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pthreads: add support for recursive mutexes 

Fixes #971.
This commit is contained in:
Christian Prochaska 2013-11-07 20:37:34 +01:00 committed by Norman Feske
parent 4e9303ff6e
commit 8e30a07b90
1 changed files with 92 additions and 1 deletions
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93
libports/src/lib/pthread/thread.cc
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@ -199,15 +199,106 @@ extern "C" {
};
struct pthread_mutex : Lock
struct pthread_mutex
{
pthread_mutex_attr mutexattr;
Lock mutex_lock;
pthread_t owner;
int lock_count;
Lock owner_and_counter_lock;
pthread_mutex(const pthread_mutexattr_t *__restrict attr)
: owner(0),
lock_count(0)
{
if (attr && *attr)
mutexattr = **attr;
}
int lock()
{
if (mutexattr.type == PTHREAD_MUTEX_RECURSIVE) {
Lock::Guard lock_guard(owner_and_counter_lock);
if (lock_count == 0) {
owner = pthread_self();
lock_count++;
mutex_lock.lock();
return 0;
}
/* the mutex is already locked */
if (pthread_self() == owner) {
lock_count++;
return 0;
} else {
mutex_lock.lock();
return 0;
}
}
if (mutexattr.type == PTHREAD_MUTEX_ERRORCHECK) {
Lock::Guard lock_guard(owner_and_counter_lock);
if (lock_count == 0) {
owner = pthread_self();
mutex_lock.lock();
return 0;
}
/* the mutex is already locked */
if (pthread_self() != owner) {
mutex_lock.lock();
return 0;
} else
return EDEADLK;
}
/* PTHREAD_MUTEX_NORMAL or PTHREAD_MUTEX_DEFAULT */
mutex_lock.lock();
return 0;
}
int unlock()
{
if (mutexattr.type == PTHREAD_MUTEX_RECURSIVE) {
Lock::Guard lock_guard(owner_and_counter_lock);
if (pthread_self() != owner)
return EPERM;
lock_count--;
if (lock_count == 0) {
owner = 0;
mutex_lock.unlock();
}
return 0;
}
if (mutexattr.type == PTHREAD_MUTEX_ERRORCHECK) {
Lock::Guard lock_guard(owner_and_counter_lock);
if (pthread_self() != owner)
return EPERM;
owner = 0;
mutex_lock.unlock();
return 0;
}
/* PTHREAD_MUTEX_NORMAL or PTHREAD_MUTEX_DEFAULT */
mutex_lock.unlock();
return 0;
}
};