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glib2.0/glib/gthread.h

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/* GLIB - Library of useful routines for C programming
* Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
/*
* Modified by the GLib Team and others 1997-2000. See the AUTHORS
* file for a list of people on the GLib Team. See the ChangeLog
* files for a list of changes. These files are distributed with
* GLib at ftp://ftp.gtk.org/pub/gtk/.
*/
#ifndef __G_THREAD_H__
#define __G_THREAD_H__
#if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
#error "Only <glib.h> can be included directly."
#endif
#include <glib/gatomic.h>
#include <glib/gerror.h>
#include <glib/gutils.h>
G_BEGIN_DECLS
#define G_THREAD_ERROR g_thread_error_quark ()
GLIB_AVAILABLE_IN_ALL
GQuark g_thread_error_quark (void);
typedef enum
{
G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
} GThreadError;
typedef gpointer (*GThreadFunc) (gpointer data);
typedef struct _GThread GThread;
typedef union _GMutex GMutex;
typedef struct _GRecMutex GRecMutex;
typedef struct _GRWLock GRWLock;
typedef struct _GCond GCond;
typedef struct _GPrivate GPrivate;
typedef struct _GOnce GOnce;
union _GMutex
{
/*< private >*/
gpointer p;
guint i[2];
};
struct _GRWLock
{
/*< private >*/
gpointer p;
guint i[2];
};
struct _GCond
{
/*< private >*/
gpointer p;
guint i[2];
};
struct _GRecMutex
{
/*< private >*/
gpointer p;
guint i[2];
};
#define G_PRIVATE_INIT(notify) { NULL, (notify), { NULL, NULL } }
struct _GPrivate
{
/*< private >*/
gpointer p;
GDestroyNotify notify;
gpointer future[2];
};
typedef enum
{
G_ONCE_STATUS_NOTCALLED,
G_ONCE_STATUS_PROGRESS,
G_ONCE_STATUS_READY
} GOnceStatus;
#define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
struct _GOnce
{
volatile GOnceStatus status;
volatile gpointer retval;
};
#define G_LOCK_NAME(name) g__ ## name ## _lock
#define G_LOCK_DEFINE_STATIC(name) static G_LOCK_DEFINE (name)
#define G_LOCK_DEFINE(name) GMutex G_LOCK_NAME (name)
#define G_LOCK_EXTERN(name) extern GMutex G_LOCK_NAME (name)
#ifdef G_DEBUG_LOCKS
# define G_LOCK(name) G_STMT_START{ \
g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
"file %s: line %d (%s): locking: %s ", \
__FILE__, __LINE__, G_STRFUNC, \
#name); \
g_mutex_lock (&G_LOCK_NAME (name)); \
}G_STMT_END
# define G_UNLOCK(name) G_STMT_START{ \
g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
"file %s: line %d (%s): unlocking: %s ", \
__FILE__, __LINE__, G_STRFUNC, \
#name); \
g_mutex_unlock (&G_LOCK_NAME (name)); \
}G_STMT_END
# define G_TRYLOCK(name) \
(g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
"file %s: line %d (%s): try locking: %s ", \
__FILE__, __LINE__, G_STRFUNC, \
#name), g_mutex_trylock (&G_LOCK_NAME (name)))
#else /* !G_DEBUG_LOCKS */
# define G_LOCK(name) g_mutex_lock (&G_LOCK_NAME (name))
# define G_UNLOCK(name) g_mutex_unlock (&G_LOCK_NAME (name))
# define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
#endif /* !G_DEBUG_LOCKS */
#ifdef g_autoptr
#define G_AUTO_LOCK(name) G_MUTEX_AUTO_LOCK (&G_LOCK_NAME (name), g__##name##_locker)
