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#include <stddef.h>
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#include <sys/types.h>
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#include "ovs-atomic.h"
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#include "openvswitch/thread.h"
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struct OVS_LOCKABLE ovs_mutex {
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const char *where; /* NULL if and only if uninitialized. */
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/* Poll-block()-able barrier similar to pthread_barrier_t. */
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struct ovs_barrier {
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uint32_t size; /* Number of threads to wait. */
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atomic_uint32_t count; /* Number of threads already hit the barrier. */
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atomic_count count; /* Number of threads already hit the barrier. */
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/* "struct ovs_mutex" initializer. */
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#ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
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#define OVS_MUTEX_INITIALIZER { PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP, \
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#define OVS_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER, "<unlocked>" }
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#ifdef PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
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#define OVS_ADAPTIVE_MUTEX_INITIALIZER \
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{ PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP, "<unlocked>" }
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#define OVS_ADAPTIVE_MUTEX_INITIALIZER OVS_MUTEX_INITIALIZER
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/* ovs_mutex functions analogous to pthread_mutex_*() functions.
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* Most of these functions abort the process with an error message on any
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* error. ovs_mutex_trylock() is an exception: it passes through a 0 or EBUSY
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* return value to the caller and aborts on any other error. */
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void ovs_mutex_init(const struct ovs_mutex *);
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void ovs_mutex_init_recursive(const struct ovs_mutex *);
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void ovs_mutex_init_adaptive(const struct ovs_mutex *);
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void ovs_mutex_destroy(const struct ovs_mutex *);
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void ovs_mutex_unlock(const struct ovs_mutex *mutex) OVS_RELEASES(mutex);
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void ovs_mutex_lock_at(const struct ovs_mutex *mutex, const char *where)
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#define ovs_mutex_lock(mutex) \
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ovs_mutex_lock_at(mutex, SOURCE_LOCATOR)
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int ovs_mutex_trylock_at(const struct ovs_mutex *mutex, const char *where)
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OVS_TRY_LOCK(0, mutex);
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#define ovs_mutex_trylock(mutex) \
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ovs_mutex_trylock_at(mutex, SOURCE_LOCATOR)
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void ovs_mutex_cond_wait(pthread_cond_t *, const struct ovs_mutex *);
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/* Wrappers for pthread_mutex_*() that abort the process on any error.
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* This is still needed when ovs-atomic-pthreads.h is used. */
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void xpthread_mutex_lock(pthread_mutex_t *mutex);
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void ovs_rwlock_wrlock_at(const struct ovs_rwlock *rwlock, const char *where)
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OVS_ACQ_WRLOCK(rwlock);
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#define ovs_rwlock_wrlock(rwlock) \
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ovs_rwlock_wrlock_at(rwlock, SOURCE_LOCATOR)
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ovs_rwlock_wrlock_at(rwlock, OVS_SOURCE_LOCATOR)
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int ovs_rwlock_trywrlock_at(const struct ovs_rwlock *rwlock, const char *where)
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OVS_TRY_WRLOCK(0, rwlock);
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#define ovs_rwlock_trywrlock(rwlock) \
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ovs_rwlock_trywrlock_at(rwlock, SOURCE_LOCATOR)
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ovs_rwlock_trywrlock_at(rwlock, OVS_SOURCE_LOCATOR)
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void ovs_rwlock_rdlock_at(const struct ovs_rwlock *rwlock, const char *where)
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OVS_ACQ_RDLOCK(rwlock);
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#define ovs_rwlock_rdlock(rwlock) \
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ovs_rwlock_rdlock_at(rwlock, SOURCE_LOCATOR)
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ovs_rwlock_rdlock_at(rwlock, OVS_SOURCE_LOCATOR)
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int ovs_rwlock_tryrdlock_at(const struct ovs_rwlock *rwlock, const char *where)
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OVS_TRY_RDLOCK(0, rwlock);
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#define ovs_rwlock_tryrdlock(rwlock) \
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ovs_rwlock_tryrdlock_at(rwlock, SOURCE_LOCATOR)
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ovs_rwlock_tryrdlock_at(rwlock, OVS_SOURCE_LOCATOR)
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/* ovs_barrier functions analogous to pthread_barrier_*() functions. */
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void ovs_barrier_init(struct ovs_barrier *, uint32_t count);
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void xpthread_key_delete(pthread_key_t);
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void xpthread_setspecific(pthread_key_t, const void *);
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void xpthread_sigmask(int, const sigset_t *, sigset_t *);
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pthread_t ovs_thread_create(const char *name, void *(*)(void *), void *);
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void xpthread_join(pthread_t, void **);
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void ovsthread_setspecific(ovsthread_key_t, const void *);
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void *ovsthread_getspecific(ovsthread_key_t);
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/* Convenient once-only execution.
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* POSIX provides pthread_once_t and pthread_once() as primitives for running a
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* set of code only once per process execution. They are used like this:
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* static void run_once(void) { ...initialization... }
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* static pthread_once_t once = PTHREAD_ONCE_INIT;
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* pthread_once(&once, run_once);
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* pthread_once() does not allow passing any parameters to the initialization
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* function, which is often inconvenient, because it means that the function
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* can only access data declared at file scope.
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* Use ovsthread_once, like this, instead:
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* static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
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* if (ovsthread_once_start(&once)) {
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* ...initialization...
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* ovsthread_once_done(&once);
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struct ovsthread_once {
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struct ovs_mutex mutex;
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#define OVSTHREAD_ONCE_INITIALIZER \
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ATOMIC_VAR_INIT(false), \
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OVS_MUTEX_INITIALIZER, \
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static inline bool ovsthread_once_start(struct ovsthread_once *once)
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OVS_TRY_LOCK(true, once->mutex);
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void ovsthread_once_done(struct ovsthread_once *once)
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OVS_RELEASES(once->mutex);
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bool ovsthread_once_start__(struct ovsthread_once *once)
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OVS_TRY_LOCK(false, once->mutex);
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ovsthread_once_is_done__(struct ovsthread_once *once)
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atomic_read_explicit(&once->done, &done, memory_order_relaxed);
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/* Returns true if this is the first call to ovsthread_once_start() for
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* 'once'. In this case, the caller should perform whatever initialization
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* actions it needs to do, then call ovsthread_once_done() for 'once'.
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* Returns false if this is not the first call to ovsthread_once_start() for
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* 'once'. In this case, the call will not return until after
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* ovsthread_once_done() has been called. */
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ovsthread_once_start(struct ovsthread_once *once)
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return OVS_UNLIKELY(!ovsthread_once_is_done__(once)
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&& !ovsthread_once_start__(once));
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* pthread_t isn't so nice for some purposes. Its size and representation are
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bool single_threaded(void);
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void assert_single_threaded_at(const char *where);
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#define assert_single_threaded() assert_single_threaded_at(SOURCE_LOCATOR)
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#define assert_single_threaded() assert_single_threaded_at(OVS_SOURCE_LOCATOR)
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pid_t xfork_at(const char *where);
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#define xfork() xfork_at(SOURCE_LOCATOR)
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#define xfork() xfork_at(OVS_SOURCE_LOCATOR)
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void forbid_forking(const char *reason);
added
removed
lib/ovs-thread.h
