X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fovs-thread.h;h=b7bc5d198136de048464879d4bdf0204b7cfb344;hb=591cb419cf3694e0ae66a95973e73c61bad9e03d;hp=05461e2016f4d7798e53c9c1b9489feb50b934a5;hpb=1514b275558304c63bc3838c2da5c4be0c1cbef0;p=sliver-openvswitch.git diff --git a/lib/ovs-thread.h b/lib/ovs-thread.h index 05461e201..b7bc5d198 100644 --- a/lib/ovs-thread.h +++ b/lib/ovs-thread.h @@ -18,59 +18,128 @@ #define OVS_THREAD_H 1 #include +#include +#include #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 -/* 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 @@ -84,8 +153,10 @@ void xpthread_cond_wait(pthread_cond_t *, pthread_mutex_t *mutex) #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 **); /* Per-thread data. * @@ -123,7 +194,15 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); * 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). @@ -161,23 +240,40 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); #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; \ \ @@ -208,7 +304,44 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); \ 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; \ } @@ -279,7 +412,7 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); NAME##_set_unsafe(TYPE value) \ { \ TYPE old_value = NAME##_get_unsafe(); \ - pthread_setspecific(NAME##_key, value); \ + xpthread_setspecific(NAME##_key, value); \ return old_value; \ } \ \ @@ -324,19 +457,22 @@ void xpthread_create(pthread_t *, pthread_attr_t *, void *(*)(void *), void *); 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) @@ -360,10 +496,31 @@ ovsthread_once_start(struct ovsthread_once *once) return OVS_UNLIKELY(!ovsthread_once_is_done__(once) && !ovsthread_once_start__(once)); } + +/* 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(); +} + +void assert_single_threaded_at(const char *where); +#define assert_single_threaded() assert_single_threaded_at(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); #endif /* ovs-thread.h */