#include "ovs-atomic.h"
#include "util.h"
-/* glibc has some non-portable mutex types and initializers:
- *
- * - PTHREAD_MUTEX_ADAPTIVE_NP is a mutex type that works as a spinlock that
- * falls back to a mutex after spinning for some number of iterations.
+
+/* Mutex. */
+struct OVS_LOCKABLE ovs_mutex {
+ pthread_mutex_t lock;
+ const char *where;
+};
+
+/* "struct ovs_mutex" initializers:
*
- * - PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP is a non-portable initializer
- * for an error-checking mutex.
+ * - OVS_MUTEX_INITIALIZER: common case.
*
- * We use these definitions to fall back to PTHREAD_MUTEX_NORMAL instead in
- * these cases.
+ * - OVS_ADAPTIVE_MUTEX_INITIALIZER for a mutex that spins briefly then goes
+ * to sleeps after some number of iterations.
*
- * (glibc has other non-portable initializers, but we can't reasonably
- * substitute for them here.) */
+ * - OVS_ERRORCHECK_MUTEX_INITIALIZER for a mutex that is used for
+ * error-checking. */
+#define OVS_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, NULL }
#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
-#define PTHREAD_MUTEX_ADAPTIVE PTHREAD_MUTEX_ADAPTIVE_NP
-#define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER \
- PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
+#define OVS_ADAPTIVE_MUTEX_INITIALIZER \
+ { PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP, NULL }
#else
-#define PTHREAD_MUTEX_ADAPTIVE PTHREAD_MUTEX_NORMAL
-#define PTHREAD_ADAPTIVE_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
+#define OVS_ADAPTIVE_MUTEX_INITIALIZER OVS_MUTEX_INITIALIZER
#endif
-
#ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
-#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER \
- PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
+#define OVS_ERRORCHECK_MUTEX_INITIALIZER \
+ { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, NULL }
#else
-#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
+#define OVS_ERRORCHECK_MUTEX_INITIALIZER OVS_MUTEX_INITIALIZER
#endif
\f
-/* Simple wrappers for pthreads functions. Most of these functions abort the
- * process with an error message on any error. The *_trylock() functions are
- * exceptions: they pass through a 0 or EBUSY return value to the caller and
- * abort on any other error. */
-void xpthread_mutex_init(pthread_mutex_t *, pthread_mutexattr_t *);
-void xpthread_mutex_lock(pthread_mutex_t *mutex) OVS_ACQUIRES(mutex);
-void xpthread_mutex_unlock(pthread_mutex_t *mutex) OVS_RELEASES(mutex);
-int xpthread_mutex_trylock(pthread_mutex_t *);
-
-void xpthread_rwlock_init(pthread_rwlock_t *, pthread_rwlockattr_t *);
-void xpthread_rwlock_rdlock(pthread_rwlock_t *rwlock) OVS_ACQUIRES(rwlock);
-void xpthread_rwlock_wrlock(pthread_rwlock_t *rwlock) OVS_ACQUIRES(rwlock);
-void xpthread_rwlock_unlock(pthread_rwlock_t *rwlock) OVS_RELEASES(rwlock);
-int xpthread_rwlock_tryrdlock(pthread_rwlock_t *);
-int xpthread_rwlock_trywrlock(pthread_rwlock_t *);
+/* Mutex types, suitable for use with pthread_mutexattr_settype().
+ * There is only one nonstandard type:
+ *
+ * - PTHREAD_MUTEX_ADAPTIVE_NP, the type used for
+ * OVS_ADAPTIVE_MUTEX_INITIALIZER. */
+#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
+#define OVS_MUTEX_ADAPTIVE PTHREAD_MUTEX_ADAPTIVE_NP
+#else
+#define OVS_MUTEX_ADAPTIVE PTHREAD_MUTEX_NORMAL
+#endif
+
+/* ovs_mutex functions analogous to pthread_mutex_*() functions.
+ *
+ * Most of these functions abort the process with an error message on any
+ * error. ovs_mutex_trylock() is an exception: it passes through a 0 or EBUSY
+ * return value to the caller and aborts on any other error. */
+void ovs_mutex_init(const struct ovs_mutex *, int type);
+void ovs_mutex_destroy(const struct ovs_mutex *);
+void ovs_mutex_unlock(const struct ovs_mutex *mutex) OVS_RELEASES(mutex);
+void ovs_mutex_lock_at(const struct ovs_mutex *mutex, const char *where)
+ OVS_ACQUIRES(mutex);
+#define ovs_mutex_lock(mutex) \
+ ovs_mutex_lock_at(mutex, SOURCE_LOCATOR)
+
+int ovs_mutex_trylock_at(const struct ovs_mutex *mutex, const char *where)
+ OVS_TRY_LOCK(0, mutex);
+#define ovs_mutex_trylock(mutex) \
+ ovs_mutex_trylock_at(mutex, SOURCE_LOCATOR)
+
+void ovs_mutex_cond_wait(pthread_cond_t *, const struct ovs_mutex *);
+
+/* Wrappers for pthread_mutex_*() that abort the process on any error.
