qemu-e2k/include/qemu/thread.h
Guillaume Delbergue ac9a9eba1e qemu-thread: add simple test-and-set spinlock
Reviewed-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Signed-off-by: Guillaume Delbergue <guillaume.delbergue@greensocs.com>
[Rewritten. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Emilio's additions: use TAS instead of atomic_xchg; emit acquire/release
 barriers; return bool from trylock; call cpu_relax() while spinning;
 optimize for uncontended locks by acquiring the lock with TAS instead
 of TATAS; add qemu_spin_locked().]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1465412133-3029-6-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
2016-06-11 23:10:18 +00:00

99 lines
2.6 KiB
C

#ifndef __QEMU_THREAD_H
#define __QEMU_THREAD_H 1
#include "qemu/processor.h"
#include "qemu/atomic.h"
typedef struct QemuMutex QemuMutex;
typedef struct QemuCond QemuCond;
typedef struct QemuSemaphore QemuSemaphore;
typedef struct QemuEvent QemuEvent;
typedef struct QemuThread QemuThread;
#ifdef _WIN32
#include "qemu/thread-win32.h"
#else
#include "qemu/thread-posix.h"
#endif
#define QEMU_THREAD_JOINABLE 0
#define QEMU_THREAD_DETACHED 1
void qemu_mutex_init(QemuMutex *mutex);
void qemu_mutex_destroy(QemuMutex *mutex);
void qemu_mutex_lock(QemuMutex *mutex);
int qemu_mutex_trylock(QemuMutex *mutex);
void qemu_mutex_unlock(QemuMutex *mutex);
void qemu_cond_init(QemuCond *cond);
void qemu_cond_destroy(QemuCond *cond);
/*
* IMPORTANT: The implementation does not guarantee that pthread_cond_signal
* and pthread_cond_broadcast can be called except while the same mutex is
* held as in the corresponding pthread_cond_wait calls!
*/
void qemu_cond_signal(QemuCond *cond);
void qemu_cond_broadcast(QemuCond *cond);
void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex);
void qemu_sem_init(QemuSemaphore *sem, int init);
void qemu_sem_post(QemuSemaphore *sem);
void qemu_sem_wait(QemuSemaphore *sem);
int qemu_sem_timedwait(QemuSemaphore *sem, int ms);
void qemu_sem_destroy(QemuSemaphore *sem);
void qemu_event_init(QemuEvent *ev, bool init);
void qemu_event_set(QemuEvent *ev);
void qemu_event_reset(QemuEvent *ev);
void qemu_event_wait(QemuEvent *ev);
void qemu_event_destroy(QemuEvent *ev);
void qemu_thread_create(QemuThread *thread, const char *name,
void *(*start_routine)(void *),
void *arg, int mode);
void *qemu_thread_join(QemuThread *thread);
void qemu_thread_get_self(QemuThread *thread);
bool qemu_thread_is_self(QemuThread *thread);
void qemu_thread_exit(void *retval);
void qemu_thread_naming(bool enable);
struct Notifier;
void qemu_thread_atexit_add(struct Notifier *notifier);
void qemu_thread_atexit_remove(struct Notifier *notifier);
typedef struct QemuSpin {
int value;
} QemuSpin;
static inline void qemu_spin_init(QemuSpin *spin)
{
__sync_lock_release(&spin->value);
}
static inline void qemu_spin_lock(QemuSpin *spin)
{
while (unlikely(__sync_lock_test_and_set(&spin->value, true))) {
while (atomic_read(&spin->value)) {
cpu_relax();
}
}
}
static inline bool qemu_spin_trylock(QemuSpin *spin)
{
return __sync_lock_test_and_set(&spin->value, true);
}
static inline bool qemu_spin_locked(QemuSpin *spin)
{
return atomic_read(&spin->value);
}
static inline void qemu_spin_unlock(QemuSpin *spin)
{
__sync_lock_release(&spin->value);
}
#endif