Message ID | 1275118686-15649-3-git-send-email-corentincj@iksaif.net |
---|---|
State | New |
Headers | show |
> From pthread man: > > These functions manipulate the calling thread's stack of > thread-cancellation clean-up handlers. A clean-up handler is > a function that is automatically executed when a thread is canceled > [...] it might, for example, unlock a mutex so that it becomes > available to other threads in the process. Do we really need to use thread cancellation? It's one of those features that makes me extremely nervous. Especially in C code where people generally aren't expecting exceptions to be thrown. Paul
On 05/29/2010 09:38 AM, Corentin Chary wrote: > Signed-off-by: Corentin Chary<corentincj@iksaif.net> > --- > qemu-thread.h | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/qemu-thread.h b/qemu-thread.h > index 19bb30c..e5006bb 100644 > --- a/qemu-thread.h > +++ b/qemu-thread.h > @@ -41,4 +41,8 @@ void qemu_thread_self(QemuThread *thread); > int qemu_thread_equal(QemuThread *thread1, QemuThread *thread2); > void qemu_thread_exit(void *retval); > > +#define qemu_thread_cleanup_pop(execute) pthread_cleanup_pop(execute) > +#define qemu_thread_cleanup_push(routine, arg) \ > + pthread_cleanup_push(routine, arg) I agree with Paul that this isn't necessary. Also you're not using pthread_exit. Probably stale from a previous version of the patch? Paolo
On Thu, Jun 3, 2010 at 9:27 AM, Paolo Bonzini <pbonzini@redhat.com> wrote: > On 05/29/2010 09:38 AM, Corentin Chary wrote: >> >> Signed-off-by: Corentin Chary<corentincj@iksaif.net> >> --- >> qemu-thread.h | 4 ++++ >> 1 files changed, 4 insertions(+), 0 deletions(-) >> >> diff --git a/qemu-thread.h b/qemu-thread.h >> index 19bb30c..e5006bb 100644 >> --- a/qemu-thread.h >> +++ b/qemu-thread.h >> @@ -41,4 +41,8 @@ void qemu_thread_self(QemuThread *thread); >> int qemu_thread_equal(QemuThread *thread1, QemuThread *thread2); >> void qemu_thread_exit(void *retval); >> >> +#define qemu_thread_cleanup_pop(execute) pthread_cleanup_pop(execute) >> +#define qemu_thread_cleanup_push(routine, arg) \ >> + pthread_cleanup_push(routine, arg) > > I agree with Paul that this isn't necessary. Also you're not using > pthread_exit. Probably stale from a previous version of the patch? Right pthread_exit() is missing. Anyway, I don't use thread cancellation in the threaded vnc server (I send a signal to the condition with an empty queue to stop the thread), so we can skip this patch.
diff --git a/qemu-thread.h b/qemu-thread.h index 19bb30c..e5006bb 100644 --- a/qemu-thread.h +++ b/qemu-thread.h @@ -41,4 +41,8 @@ void qemu_thread_self(QemuThread *thread); int qemu_thread_equal(QemuThread *thread1, QemuThread *thread2); void qemu_thread_exit(void *retval); +#define qemu_thread_cleanup_pop(execute) pthread_cleanup_pop(execute) +#define qemu_thread_cleanup_push(routine, arg) \ + pthread_cleanup_push(routine, arg) + #endif
From pthread man: These functions manipulate the calling thread's stack of thread-cancellation clean-up handlers. A clean-up handler is a function that is automatically executed when a thread is canceled [...] it might, for example, unlock a mutex so that it becomes available to other threads in the process. These two functions are implemented using macros because there is no other way to do that (pthread man, again): On Linux, the pthread_cleanup_push() and pthread_cleanup_pop() functions are implemented as macros that expand to text containing '{' and '}', respectively. This means that variables declared within the scope of paired calls to these functions will only be visible within that scope. Signed-off-by: Corentin Chary <corentincj@iksaif.net> --- qemu-thread.h | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)