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/*
* Copyright (c) 2008-2012 Niels Provos, Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef EVTHREAD_INTERNAL_H_INCLUDED_
#define EVTHREAD_INTERNAL_H_INCLUDED_
#ifdef __cplusplus
extern "C" {
#endif
#include "event2/event-config.h"
#include "evconfig-private.h"
#include "event2/thread.h"
#include "util-internal.h"
struct event_base;
#if !defined(_WIN32) && !defined(__CYGWIN__)
/* 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. */
EVENT2_EXPORT_SYMBOL
extern struct evthread_lock_callbacks evthread_lock_fns_;
EVENT2_EXPORT_SYMBOL
extern struct evthread_condition_callbacks evthread_cond_fns_;
extern unsigned long (*evthread_id_fn_)(void);
EVENT2_EXPORT_SYMBOL
extern int evthread_lock_debugging_enabled_;
/** Return the ID of the current thread, or 1 if threading isn't enabled. */
#define EVTHREAD_GET_ID() \
(evthread_id_fn_ ? evthread_id_fn_() : 1)
/** Return true iff we're in the thread that is currently (or most recently)
* running a given event_base's loop. Requires lock. */
#define EVBASE_IN_THREAD(base) \
(evthread_id_fn_ == NULL || \
(base)->th_owner_id == evthread_id_fn_())
/** Return true iff we need to notify the base's main thread about changes to
* its state, because it's currently running the main loop in another
* thread. Requires lock. */
#define EVBASE_NEED_NOTIFY(base) \
(evthread_id_fn_ != NULL && \
(base)->running_loop && \
(base)->th_owner_id != evthread_id_fn_())
/** Allocate a new lock, and store it in lockvar, a void*. Sets lockvar to
NULL if locking is not enabled. */
#define EVTHREAD_ALLOC_LOCK(lockvar, locktype) \
((lockvar) = evthread_lock_fns_.alloc ? \
evthread_lock_fns_.alloc(locktype) : NULL)
/** Free a given lock, if it is present and locking is enabled. */
#define EVTHREAD_FREE_LOCK(lockvar, locktype) \
do { \
void *lock_tmp_ = (lockvar); \
if (lock_tmp_ && evthread_lock_fns_.free) \
evthread_lock_fns_.free(lock_tmp_, (locktype)); \
} while (0)
/** Acquire a lock. */
#define EVLOCK_LOCK(lockvar,mode) \
do { \
if (lockvar) \
evthread_lock_fns_.lock(mode, lockvar); \
} while (0)
/** Release a lock */
#define EVLOCK_UNLOCK(lockvar,mode) \
do { \
if (lockvar) \
evthread_lock_fns_.unlock(mode, lockvar); \
} while (0)
/** 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)
/** 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) && evthread_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 && evthread_lock_fns_.lock) {
int r = evthread_lock_fns_.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) = evthread_cond_fns_.alloc_condition ? \
evthread_cond_fns_.alloc_condition(0) : NULL; \
} while (0)
/** Deallocate and free a condition variable in condvar */
#define EVTHREAD_FREE_COND(cond) \
do { \
if (cond) \
evthread_cond_fns_.free_condition((cond)); \
} while (0)
/** Signal one thread waiting on cond */
#define EVTHREAD_COND_SIGNAL(cond) \
( (cond) ? evthread_cond_fns_.signal_condition((cond), 0) : 0 )
/** Signal all threads waiting on cond */
#define EVTHREAD_COND_BROADCAST(cond) \
( (cond) ? evthread_cond_fns_.signal_condition((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) ? evthread_cond_fns_.wait_condition((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) ? evthread_cond_fns_.wait_condition((cond), (lock), (tv)) : 0 )
/** True iff locking functions have been configured. */
#define EVTHREAD_LOCKING_ENABLED() \
(evthread_lock_fns_.lock != NULL)
