RepoMirrors
/
musl
mirror of git://git.musl-libc.org/musl
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

unify lock and owner fields of mutex structure 

this change is necessary to free up one slot in the mutex structure so
that we can use doubly-linked lists in the implementation of robust
mutexes.
This commit is contained in:
Rich Felker 2011-03-17 12:21:32 -04:00
parent e914f8b7ec
commit b1c43161c2
4 changed files with 6 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/internal/pthread_impl.h
View File

@ -47,7 +47,6 @@ struct pthread {
#define _m_type __u.__i[0]
#define _m_lock __u.__i[1]
#define _m_waiters __u.__i[2]
#define _m_owner __u.__i[3]
#define _m_count __u.__i[4]
#define _c_block __u.__i[0]
#define _c_clock __u.__i[1]

5
src/thread/pthread_mutex_lock.c
View File

@ -4,10 +4,11 @@ int pthread_mutex_lock(pthread_mutex_t *m)
{
int r;
while ((r=pthread_mutex_trylock(m)) == EBUSY) {
if (!(r=m->_m_lock)) continue;
if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK
&& m->_m_owner == pthread_self()->tid)
&& r == pthread_self()->tid)
return EDEADLK;
__wait(&m->_m_lock, &m->_m_waiters, 1, 0);
__wait(&m->_m_lock, &m->_m_waiters, r, 0);
}
return r;
}

5
src/thread/pthread_mutex_trylock.c
View File

@ -9,14 +9,13 @@ int pthread_mutex_trylock(pthread_mutex_t *m)
tid = pthread_self()->tid;
if (m->_m_owner == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
if (m->_m_lock == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
m->_m_count++;
return 0;
}
if (m->_m_owner || a_xchg(&m->_m_lock, 1)) return EBUSY;
m->_m_owner = tid;
if (m->_m_lock || a_cas(&m->_m_lock, 0, tid)) return EBUSY;
m->_m_count = 1;
return 0;
}

3
src/thread/pthread_mutex_unlock.c
View File

@ -3,13 +3,12 @@
int pthread_mutex_unlock(pthread_mutex_t *m)
{
if (m->_m_type != PTHREAD_MUTEX_NORMAL) {
if (m->_m_owner != pthread_self()->tid)
if (m->_m_lock != pthread_self()->tid)
return EPERM;
if (m->_m_type == PTHREAD_MUTEX_RECURSIVE && --m->_m_count)
return 0;
}
m->_m_owner = 0;
m->_m_lock = 0;
if (m->_m_waiters) __wake(&m->_m_lock, 1, 0);
return 0;