Module: xenomai-2.6
Branch: master
Commit: 8047147aff9dee9529f5561ecd7afc29c48d14db
URL:
http://git.xenomai.org/?p=xenomai-2.6.git;a=commit;h=8047147aff9dee9529f5561ecd7afc29c48d14db
Author: Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org>
Date: Thu Jun 16 12:40:59 2016 +0200
posix/mutex: handle recursion count completely in user-space
This fixes recursive pthread_mutex*lock with XNOTHER threads
---
src/skins/posix/mutex.c | 87 ++++++++++++++++++++++-------------------------
1 file changed, 40 insertions(+), 47 deletions(-)
diff --git a/src/skins/posix/mutex.c b/src/skins/posix/mutex.c
index 0323fe0..c3d1f3d 100644
--- a/src/skins/posix/mutex.c
+++ b/src/skins/posix/mutex.c
@@ -167,17 +167,20 @@ int __wrap_pthread_mutex_lock(pthread_mutex_t *mutex)
/*
* We track resource ownership for non real-time shadows in
* order to handle the auto-relax feature, so we must always
- * obtain them via a syscall.
+ * obtain them via a syscall. This is not necessary if the mutex
+ * is recursive and we already own it though.
*/
status = xeno_get_current_mode();
- if (unlikely(status & (XNRELAX|XNOTHER)))
- goto do_syscall;
-
- err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
- if (likely(!err)) {
- shadow->lockcnt = 1;
- cb_read_unlock(&shadow->lock, s);
- return 0;
+ if ((status & (XNRELAX|XNOTHER)) == 0) {
+ err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
+ if (likely(!err)) {
+ shadow->lockcnt = 1;
+ goto out;
+ }
+ } else {
+ err = xnsynch_fast_owner_check(get_ownerp(shadow), cur);
+ if (err == 0)
+ err = -EBUSY;
}
if (err == -EBUSY)
@@ -239,14 +242,16 @@ int __wrap_pthread_mutex_timedlock(pthread_mutex_t *mutex,
/* See __wrap_pthread_mutex_lock() */
status = xeno_get_current_mode();
- if (unlikely(status & (XNRELAX|XNOTHER)))
- goto do_syscall;
-
- err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
- if (likely(!err)) {
- shadow->lockcnt = 1;
- cb_read_unlock(&shadow->lock, s);
- return 0;
+ if ((status & (XNRELAX|XNOTHER)) == 0) {
+ err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
+ if (likely(!err)) {
+ shadow->lockcnt = 1;
+ goto out;
+ }
+ } else {
+ err = xnsynch_fast_owner_check(get_ownerp(shadow), cur);
+ if (err == 0)
+ err = -EBUSY;
}
if (err == -EBUSY)
@@ -310,25 +315,18 @@ int __wrap_pthread_mutex_trylock(pthread_mutex_t *mutex)
}
status = xeno_get_current_mode();
- if (unlikely(status & XNOTHER))
- goto do_syscall;
-
- if (unlikely(status & XNRELAX)) {
- do {
- err = XENOMAI_SYSCALL1(__xn_sys_migrate,
- XENOMAI_XENO_DOMAIN);
- } while (err == -EINTR);
-
- if (err < 0)
+ if ((status & (XNRELAX|XNOTHER)) == 0) {
+ err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
+ if (likely(!err)) {
+ shadow->lockcnt = 1;
goto out;
- }
-
- err = xnsynch_fast_acquire(get_ownerp(shadow), cur);
+ }
+ } else {
+ err = xnsynch_fast_owner_check(get_ownerp(shadow), cur);
+ if (err < 0)
+ goto do_syscall;
- if (likely(!err)) {
- shadow->lockcnt = 1;
- cb_read_unlock(&shadow->lock, s);
- return 0;
+ err = -EBUSY;
}
if (err == -EBUSY && shadow->attr.type == PTHREAD_MUTEX_RECURSIVE) {
@@ -376,7 +374,6 @@ int __wrap_pthread_mutex_unlock(pthread_mutex_t *mutex)
#ifdef CONFIG_XENO_FASTSYNCH
xnarch_atomic_t *ownerp;
- unsigned long status;
xnhandle_t cur;
cur = xeno_get_current();
@@ -388,29 +385,25 @@ int __wrap_pthread_mutex_unlock(pthread_mutex_t *mutex)
if (unlikely(shadow->magic != PSE51_MUTEX_MAGIC)) {
err = -EINVAL;
- goto out_err;
+ goto out;
}
- status = xeno_get_current_mode();
- if (unlikely(status & XNOTHER))
- goto do_syscall;
-
ownerp = get_ownerp(shadow);
err = xnsynch_fast_owner_check(ownerp, cur);
if (unlikely(err))
- goto out_err;
+ goto out;
if (shadow->lockcnt > 1) {
--shadow->lockcnt;
goto out;
}
- if (likely(xnsynch_fast_release(ownerp, cur))) {
- out:
- cb_read_unlock(&shadow->lock, s);
- return 0;
- }
+ if (unlikely(xeno_get_current_mode() & XNOTHER))
+ goto do_syscall;
+
+ if (likely(xnsynch_fast_release(ownerp, cur)))
+ goto out;
do_syscall:
#endif /* CONFIG_XENO_FASTSYNCH */
@@ -421,7 +414,7 @@ do_syscall:
} while (err == -EINTR);
#ifdef CONFIG_XENO_FASTSYNCH
- out_err:
+ out:
cb_read_unlock(&shadow->lock, s);
#endif /* CONFIG_XENO_FASTSYNCH */
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