Artifact 5c06ee482be3dbe36f32436a5b5c0df5abc03f54fcae90c006ede8147602f6e2:
- File
src/mutex.h
— part of check-in
[5b37fbeb82]
at
2020-12-20 21:26:08
on branch trunk
— Return error instead of using errno for threading
errno is problematic for Amiga libraries and is also not thread-safe on
some systems, even though it should. (user: js, size: 3979) [annotate] [blame] [check-ins using] [more...]
/* * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, * 2018, 2019, 2020 * Jonathan Schleifer <js@nil.im> * * All rights reserved. * * This file is part of ObjFW. It may be distributed under the terms of the * Q Public License 1.0, which can be found in the file LICENSE.QPL included in * the packaging of this file. * * Alternatively, it may be distributed under the terms of the GNU General * Public License, either version 2 or 3, which can be found in the file * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this * file. */ #include "objfw-defs.h" #include <errno.h> #include "platform.h" #if !defined(OF_HAVE_THREADS) || \ (!defined(OF_HAVE_PTHREADS) && !defined(OF_WINDOWS) && !defined(OF_AMIGAOS)) # error No mutexes available! #endif #import "macros.h" #if defined(OF_HAVE_PTHREADS) # include <pthread.h> typedef pthread_mutex_t of_mutex_t; #elif defined(OF_WINDOWS) # include <windows.h> typedef CRITICAL_SECTION of_mutex_t; #elif defined(OF_AMIGAOS) # include <exec/semaphores.h> typedef struct SignalSemaphore of_mutex_t; #endif #if defined(OF_HAVE_ATOMIC_OPS) # import "atomic.h" typedef volatile int of_spinlock_t; # define OF_SPINCOUNT 10 #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) typedef pthread_spinlock_t of_spinlock_t; #else typedef of_mutex_t of_spinlock_t; #endif #ifdef OF_HAVE_SCHED_YIELD # include <sched.h> #endif #if defined(OF_HAVE_RECURSIVE_PTHREAD_MUTEXES) || defined(OF_WINDOWS) || \ defined(OF_AMIGAOS) # define of_rmutex_t of_mutex_t #else # import "tlskey.h" typedef struct { of_mutex_t mutex; of_tlskey_t count; } of_rmutex_t; #endif #ifdef __cplusplus extern "C" { #endif extern int of_mutex_new(of_mutex_t *mutex); extern int of_mutex_lock(of_mutex_t *mutex); extern int of_mutex_trylock(of_mutex_t *mutex); extern int of_mutex_unlock(of_mutex_t *mutex); extern int of_mutex_free(of_mutex_t *mutex); extern int of_rmutex_new(of_rmutex_t *rmutex); extern int of_rmutex_lock(of_rmutex_t *rmutex); extern int of_rmutex_trylock(of_rmutex_t *rmutex); extern int of_rmutex_unlock(of_rmutex_t *rmutex); extern int of_rmutex_free(of_rmutex_t *rmutex); #ifdef __cplusplus } #endif /* Spinlocks are inlined for performance. */ static OF_INLINE void of_thread_yield(void) { #if defined(OF_HAVE_SCHED_YIELD) sched_yield(); #elif defined(OF_WINDOWS) Sleep(0); #endif } static OF_INLINE int of_spinlock_new(of_spinlock_t *spinlock) { #if defined(OF_HAVE_ATOMIC_OPS) *spinlock = 0; return 0; #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) return pthread_spin_init(spinlock, 0); #else return of_mutex_new(spinlock); #endif } static OF_INLINE int of_spinlock_trylock(of_spinlock_t *spinlock) { #if defined(OF_HAVE_ATOMIC_OPS) if (of_atomic_int_cmpswap(spinlock, 0, 1)) { of_memory_barrier_acquire(); return 0; } return EBUSY; #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) return pthread_spin_trylock(spinlock); #else return of_mutex_trylock(spinlock); #endif } static OF_INLINE int of_spinlock_lock(of_spinlock_t *spinlock) { #if defined(OF_HAVE_ATOMIC_OPS) size_t i; for (i = 0; i < OF_SPINCOUNT; i++) if (of_spinlock_trylock(spinlock) == 0) return 0; while (of_spinlock_trylock(spinlock) == EBUSY) of_thread_yield(); return 0; #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) return pthread_spin_lock(spinlock); #else return of_mutex_lock(spinlock); #endif } static OF_INLINE int of_spinlock_unlock(of_spinlock_t *spinlock) { #if defined(OF_HAVE_ATOMIC_OPS) bool ret = of_atomic_int_cmpswap(spinlock, 1, 0); of_memory_barrier_release(); return (ret ? 0 : EINVAL); #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) return pthread_spin_unlock(spinlock); #else return of_mutex_unlock(spinlock); #endif } static OF_INLINE int of_spinlock_free(of_spinlock_t *spinlock) { #if defined(OF_HAVE_ATOMIC_OPS) return 0; #elif defined(OF_HAVE_PTHREAD_SPINLOCKS) return pthread_spin_destroy(spinlock); #else return of_mutex_free(spinlock); #endif }