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Diffstat (limited to 'lib/std/threads.nim')
| -rw-r--r-- | lib/std/threads.nim | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/lib/std/threads.nim b/lib/std/threads.nim new file mode 100644 index 000000000..5726a5cdc --- /dev/null +++ b/lib/std/threads.nim @@ -0,0 +1,276 @@ +# +# +# Nim's Runtime Library +# (c) Copyright 2012 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +## Thread support for Nim. +## +## Nim's memory model for threads is quite different from other common +## programming languages (C, Pascal): Each thread has its own +## (garbage collected) heap and sharing of memory is restricted. This helps +## to prevent race conditions and improves efficiency. See `the manual for +## details of this memory model <manual.html#threads>`_. +## +## Examples +## ======== +## +## .. code-block:: Nim +## +## import std/locks +## +## var +## thr: array[0..4, Thread[tuple[a,b: int]]] +## L: Lock +## +## proc threadFunc(interval: tuple[a,b: int]) {.thread.} = +## for i in interval.a..interval.b: +## acquire(L) # lock stdout +## echo i +## release(L) +## +## initLock(L) +## +## for i in 0..high(thr): +## createThread(thr[i], threadFunc, (i*10, i*10+5)) +## joinThreads(thr) +## +## deinitLock(L) + +import std/private/[threadtypes] +export Thread + +import system/ansi_c + +when defined(nimPreviewSlimSystem): + import std/assertions + +when defined(genode): + import genode/env + + +when hasAllocStack or defined(zephyr) or defined(freertos): + const + nimThreadStackSize {.intdefine.} = 8192 + nimThreadStackGuard {.intdefine.} = 128 + + StackGuardSize = nimThreadStackGuard + ThreadStackSize = nimThreadStackSize - nimThreadStackGuard +else: + const + StackGuardSize = 4096 + ThreadStackMask = + when defined(genode): + 1024*64*sizeof(int)-1 + else: + 1024*256*sizeof(int)-1 + + ThreadStackSize = ThreadStackMask+1 - StackGuardSize + + +when defined(gcDestructors): + proc allocThreadStorage(size: int): pointer = + result = c_malloc(csize_t size) + zeroMem(result, size) +else: + template allocThreadStorage(size: untyped): untyped = allocShared0(size) + +#const globalsSlot = ThreadVarSlot(0) +#sysAssert checkSlot.int == globalsSlot.int + +# Zephyr doesn't include this properly without some help +when defined(zephyr): + {.emit: """/*INCLUDESECTION*/ + #include <pthread.h> + """.} + + +# We jump through some hops here to ensure that Nim thread procs can have +# the Nim calling convention. This is needed because thread procs are +# ``stdcall`` on Windows and ``noconv`` on UNIX. Alternative would be to just +# use ``stdcall`` since it is mapped to ``noconv`` on UNIX anyway. + + + +proc onThreadDestruction*(handler: proc () {.closure, gcsafe, raises: [].}) = + ## Registers a *thread local* handler that is called at the thread's + ## destruction. + ## + ## A thread is destructed when the `.thread` proc returns + ## normally or when it raises an exception. Note that unhandled exceptions + ## in a thread nevertheless cause the whole process to die. + nimThreadDestructionHandlers.add handler + + +{.push stack_trace:off.} +when defined(windows): + proc threadProcWrapper[TArg](closure: pointer): int32 {.stdcall.} = + nimThreadProcWrapperBody(closure) + # implicitly return 0 +elif defined(genode): + proc threadProcWrapper[TArg](closure: pointer) {.noconv.} = + nimThreadProcWrapperBody(closure) +else: + proc threadProcWrapper[TArg](closure: pointer): pointer {.noconv.} = + nimThreadProcWrapperBody(closure) +{.pop.} + +proc running*[TArg](t: Thread[TArg]): bool {.inline.} = + ## Returns true if `t` is running. + result = t.dataFn != nil + +proc handle*[TArg](t: Thread[TArg]): SysThread {.inline.} = + ## Returns the thread handle of `t`. + result = t.sys + +when hostOS == "windows": + const MAXIMUM_WAIT_OBJECTS = 64 + + proc joinThread*[TArg](t: Thread[TArg]) {.inline.} = + ## Waits for the thread `t` to finish. + discard waitForSingleObject(t.sys, -1'i32) + + proc joinThreads*[TArg](t: varargs[Thread[TArg]]) = + ## Waits for every thread in `t` to finish. + var a: array[MAXIMUM_WAIT_OBJECTS, SysThread] + var k = 0 + while k < len(t): + var count = min(len(t) - k, MAXIMUM_WAIT_OBJECTS) + for i in 0..(count - 1): a[i] = t[i + k].sys + discard waitForMultipleObjects(int32(count), + cast[ptr SysThread](addr(a)), 1, -1) + inc(k, MAXIMUM_WAIT_OBJECTS) + +elif defined(genode): + proc joinThread*[TArg](t: Thread[TArg]) {.importcpp.