michael@0: /*
michael@0:  * Copyright (c) 2008-2012 Niels Provos, Nick Mathewson
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. The name of the author may not be used to endorse or promote products
michael@0:  *    derived from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
michael@0:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
michael@0:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
michael@0:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
michael@0:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
michael@0:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: #ifndef _EVTHREAD_INTERNAL_H_
michael@0: #define _EVTHREAD_INTERNAL_H_
michael@0: 
michael@0: #ifdef __cplusplus
michael@0: extern "C" {
michael@0: #endif
michael@0: 
michael@0: #include "event2/thread.h"
michael@0: #include "event2/event-config.h"
michael@0: #include "util-internal.h"
michael@0: 
michael@0: struct event_base;
michael@0: 
michael@0: #ifndef WIN32
michael@0: /* On Windows, the way we currently make DLLs, it's not allowed for us to
michael@0:  * have shared global structures.  Thus, we only do the direct-call-to-function
michael@0:  * code path if we know that the local shared library system supports it.
michael@0:  */
michael@0: #define EVTHREAD_EXPOSE_STRUCTS
michael@0: #endif
michael@0: 
michael@0: #if ! defined(_EVENT_DISABLE_THREAD_SUPPORT) && defined(EVTHREAD_EXPOSE_STRUCTS)
michael@0: /* Global function pointers to lock-related functions. NULL if locking isn't
michael@0:    enabled. */
michael@0: extern struct evthread_lock_callbacks _evthread_lock_fns;
michael@0: extern struct evthread_condition_callbacks _evthread_cond_fns;
michael@0: extern unsigned long (*_evthread_id_fn)(void);
michael@0: extern int _evthread_lock_debugging_enabled;
michael@0: 
michael@0: /** Return the ID of the current thread, or 1 if threading isn't enabled. */
michael@0: #define EVTHREAD_GET_ID() \
michael@0: 	(_evthread_id_fn ? _evthread_id_fn() : 1)
michael@0: 
michael@0: /** Return true iff we're in the thread that is currently (or most recently)
michael@0:  * running a given event_base's loop. Requires lock. */
michael@0: #define EVBASE_IN_THREAD(base)				 \
michael@0: 	(_evthread_id_fn == NULL ||			 \
michael@0: 	(base)->th_owner_id == _evthread_id_fn())
michael@0: 
michael@0: /** Return true iff we need to notify the base's main thread about changes to
michael@0:  * its state, because it's currently running the main loop in another
michael@0:  * thread. Requires lock. */
michael@0: #define EVBASE_NEED_NOTIFY(base)			 \
michael@0: 	(_evthread_id_fn != NULL &&			 \
michael@0: 	    (base)->running_loop &&			 \
michael@0: 	    (base)->th_owner_id != _evthread_id_fn())
michael@0: 
michael@0: /** Allocate a new lock, and store it in lockvar, a void*.  Sets lockvar to
michael@0:     NULL if locking is not enabled. */
michael@0: #define EVTHREAD_ALLOC_LOCK(lockvar, locktype)		\
michael@0: 	((lockvar) = _evthread_lock_fns.alloc ?		\
michael@0: 	    _evthread_lock_fns.alloc(locktype) : NULL)
michael@0: 
michael@0: /** Free a given lock, if it is present and locking is enabled. */
michael@0: #define EVTHREAD_FREE_LOCK(lockvar, locktype)				\
michael@0: 	do {								\
michael@0: 		void *_lock_tmp_ = (lockvar);				\
michael@0: 		if (_lock_tmp_ && _evthread_lock_fns.free)		\
michael@0: 			_evthread_lock_fns.free(_lock_tmp_, (locktype)); \
michael@0: 	} while (0)
