diff --git a/evthread-internal.h b/evthread-internal.h index d710939a..b768a753 100644 --- a/evthread-internal.h +++ b/evthread-internal.h @@ -36,7 +36,15 @@ extern "C" { struct event_base; -#ifndef _EVENT_DISABLE_THREAD_SUPPORT +#ifndef WIN32 +/* On Windows, the way we currently make DLLs, it's not allowed for us to + * have shared global structures. Thus, we only do the direct-call-to-function + * code path if we know that the local shared library system supports it. + */ +#define EVTHREAD_EXPOSE_STRUCTS +#endif + +#if ! defined(_EVENT_DISABLE_THREAD_SUPPORT) && defined(EVTHREAD_EXPOSE_STRUCTS) /* Global function pointers to lock-related functions. NULL if locking isn't enabled. */ extern struct evthread_lock_callbacks _evthread_lock_fns; @@ -92,30 +100,6 @@ extern int _evthread_lock_debugging_enabled; } \ } while (0) -/** Acquire both lock1 and lock2. Always allocates locks in the same order, - * so that two threads locking two locks with LOCK2 will not deadlock. */ -#define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) \ - do { \ - void *_lock1_tmplock = (lock1); \ - void *_lock2_tmplock = (lock2); \ - _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ - EVLOCK_LOCK(_lock1_tmplock,mode1); \ - if (_lock2_tmplock != _lock1_tmplock) \ - EVLOCK_LOCK(_lock2_tmplock,mode2); \ - } while (0) - -/** Release both lock1 and lock2. */ -#define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) \ - do { \ - void *_lock1_tmplock = (lock1); \ - void *_lock2_tmplock = (lock2); \ - _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ - if (_lock2_tmplock != _lock1_tmplock) \ - EVLOCK_UNLOCK(_lock2_tmplock,mode2); \ - EVLOCK_UNLOCK(_lock1_tmplock,mode1); \ - } while (0) - - /** Lock an event_base, if it is set up for locking. Acquires the lock in the base structure whose field is named 'lockvar'. */ #define EVBASE_ACQUIRE_LOCK(base, lockvar) do { \ @@ -127,9 +111,6 @@ extern int _evthread_lock_debugging_enabled; EVLOCK_UNLOCK((base)->lockvar, 0); \ } while (0) -int _evthread_is_debug_lock_held(void *lock); -void *_evthread_debug_get_real_lock(void *lock); - /** If lock debugging is enabled, and lock is non-null, assert that 'lock' is * locked and held by us. */ #define EVLOCK_ASSERT_LOCKED(lock) \ @@ -184,6 +165,110 @@ EVLOCK_TRY_LOCK(void *lock) #define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv) \ ( (cond) ? _evthread_cond_fns.wait_condition((cond), (lock), (tv)) : 0 ) +#elif ! defined(_EVENT_DISABLE_THREAD_SUPPORT) + +unsigned long _evthreadimpl_get_id(void); +int _evthreadimpl_is_lock_debugging_enabled(void); +void *_evthreadimpl_lock_alloc(unsigned locktype); +void _evthreadimpl_lock_free(void *lock, unsigned locktype); +int _evthreadimpl_lock_lock(unsigned mode, void *lock); +int _evthreadimpl_lock_unlock(unsigned mode, void *lock); +void *_evthreadimpl_cond_alloc(unsigned condtype); +void _evthreadimpl_cond_free(void *cond); +int _evthreadimpl_cond_signal(void *cond, int broadcast); +int _evthreadimpl_cond_wait(void *cond, void *lock, const struct timeval *tv); + +#define EVTHREAD_GET_ID() _evthreadimpl_get_id() +#define EVBASE_IN_THREAD(base) \ + ((base)->th_owner_id == _evthreadimpl_get_id()) +#define EVTHREAD_ALLOC_LOCK(lockvar, locktype) \ + ((lockvar) = _evthreadimpl_lock_alloc(locktype)) + +#define EVTHREAD_FREE_LOCK(lockvar, locktype) \ + do { \ + void *_lock_tmp_ = (lockvar); \ + if (_lock_tmp_) \ + _evthreadimpl_lock_free(_lock_tmp_, (locktype)); \ + } while (0) + +/** Acquire a lock. */ +#define EVLOCK_LOCK(lockvar,mode) \ + do { \ + if (lockvar) \ + _evthreadimpl_lock_lock(mode, lockvar); \ + } while (0) + +/** Release a lock */ +#define EVLOCK_UNLOCK(lockvar,mode) \ + do { \ + if (lockvar) \ + _evthreadimpl_lock_unlock(mode, lockvar); \ + } while (0) + +/** Lock an event_base, if it is set up for locking. Acquires the lock + in the base structure whose field is named 'lockvar'. */ +#define EVBASE_ACQUIRE_LOCK(base, lockvar) do { \ + EVLOCK_LOCK((base)->lockvar, 0); \ + } while (0) + +/** Unlock an event_base, if it is set up for locking. */ +#define EVBASE_RELEASE_LOCK(base, lockvar) do { \ + EVLOCK_UNLOCK((base)->lockvar, 0); \ + } while (0) + +/** If lock debugging is enabled, and lock is non-null, assert that 'lock' is + * locked and held by us. */ +#define EVLOCK_ASSERT_LOCKED(lock) \ + do { \ + if ((lock) && _evthreadimpl_is_lock_debugging_enabled()) { \ + EVUTIL_ASSERT(_evthread_is_debug_lock_held(lock)); \ + } \ + } while (0) + +/** Try to grab the lock for 'lockvar' without blocking, and return 1 if we + * manage to get it. */ +static inline int EVLOCK_TRY_LOCK(void *lock); +static inline int +EVLOCK_TRY_LOCK(void *lock) +{ + if (lock) { + int r = _evthreadimpl_lock_lock(EVTHREAD_TRY, lock); + return !r; + } else { + /* Locking is disabled either globally or for this thing; + * of course we count as having the lock. */ + return 1; + } +} + +/** Allocate a new condition variable and store it in the void *, condvar */ +#define EVTHREAD_ALLOC_COND(condvar) \ + do { \ + (condvar) = _evthreadimpl_cond_alloc(0); \ + } while (0) +/** Deallocate and free a condition variable in condvar */ +#define EVTHREAD_FREE_COND(cond) \ + do { \ + if (cond) \ + _evthreadimpl_cond_free((cond)); \ + } while (0) +/** Signal one thread waiting on cond */ +#define EVTHREAD_COND_SIGNAL(cond) \ + ( (cond) ? _evthreadimpl_cond_signal((cond), 0) : 0 ) +/** Signal all threads waiting on cond */ +#define EVTHREAD_COND_BROADCAST(cond) \ + ( (cond) ? _evthreadimpl_cond_signal((cond), 1) : 0 ) +/** Wait until the condition 'cond' is signalled. Must be called while + * holding 'lock'. The lock will be released until the condition is + * signalled, at which point it will be acquired again. Returns 0 for + * success, -1 for failure. */ +#define EVTHREAD_COND_WAIT(cond, lock) \ + ( (cond) ? _evthreadimpl_cond_wait((cond), (lock), NULL) : 0 ) +/** As EVTHREAD_COND_WAIT, but gives up after 'tv' has elapsed. Returns 1 + * on timeout. */ +#define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv) \ + ( (cond) ? _evthreadimpl_cond_wait((cond), (lock), (tv)) : 0 ) + #else /* _EVENT_DISABLE_THREAD_SUPPORT */ #define EVTHREAD_GET_ID() 1 @@ -211,6 +296,44 @@ EVLOCK_TRY_LOCK(void *lock) #endif +/* This code is shared between both lock impls */ +#if ! defined(_EVENT_DISABLE_THREAD_SUPPORT) +/** Helper: put lockvar1 and lockvar2 into pointerwise ascending order. */ +#define _EVLOCK_SORTLOCKS(lockvar1, lockvar2) \ + do { \ + if (lockvar1 && lockvar2 && lockvar1 > lockvar2) { \ + void *tmp = lockvar1; \ + lockvar1 = lockvar2; \ + lockvar2 = tmp; \ + } \ + } while (0) + +/** Acquire both lock1 and lock2. Always allocates locks in the same order, + * so