#endif /* g_autoptr */
GLIB_AVAILABLE_IN_2_32
GThread * g_thread_ref (GThread *thread);
GLIB_AVAILABLE_IN_2_32
void g_thread_unref (GThread *thread);
GLIB_AVAILABLE_IN_2_32
GThread * g_thread_new (const gchar *name,
GThreadFunc func,
gpointer data);
GLIB_AVAILABLE_IN_2_32
GThread * g_thread_try_new (const gchar *name,
GThreadFunc func,
gpointer data,
GError **error);
GLIB_AVAILABLE_IN_ALL
GThread * g_thread_self (void);
G_NORETURN GLIB_AVAILABLE_IN_ALL
void g_thread_exit (gpointer retval);
GLIB_AVAILABLE_IN_ALL
gpointer g_thread_join (GThread *thread);
GLIB_AVAILABLE_IN_ALL
void g_thread_yield (void);
GLIB_AVAILABLE_IN_2_32
void g_mutex_init (GMutex *mutex);
GLIB_AVAILABLE_IN_2_32
void g_mutex_clear (GMutex *mutex);
GLIB_AVAILABLE_IN_ALL
void g_mutex_lock (GMutex *mutex);
GLIB_AVAILABLE_IN_ALL
gboolean g_mutex_trylock (GMutex *mutex);
GLIB_AVAILABLE_IN_ALL
void g_mutex_unlock (GMutex *mutex);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_init (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_clear (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_writer_lock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
gboolean g_rw_lock_writer_trylock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_writer_unlock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_reader_lock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
gboolean g_rw_lock_reader_trylock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rw_lock_reader_unlock (GRWLock *rw_lock);
GLIB_AVAILABLE_IN_2_32
void g_rec_mutex_init (GRecMutex *rec_mutex);
GLIB_AVAILABLE_IN_2_32
void g_rec_mutex_clear (GRecMutex *rec_mutex);
GLIB_AVAILABLE_IN_2_32
void g_rec_mutex_lock (GRecMutex *rec_mutex);
GLIB_AVAILABLE_IN_2_32
gboolean g_rec_mutex_trylock (GRecMutex *rec_mutex);
GLIB_AVAILABLE_IN_2_32
void g_rec_mutex_unlock (GRecMutex *rec_mutex);
GLIB_AVAILABLE_IN_2_32
void g_cond_init (GCond *cond);
GLIB_AVAILABLE_IN_2_32
void g_cond_clear (GCond *cond);
GLIB_AVAILABLE_IN_ALL
void g_cond_wait (GCond *cond,
GMutex *mutex);
GLIB_AVAILABLE_IN_ALL
void g_cond_signal (GCond *cond);
GLIB_AVAILABLE_IN_ALL
void g_cond_broadcast (GCond *cond);
GLIB_AVAILABLE_IN_2_32
gboolean g_cond_wait_until (GCond *cond,
GMutex *mutex,
gint64 end_time);
GLIB_AVAILABLE_IN_ALL
gpointer g_private_get (GPrivate *key);
GLIB_AVAILABLE_IN_ALL
void g_private_set (GPrivate *key,
gpointer value);
GLIB_AVAILABLE_IN_2_32
void g_private_replace (GPrivate *key,
gpointer value);
GLIB_AVAILABLE_IN_ALL
gpointer g_once_impl (GOnce *once,
GThreadFunc func,
gpointer arg);
GLIB_AVAILABLE_IN_ALL
gboolean g_once_init_enter (volatile void *location);
GLIB_AVAILABLE_IN_ALL
void g_once_init_leave (volatile void *location,
gsize result);
GLIB_AVAILABLE_IN_2_80
gboolean g_once_init_enter_pointer (void *location);
GLIB_AVAILABLE_IN_2_80
void g_once_init_leave_pointer (void *location,
gpointer result);
/* Use C11-style atomic extensions to check the fast path for status=ready. If
* they are not available, fall back to using a mutex and condition variable in
* g_once_impl().