} + ## Waits for the thread `t` to finish. + + proc joinThreads*[TArg](t: varargs[Thread[TArg]]) = + ## Waits for every thread in `t` to finish. + for i in 0..t.high: joinThread(t[i]) + +else: + proc joinThread*[TArg](t: Thread[TArg]) {.inline.} = + ## Waits for the thread `t` to finish. + discard pthread_join(t.sys, nil) + + proc joinThreads*[TArg](t: varargs[Thread[TArg]]) = + ## Waits for every thread in `t` to finish. + for i in 0..t.high: joinThread(t[i]) + +when false: + # XXX a thread should really release its heap here somehow: + proc destroyThread*[TArg](t: var Thread[TArg]) = + ## Forces the thread `t` to terminate. This is potentially dangerous if + ## you don't have full control over `t` and its acquired resources. + when hostOS == "windows": + discard TerminateThread(t.sys, 1'i32) + else: + discard pthread_cancel(t.sys) + when declared(registerThread): unregisterThread(addr(t)) + t.dataFn = nil + ## if thread `t` already exited, `t.core` will be `null`. + if not isNil(t.core): + deallocThreadStorage(t.core) + t.core = nil + +when hostOS == "windows": + proc createThread*[TArg](t: var Thread[TArg], + tp: proc (arg: TArg) {.thread, nimcall.}, + param: TArg) = + ## Creates a new thread `t` and starts its execution. + ## + ## Entry point is the proc `tp`. + ## `param` is passed to `tp`. `TArg` can be `void` if you + ## don't need to pass any data to the thread. + t.core = cast[PGcThread](allocThreadStorage(sizeof(GcThread))) + + when TArg isnot void: t.data = param + t.dataFn = tp + when hasSharedHeap: t.core.stackSize = ThreadStackSize + var dummyThreadId: int32 + t.sys = createThread(nil, ThreadStackSize, threadProcWrapper[TArg], + addr(t), 0'i32, dummyThreadId) + if t.sys <= 0: + raise newException(ResourceExhaustedError, "cannot create thread") + + proc pinToCpu*[Arg](t: var Thread[Arg]; cpu: Natural) = + ## Pins a thread to a `CPU`:idx:. + ## + ## In other words sets a thread's `affinity`:idx:. + ## If you don't know what this means, you shouldn't use this proc. + setThreadAffinityMask(t.sys, uint(1 shl cpu)) + +elif defined(genode): + var affinityOffset: cuint = 1 + ## CPU affinity offset for next thread, safe to roll-over. + + proc createThread*[TArg](t: var Thread[TArg], + tp: proc (arg: TArg) {.thread, nimcall.}, + param: TArg) = + t.core = cast[PGcThread](allocThreadStorage(sizeof(GcThread))) + + when TArg isnot void: t.data = param + t.dataFn = tp + when hasSharedHeap: t.stackSize = ThreadStackSize + t.sys.initThread( + runtimeEnv, + ThreadStackSize.culonglong, + threadProcWrapper[TArg], addr(t), affinityOffset) + inc affinityOffset + + proc pinToCpu*[Arg](t: var Thread[Arg]; cpu: Natural) = + {.hint: "cannot change Genode thread CPU affinity after initialization".} + discard + +else: + proc createThread*[TArg](t: var Thread[TArg], + tp: proc (arg: TArg) {.thread, nimcall.}, + param: TArg) = + ## Creates a new thread `t` and starts its execution. + ## + ## Entry point is the proc `tp`. `param` is passed to `tp`. + ## `TArg` can be `void` if you + ## don't need to pass any data to the thread. + t.core = cast[PGcThread](allocThreadStorage(sizeof(GcThread))) + + when TArg isnot void: t.data = param + t.dataFn = tp + when hasSharedHeap: t.core.stackSize = ThreadStackSize + var a {.noinit.}: Pthread_attr + doAssert pthread_attr_init(a) == 0 + when hasAllocStack: + var + rawstk = allocThreadStorage(ThreadStackSize + StackGuardSize) + stk = cast[pointer](cast[uint](rawstk) + StackGuardSize) + let setstacksizeResult = pthread_attr_setstack(addr a, stk, ThreadStackSize) + t.rawStack = rawstk + else: + let setstacksizeResult = pthread_attr_setstacksize(a, ThreadStackSize) + + when not defined(ios): + # This fails on iOS + doAssert(setstacksizeResult == 0) + if pthread_create(t.sys, a, threadProcWrapper[TArg], addr(t)) != 0: + raise newException(ResourceExhaustedError, "cannot create thread") + doAssert pthread_attr_destroy(a) == 0 + + proc pinToCpu*[Arg](t: var Thread[Arg]; cpu: Natural) = + ## Pins a thread to a `CPU`:idx:. + ## + ## In other words sets a thread's `affinity`:idx:. + ## If you don't know what this means, you shouldn't use this proc. + when not defined(macosx): + var s {.noinit.}: CpuSet + cpusetZero(s) + cpusetIncl(cpu.cint, s) + setAffinity(t.sys, csize_t(sizeof(s)), s) + +proc createThread*(t: var Thread[void], tp: proc () {.thread, nimcall.}) = + createThread[void](t, tp) + +when not defined(gcOrc): + include system/threadids |