that two threads locking two locks with LOCK2 will not deadlock. */ +#define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) \ + do { \ + void *_lock1_tmplock = (lock1); \ + void *_lock2_tmplock = (lock2); \ + _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ + EVLOCK_LOCK(_lock1_tmplock,mode1); \ + if (_lock2_tmplock != _lock1_tmplock) \ + EVLOCK_LOCK(_lock2_tmplock,mode2); \ + } while (0) +/** Release both lock1 and lock2. */ +#define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) \ + do { \ + void *_lock1_tmplock = (lock1); \ + void *_lock2_tmplock = (lock2); \ + _EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock); \ + if (_lock2_tmplock != _lock1_tmplock) \ + EVLOCK_UNLOCK(_lock2_tmplock,mode2); \ + EVLOCK_UNLOCK(_lock1_tmplock,mode1); \ + } while (0) + +int _evthread_is_debug_lock_held(void *lock); +void *_evthread_debug_get_real_lock(void *lock); +#endif + #ifdef __cplusplus } #endif diff --git a/evthread.c b/evthread.c index 99718f34..eb6d17cc 100644 --- a/evthread.c +++ b/evthread.c @@ -38,13 +38,19 @@ #include "util-internal.h" #include "evthread-internal.h" +#ifdef EVTHREAD_EXPOSE_STRUCTS +#define GLOBAL +#else +#define GLOBAL static +#endif + /* globals */ -int _evthread_lock_debugging_enabled = 0; -struct evthread_lock_callbacks _evthread_lock_fns = { +GLOBAL int _evthread_lock_debugging_enabled = 0; +GLOBAL struct evthread_lock_callbacks _evthread_lock_fns = { 0, 0, NULL, NULL, NULL, NULL }; -unsigned long (*_evthread_id_fn)(void) = NULL; -struct evthread_condition_callbacks _evthread_cond_fns = { +GLOBAL unsigned long (*_evthread_id_fn)(void) = NULL; +GLOBAL struct evthread_condition_callbacks _evthread_cond_fns = { 0, NULL, NULL, NULL, NULL }; @@ -263,4 +269,73 @@ _evthread_debug_get_real_lock(void *lock_) return lock->lock; } +#ifndef EVTHREAD_EXPOSE_STRUCTS +unsigned long +_evthreadimpl_get_id() +{ + return _evthread_id_fn ? _evthread_id_fn() : 1; +} +void * +_evthreadimpl_lock_alloc(unsigned locktype) +{ + return _evthread_lock_fns.alloc ? + _evthread_lock_fns.alloc(locktype) : NULL; +} +void +_evthreadimpl_lock_free(void *lock, unsigned locktype) +{ + if (_evthread_lock_fns.free) + _evthread_lock_fns.free(lock, locktype); +} +int +_evthreadimpl_lock_lock(unsigned mode, void *lock) +{ + if (_evthread_lock_fns.lock) + return _evthread_lock_fns.lock(mode, lock); + else + return 0; +} +int +_evthreadimpl_lock_unlock(unsigned mode, void *lock) +{ + if (_evthread_lock_fns.unlock) + return _evthread_lock_fns.unlock(mode, lock); + else + return 0; +} +void * +_evthreadimpl_cond_alloc(unsigned condtype) +{ + return _evthread_cond_fns.alloc_condition ? + _evthread_cond_fns.alloc_condition(condtype) : NULL; +} +void +_evthreadimpl_cond_free(void *cond) +{ + if (_evthread_cond_fns.free_condition) + _evthread_cond_fns.free_condition(cond); +} +int +_evthreadimpl_cond_signal(void *cond, int broadcast) +{ + if (_evthread_cond_fns.signal_condition) + return _evthread_cond_fns.signal_condition(cond, broadcast); + else + return 0; +} +int +_evthreadimpl_cond_wait(void *cond, void *lock, const struct timeval *tv) +{ + if (_evthread_cond_fns.wait_condition) + return _evthread_cond_fns.wait_condition(cond, lock, tv); + else + return 0; +} +int +_evthreadimpl_is_lock_debugging_enabled(void) +{ + return _evthread_lock_debugging_enabled; +} +#endif + #endif