+ * This is still needed when ovs-atomic-pthreads.h is used. */
+void xpthread_mutex_lock(pthread_mutex_t *mutex);
+void xpthread_mutex_unlock(pthread_mutex_t *mutex);
+
+/* Wrappers for pthread_mutexattr_*() that abort the process on any error. */
+void xpthread_mutexattr_init(pthread_mutexattr_t *);
+void xpthread_mutexattr_destroy(pthread_mutexattr_t *);
+void xpthread_mutexattr_settype(pthread_mutexattr_t *, int type);
+void xpthread_mutexattr_gettype(pthread_mutexattr_t *, int *typep);
+
+/* Read-write lock. */
+struct OVS_LOCKABLE ovs_rwlock {
+ pthread_rwlock_t lock;
+ const char *where;
+};
+
+/* Initializer. */
+#define OVS_RWLOCK_INITIALIZER { PTHREAD_RWLOCK_INITIALIZER, NULL }
+
+/* ovs_rwlock functions analogous to pthread_rwlock_*() functions.
+ *
+ * Most of these functions abort the process with an error message on any
+ * error. The "trylock" functions are exception: they pass through a 0 or
+ * EBUSY return value to the caller and abort on any other error. */
+void ovs_rwlock_init(const struct ovs_rwlock *);
+void ovs_rwlock_destroy(const struct ovs_rwlock *);
+void ovs_rwlock_unlock(const struct ovs_rwlock *rwlock) OVS_RELEASES(rwlock);
+
+void ovs_rwlock_wrlock_at(const struct ovs_rwlock *rwlock, const char *where)
+ OVS_ACQ_WRLOCK(rwlock);
+#define ovs_rwlock_wrlock(rwlock) \
+ ovs_rwlock_wrlock_at(rwlock, SOURCE_LOCATOR)
+
+int ovs_rwlock_trywrlock_at(const struct ovs_rwlock *rwlock, const char *where)
+ OVS_TRY_WRLOCK(0, rwlock);
+#define ovs_rwlock_trywrlock(rwlock) \
+ ovs_rwlock_trywrlock_at(rwlock, SOURCE_LOCATOR)
+
+void ovs_rwlock_rdlock_at(const struct ovs_rwlock *rwlock, const char *where)
+ OVS_ACQ_RDLOCK(rwlock);
+#define ovs_rwlock_rdlock(rwlock) \
+ ovs_rwlock_rdlock_at(rwlock, SOURCE_LOCATOR)
+int ovs_rwlock_tryrdlock_at(const struct ovs_rwlock *rwlock, const char *where)
+ OVS_TRY_RDLOCK(0, rwlock);
+#define ovs_rwlock_tryrdlock(rwlock) \
+ ovs_rwlock_tryrdlock_at(rwlock, SOURCE_LOCATOR)
+
+/* Wrappers for xpthread_cond_*() that abort the process on any error.
+ *
+ * Use ovs_mutex_cond_wait() to wait for a condition. */
void xpthread_cond_init(pthread_cond_t *, pthread_condattr_t *);
+void xpthread_cond_destroy(pthread_cond_t *);
void xpthread_cond_signal(pthread_cond_t *);
void xpthread_cond_broadcast(pthread_cond_t *);
-void xpthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex)
- OVS_MUST_HOLD(mutex);
#ifdef __CHECKER__
/* Replace these functions by the macros already defined in the <pthread.h>
#endif
void xpthread_key_create(pthread_key_t *, void (*destructor)(void *));
+void xpthread_setspecific(pthread_key_t, const void *);
void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *);
+void xpthread_join(pthread_t, void **);
\f
/* Per-thread data.
*
* cross-thread access? yes no yes
*/
-/* DEFINE_PER_THREAD_DATA(TYPE, NAME, INITIALIZER).
+/* For static data, use this macro in a source file:
+ *
+ * DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, INITIALIZER).
+ *
+ * For global data, "declare" the data in the header and "define" it in
+ * the source file, with:
+ *
+ * DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME).
+ * DEFINE_EXTERN_PER_THREAD_DATA(NAME, INITIALIZER).
*
* One should prefer to use POSIX per-thread data, via pthread_key_t, when its
* performance is acceptable, because of its portability (see the table above).
