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