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// Copyright 2009 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 {
initialized bool
mutex pthreadmutex
cond pthreadcond
count int
}
func unimplemented(name string) {
println(name, "not implemented")
*(*int)(unsafe.Pointer(uintptr(1231))) = 1231
}
//go:nosplit
func semacreate(mp *m) {
if mp.initialized {
return
}
mp.initialized = true
if err := pthread_mutex_init(&mp.mutex, nil); err != 0 {
throw("pthread_mutex_init")
}
if err := pthread_cond_init(&mp.cond, nil); err != 0 {
throw("pthread_cond_init")
}
}
//go:nosplit
func semasleep(ns int64) int32 {
var start int64
if ns >= 0 {
start = nanotime()
}
mp := getg().m
pthread_mutex_lock(&mp.mutex)
for {
if mp.count > 0 {
mp.count--
pthread_mutex_unlock(&mp.mutex)
return 0
}
if ns >= 0 {
spent := nanotime() - start
if spent >= ns {
pthread_mutex_unlock(&mp.mutex)
return -1
}
var t timespec
t.setNsec(ns - spent)
err := pthread_cond_timedwait_relative_np(&mp.cond, &mp.mutex, &t)
if err == _ETIMEDOUT {
pthread_mutex_unlock(&mp.mutex)
return -1
}
} else {
pthread_cond_wait(&mp.cond, &mp.mutex)
}
}
}
//go:nosplit
func semawakeup(mp *m) {
pthread_mutex_lock(&mp.mutex)
mp.count++
if mp.count > 0 {
pthread_cond_signal(&mp.cond)
}
pthread_mutex_unlock(&mp.mutex)
}
// The read and write file descriptors used by the sigNote functions.
var sigNoteRead, sigNoteWrite int32
// sigNoteSetup initializes an async-signal-safe note.
//
// The current implementation of notes on Darwin is not async-signal-safe,
// because the functions pthread_mutex_lock, pthread_cond_signal, and
// pthread_mutex_unlock, called by semawakeup, are not async-signal-safe.
// There is only one case where we need to wake up a note from a signal
// handler: the sigsend function. The signal handler code does not require
// all the features of notes: it does not need to do a timed wait.
// This is a separate implementation of notes, based on a pipe, that does
// not support timed waits but is async-signal-safe.
func sigNoteSetup(*note) {
if sigNoteRead != 0 || sigNoteWrite != 0 {
throw("duplicate sigNoteSetup")
}
var errno int32
sigNoteRead, sigNoteWrite, errno = pipe()
if errno != 0 {
throw("pipe failed")
}
closeonexec(sigNoteRead)
closeonexec(sigNoteWrite)
// Make the write end of the pipe non-blocking, so that if the pipe
// buffer is somehow full we will not block in the signal handler.
// Leave the read end of the pipe blocking so that we will block
// in sigNoteSleep.
setNonblock(sigNoteWrite)
}
// sigNoteWakeup wakes up a thread sleeping on a note created by sigNoteSetup.
func sigNoteWakeup(*note) {
var b byte
write(uintptr(sigNoteWrite), unsafe.Pointer(&b), 1)
}
// sigNoteSleep waits for a note created by sigNoteSetup to be woken.
func sigNoteSleep(*note) {
entersyscallblock()
var b byte
read(sigNoteRead, unsafe.Pointer(&b), 1)
exitsyscall()
}
// BSD interface for threading.
func osinit() {
// pthread_create delayed until end of goenvs so that we
// can look at the environment first.
ncpu = getncpu()
physPageSize = getPageSize()
}
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