*
* On the C11-style codepath, only the load of once->status needs to be atomic,
* as the writes to it and once->retval in g_once_impl() are related by a
* happens-before relation. Release-acquire semantics are defined such that any
* atomic/non-atomic write which happens-before a store/release is guaranteed to
* be seen by the load/acquire of the same atomic variable. */
#if defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) && defined(__ATOMIC_SEQ_CST)
# define g_once(once, func, arg) \
((__atomic_load_n (&(once)->status, __ATOMIC_ACQUIRE) == G_ONCE_STATUS_READY) ? \
(once)->retval : \
g_once_impl ((once), (func), (arg)))
#else
# define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
#endif
#ifdef __GNUC__
# define g_once_init_enter(location) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
(void) (0 ? (gpointer) *(location) : NULL); \
(!g_atomic_pointer_get (location) && \
g_once_init_enter (location)); \
}))
# define g_once_init_leave(location, result) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
0 ? (void) (*(location) = (result)) : (void) 0; \
g_once_init_leave ((location), (gsize) (result)); \
}))
# define g_once_init_enter_pointer(location) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
(void) (0 ? (gpointer) * (location) : NULL); \
(!g_atomic_pointer_get (location) && \
g_once_init_enter_pointer (location)); \
})) GLIB_AVAILABLE_MACRO_IN_2_80
# define g_once_init_leave_pointer(location, result) \
(G_GNUC_EXTENSION ({ \
G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer)); \
0 ? (void) (*(location) = (result)) : (void) 0; \
g_once_init_leave_pointer ((location), (gpointer) (guintptr) (result)); \
})) GLIB_AVAILABLE_MACRO_IN_2_80
#else
# define g_once_init_enter(location) \
(g_once_init_enter((location)))
# define g_once_init_leave(location, result) \
(g_once_init_leave((location), (gsize) (result)))
# define g_once_init_enter_pointer(location) \
(g_once_init_enter_pointer((location))) \
GLIB_AVAILABLE_MACRO_IN_2_80
# define g_once_init_leave_pointer(location, result) \
(g_once_init_leave_pointer((location), (gpointer) (guintptr) (result))) \
GLIB_AVAILABLE_MACRO_IN_2_80
#endif
GLIB_AVAILABLE_IN_2_36
guint g_get_num_processors (void);
/**
* GMutexLocker:
*
* Opaque type. See g_mutex_locker_new() for details.
* Since: 2.44
*/
typedef void GMutexLocker;
/**
* g_mutex_locker_new:
* @mutex: a mutex to lock
*
* Lock @mutex and return a new #GMutexLocker. Unlock with
* g_mutex_locker_free(). Using g_mutex_unlock() on @mutex
* while a #GMutexLocker exists can lead to undefined behaviour.
*
* No allocation is performed, it is equivalent to a g_mutex_lock() call.
*
* This is intended to be used with g_autoptr(). Note that g_autoptr()
* is only available when using GCC or clang, so the following example
* will only work with those compilers:
* |[
* typedef struct
* {
* ...
* GMutex mutex;
* ...
* } MyObject;
*
* static void
* my_object_do_stuff (MyObject *self)
* {
* g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&self->mutex);
*
* // Code with mutex locked here
*
* if (condition)
* // No need to unlock
* return;
*
* // Optionally early unlock
* g_clear_pointer (&locker, g_mutex_locker_free);
*
* // Code with mutex unlocked here
* }
* ]|
*
* Note that it is common for the declared variable to not be used in the scope,
* which causes some compilers to warn. That can be avoided by using
* `G_GNUC_UNUSED` or, since 2.80, [func@GLib.MUTEX_AUTO_LOCK].
*
* Returns: a #GMutexLocker
* Since: 2.44
*/
GLIB_AVAILABLE_STATIC_INLINE_IN_2_44
static inline GMutexLocker *
g_mutex_locker_new (GMutex *mutex)
{
g_mutex_lock (mutex);
return (GMutexLocker *) mutex;
}
/**
* g_mutex_locker_free:
* @locker: a GMutexLocker
*
* Unlock @locker's mutex. See g_mutex_locker_new() for details.
*
* No memory is freed, it is equivalent to a g_mutex_unlock() call.
*
* Since: 2.44
*/
GLIB_AVAILABLE_STATIC_INLINE_IN_2_44
static inline void
g_mutex_locker_free (GMutexLocker *locker)
{
g_mutex_unlock ((GMutex *) locker);
}
/**
* G_MUTEX_AUTO_LOCK:
* @mutex: a [type@GLib.Mutex]
* @var: a variable name to be declared
*
* Declare a [type@GLib.MutexLocker] variable with `g_autoptr()` and lock the
* mutex. The mutex will be unlocked automatically when leaving the scope. The
* variable is declared with `G_GNUC_UNUSED` to avoid compiler warning if it is
* not used in the scope.
*
* This feature is only supported on GCC and clang. This macro is not defined on
* other compilers and should not be used in programs that are intended to be
* portable to those compilers.
*
* Note that this should be used in a place where it is allowed to declare a
* variable, which could be before any statement in the case
* `-Wdeclaration-after-statement` is used, or C standard prior to C99.
