gch.phase) - #discard allocInv(gch.region) - of Phase.Marking: - when hasThreadSupport: - for c in gch.toDispose: - nimGCunref(c) - prepareForInteriorPointerChecking(gch.region) - markStackAndRegisters(gch) - inc(gch.stat.stackScans) - if markIncremental(gch): - gch.phase = Phase.Sweeping - gch.red = 1 - gch.red - of Phase.Sweeping: - gcAssert gch.greyStack.len == 0, "greystack not empty" - when hasThreadSupport: - for c in gch.toDispose: - nimGCunref(c) - if sweep(gch): - gch.phase = Phase.None - # flip black/white meanings: - gch.black = 1 - gch.black - gcAssert gch.red == 1 - gch.black, "red color is wrong" - inc(gch.stat.completedCollections) - result = true - -proc collectCTBody(gch: var GcHeap) = - when withRealTime: - let t0 = getticks() - sysAssert(allocInv(gch.region), "collectCT: begin") - - when not nimCoroutines: - gch.stat.maxStackSize = max(gch.stat.maxStackSize, stackSize()) - #gch.stat.maxStackCells = max(gch.stat.maxStackCells, gch.decStack.len) - if collectALittle(gch): - gch.cycleThreshold = max(InitialCycleThreshold, getOccupiedMem() * - CycleIncrease) - gch.stat.maxThreshold = max(gch.stat.maxThreshold, gch.cycleThreshold) - 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(stdout, "[GC] missed deadline: %ld\n", duration) - -when nimCoroutines: - proc currentStackSizes(): int = - for stack in items(gch.stack): - result = result + stack.stackSize() - -proc collectCT(gch: var GcHeap) = - # stackMarkCosts prevents some pathological behaviour: Stack marking - # becomes more expensive with large stacks and large stacks mean that - # cells with RC=0 are more likely to be kept alive by the stack. - when nimCoroutines: - let stackMarkCosts = max(currentStackSizes() div (16*sizeof(int)), ZctThreshold) - else: - let stackMarkCosts = max(stackSize() div (16*sizeof(int)), ZctThreshold) - if (gch.greyStack.len >= stackMarkCosts or (cycleGC and - getOccupiedMem(gch.region)>=gch.cycleThreshold) or alwaysGC) and - gch.recGcLock == 0: - collectCTBody(gch) - -when withRealTime: - proc toNano(x: int): Nanos {.inline.} = - result = x * 1000 - - proc GC_setMaxPause*(MaxPauseInUs: int) = - gch.maxPause = MaxPauseInUs.toNano - - proc GC_step(gch: var GcHeap, us: int, strongAdvice: bool) = - gch.maxPause = us.toNano - #if (getOccupiedMem(gch.region)>=gch.cycleThreshold) or - # alwaysGC or strongAdvice: - collectCTBody(gch) - - proc GC_step*(us: int, strongAdvice = false, stackSize = -1) {.noinline.} = - if stackSize >= 0: - var stackTop {.volatile.}: pointer - gch.getActiveStack().pos = addr(stackTop) - - for stack in gch.stack.items(): - stack.bottomSaved = stack.bottom - when stackIncreases: - stack.bottom = cast[pointer]( - cast[int](stack.pos) - sizeof(pointer) * 6 - stackSize) - else: - stack.bottom = cast[pointer]( - cast[int](stack.pos) + sizeof(pointer) * 6 + stackSize) - - GC_step(gch, us, strongAdvice) - - if stackSize >= 0: - for stack in gch.stack.items(): - stack.bottom = stack.bottomSaved - -when not defined(useNimRtl): - proc GC_disable() = - inc(gch.recGcLock) - proc GC_enable() = - if gch.recGcLock > 0: - dec(gch.recGcLock) - - proc GC_setStrategy(strategy: GC_Strategy) = - discard - - proc GC_enableMarkAndSweep() = discard - proc GC_disableMarkAndSweep() = discard - - proc GC_fullCollect() = - var oldThreshold = gch.cycleThreshold - gch.cycleThreshold = 0 # forces cycle collection - collectCT(gch) - gch.cycleThreshold = oldThreshold - - 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] completed collections: " & $gch.stat.completedCollections & "\n" & - "[GC] max threshold: " & $gch.stat.maxThreshold & "\n" & - "[GC] grey stack capacity: " & $gch.greyStack.cap & "\n" & - "[GC] max cycle table size: " & $gch.stat.cycleTableSize & "\n" & - "[GC] max pause time [ms]: " & $(gch.stat.maxPause div 1000_000) & "\n" - when nimCoroutines: - result.add "[GC] number of stacks: " & $gch.stack.len & "\n" - for stack in items(gch.stack): - result.add "[GC] stack " & stack.bottom.repr & "[GC] max stack size " & $stack.maxStackSize & "\n" - else: - result.add "[GC] max stack size: " & $gch.stat.maxStackSize & "\n" - GC_enable() - -{.pop.} |