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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_MUTEX_H
#define __PERF_MUTEX_H
#include <pthread.h>
#include <stdbool.h>
/*
* A function-like feature checking macro that is a wrapper around
* `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a
* nonzero constant integer if the attribute is supported or 0 if not.
*/
#ifdef __has_attribute
#define HAVE_ATTRIBUTE(x) __has_attribute(x)
#else
#define HAVE_ATTRIBUTE(x) 0
#endif
#if HAVE_ATTRIBUTE(guarded_by) && HAVE_ATTRIBUTE(pt_guarded_by) && \
HAVE_ATTRIBUTE(lockable) && HAVE_ATTRIBUTE(exclusive_lock_function) && \
HAVE_ATTRIBUTE(exclusive_trylock_function) && HAVE_ATTRIBUTE(exclusive_locks_required) && \
HAVE_ATTRIBUTE(no_thread_safety_analysis)
/* Documents if a shared field or global variable needs to be protected by a mutex. */
#define GUARDED_BY(x) __attribute__((guarded_by(x)))
/*
* Documents if the memory location pointed to by a pointer should be guarded by
* a mutex when dereferencing the pointer.
*/
#define PT_GUARDED_BY(x) __attribute__((pt_guarded_by(x)))
/* Documents if a type is a lockable type. */
#define LOCKABLE __attribute__((lockable))
/* Documents functions that acquire a lock in the body of a function, and do not release it. */
#define EXCLUSIVE_LOCK_FUNCTION(...) __attribute__((exclusive_lock_function(__VA_ARGS__)))
/*
* Documents functions that expect a lock to be held on entry to the function,
* and release it in the body of the function.
*/
#define UNLOCK_FUNCTION(...) __attribute__((unlock_function(__VA_ARGS__)))
/* Documents functions that try to acquire a lock, and return success or failure. */
#define EXCLUSIVE_TRYLOCK_FUNCTION(...) \
__attribute__((exclusive_trylock_function(__VA_ARGS__)))
/* Documents a function that expects a mutex to be held prior to entry. */
#define EXCLUSIVE_LOCKS_REQUIRED(...) __attribute__((exclusive_locks_required(__VA_ARGS__)))
/* Turns off thread safety checking within the body of a particular function. */
#define NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
#else
#define GUARDED_BY(x)
#define PT_GUARDED_BY(x)
#define LOCKABLE
#define EXCLUSIVE_LOCK_FUNCTION(...)
#define UNLOCK_FUNCTION(...)
#define EXCLUSIVE_TRYLOCK_FUNCTION(...)
#define EXCLUSIVE_LOCKS_REQUIRED(...)
#define NO_THREAD_SAFETY_ANALYSIS
#endif
/*
* A wrapper around the mutex implementation that allows perf to error check
* usage, etc.
*/
struct LOCKABLE mutex {
pthread_mutex_t lock;
};
/* A wrapper around the condition variable implementation. */
struct cond {
pthread_cond_t cond;
};
/* Default initialize the mtx struct. */
void mutex_init(struct mutex *mtx);
/*
* Initialize the mtx struct and set the process-shared rather than default
* process-private attribute.
*/
void mutex_init_pshared(struct mutex *mtx);
void mutex_destroy(struct mutex *mtx);
void mutex_lock(struct mutex *mtx) EXCLUSIVE_LOCK_FUNCTION(*mtx);
void mutex_unlock(struct mutex *mtx) UNLOCK_FUNCTION(*mtx);
/* Tries to acquire the lock and returns true on success. */
bool mutex_trylock(struct mutex *mtx) EXCLUSIVE_TRYLOCK_FUNCTION(true, *mtx);
/* Default initialize the cond struct. */
void cond_init(struct cond *cnd);
/*
* Initialize the cond struct and specify the process-shared rather than default
* process-private attribute.
*/
void cond_init_pshared(struct cond *cnd);
void cond_destroy(struct cond *cnd);
void cond_wait(struct cond *cnd, struct mutex *mtx) EXCLUSIVE_LOCKS_REQUIRED(mtx);
void cond_signal(struct cond *cnd);
void cond_broadcast(struct cond *cnd);
#endif /* __PERF_MUTEX_H */
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