*
* ```c
* {
* G_MUTEX_AUTO_LOCK (&obj->mutex, locker);
*
* obj->stuff_with_lock ();
* if (condition)
* {
* // No need to unlock
* return;
* }
*
* // Unlock before end of scope
* g_clear_pointer (&locker, g_mutex_locker_free);
* obj->stuff_without_lock ();
* }
* ```
*
* Since: 2.80.0
*/
#ifdef g_autoptr
#define G_MUTEX_AUTO_LOCK(mutex, var) \
GLIB_AVAILABLE_MACRO_IN_2_80 g_autoptr (GMutexLocker) \
G_GNUC_UNUSED var = g_mutex_locker_new (mutex)
#endif /* g_autoptr */
/**
* GRecMutexLocker:
*
* Opaque type. See g_rec_mutex_locker_new() for details.
* Since: 2.60
*/
typedef void GRecMutexLocker;
/**
* g_rec_mutex_locker_new:
* @rec_mutex: a recursive mutex to lock
*
* Lock @rec_mutex and return a new #GRecMutexLocker. Unlock with
* g_rec_mutex_locker_free(). Using g_rec_mutex_unlock() on @rec_mutex
* while a #GRecMutexLocker exists can lead to undefined behaviour.
*
* No allocation is performed, it is equivalent to a g_rec_mutex_lock() call.
*
* This is intended to be used with g_autoptr(). Note that g_autoptr()
* is only available when using GCC or clang, so the following example
* will only work with those compilers:
* |[
* typedef struct
* {
* ...
* GRecMutex rec_mutex;
* ...
* } MyObject;
*
* static void
* my_object_do_stuff (MyObject *self)
* {
* g_autoptr(GRecMutexLocker) locker = g_rec_mutex_locker_new (&self->rec_mutex);
*
* // Code with rec_mutex locked here
*
* if (condition)
* // No need to unlock
* return;
*
* // Optionally early unlock
* g_clear_pointer (&locker, g_rec_mutex_locker_free);
*
* // Code with rec_mutex unlocked here
* }
* ]|
*
* Note that it is common for the declared variable to not be used in the scope,
* which causes some compilers to warn. That can be avoided by using
* `G_GNUC_UNUSED` or, since 2.80, [func@GLib.REC_MUTEX_AUTO_LOCK].
*
* Returns: a #GRecMutexLocker
* Since: 2.60
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_60
static inline GRecMutexLocker *
g_rec_mutex_locker_new (GRecMutex *rec_mutex)
{
g_rec_mutex_lock (rec_mutex);
return (GRecMutexLocker *) rec_mutex;
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* g_rec_mutex_locker_free:
* @locker: a GRecMutexLocker
*
* Unlock @locker's recursive mutex. See g_rec_mutex_locker_new() for details.
*
* No memory is freed, it is equivalent to a g_rec_mutex_unlock() call.
*
* Since: 2.60
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_60
static inline void
g_rec_mutex_locker_free (GRecMutexLocker *locker)
{
g_rec_mutex_unlock ((GRecMutex *) locker);
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* G_REC_MUTEX_AUTO_LOCK:
* @mutex: a [type@GLib.RecMutex]
* @var: a variable name to be declared
*
* Declare a [type@GLib.RecMutexLocker] variable with `g_autoptr()` and lock the
* mutex. The mutex will be unlocked automatically when leaving the scope. The
* variable is declared with `G_GNUC_UNUSED` to avoid compiler warning if it is
* not used in the scope.
*
* This feature is only supported on GCC and clang. This macro is not defined on
* other compilers and should not be used in programs that are intended to be
* portable to those compilers.
*
* Note that this should be used in a place where it is allowed to declare a
* variable, which could be before any statement in the case
* `-Wdeclaration-after-statement` is used, or C standard prior to C99.
*
* ```c
* {
* G_REC_MUTEX_AUTO_LOCK (&obj->rec_mutex, locker);
*
* obj->stuff_with_lock ();
* if (condition)
* {
* // No need to unlock
* return;
* }
*
* // Unlock before end of scope
* g_clear_pointer (&locker, g_rec_mutex_locker_free);
* obj->stuff_without_lock ();
* }
* ```
*
* Since: 2.80.0
*/
#ifdef g_autoptr
#define G_REC_MUTEX_AUTO_LOCK(mutex, var) \
GLIB_AVAILABLE_MACRO_IN_2_80 g_autoptr (GRecMutexLocker) \
G_GNUC_UNUSED var = g_rec_mutex_locker_new (mutex)
#endif /* g_autoptr */
/**
* GRWLockWriterLocker:
*
* Opaque type. See g_rw_lock_writer_locker_new() for details.