#elif ! defined(EVENT__DISABLE_THREAD_SUPPORT)
unsigned long evthreadimpl_get_id_(void);
EVENT2_EXPORT_SYMBOL
int evthreadimpl_is_lock_debugging_enabled_(void);
EVENT2_EXPORT_SYMBOL
void *evthreadimpl_lock_alloc_(unsigned locktype);
EVENT2_EXPORT_SYMBOL
void evthreadimpl_lock_free_(void *lock, unsigned locktype);
EVENT2_EXPORT_SYMBOL
int evthreadimpl_lock_lock_(unsigned mode, void *lock);
EVENT2_EXPORT_SYMBOL
int evthreadimpl_lock_unlock_(unsigned mode, void *lock);
EVENT2_EXPORT_SYMBOL
void *evthreadimpl_cond_alloc_(unsigned condtype);
EVENT2_EXPORT_SYMBOL
void evthreadimpl_cond_free_(void *cond);
EVENT2_EXPORT_SYMBOL
int evthreadimpl_cond_signal_(void *cond, int broadcast);
EVENT2_EXPORT_SYMBOL
int evthreadimpl_cond_wait_(void *cond, void *lock, const struct timeval *tv);
int evthreadimpl_locking_enabled_(void);
#define EVTHREAD_GET_ID() evthreadimpl_get_id_()
#define EVBASE_IN_THREAD(base) \
((base)->th_owner_id == evthreadimpl_get_id_())
#define EVBASE_NEED_NOTIFY(base) \
((base)->running_loop && \
((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 )
#define EVTHREAD_LOCKING_ENABLED() \
(evthreadimpl_locking_enabled_())
#else /* EVENT__DISABLE_THREAD_SUPPORT */
#define EVTHREAD_GET_ID() 1
#define EVTHREAD_ALLOC_LOCK(lockvar, locktype) EVUTIL_NIL_STMT_
#define EVTHREAD_FREE_LOCK(lockvar, locktype) EVUTIL_NIL_STMT_
#define EVLOCK_LOCK(lockvar, mode) EVUTIL_NIL_STMT_
#define EVLOCK_UNLOCK(lockvar, mode) EVUTIL_NIL_STMT_
#define EVLOCK_LOCK2(lock1,lock2,mode1,mode2) EVUTIL_NIL_STMT_
#define EVLOCK_UNLOCK2(lock1,lock2,mode1,mode2) EVUTIL_NIL_STMT_
#define EVBASE_IN_THREAD(base) 1
#define EVBASE_NEED_NOTIFY(base) 0
#define EVBASE_ACQUIRE_LOCK(base, lock) EVUTIL_NIL_STMT_
#define EVBASE_RELEASE_LOCK(base, lock) EVUTIL_NIL_STMT_
#define EVLOCK_ASSERT_LOCKED(lock) EVUTIL_NIL_STMT_
#define EVLOCK_TRY_LOCK_(lock) 1
#define EVTHREAD_ALLOC_COND(condvar) EVUTIL_NIL_STMT_
#define EVTHREAD_FREE_COND(cond) EVUTIL_NIL_STMT_
#define EVTHREAD_COND_SIGNAL(cond) EVUTIL_NIL_STMT_
#define EVTHREAD_COND_BROADCAST(cond) EVUTIL_NIL_STMT_
#define EVTHREAD_COND_WAIT(cond, lock) EVUTIL_NIL_STMT_
#define EVTHREAD_COND_WAIT_TIMED(cond, lock, howlong) EVUTIL_NIL_STMT_
#define EVTHREAD_LOCKING_ENABLED() 0
#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)
EVENT2_EXPORT_SYMBOL
int evthread_is_debug_lock_held_(void *lock);
void *evthread_debug_get_real_lock_(void *lock);
void *evthread_setup_global_lock_(void *lock_, unsigned locktype,
int enable_locks);
#define EVTHREAD_SETUP_GLOBAL_LOCK(lockvar, locktype) \
do { \
lockvar = evthread_setup_global_lock_(lockvar, \
(locktype), enable_locks); \
if (!lockvar) { \
event_warn("Couldn't allocate %s", #lockvar); \
return -1; \
} \
} while (0);
int event_global_setup_locks_(const int enable_locks);
int evsig_global_setup_locks_(const int enable_locks);
int evutil_global_setup_locks_(const int enable_locks);
int evutil_secure_rng_global_setup_locks_(const int enable_locks);
/** Return current evthread_lock_callbacks */
EVENT2_EXPORT_SYMBOL
struct evthread_lock_callbacks *evthread_get_lock_callbacks(void);
/** Return current evthread_condition_callbacks */
struct evthread_condition_callbacks *evthread_get_condition_callbacks(void);
/** Disable locking for internal usage (like global shutdown) */
void evthreadimpl_disable_lock_debugging_(void);
#endif
#ifdef __cplusplus
}
#endif
#endif /* EVTHREAD_INTERNAL_H_INCLUDED_ */