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Diffstat (limited to 'lib/system/channels.nim')
| -rwxr-xr-x | lib/system/channels.nim | 247 |
1 files changed, 0 insertions, 247 deletions
diff --git a/lib/system/channels.nim b/lib/system/channels.nim deleted file mode 100755 index 13d751d80..000000000 --- a/lib/system/channels.nim +++ /dev/null @@ -1,247 +0,0 @@ -# -# -# Nimrod's Runtime Library -# (c) Copyright 2012 Andreas Rumpf -# -# See the file "copying.txt", included in this -# distribution, for details about the copyright. -# - -## Channel support for threads. **Note**: This is part of the system module. -## Do not import it directly. To activate thread support you need to compile -## with the ``--threads:on`` command line switch. -## -## **Note:** The current implementation of message passing is slow and does -## not work with cyclic data structures. - -type - pbytes = ptr array[0.. 0xffff, byte] - TRawChannel {.pure, final.} = object ## msg queue for a thread - rd, wr, count, mask: int - data: pbytes - lock: TSysLock - cond: TSysCond - elemType: PNimType - ready: bool - region: TMemRegion - PRawChannel = ptr TRawChannel - TLoadStoreMode = enum mStore, mLoad - TChannel*[TMsg] = TRawChannel ## a channel for thread communication - -const ChannelDeadMask = -2 - -proc initRawChannel(p: pointer) = - var c = cast[PRawChannel](p) - initSysLock(c.lock) - initSysCond(c.cond) - c.mask = -1 - -proc deinitRawChannel(p: pointer) = - var c = cast[PRawChannel](p) - # we need to grab the lock to be safe against sending threads! - acquireSys(c.lock) - c.mask = ChannelDeadMask - deallocOsPages(c.region) - deinitSys(c.lock) - deinitSysCond(c.cond) - -proc storeAux(dest, src: Pointer, mt: PNimType, t: PRawChannel, - mode: TLoadStoreMode) -proc storeAux(dest, src: Pointer, n: ptr TNimNode, t: PRawChannel, - mode: TLoadStoreMode) = - var - d = cast[TAddress](dest) - s = cast[TAddress](src) - case n.kind - of nkSlot: storeAux(cast[pointer](d +% n.offset), - cast[pointer](s +% n.offset), n.typ, t, mode) - of nkList: - for i in 0..n.len-1: storeAux(dest, src, n.sons[i], t, mode) - of nkCase: - copyMem(cast[pointer](d +% n.offset), cast[pointer](s +% n.offset), - n.typ.size) - var m = selectBranch(src, n) - if m != nil: storeAux(dest, src, m, t, mode) - of nkNone: sysAssert(false, "storeAux") - -proc storeAux(dest, src: Pointer, mt: PNimType, t: PRawChannel, - mode: TLoadStoreMode) = - var - d = cast[TAddress](dest) - s = cast[TAddress](src) - sysAssert(mt != nil, "mt == nil") - case mt.Kind - of tyString: - if mode == mStore: - var x = cast[ppointer](dest) - var s2 = cast[ppointer](s)[] - if s2 == nil: - x[] = nil - else: - var ss = cast[NimString](s2) - var ns = cast[NimString](Alloc(t.region, ss.len+1 + GenericSeqSize)) - copyMem(ns, ss, ss.len+1 + GenericSeqSize) - x[] = ns - else: - var x = cast[ppointer](dest) - var s2 = cast[ppointer](s)[] - if s2 == nil: - unsureAsgnRef(x, s2) - else: - unsureAsgnRef(x, copyString(cast[NimString](s2))) - Dealloc(t.region, s2) - of tySequence: - var s2 = cast[ppointer](src)[] - var seq = cast[PGenericSeq](s2) - var x = cast[ppointer](dest) - if s2 == nil: - if mode == mStore: - x[] = nil - else: - unsureAsgnRef(x, nil) - else: - sysAssert(dest != nil, "dest == nil") - if mode == mStore: - x[] = Alloc(t.region, seq.len *% mt.base.size +% GenericSeqSize) - else: - unsureAsgnRef(x, newObj(mt, seq.len * mt.base.size + GenericSeqSize)) - var dst = cast[taddress](cast[ppointer](dest)[]) - for i in 0..seq.len-1: - storeAux( - cast[pointer](dst +% i*% mt.base.size +% GenericSeqSize), - cast[pointer](cast[TAddress](s2) +% i *% mt.base.size +% - GenericSeqSize), - mt.Base, t, mode) - var dstseq = cast[PGenericSeq](dst) - dstseq.len = seq.len - dstseq.reserved = seq.len - if mode != mStore: Dealloc(t.region, s2) - of tyObject: - # copy type field: - var pint = cast[ptr PNimType](dest) - # XXX use dynamic type here! - pint[] = mt - storeAux(dest, src, mt.node, t, mode) - of tyTuple: - storeAux(dest, src, mt.node, t, mode) - of tyArray, tyArrayConstr: - for i in 0..