* Since: 2.62
*/
typedef void GRWLockWriterLocker;
/**
* g_rw_lock_writer_locker_new:
* @rw_lock: a #GRWLock
*
* Obtain a write lock on @rw_lock and return a new #GRWLockWriterLocker.
* Unlock with g_rw_lock_writer_locker_free(). Using g_rw_lock_writer_unlock()
* on @rw_lock while a #GRWLockWriterLocker exists can lead to undefined
* behaviour.
*
* No allocation is performed, it is equivalent to a g_rw_lock_writer_lock() call.
*
* This is intended to be used with g_autoptr(). Note that g_autoptr()
* is only available when using GCC or clang, so the following example
* will only work with those compilers:
* |[
* typedef struct
* {
* ...
* GRWLock rw_lock;
* GPtrArray *array;
* ...
* } MyObject;
*
* static gchar *
* my_object_get_data (MyObject *self, guint index)
* {
* g_autoptr(GRWLockReaderLocker) locker = g_rw_lock_reader_locker_new (&self->rw_lock);
*
* // Code with a read lock obtained on rw_lock here
*
* if (self->array == NULL)
* // No need to unlock
* return NULL;
*
* if (index < self->array->len)
* // No need to unlock
* return g_ptr_array_index (self->array, index);
*
* // Optionally early unlock
* g_clear_pointer (&locker, g_rw_lock_reader_locker_free);
*
* // Code with rw_lock unlocked here
* return NULL;
* }
*
* static void
* my_object_set_data (MyObject *self, guint index, gpointer data)
* {
* g_autoptr(GRWLockWriterLocker) locker = g_rw_lock_writer_locker_new (&self->rw_lock);
*
* // Code with a write lock obtained on rw_lock here
*
* if (self->array == NULL)
* self->array = g_ptr_array_new ();
*
* if (condition)
* // No need to unlock
* return;
*
* if (index >= self->array->len)
* g_ptr_array_set_size (self->array, index+1);
* g_ptr_array_index (self->array, index) = data;
*
* // Optionally early unlock
* g_clear_pointer (&locker, g_rw_lock_writer_locker_free);
*
* // Code with rw_lock unlocked here
* }
* ]|
*
* Note that it is common for the declared variable to not be used in the scope,
* which causes some compilers to warn. That can be avoided by using
* `G_GNUC_UNUSED` or, since 2.80, [func@GLib.RW_LOCK_WRITER_AUTO_LOCK].
*
* Returns: a #GRWLockWriterLocker
* Since: 2.62
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
static inline GRWLockWriterLocker *
g_rw_lock_writer_locker_new (GRWLock *rw_lock)
{
g_rw_lock_writer_lock (rw_lock);
return (GRWLockWriterLocker *) rw_lock;
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* g_rw_lock_writer_locker_free:
* @locker: a GRWLockWriterLocker
*
* Release a write lock on @locker's read-write lock. See
* g_rw_lock_writer_locker_new() for details.
*
* No memory is freed, it is equivalent to a g_rw_lock_writer_unlock() call.
*
* Since: 2.62
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
static inline void
g_rw_lock_writer_locker_free (GRWLockWriterLocker *locker)
{
g_rw_lock_writer_unlock ((GRWLock *) locker);
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* G_RW_LOCK_WRITER_AUTO_LOCK:
* @mutex: a [type@GLib.RWLock]
* @var: a variable name to be declared
*
* Declare a [type@GLib.RWLockWriterLocker] variable with `g_autoptr()` and lock
* for writing. The mutex will be unlocked automatically when leaving the scope.
* The variable is declared with `G_GNUC_UNUSED` to avoid compiler warning if it
* is not used in the scope.
*
* This feature is only supported on GCC and clang. This macro is not defined on
* other compilers and should not be used in programs that are intended to be
* portable to those compilers.
*
* Note that this should be used in a place where it is allowed to declare a
* variable, which could be before any statement in the case
* `-Wdeclaration-after-statement` is used, or C standard prior to C99.
