ObjFW  Artifact [e37b27b008]

Artifact e37b27b008e8305a2ad6f1322136a35024d6f44393b906e16267cb47ea80ff35:

• File src/threading.h — part of check-in [c5b3c8ea87] at 2017-05-14 14:18:26 on branch trunk — Add nullability annotations to remaining headers

  This explicitly excludes threading.h, as adding nullability annotations
  requires adding them everywhere in the file. However, the types in there
  are implementation defined, and might be pointers or not: Adding none
  when it's a pointer would be an error, and adding one when it's not a
  pointer would be an error, too. (user: js, size: 6326) [annotate] [blame] [check-ins using]

/*
 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017
 *   Jonathan Schleifer <js@heap.zone>
 *
 * 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 "platform.h"

#if !defined(OF_HAVE_THREADS) || \
    (!defined(OF_HAVE_PTHREADS) && !defined(OF_WINDOWS))
# error No threads available!
#endif

#include <math.h>

#import "OFObject.h"

#if defined(OF_HAVE_PTHREADS)
# include <pthread.h>
# include <sched.h>
typedef pthread_t of_thread_t;
typedef pthread_key_t of_tlskey_t;
typedef pthread_mutex_t of_mutex_t;
typedef pthread_cond_t of_condition_t;
typedef pthread_once_t of_once_t;
# define OF_ONCE_INIT PTHREAD_ONCE_INIT
#elif defined(OF_WINDOWS)
/*
 * winsock2.h needs to be included before windows.h. Not including it here
 * would make it impossible to use sockets after threading.h has been
 * imported.
 */
# ifdef OF_HAVE_SOCKETS
#  include <winsock2.h>
# endif
# include <windows.h>
typedef HANDLE of_thread_t;
typedef DWORD of_tlskey_t;
typedef CRITICAL_SECTION of_mutex_t;
typedef struct {
	HANDLE event;
	int count;
} of_condition_t;
typedef volatile int of_once_t;
# define OF_ONCE_INIT 0
#else
# error No threads available!
#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)
# define of_rmutex_t of_mutex_t
#else
typedef struct {
	of_mutex_t mutex;
	of_tlskey_t count;
} of_rmutex_t;
#endif

typedef struct of_thread_attr_t {
	float priority;
	size_t stackSize;
} of_thread_attr_t;

#if defined(OF_HAVE_PTHREADS)
# define of_thread_is_current(t) pthread_equal(t, pthread_self())
# define of_thread_current pthread_self
#elif defined(OF_WINDOWS)
# define of_thread_is_current(t) (t == GetCurrentThread())
# define of_thread_current GetCurrentThread
#else
# error of_thread_is_current not implemented!
# error of_thread_current not implemented!
#endif

extern bool of_thread_attr_init(of_thread_attr_t *attr);
extern bool of_thread_new(of_thread_t *thread, void (*function)(id), id object,
    const of_thread_attr_t *attr);
extern void of_thread_set_name(of_thread_t thread, const char *name);
extern bool of_thread_join(of_thread_t thread);
extern bool of_thread_detach(of_thread_t thread);
extern void OF_NO_RETURN_FUNC of_thread_exit(void);
extern void of_once(of_once_t *control, void (*func)(void));
extern bool of_tlskey_new(of_tlskey_t *key);
extern bool of_tlskey_free(of_tlskey_t key);
extern bool of_mutex_new(of_mutex_t *mutex);
extern bool of_mutex_lock(of_mutex_t *mutex);
extern bool of_mutex_trylock(of_mutex_t *mutex);
extern bool of_mutex_unlock(of_mutex_t *mutex);
extern bool of_mutex_free(of_mutex_t *mutex);
extern bool of_rmutex_new(of_rmutex_t *rmutex);
extern bool of_rmutex_lock(of_rmutex_t *rmutex);
extern bool of_rmutex_trylock(of_rmutex_t *rmutex);
extern bool of_rmutex_unlock(of_rmutex_t *rmutex);
extern bool of_rmutex_free(of_rmutex_t *rmutex);
extern bool of_condition_new(of_condition_t *condition);
extern bool of_condition_signal(of_condition_t *condition);
extern bool of_condition_broadcast(of_condition_t *condition);
extern bool of_condition_wait(of_condition_t *condition, of_mutex_t *mutex);
extern bool of_condition_timed_wait(of_condition_t *condition,
    of_mutex_t *mutex, of_time_interval_t timeout);
extern bool of_condition_free(of_condition_t *condition);

/* TLS keys and spinlocks are inlined for performance. */

#if defined(OF_HAVE_PTHREADS)
static OF_INLINE void *
of_tlskey_get(of_tlskey_t key)
{
	return pthread_getspecific(key);
}

static OF_INLINE bool
of_tlskey_set(of_tlskey_t key, void *ptr)
{
	return (pthread_setspecific(key, ptr) == 0);
}
#elif defined(OF_WINDOWS)
static OF_INLINE void *
of_tlskey_get(of_tlskey_t key)
{
	return TlsGetValue(key);
}

static OF_INLINE bool
of_tlskey_set(of_tlskey_t key, void *ptr)
{
	return TlsSetValue(key, ptr);
}
#else
# error No thread local storage available!
#endif

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 bool
of_spinlock_new(of_spinlock_t *spinlock)
{
#if defined(OF_HAVE_ATOMIC_OPS)
	*spinlock = 0;
	return true;
#elif defined(OF_HAVE_PTHREAD_SPINLOCKS)
	return (pthread_spin_init(spinlock, 0) == 0);
#else
	return of_mutex_new(spinlock);
#endif
}

static OF_INLINE bool
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 true;
	}

	return false;
#elif defined(OF_HAVE_PTHREAD_SPINLOCKS)
	return (pthread_spin_trylock(spinlock) == 0);
#else
	return of_mutex_trylock(spinlock);
#endif
}

static OF_INLINE bool
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))
			return true;

	while (!of_spinlock_trylock(spinlock))
		of_thread_yield();

	return true;
#elif defined(OF_HAVE_PTHREAD_SPINLOCKS)
	return (pthread_spin_lock(spinlock) == 0);
#else
	return of_mutex_lock(spinlock);
#endif
}

static OF_INLINE bool
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;
#elif defined(OF_HAVE_PTHREAD_SPINLOCKS)
	return (pthread_spin_unlock(spinlock) == 0);
#else
	return of_mutex_unlock(spinlock);
#endif
}

static OF_INLINE bool
of_spinlock_free(of_spinlock_t *spinlock)
{
#if defined(OF_HAVE_ATOMIC_OPS)
	return true;
#elif defined(OF_HAVE_PTHREAD_SPINLOCKS)
	return (pthread_spin_destroy(spinlock) == 0);
#else
	return of_mutex_free(spinlock);
#endif
}