diff options
| author | Michael Sevakis <jethead71@rockbox.org> | 2007-10-21 19:10:03 +0000 |
|---|---|---|
| committer | Michael Sevakis <jethead71@rockbox.org> | 2007-10-21 19:10:03 +0000 |
| commit | 6fac8fcc93fa1fc8a6f288f57258f1c8443cf9db (patch) | |
| tree | 2644e1ca78bec0c345d790d23c1c93ebcd709558 | |
| parent | d4f382252d01102d997281a1f2cb58ffd6b33f97 (diff) | |
Be sure to register a new mutex owner _before_ waking it. Won't be an issue now but would be with mutex recursion on one used for > 1 core where ownership transfer and cs entry/recursion are allowed to run in parallel (by design). TODO: Add true exchange to wakeup_thread but that's not really important for the time being.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15251 a1c6a512-1295-4272-9138-f99709370657
| -rw-r--r-- | firmware/kernel.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/firmware/kernel.c b/firmware/kernel.c index 4e56c2919a..006a06dfe0 100644 --- a/firmware/kernel.c +++ b/firmware/kernel.c @@ -1076,7 +1076,13 @@ void mutex_unlock(struct mutex *m) #endif /* transfer to next queued thread if any */ - m->thread = wakeup_thread_no_listlock(&m->queue); + + /* This can become busy using SWP but is safe since only one thread + will be changing things at a time. Allowing timeout waits will + change that however but not now. There is also a hazard the thread + could be killed before performing the wakeup but that's just + irresponsible. :-) */ + m->thread = m->queue; if(m->thread == NULL) { @@ -1087,6 +1093,7 @@ void mutex_unlock(struct mutex *m) } else /* another thread is waiting - remain locked */ { + wakeup_thread_no_listlock(&m->queue); #if CONFIG_CORELOCK == SW_CORELOCK corelock_unlock(&m->cl); #elif CONFIG_CORELOCK == CORELOCK_SWAP |