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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/perf/util/mutex.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/mutex.h')
-rw-r--r--tools/perf/util/mutex.h108
1 files changed, 108 insertions, 0 deletions
diff --git a/tools/perf/util/mutex.h b/tools/perf/util/mutex.h
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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 */