154 lines
3.3 KiB
V
154 lines
3.3 KiB
V
// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module sync
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import time
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#flag -lpthread
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$if macos {
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#include <dispatch/dispatch.h>
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}
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#include <semaphore.h>
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// [init_with=new_mutex] // TODO: implement support for this struct attribute, and disallow Mutex{} from outside the sync.new_mutex() function.
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[ref_only]
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pub struct Mutex {
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mutex C.pthread_mutex_t
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}
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[ref_only]
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pub struct RwMutex {
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mutex C.pthread_rwlock_t
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}
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[ref_only]
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struct RwMutexAttr {
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attr C.pthread_rwlockattr_t
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}
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/* MacOSX has no unnamed semaphores and no `timed_wait()` at all
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so we emulate the behaviour with other devices */
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// [ref_only]
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// struct MacOSX_Semaphore {
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// sem C.dispatch_semaphore_t
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// }
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[ref_only]
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struct PosixSemaphore {
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sem C.sem_t
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}
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pub struct Semaphore {
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mut:
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sem voidptr
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}
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pub fn new_mutex() &Mutex {
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m := &Mutex{}
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C.pthread_mutex_init(&m.mutex, C.NULL)
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return m
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}
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pub fn new_rwmutex() &RwMutex {
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m := &RwMutex{}
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a := &RwMutexAttr{}
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C.pthread_rwlockattr_init(&a.attr)
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// Give writer priority over readers
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C.pthread_rwlockattr_setkind_np(&a.attr, C.PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP)
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C.pthread_rwlockattr_setpshared(&a.attr, C.PTHREAD_PROCESS_PRIVATE)
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C.pthread_rwlock_init(&m.mutex, &a.attr)
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return m
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}
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// m_lock(), for *manual* mutex handling, since `lock` is a keyword
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pub fn (mut m Mutex) m_lock() {
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C.pthread_mutex_lock(&m.mutex)
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}
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pub fn (mut m Mutex) unlock() {
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C.pthread_mutex_unlock(&m.mutex)
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}
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// RwMutex has separate read- and write locks
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pub fn (mut m RwMutex) r_lock() {
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C.pthread_rwlock_rdlock(&m.mutex)
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}
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pub fn (mut m RwMutex) w_lock() {
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C.pthread_rwlock_wrlock(&m.mutex)
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}
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// Windows SRWLocks have different function to unlock
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// So provide two functions here, too, to have a common interface
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pub fn (mut m RwMutex) r_unlock() {
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C.pthread_rwlock_unlock(&m.mutex)
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}
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pub fn (mut m RwMutex) w_unlock() {
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C.pthread_rwlock_unlock(&m.mutex)
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}
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[inline]
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pub fn new_semaphore() Semaphore {
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return new_semaphore_init(0)
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}
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pub fn new_semaphore_init(n u32) Semaphore {
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$if macos {
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s := Semaphore{
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sem: C.dispatch_semaphore_create(n)
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}
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return s
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} $else {
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s := Semaphore{
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sem: &PosixSemaphore{}
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}
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unsafe { C.sem_init(&&PosixSemaphore(s.sem).sem, 0, n) }
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return s
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}
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}
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pub fn (s Semaphore) post() {
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$if macos {
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C.dispatch_semaphore_signal(s.sem)
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} $else {
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unsafe { C.sem_post(&&PosixSemaphore(s.sem).sem) }
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}
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}
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pub fn (s Semaphore) wait() {
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$if macos {
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C.dispatch_semaphore_wait(s.sem, C.DISPATCH_TIME_FOREVER)
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} $else {
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unsafe { C.sem_wait(&&PosixSemaphore(s.sem).sem) }
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}
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}
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pub fn (s Semaphore) try_wait() bool {
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$if macos {
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return C.dispatch_semaphore_wait(s.sem, C.DISPATCH_TIME_NOW) == 0
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} $else {
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return unsafe { C.sem_trywait(&&PosixSemaphore(s.sem).sem) == 0 }
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}
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}
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pub fn (s Semaphore) timed_wait(timeout time.Duration) bool {
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$if macos {
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return C.dispatch_semaphore_wait(s.sem, C.dispatch_time(C.DISPATCH_TIME_NOW, i64(timeout))) == 0
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} $else {
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t_spec := timeout.timespec()
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return unsafe { C.sem_timedwait(&&PosixSemaphore(s.sem).sem, &t_spec) == 0 }
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}
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}
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pub fn (s Semaphore) destroy() bool {
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$if macos {
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for s.try_wait() {}
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C.dispatch_release(s.sem)
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return true
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} $else {
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return unsafe { C.sem_destroy(&&PosixSemaphore(s.sem).sem) == 0 }
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}
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}
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