RepoMirrors/musl
1
0
Fork 0
mirror of git://git.musl-libc.org/musl synced 2024-12-17 20:24:54 +00:00
Code Issues Packages Projects Releases Wiki Activity

use count=0 instead of 1 for recursive mutex with only one lock reference

Browse Source 
this simplifies the code paths slightly, but perhaps what's nicer is
that it makes recursive mutexes fully reentrant, i.e. locking and
unlocking from a signal handler works even if the interrupted code was
in the middle of locking or unlocking.
This commit is contained in:
Rich Felker 2011-10-03 00:09:08 -04:00
parent b3b00d11e8
commit 7fe58d3511
2 changed files with 2 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/thread/pthread_mutex_trylock.c
View File

@ -30,8 +30,6 @@ int pthread_mutex_trylock(pthread_mutex_t *m)
if ((own && !(own & 0x40000000)) || a_cas(&m->_m_lock, old, tid)!=old)
return EBUSY;
m->_m_count = 1;
if (m->_m_type < 4) return 0;
if (m->_m_type >= 8) {

4
src/thread/pthread_mutex_unlock.c
View File

@ -12,8 +12,8 @@ int pthread_mutex_unlock(pthread_mutex_t *m)
self = __pthread_self();
if ((m->_m_lock&0x1fffffff) != self->tid)
return EPERM;
if ((m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE && --m->_m_count)
return 0;
if ((m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
return m->_m_count--, 0;
if (m->_m_type >= 4) {
self->robust_list.pending = &m->_m_next;
*(void **)m->_m_prev = m->_m_next;