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There are consumers of rwlocks, inluding our own libc, that depend on

Browse Source 
a PTHREAD_RWLOCK_INITIALIZER to do for rwlocks what
a similarly named symbol does for statically initialized mutexes.
This symbol was dropped in The Open Group Base Specifications Issue 6
and does not exist in IEEE Std 1003.1, 2003, but it should still be
supported for backwards compatibility.

Pointy hat: mtm
This commit is contained in:
mtm 2004-02-18 15:30:10 +00:00
parent 68e65f5c5e
commit b6f281da64
1 changed files with 24 additions and 96 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

120
lib/libthr/thread/thr_rwlock.c
View File

@ -42,26 +42,18 @@
*/
enum rwlock_type {RWT_READ, RWT_WRITE};
/* hack to accomodate libc */
/* Support for staticaly initialized mutexes. */
static struct umtx init_lock = UMTX_INITIALIZER;
/*
* Single underscore versions are for libc useage. So, use double
* underscores for applications.
*/
__weak_reference(__pthread_rwlock_rdlock, pthread_rwlock_rdlock);
__weak_reference(__pthread_rwlock_timedrdlock, pthread_rwlock_timedrdlock);
__weak_reference(__pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock);
__weak_reference(__pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
__weak_reference(__pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
__weak_reference(__pthread_rwlock_wrlock, pthread_rwlock_wrlock);
/*
* No difference between libc and application usage.
*/
__weak_reference(_pthread_rwlock_destroy, pthread_rwlock_destroy);
__weak_reference(_pthread_rwlock_init, pthread_rwlock_init);
__weak_reference(_pthread_rwlock_rdlock, pthread_rwlock_rdlock);
__weak_reference(_pthread_rwlock_timedrdlock, pthread_rwlock_timedrdlock);
__weak_reference(_pthread_rwlock_timedwrlock, pthread_rwlock_timedwrlock);
__weak_reference(_pthread_rwlock_tryrdlock, pthread_rwlock_tryrdlock);
__weak_reference(_pthread_rwlock_trywrlock, pthread_rwlock_trywrlock);
__weak_reference(_pthread_rwlock_unlock, pthread_rwlock_unlock);
__weak_reference(_pthread_rwlock_wrlock, pthread_rwlock_wrlock);
static int insert_rwlock(struct pthread_rwlock *, enum rwlock_type);
static int rwlock_init_static(struct pthread_rwlock **rwlock);
@ -149,7 +141,7 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking,
int ret;
rh = NULL;
if (rwlock == NULL || *rwlock == NULL)
if (rwlock == NULL)
return(EINVAL);
/*
@ -159,6 +151,8 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking,
(timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000))
return (EINVAL);
if ((ret = rwlock_init_static(rwlock)) !=0 )
return (ret);
prwlock = *rwlock;
/* grab the monitor lock */
@ -223,57 +217,23 @@ rwlock_rdlock_common(pthread_rwlock_t *rwlock, int nonblocking,
return(0);
}
int
__pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
{
return (rwlock_rdlock_common(rwlock, 0, NULL));
}
int
_pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
error = rwlock_rdlock_common(rwlock, 0, NULL);
return (error);
}
int
__pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock,
const struct timespec *timeout)
{
return (rwlock_rdlock_common(rwlock, 0, timeout));
return (rwlock_rdlock_common(rwlock, 0, NULL));
}
int
_pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock,
const struct timespec *timeout)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
rwlock_rdlock_common(rwlock, 0, timeout);
return (error);
}
int
__pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
{
return (rwlock_rdlock_common(rwlock, 1, NULL));
return (rwlock_rdlock_common(rwlock, 0, timeout));
}
int
_pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
rwlock_rdlock_common(rwlock, 1, NULL);
return (error);
return (rwlock_rdlock_common(rwlock, 1, NULL));
}
int
@ -338,57 +298,23 @@ _pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
return(ret);
}
int
__pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
{
return (rwlock_wrlock_common(rwlock, 0, NULL));
}
int
_pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
error = rwlock_wrlock_common(rwlock, 0, NULL);
return (error);
}
int
__pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
const struct timespec *timeout)
{
return (rwlock_wrlock_common(rwlock, 0, timeout));
return (rwlock_wrlock_common(rwlock, 0, NULL));
}
int
_pthread_rwlock_timedwrlock (pthread_rwlock_t *rwlock,
const struct timespec *timeout)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
rwlock_wrlock_common(rwlock, 0, timeout);
return (error);
}
int
__pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
{
return (rwlock_wrlock_common(rwlock, 1, NULL));
return (rwlock_wrlock_common(rwlock, 0, timeout));
}
int
_pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
{
int error;
error = rwlock_init_static(rwlock);
if (error == 0)
rwlock_wrlock_common(rwlock, 1, NULL);
return (error);
return (rwlock_wrlock_common(rwlock, 1, NULL));
}
/*
@ -404,7 +330,7 @@ rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking,
int ret;
rh = NULL;
if (rwlock == NULL || *rwlock == NULL)
if (rwlock == NULL)
return(EINVAL);
/*
@ -414,6 +340,8 @@ rwlock_wrlock_common(pthread_rwlock_t *rwlock, int nonblocking,
(timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000))
return (EINVAL);
if ((ret = rwlock_init_static(rwlock)) !=0 )
return (ret);
prwlock = *rwlock;
/* grab the monitor lock */
@ -522,12 +450,12 @@ insert_rwlock(struct pthread_rwlock *prwlock, enum rwlock_type rwt)
}
/*
* libc version.
* There are several users of rwlocks in libc that depend on
* a bogus PTHREAD_RWLOCK_INITIALIZER to do for rwlocks that
* There are consumers of rwlocks, inluding our own libc, that depend on
* a PTHREAD_RWLOCK_INITIALIZER to do for rwlocks what
* a similarly named symbol does for statically initialized mutexes.
* However, this symbol does not seem to be a valid POSIX symbol. Rather
* than fix libc, I choose to "fix" libthr.
* This symbol was dropped in The Open Group Base Specifications Issue 6
* and does not exist in IEEE Std 1003.1, 2003, but it should still be
* supported for backwards compatibility.
*/
static int
rwlock_init_static(struct pthread_rwlock **rwlock)