michael@0: 
michael@0: /** Acquire a lock. */
michael@0: #define EVLOCK_LOCK(lockvar,mode)					\
michael@0: 	do {								\
michael@0: 		if (lockvar)						\
michael@0: 			_evthread_lock_fns.lock(mode, lockvar);		\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Release a lock */
michael@0: #define EVLOCK_UNLOCK(lockvar,mode)					\
michael@0: 	do {								\
michael@0: 		if (lockvar)						\
michael@0: 			_evthread_lock_fns.unlock(mode, lockvar);	\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Helper: put lockvar1 and lockvar2 into pointerwise ascending order. */
michael@0: #define _EVLOCK_SORTLOCKS(lockvar1, lockvar2)				\
michael@0: 	do {								\
michael@0: 		if (lockvar1 && lockvar2 && lockvar1 > lockvar2) {	\
michael@0: 			void *tmp = lockvar1;				\
michael@0: 			lockvar1 = lockvar2;				\
michael@0: 			lockvar2 = tmp;					\
michael@0: 		}							\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Lock an event_base, if it is set up for locking.  Acquires the lock
michael@0:     in the base structure whose field is named 'lockvar'. */
michael@0: #define EVBASE_ACQUIRE_LOCK(base, lockvar) do {				\
michael@0: 		EVLOCK_LOCK((base)->lockvar, 0);			\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Unlock an event_base, if it is set up for locking. */
michael@0: #define EVBASE_RELEASE_LOCK(base, lockvar) do {				\
michael@0: 		EVLOCK_UNLOCK((base)->lockvar, 0);			\
michael@0: 	} while (0)
michael@0: 
michael@0: /** If lock debugging is enabled, and lock is non-null, assert that 'lock' is
michael@0:  * locked and held by us. */
michael@0: #define EVLOCK_ASSERT_LOCKED(lock)					\
michael@0: 	do {								\
michael@0: 		if ((lock) && _evthread_lock_debugging_enabled) {	\
michael@0: 			EVUTIL_ASSERT(_evthread_is_debug_lock_held(lock)); \
michael@0: 		}							\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Try to grab the lock for 'lockvar' without blocking, and return 1 if we
michael@0:  * manage to get it. */
michael@0: static inline int EVLOCK_TRY_LOCK(void *lock);
michael@0: static inline int
michael@0: EVLOCK_TRY_LOCK(void *lock)
michael@0: {
michael@0: 	if (lock && _evthread_lock_fns.lock) {
michael@0: 		int r = _evthread_lock_fns.lock(EVTHREAD_TRY, lock);
michael@0: 		return !r;
michael@0: 	} else {
michael@0: 		/* Locking is disabled either globally or for this thing;
michael@0: 		 * of course we count as having the lock. */
michael@0: 		return 1;
michael@0: 	}
michael@0: }
michael@0: 
michael@0: /** Allocate a new condition variable and store it in the void *, condvar */
michael@0: #define EVTHREAD_ALLOC_COND(condvar)					\
michael@0: 	do {								\
michael@0: 		(condvar) = _evthread_cond_fns.alloc_condition ?	\
michael@0: 		    _evthread_cond_fns.alloc_condition(0) : NULL;	\
michael@0: 	} while (0)
michael@0: /** Deallocate and free a condition variable in condvar */
michael@0: #define EVTHREAD_FREE_COND(cond)					\
michael@0: 	do {								\
michael@0: 		if (cond)						\
michael@0: 			_evthread_cond_fns.free_condition((cond));	\
michael@0: 	} while (0)
michael@0: /** Signal one thread waiting on cond */
michael@0: #define EVTHREAD_COND_SIGNAL(cond)					\
michael@0: 	( (cond) ? _evthread_cond_fns.signal_condition((cond), 0) : 0 )
michael@0: /** Signal all threads waiting on cond */
michael@0: #define EVTHREAD_COND_BROADCAST(cond)					\
michael@0: 	( (cond) ? _evthread_cond_fns.signal_condition((cond), 1) : 0 )
