On 01/08/2014 01:23 PM, Kim De Mey wrote:
2014/1/8 Philippe Gerum <r...@xenomai.org>:
On 01/08/2014 10:25 AM, Kim De Mey wrote:
Here are the backtraces:
main thread:
(gdb) bt
#0 clock_nanosleep (clock_id=<optimized out>, flags=<optimized out>,
req=<optimized out>, rem=<optimized out>)
at ../sysdeps/unix/sysv/linux/clock_nanosleep.c:51
#1 0x00b45e10 in threadobj_sleep () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#2 0x00b2b618 in tm_wkafter () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libpsos.so.0
#3 0x10000b3c in main (argc=1, argv=0x104120e0) at suspend_delete_easy.c:42
first psos task:
(gdb) bt
#0 0x00b6b5c8 in __old_sem_wait (sem=<optimized out>) at
../nptl/sysdeps/unix/sysv/linux/sem_wait.c:105
#1 0x00b45c84 in threadobj_cancel () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#2 0x00b2ac44 in t_delete () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libpsos.so.0
#3 0x10000a70 in test (a=0, b=0, c=0, d=0) at suspend_delete_easy.c:22
#4 0x00b2a658 in task_trampoline () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libpsos.so.0
#5 0x00b63824 in start_thread (arg=<optimized out>) at pthread_create.c:299
#6 0x00c7df4c in __thread_start () from
output/host/usr/mips64-buildroot-linux-gnu/sysroot/lib32/libc.so.6
second psos task:
(gdb) bt
#0 0x00b6cbbc in read () from
output/host/usr/mips64-buildroot-linux-gnu/sysroot/lib32/libpthread.so.0
#1 0x00b47bd8 in notifier_wait () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#2 0x00b460b0 in notifier_callback () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#3 0x00b47d30 in notifier_sighandler () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#4 <signal handler called>
#5 sigcancel_handler (sig=32, si=0x1e03aa8, ctx=0x1e03b28) at init.c:136
#6 <signal handler called>
#7 clock_nanosleep (clock_id=<optimized out>, flags=<optimized out>,
req=<optimized out>, rem=<optimized out>)
at ../sysdeps/unix/sysv/linux/clock_nanosleep.c:51
#8 0x00b45e10 in threadobj_sleep () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libcopperplate.so.0
#9 0x00b2b618 in tm_wkafter () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libpsos.so.0
#10 0x100009bc in idle_task (a=0, b=0, c=0, d=0) at suspend_delete_easy.c:9
#11 0x00b2a658 in task_trampoline () from
/repo/kdemey/buildroot/output/host/usr/mips64-buildroot-linux-gnu/sysroot/usr/lib/libpsos.so.0
#12 0x00b63824 in start_thread (arg=<optimized out>) at pthread_create.c:299
#13 0x00c7df4c in __thread_start () from
output/host/usr/mips64-buildroot-linux-gnu/sysroot/lib32/libc.so.6
Invocation command line was
$ ./configure --target=mips64-buildroot-linux-gnu
--host=mips64-buildroot-linux-gnu --build=x86_64-unknown-linux-gnu
--prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --program-prefix=
--disable-gtk-doc --disable-doc --disable-docs --disable-documentation
--with-xmlto=no --with-fop=no --enable-ipv6 --enable-static
--enable-shared --with-core=mercury
--includedir=/usr/include/xenomai-forge --disable-doc-install
--enable-lores-clock
Is this what you were asking?
Yes, thanks.
By the way, I forgot the mention the following test that I did:
When the application is blocked I've done an "echo 1 > /proc/pid/fd/xx",
where xx is the file descriptor that is being read from in the notifier_wait().
This kinda emulates a t_resume.
After doing this the t_delete gets finalized and the application unblocks.
This should fix the race, until the notifier is reworked.
diff --git a/include/copperplate/threadobj.h b/include/copperplate/threadobj.h
index 184c711..218c274 100644
--- a/include/copperplate/threadobj.h
+++ b/include/copperplate/threadobj.h
@@ -124,6 +124,7 @@ void threadobj_save_timeout(struct threadobj_corespec
*corespec,
#define __THREAD_S_ACTIVE (1 << 5) /* Running user code. */
#define __THREAD_S_SUSPENDED (1 << 6) /* Suspended via
threadobj_suspend(). */
#define __THREAD_S_SAFE (1 << 7) /* TCB release
deferred. */
+#define __THREAD_S_ZOMBIE (1 << 8) /* Deletion process ongoing. */
#define __THREAD_S_DEBUG (1 << 31) /* Debug mode enabled. */
/*
* threadobj->run_state, locklessly updated by "current", merged
diff --git a/lib/copperplate/threadobj.c b/lib/copperplate/threadobj.c
index a31479c..c54cdf8 100644
--- a/lib/copperplate/threadobj.c
+++ b/lib/copperplate/threadobj.c
@@ -420,11 +420,13 @@ static void notifier_callback(const struct notifier *nf)
* threadobj_suspend().
*/
threadobj_lock(current);
- current->status |= __THREAD_S_SUSPENDED;
- threadobj_unlock(current);
- notifier_wait(nf); /* Wait for threadobj_resume(). */
- threadobj_lock(current);
- current->status &= ~__THREAD_S_SUSPENDED;
+ if ((current->status & __THREAD_S_ZOMBIE) == 0) {
+ current->status |= __THREAD_S_SUSPENDED;
+ threadobj_unlock(current);
+ notifier_wait(nf); /* Wait for threadobj_resume(). */
+ threadobj_lock(current);
+ current->status &= ~__THREAD_S_SUSPENDED;
+ }
threadobj_unlock(current);
}
@@ -488,7 +490,7 @@ static inline void threadobj_run_corespec(struct threadobj
*thobj)
{
}
-static inline void threadobj_cancel_corespec(struct threadobj *thobj)
+static inline void threadobj_cancel_corespec(struct threadobj *thobj) /*
thobj->lock held */
{
}
@@ -872,9 +874,9 @@ void threadobj_init(struct threadobj *thobj,
static void destroy_thread(struct threadobj *thobj)
{
+ threadobj_cleanup_corespec(thobj);
__RT(pthread_cond_destroy(&thobj->barrier));
__RT(pthread_mutex_destroy(&thobj->lock));
- threadobj_cleanup_corespec(thobj);
}
void threadobj_destroy(struct threadobj *thobj) /* thobj->lock free */
@@ -1089,8 +1091,6 @@ static void cancel_sync(struct threadobj *thobj) /*
thobj->lock held */
int oldstate, ret = 0;
sem_t *sem;
- __threadobj_check_locked(thobj);
-
/*
* We have to allocate the cancel sync sema4 in the main heap
* dynamically, so that it always live in valid memory when we
@@ -1106,6 +1106,7 @@ static void cancel_sync(struct threadobj *thobj) /*
thobj->lock held */
__STD(sem_init(sem, sem_scope_attribute, 0));
thobj->cancel_sem = sem;
+ thobj->status |= __THREAD_S_ZOMBIE;
/*
* If the thread to delete is warming up, wait until it
--
Philippe.
