| // Copyright 2011 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package runtime |
| |
| import "unsafe" |
| |
| type mOS struct { |
| waitsema uintptr // semaphore for parking on locks |
| } |
| |
| func getProcID() uint64 { |
| return uint64(gettid()) |
| } |
| |
| //extern malloc |
| func libc_malloc(uintptr) unsafe.Pointer |
| |
| //go:noescape |
| //extern sem_init |
| func sem_init(sem *semt, pshared int32, value uint32) int32 |
| |
| //go:noescape |
| //extern sem_wait |
| func sem_wait(sem *semt) int32 |
| |
| //go:noescape |
| //extern sem_post |
| func sem_post(sem *semt) int32 |
| |
| //go:noescape |
| //extern sem_reltimedwait_np |
| func sem_reltimedwait_np(sem *semt, timeout *timespec) int32 |
| |
| //go:nosplit |
| func semacreate(mp *m) { |
| if mp.waitsema != 0 { |
| return |
| } |
| |
| var sem *semt |
| |
| // Call libc's malloc rather than malloc. This will |
| // allocate space on the C heap. We can't call malloc |
| // here because it could cause a deadlock. |
| sem = (*semt)(libc_malloc(unsafe.Sizeof(*sem))) |
| if sem_init(sem, 0, 0) != 0 { |
| throw("sem_init") |
| } |
| mp.waitsema = uintptr(unsafe.Pointer(sem)) |
| } |
| |
| //go:nosplit |
| func semasleep(ns int64) int32 { |
| _m_ := getg().m |
| if ns >= 0 { |
| var ts timespec |
| ts.setNsec(ns) |
| |
| if sem_reltimedwait_np((*semt)(unsafe.Pointer(_m_.waitsema)), &ts) != 0 { |
| err := errno() |
| if err == _ETIMEDOUT || err == _EAGAIN || err == _EINTR { |
| return -1 |
| } |
| throw("sem_reltimedwait_np") |
| } |
| return 0 |
| } |
| for { |
| r1 := sem_wait((*semt)(unsafe.Pointer(_m_.waitsema))) |
| if r1 == 0 { |
| break |
| } |
| if errno() == _EINTR { |
| continue |
| } |
| throw("sem_wait") |
| } |
| return 0 |
| } |
| |
| //go:nosplit |
| func semawakeup(mp *m) { |
| if sem_post((*semt)(unsafe.Pointer(mp.waitsema))) != 0 { |
| throw("sem_post") |
| } |
| } |