michael@0: /** Wait until the condition 'cond' is signalled.  Must be called while
michael@0:  * holding 'lock'.  The lock will be released until the condition is
michael@0:  * signalled, at which point it will be acquired again.  Returns 0 for
michael@0:  * success, -1 for failure. */
michael@0: #define EVTHREAD_COND_WAIT(cond, lock)					\
michael@0: 	( (cond) ? _evthread_cond_fns.wait_condition((cond), (lock), NULL) : 0 )
michael@0: /** As EVTHREAD_COND_WAIT, but gives up after 'tv' has elapsed.  Returns 1
michael@0:  * on timeout. */
michael@0: #define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv)			\
michael@0: 	( (cond) ? _evthread_cond_fns.wait_condition((cond), (lock), (tv)) : 0 )
michael@0: 
michael@0: /** True iff locking functions have been configured. */
michael@0: #define EVTHREAD_LOCKING_ENABLED()		\
michael@0: 	(_evthread_lock_fns.lock != NULL)
michael@0: 
michael@0: #elif ! defined(_EVENT_DISABLE_THREAD_SUPPORT)
michael@0: 
michael@0: unsigned long _evthreadimpl_get_id(void);
michael@0: int _evthreadimpl_is_lock_debugging_enabled(void);
michael@0: void *_evthreadimpl_lock_alloc(unsigned locktype);
michael@0: void _evthreadimpl_lock_free(void *lock, unsigned locktype);
michael@0: int _evthreadimpl_lock_lock(unsigned mode, void *lock);
michael@0: int _evthreadimpl_lock_unlock(unsigned mode, void *lock);
michael@0: void *_evthreadimpl_cond_alloc(unsigned condtype);
michael@0: void _evthreadimpl_cond_free(void *cond);
michael@0: int _evthreadimpl_cond_signal(void *cond, int broadcast);
michael@0: int _evthreadimpl_cond_wait(void *cond, void *lock, const struct timeval *tv);
michael@0: int _evthreadimpl_locking_enabled(void);
michael@0: 
michael@0: #define EVTHREAD_GET_ID() _evthreadimpl_get_id()
michael@0: #define EVBASE_IN_THREAD(base)				\
michael@0: 	((base)->th_owner_id == _evthreadimpl_get_id())
michael@0: #define EVBASE_NEED_NOTIFY(base)			 \
michael@0: 	((base)->running_loop &&			 \
michael@0: 	    ((base)->th_owner_id != _evthreadimpl_get_id()))
michael@0: 
michael@0: #define EVTHREAD_ALLOC_LOCK(lockvar, locktype)		\
michael@0: 	((lockvar) = _evthreadimpl_lock_alloc(locktype))
michael@0: 
michael@0: #define EVTHREAD_FREE_LOCK(lockvar, locktype)				\
michael@0: 	do {								\
michael@0: 		void *_lock_tmp_ = (lockvar);				\
michael@0: 		if (_lock_tmp_)						\
michael@0: 			_evthreadimpl_lock_free(_lock_tmp_, (locktype)); \
michael@0: 	} while (0)
michael@0: 
michael@0: /** Acquire a lock. */
michael@0: #define EVLOCK_LOCK(lockvar,mode)					\
michael@0: 	do {								\
michael@0: 		if (lockvar)						\
michael@0: 			_evthreadimpl_lock_lock(mode, lockvar);		\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Release a lock */
michael@0: #define EVLOCK_UNLOCK(lockvar,mode)					\
michael@0: 	do {								\
michael@0: 		if (lockvar)						\
michael@0: 			_evthreadimpl_lock_unlock(mode, lockvar);	\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Lock an event_base, if it is set up for locking.  Acquires the lock
michael@0:     in the base structure whose field is named 'lockvar'. */
michael@0: #define EVBASE_ACQUIRE_LOCK(base, lockvar) do {				\
michael@0: 		EVLOCK_LOCK((base)->lockvar, 0);			\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Unlock an event_base, if it is set up for locking. */
michael@0: #define EVBASE_RELEASE_LOCK(base, lockvar) do {				\
michael@0: 		EVLOCK_UNLOCK((base)->lockvar, 0);			\
michael@0: 	} while (0)
