Thread support for Nim.
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.
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.
Examples
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)
Procs
proc createThread*(t: var Thread[void]; tp: proc () {.thread, nimcall.})
- Source Edit
proc createThread*[TArg](t: var Thread[TArg]; tp: proc (arg: TArg) {.thread, nimcall.}; param: TArg)
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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.
Source Edit proc getThreadId*(): int
- Gets the ID of the currently running thread. Source Edit
proc handle*[TArg](t: Thread[TArg]): SysThread {.inline.}
- Returns the thread handle of t. Source Edit
proc joinThread*[TArg](t: Thread[TArg]) {.inline.}
- Waits for the thread t to finish. Source Edit
proc joinThreads*[TArg](t: varargs[Thread[TArg]])
- Waits for every thread in t to finish. Source Edit
proc onThreadDestruction*(handler: proc () {.closure, ...gcsafe, raises: [].})
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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.
Source Edit