#error
#endif
-#define DEFINE_PER_THREAD_DATA(TYPE, NAME, ...) \
- typedef TYPE NAME##_type; \
- static thread_local NAME##_type NAME##_var = __VA_ARGS__; \
- \
- static NAME##_type * \
- NAME##_get_unsafe(void) \
- { \
- return &NAME##_var; \
- } \
- \
- static NAME##_type * \
- NAME##_get(void) \
- { \
- return NAME##_get_unsafe(); \
+#define DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, ...) \
+ typedef TYPE NAME##_type; \
+ \
+ static NAME##_type * \
+ NAME##_get_unsafe(void) \
+ { \
+ static thread_local NAME##_type var = __VA_ARGS__; \
+ return &var; \
+ } \
+ \
+ static NAME##_type * \
+ NAME##_get(void) \
+ { \
+ return NAME##_get_unsafe(); \
+ }
+#define DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME) \
+ typedef TYPE NAME##_type; \
+ extern thread_local NAME##_type NAME##_var; \
+ \
+ static inline NAME##_type * \
+ NAME##_get_unsafe(void) \
+ { \
+ return &NAME##_var; \
+ } \
+ \
+ static inline NAME##_type * \
+ NAME##_get(void) \
+ { \
+ return NAME##_get_unsafe(); \
}
+#define DEFINE_EXTERN_PER_THREAD_DATA(NAME, ...) \
+ thread_local NAME##_type NAME##_var = __VA_ARGS__;
#else /* no C implementation support for thread-local storage */
-#define DEFINE_PER_THREAD_DATA(TYPE, NAME, ...) \
+#define DEFINE_STATIC_PER_THREAD_DATA(TYPE, NAME, ...) \
typedef TYPE NAME##_type; \
static pthread_key_t NAME##_key; \
\
\
value = xmalloc(sizeof *value); \
*value = initial_value; \
- pthread_setspecific(NAME##_key, value); \
+ xpthread_setspecific(NAME##_key, value); \
+ } \
+ return value; \
+ }
+#define DECLARE_EXTERN_PER_THREAD_DATA(TYPE, NAME) \
+ typedef TYPE NAME##_type; \
+ static pthread_key_t NAME##_key; \
+ \
+ static inline NAME##_type * \
+ NAME##_get_unsafe(void) \
+ { \
+ return pthread_getspecific(NAME##_key); \
+ } \
+ \
+ NAME##_type *NAME##_get(void);
+#define DEFINE_EXTERN_PER_THREAD_DATA(NAME, ...) \
+ static void \
+ NAME##_once_init(void) \
+ { \
+ if (pthread_key_create(&NAME##_key, free)) { \
+ abort(); \
+ } \
+ } \
+ \
+ NAME##_type * \
+ NAME##_get(void) \
+ { \
+ static pthread_once_t once = PTHREAD_ONCE_INIT; \
+ NAME##_type *value; \
+ \
+ pthread_once(&once, NAME##_once_init); \
+ value = NAME##_get_unsafe(); \
+ if (!value) { \
+ static const NAME##_type initial_value = __VA_ARGS__; \
+ \
+ value = xmalloc(sizeof *value); \
+ *value = initial_value; \
+ xpthread_setspecific(NAME##_key, value); \
} \
return value; \
}
NAME##_set_unsafe(TYPE value) \
{ \
TYPE old_value = NAME##_get_unsafe(); \
- pthread_setspecific(NAME##_key, value); \
+ xpthread_setspecific(NAME##_key, value); \
return old_value; \
} \
\
struct ovsthread_once {
atomic_bool done;
- pthread_mutex_t mutex;
+ struct ovs_mutex mutex;
};
#define OVSTHREAD_ONCE_INITIALIZER \
{ \
ATOMIC_VAR_INIT(false), \
- PTHREAD_ADAPTIVE_MUTEX_INITIALIZER, \
+ OVS_ADAPTIVE_MUTEX_INITIALIZER, \
}
-static inline bool ovsthread_once_start(struct ovsthread_once *);
-void ovsthread_once_done(struct ovsthread_once *once) OVS_RELEASES(once);
+static inline bool ovsthread_once_start(struct ovsthread_once *once)
+ OVS_TRY_LOCK(true, once->mutex);
+void ovsthread_once_done(struct ovsthread_once *once)
+ OVS_RELEASES(once->mutex);
-bool ovsthread_once_start__(struct ovsthread_once *);
+bool ovsthread_once_start__(struct ovsthread_once *once)
+ OVS_TRY_LOCK(false, once->mutex);
static inline bool
ovsthread_once_is_done__(const struct ovsthread_once *once)
return OVS_UNLIKELY(!ovsthread_once_is_done__(once)
&& !ovsthread_once_start__(once));
}
+\f
+/* Thread ID.
+ *
+ * pthread_t isn't so nice for some purposes. Its size and representation are
+ * implementation dependent, which means that there is no way to hash it.
+ * This thread ID avoids the problem.
+ */
-#ifdef __CHECKER__
-#define ovsthread_once_start(ONCE) \
- ((ONCE)->done ? false : ({ OVS_ACQUIRE(ONCE); true; }))
-#endif
+DECLARE_EXTERN_PER_THREAD_DATA(unsigned int, ovsthread_id);
+
+/* Returns a per-thread identifier unique within the lifetime of the
+ * process. */
+static inline unsigned int
+ovsthread_id_self(void)
+{
+ return *ovsthread_id_get();
+}
\f
-void assert_single_threaded(const char *where);
-#define assert_single_threaded() assert_single_threaded(SOURCE_LOCATOR)
+void assert_single_threaded_at(const char *where);
+#define assert_single_threaded() assert_single_threaded_at(SOURCE_LOCATOR)
-pid_t xfork(const char *where);
-#define xfork() xfork(SOURCE_LOCATOR)
+pid_t xfork_at(const char *where);
+#define xfork() xfork_at(SOURCE_LOCATOR)
void forbid_forking(const char *reason);
bool may_fork(void);