michael@0: 
michael@0: /** If lock debugging is enabled, and lock is non-null, assert that 'lock' is
michael@0:  * locked and held by us. */
michael@0: #define EVLOCK_ASSERT_LOCKED(lock)					\
michael@0: 	do {								\
michael@0: 		if ((lock) && _evthreadimpl_is_lock_debugging_enabled()) { \
michael@0: 			EVUTIL_ASSERT(_evthread_is_debug_lock_held(lock)); \
michael@0: 		}							\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Try to grab the lock for 'lockvar' without blocking, and return 1 if we
michael@0:  * manage to get it. */
michael@0: static inline int EVLOCK_TRY_LOCK(void *lock);
michael@0: static inline int
michael@0: EVLOCK_TRY_LOCK(void *lock)
michael@0: {
michael@0: 	if (lock) {
michael@0: 		int r = _evthreadimpl_lock_lock(EVTHREAD_TRY, lock);
michael@0: 		return !r;
michael@0: 	} else {
michael@0: 		/* Locking is disabled either globally or for this thing;
michael@0: 		 * of course we count as having the lock. */
michael@0: 		return 1;
michael@0: 	}
michael@0: }
michael@0: 
michael@0: /** Allocate a new condition variable and store it in the void *, condvar */
michael@0: #define EVTHREAD_ALLOC_COND(condvar)					\
michael@0: 	do {								\
michael@0: 		(condvar) = _evthreadimpl_cond_alloc(0);		\
michael@0: 	} while (0)
michael@0: /** Deallocate and free a condition variable in condvar */
michael@0: #define EVTHREAD_FREE_COND(cond)					\
michael@0: 	do {								\
michael@0: 		if (cond)						\
michael@0: 			_evthreadimpl_cond_free((cond));		\
michael@0: 	} while (0)
michael@0: /** Signal one thread waiting on cond */
michael@0: #define EVTHREAD_COND_SIGNAL(cond)					\
michael@0: 	( (cond) ? _evthreadimpl_cond_signal((cond), 0) : 0 )
michael@0: /** Signal all threads waiting on cond */
michael@0: #define EVTHREAD_COND_BROADCAST(cond)					\
michael@0: 	( (cond) ? _evthreadimpl_cond_signal((cond), 1) : 0 )
michael@0: /** Wait until the condition 'cond' is signalled.  Must be called while
michael@0:  * holding 'lock'.  The lock will be released until the condition is
michael@0:  * signalled, at which point it will be acquired again.  Returns 0 for
michael@0:  * success, -1 for failure. */
michael@0: #define EVTHREAD_COND_WAIT(cond, lock)					\
michael@0: 	( (cond) ? _evthreadimpl_cond_wait((cond), (lock), NULL) : 0 )
michael@0: /** As EVTHREAD_COND_WAIT, but gives up after 'tv' has elapsed.  Returns 1
michael@0:  * on timeout. */
michael@0: #define EVTHREAD_COND_WAIT_TIMED(cond, lock, tv)			\
michael@0: 	( (cond) ? _evthreadimpl_cond_wait((cond), (lock), (tv)) : 0 )
michael@0: 
michael@0: #define EVTHREAD_LOCKING_ENABLED()		\
michael@0: 	(_evthreadimpl_locking_enabled())
michael@0: 
michael@0: #else /* _EVENT_DISABLE_THREAD_SUPPORT */
michael@0: 
michael@0: #define EVTHREAD_GET_ID()	1
michael@0: #define EVTHREAD_ALLOC_LOCK(lockvar, locktype) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_FREE_LOCK(lockvar, locktype) _EVUTIL_NIL_STMT
michael@0: 
michael@0: #define EVLOCK_LOCK(lockvar, mode) _EVUTIL_NIL_STMT
michael@0: #define EVLOCK_UNLOCK(lockvar, mode) _EVUTIL_NIL_STMT
michael@0: #define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) _EVUTIL_NIL_STMT
michael@0: #define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) _EVUTIL_NIL_STMT
michael@0: 
michael@0: #define EVBASE_IN_THREAD(base)	1
michael@0: #define EVBASE_NEED_NOTIFY(base) 0
michael@0: #define EVBASE_ACQUIRE_LOCK(base, lock) _EVUTIL_NIL_STMT