(mt.size div mt.base.size)-1: - storeAux(cast[pointer](d +% i*% mt.base.size), - cast[pointer](s +% i*% mt.base.size), mt.base, t, mode) - of tyRef: - var s = cast[ppointer](src)[] - var x = cast[ppointer](dest) - if s == nil: - if mode == mStore: - x[] = nil - else: - unsureAsgnRef(x, nil) - else: - if mode == mStore: - x[] = Alloc(t.region, mt.base.size) - else: - # XXX we should use the dynamic type here too, but that is not stored - # in the inbox at all --> use source[]'s object type? but how? we need - # a tyRef to the object! - var obj = newObj(mt.base, mt.base.size) - unsureAsgnRef(x, obj) - storeAux(x[], s, mt.base, t, mode) - if mode != mStore: Dealloc(t.region, s) - else: - copyMem(dest, src, mt.size) # copy raw bits - -proc rawSend(q: PRawChannel, data: pointer, typ: PNimType) = - ## adds an `item` to the end of the queue `q`. - var cap = q.mask+1 - if q.count >= cap: - # start with capacity for 2 entries in the queue: - if cap == 0: cap = 1 - var n = cast[pbytes](Alloc0(q.region, cap*2*typ.size)) - var z = 0 - var i = q.rd - var c = q.count - while c > 0: - dec c - copyMem(addr(n[z*typ.size]), addr(q.data[i*typ.size]), typ.size) - i = (i + 1) and q.mask - inc z - if q.data != nil: Dealloc(q.region, q.data) - q.data = n - q.mask = cap*2 - 1 - q.wr = q.count - q.rd = 0 - storeAux(addr(q.data[q.wr * typ.size]), data, typ, q, mStore) - inc q.count - q.wr = (q.wr + 1) and q.mask - -proc rawRecv(q: PRawChannel, data: pointer, typ: PNimType) = - sysAssert q.count > 0, "rawRecv" - dec q.count - storeAux(data, addr(q.data[q.rd * typ.size]), typ, q, mLoad) - q.rd = (q.rd + 1) and q.mask - -template lockChannel(q: expr, action: stmt) {.immediate.} = - acquireSys(q.lock) - action - releaseSys(q.lock) - -template sendImpl(q: expr) {.immediate.} = - if q.mask == ChannelDeadMask: - raise newException(EDeadThread, "cannot send message; thread died") - acquireSys(q.lock) - var m: TMsg - shallowCopy(m, msg) - var typ = cast[PNimType](getTypeInfo(msg)) - rawSend(q, addr(m), typ) - q.elemType = typ - releaseSys(q.lock) - SignalSysCond(q.cond) - -proc send*[TMsg](c: var TChannel[TMsg], msg: TMsg) = - ## sends a message to a thread. `msg` is deeply copied. - var q = cast[PRawChannel](addr(c)) - sendImpl(q) - -proc llRecv(q: PRawChannel, res: pointer, typ: PNimType) = - # to save space, the generic is as small as possible - acquireSys(q.lock) - q.ready = true - while q.count <= 0: - WaitSysCond(q.cond, q.lock) - q.ready = false - if typ != q.elemType: - releaseSys(q.lock) - raise newException(EInvalidValue, "cannot receive message of wrong type") - rawRecv(q, res, typ) - releaseSys(q.lock) - -proc recv*[TMsg](c: var TChannel[TMsg]): TMsg = - ## receives a message from the channel `c`. This blocks until - ## a message has arrived! You may use ``peek`` to avoid the blocking. - var q = cast[PRawChannel](addr(c)) - llRecv(q, addr(result), cast[PNimType](getTypeInfo(result))) - -proc peek*[TMsg](c: var TChannel[TMsg]): int = - ## returns the current number of messages in the channel `c`. Returns -1 - ## if the channel has been closed. - var q = cast[PRawChannel](addr(c)) - if q.mask != ChannelDeadMask: - lockChannel(q): - result = q.count - else: - result = -1 - -proc open*[TMsg](c: var TChannel[TMsg]) = - ## opens a channel `c` for inter thread communication. - initRawChannel(addr(c)) - -proc close*[TMsg](c: var TChannel[TMsg]) = - ## closes a channel `c` and frees its associated resources. - deinitRawChannel(addr(c)) - -proc ready*[TMsg](c: var TChannel[TMsg]): bool = - ## returns true iff some thread is waiting on the channel `c` for - ## new messages. - var q = cast[PRawChannel](addr(c)) - result = q.ready - |