mirror of
https://github.com/ziglang/zig.git
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18f3034629
* std: start removing redundant ResetEvents * src: fix other uses of std.Thread.ResetEvent * src: add builtin.sanitize_thread for tsan detection * atomic: add Atomic.fence for proper fencing with tsan * Thread: remove the other ResetEvent's and rewrite the current one * Thread: ResetEvent docs * zig fmt + WaitGroup.reset() fix * src: fix build issues for ResetEvent + tsan * Thread: ResetEvent tests * Thread: ResetEvent module doc * Atomic: replace llvm *p memory constraint with *m * panicking: handle spurious wakeups in futex.wait() when waiting for abort() * zig fmt
40 lines
1.0 KiB
Zig
40 lines
1.0 KiB
Zig
const std = @import("std");
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const Atomic = std.atomic.Atomic;
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const assert = std.debug.assert;
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const WaitGroup = @This();
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const is_waiting: usize = 1 << 0;
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const one_pending: usize = 1 << 1;
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state: Atomic(usize) = Atomic(usize).init(0),
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event: std.Thread.ResetEvent = .{},
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pub fn start(self: *WaitGroup) void {
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const state = self.state.fetchAdd(one_pending, .Monotonic);
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assert((state / one_pending) < (std.math.maxInt(usize) / one_pending));
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}
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pub fn finish(self: *WaitGroup) void {
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const state = self.state.fetchSub(one_pending, .Release);
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assert((state / one_pending) > 0);
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if (state == (one_pending | is_waiting)) {
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self.state.fence(.Acquire);
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self.event.set();
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}
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}
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pub fn wait(self: *WaitGroup) void {
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var state = self.state.fetchAdd(is_waiting, .Acquire);
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assert(state & is_waiting == 0);
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if ((state / one_pending) > 0) {
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self.event.wait();
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}
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}
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pub fn reset(self: *WaitGroup) void {
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self.state.store(0, .Monotonic);
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self.event.reset();
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}
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