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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 | /* 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 */ |