michael@0: #define EVBASE_RELEASE_LOCK(base, lock) _EVUTIL_NIL_STMT
michael@0: #define EVLOCK_ASSERT_LOCKED(lock) _EVUTIL_NIL_STMT
michael@0: 
michael@0: #define EVLOCK_TRY_LOCK(lock) 1
michael@0: 
michael@0: #define EVTHREAD_ALLOC_COND(condvar) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_FREE_COND(cond) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_COND_SIGNAL(cond) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_COND_BROADCAST(cond) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_COND_WAIT(cond, lock) _EVUTIL_NIL_STMT
michael@0: #define EVTHREAD_COND_WAIT_TIMED(cond, lock, howlong) _EVUTIL_NIL_STMT
michael@0: 
michael@0: #define EVTHREAD_LOCKING_ENABLED() 0
michael@0: 
michael@0: #endif
michael@0: 
michael@0: /* This code is shared between both lock impls */
michael@0: #if ! defined(_EVENT_DISABLE_THREAD_SUPPORT)
michael@0: /** Helper: put lockvar1 and lockvar2 into pointerwise ascending order. */
michael@0: #define _EVLOCK_SORTLOCKS(lockvar1, lockvar2)				\
michael@0: 	do {								\
michael@0: 		if (lockvar1 && lockvar2 && lockvar1 > lockvar2) {	\
michael@0: 			void *tmp = lockvar1;				\
michael@0: 			lockvar1 = lockvar2;				\
michael@0: 			lockvar2 = tmp;					\
michael@0: 		}							\
michael@0: 	} while (0)
michael@0: 
michael@0: /** Acquire both lock1 and lock2.  Always allocates locks in the same order,
michael@0:  * so that two threads locking two locks with LOCK2 will not deadlock. */
michael@0: #define EVLOCK_LOCK2(lock1,lock2,mode1,mode2)				\
michael@0: 	do {								\
michael@0: 		void *_lock1_tmplock = (lock1);				\
michael@0: 		void *_lock2_tmplock = (lock2);				\
michael@0: 		_EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock);	\
michael@0: 		EVLOCK_LOCK(_lock1_tmplock,mode1);			\
michael@0: 		if (_lock2_tmplock != _lock1_tmplock)			\
michael@0: 			EVLOCK_LOCK(_lock2_tmplock,mode2);		\
michael@0: 	} while (0)
michael@0: /** Release both lock1 and lock2.  */
michael@0: #define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2)				\
michael@0: 	do {								\
michael@0: 		void *_lock1_tmplock = (lock1);				\
michael@0: 		void *_lock2_tmplock = (lock2);				\
michael@0: 		_EVLOCK_SORTLOCKS(_lock1_tmplock,_lock2_tmplock);	\
michael@0: 		if (_lock2_tmplock != _lock1_tmplock)			\
michael@0: 			EVLOCK_UNLOCK(_lock2_tmplock,mode2);		\
michael@0: 		EVLOCK_UNLOCK(_lock1_tmplock,mode1);			\
michael@0: 	} while (0)
michael@0: 
michael@0: int _evthread_is_debug_lock_held(void *lock);
michael@0: void *_evthread_debug_get_real_lock(void *lock);
michael@0: 
michael@0: void *evthread_setup_global_lock_(void *lock_, unsigned locktype,
michael@0:     int enable_locks);
michael@0: 
michael@0: #define EVTHREAD_SETUP_GLOBAL_LOCK(lockvar, locktype)			\
michael@0: 	do {								\
michael@0: 		lockvar = evthread_setup_global_lock_(lockvar,		\
michael@0: 		    (locktype), enable_locks);				\
michael@0: 		if (!lockvar) {						\
michael@0: 			event_warn("Couldn't allocate %s", #lockvar);	\
michael@0: 			return -1;					\
michael@0: 		}							\
michael@0: 	} while (0);
michael@0: 
michael@0: int event_global_setup_locks_(const int enable_locks);
michael@0: int evsig_global_setup_locks_(const int enable_locks);
michael@0: int evutil_secure_rng_global_setup_locks_(const int enable_locks);
michael@0: 
michael@0: #endif
michael@0: 
michael@0: #ifdef __cplusplus
michael@0: }
michael@0: #endif
michael@0: 
michael@0: #endif /* _EVTHREAD_INTERNAL_H_ */