mirror of git://gcc.gnu.org/git/gcc.git
86 lines
1.7 KiB
Go
86 lines
1.7 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package runtime
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import "unsafe"
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type mOS struct {
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waitsema uintptr // semaphore for parking on locks
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}
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//extern malloc
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func libc_malloc(uintptr) unsafe.Pointer
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//go:noescape
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//extern sem_init
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func sem_init(sem *semt, pshared int32, value uint32) int32
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//go:noescape
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//extern sem_wait
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func sem_wait(sem *semt) int32
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//go:noescape
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//extern sem_post
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func sem_post(sem *semt) int32
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//go:noescape
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//extern sem_reltimedwait_np
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func sem_reltimedwait_np(sem *semt, timeout *timespec) int32
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//go:nosplit
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func semacreate(mp *m) {
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if mp.mos.waitsema != 0 {
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return
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}
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var sem *semt
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// Call libc's malloc rather than malloc. This will
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// allocate space on the C heap. We can't call malloc
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// here because it could cause a deadlock.
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sem = (*semt)(libc_malloc(unsafe.Sizeof(*sem)))
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if sem_init(sem, 0, 0) != 0 {
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throw("sem_init")
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}
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mp.mos.waitsema = uintptr(unsafe.Pointer(sem))
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}
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//go:nosplit
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func semasleep(ns int64) int32 {
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_m_ := getg().m
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if ns >= 0 {
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var ts timespec
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ts.set_sec(ns / 1000000000)
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ts.set_nsec(int32(ns % 1000000000))
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if sem_reltimedwait_np((*semt)(unsafe.Pointer(_m_.mos.waitsema)), &ts) != 0 {
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err := errno()
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if err == _ETIMEDOUT || err == _EAGAIN || err == _EINTR {
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return -1
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}
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throw("sem_reltimedwait_np")
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}
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return 0
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}
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for {
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r1 := sem_wait((*semt)(unsafe.Pointer(_m_.mos.waitsema)))
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if r1 == 0 {
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break
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}
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if errno() == _EINTR {
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continue
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}
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throw("sem_wait")
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}
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return 0
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}
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//go:nosplit
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func semawakeup(mp *m) {
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if sem_post((*semt)(unsafe.Pointer(mp.mos.waitsema))) != 0 {
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throw("sem_post")
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}
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}
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