*
* ```c
* {
* G_RW_LOCK_WRITER_AUTO_LOCK (&obj->rw_lock, locker);
*
* obj->stuff_with_lock ();
* if (condition)
* {
* // No need to unlock
* return;
* }
*
* // Unlock before end of scope
* g_clear_pointer (&locker, g_rw_lock_writer_locker_free);
* obj->stuff_without_lock ();
* }
* ```
*
* Since: 2.80.0
*/
#ifdef g_autoptr
#define G_RW_LOCK_WRITER_AUTO_LOCK(mutex, var) \
GLIB_AVAILABLE_MACRO_IN_2_80 g_autoptr (GRWLockWriterLocker) \
G_GNUC_UNUSED var = g_rw_lock_writer_locker_new (mutex)
#endif /* g_autoptr */
/**
* GRWLockReaderLocker:
*
* Opaque type. See g_rw_lock_reader_locker_new() for details.
* Since: 2.62
*/
typedef void GRWLockReaderLocker;
/**
* g_rw_lock_reader_locker_new:
* @rw_lock: a #GRWLock
*
* Obtain a read lock on @rw_lock and return a new #GRWLockReaderLocker.
* Unlock with g_rw_lock_reader_locker_free(). Using g_rw_lock_reader_unlock()
* on @rw_lock while a #GRWLockReaderLocker exists can lead to undefined
* behaviour.
*
* No allocation is performed, it is equivalent to a g_rw_lock_reader_lock() call.
*
* This is intended to be used with g_autoptr(). For a code sample, see
* g_rw_lock_writer_locker_new().
*
* Returns: a #GRWLockReaderLocker
* Since: 2.62
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
static inline GRWLockReaderLocker *
g_rw_lock_reader_locker_new (GRWLock *rw_lock)
{
g_rw_lock_reader_lock (rw_lock);
return (GRWLockReaderLocker *) rw_lock;
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* g_rw_lock_reader_locker_free:
* @locker: a GRWLockReaderLocker
*
* Release a read lock on @locker's read-write lock. See
* g_rw_lock_reader_locker_new() for details.
*
* No memory is freed, it is equivalent to a g_rw_lock_reader_unlock() call.
*
* Since: 2.62
*/
G_GNUC_BEGIN_IGNORE_DEPRECATIONS
GLIB_AVAILABLE_STATIC_INLINE_IN_2_62
static inline void
g_rw_lock_reader_locker_free (GRWLockReaderLocker *locker)
{
g_rw_lock_reader_unlock ((GRWLock *) locker);
}
G_GNUC_END_IGNORE_DEPRECATIONS
/**
* G_RW_LOCK_READER_AUTO_LOCK:
* @mutex: a [type@GLib.RWLock]
* @var: a variable name to be declared
*
* Declare a [type@GLib.RWLockReaderLocker] variable with `g_autoptr()` and lock
* for reading. The mutex will be unlocked automatically when leaving the scope.
* The variable is declared with `G_GNUC_UNUSED` to avoid compiler warning if it
* is not used in the scope.
*
* This feature is only supported on GCC and clang. This macro is not defined on
* other compilers and should not be used in programs that are intended to be
* portable to those compilers.
*
* Note that this should be used in a place where it is allowed to declare a
* variable, which could be before any statement in the case
* `-Wdeclaration-after-statement` is used, or C standard prior to C99.
*
* ```c
* {
* G_RW_LOCK_READER_AUTO_LOCK (&obj->rw_lock, locker);
*
* obj->stuff_with_lock ();
* if (condition)
* {
* // No need to unlock
* return;
* }
*
* // Unlock before end of scope
* g_clear_pointer (&locker, g_rw_lock_reader_locker_free);
* obj->stuff_without_lock ();
* }
* ```
*
* Since: 2.80.0
*/
#ifdef g_autoptr
#define G_RW_LOCK_READER_AUTO_LOCK(mutex, var) \
GLIB_AVAILABLE_MACRO_IN_2_80 g_autoptr (GRWLockReaderLocker) \
G_GNUC_UNUSED var = g_rw_lock_reader_locker_new (mutex)
#endif /* g_autoptr */
G_END_DECLS
#endif /* __G_THREAD_H__ */
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