If enabled, set the thread name at creation (on GNU systems with
  pthread_set_np)
Fix up all the callers with a thread name
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>

Add flag storage to qemu-thread-* to store the namethreads flag
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>

This emulates Win32 manual-reset events using futexes or conditional
variables.  Typical ways to use them are with multi-producer,
single-consumer data structures, to test for a complex condition whose
elements come from different threads:

    for (;;) {
        qemu_event_reset(ev);
        ... test complex condition ...
        if (condition is true) {
            break;
        }
        qemu_event_wait(ev);
    }

Or more efficiently (but with some duplication):

    ... evaluate condition ...
    while (!condition) {
        qemu_event_reset(ev);
        ... evaluate condition ...
        if (!condition) {
            qemu_event_wait(ev);
            ... evaluate condition ...
        }
    }

QemuEvent provides a very fast userspace path in the common case when
no other thread is waiting, or the event is not changing state.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Fix following bugs in "fallback implementation of counting semaphores
with mutex+condvar" added in c166cb72:
 - waiting threads are not restarted properly if more than one threads
   are waiting unblock signals in qemu_sem_timedwait()
 - possible missing pthread_cond_signal(3) calls when waiting threads
   are returned by ETIMEDOUT
 - fix an uninitialized variable
The problem is analyzed by and fix is provided by Noriyuki Soda.

Also put additional cleanup suggested by Laszlo Ersek:
 - make QemuSemaphore.count unsigned (it won't be negative)
 - check a return value of in pthread_cond_wait() in qemu_sem_wait()
Signed-off-by: NIzumi Tsutsui <tsutsui@ceres.dti.ne.jp>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>
Message-id: 1372841894-10634-1-git-send-email-tsutsui@ceres.dti.ne.jp
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

As reported in bug 1087114 the semaphores fallback code is broken which
results in QEMU crashing and making QEMU unusable.

This patch is from Paolo.

This needs to be back ported to the 1.3 stable tree as well.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBrad Smith <brad@comstyle.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Disable the semaphores fallback code for OpenBSD as modern OpenBSD
releases now have sem_timedwait().
Signed-off-by: NBrad Smith <brad@comstyle.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

OpenBSD and Darwin do not have sem_timedwait.  Implement a fallback
for them.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The new thread pool will use semaphores instead of condition
variables, because QemuCond does not have qemu_cond_timedwait.
(I also like it more this way).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

qemu_cpu_is_self(), passing the return value through, will later be
adapted to return bool as well.
Signed-off-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NStefan Weil <sw@weilnetz.de>

Allow to control if a QEMU thread is created joinable or not. Make it
not joinable by default to avoid that we keep the associated resources
around when terminating a thread without joining it (what we couldn't do
so far for obvious reasons).

The audio subsystem will need the join feature when converting it to
QEMU threading/locking abstractions, so provide that service.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Split from Jan's original qemu-thread-posix.c patch.  No semantic change,
just introduce the new API that POSIX and Win32 implementations will
conform to.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Makes it easier to catch the bug in gdb as there is no need to set an
explicit breakpoint.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

qemu_mutex_timedlock() and qemu_cond_timedwait() are no longer used.

Remove them and their helper timespec_add_ms().
Reported-by: NFrançois Revol <revol@free.fr>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

These are already present in the Win32 implementation, add them to
the pthread wrappers as well.  Use PTHREAD_MUTEX_ERRORCHECK for mutex
operations. Later we'll add tracking of the owner for cond_signal/broadcast.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

For now, qemu_cond_timedwait and qemu_mutex_timedlock are left as
POSIX-only functions.  They can be removed later, once the patches
that remove their uses are in.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

We have qemu_cpu_self and qemu_thread_self. The latter is retrieving the
current thread, the former is checking for equality (using CPUState). We
also have qemu_thread_equal which is only used like qemu_cpu_self.

This refactors the interfaces, creating qemu_cpu_is_self and
qemu_thread_is_self as well ass qemu_thread_get_self.
Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Add some missing functions in qemu-thread. Currently qemu-thread
is only used for io-thread but it will used by the vnc server soon
and we need those functions instead of calling pthread directly.
Signed-off-by: NCorentin Chary <corentincj@iksaif.net>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

All signals will thus be routed through the IO thread.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Fixes

qemu-thread.c: In function `qemu_thread_equal':
qemu-thread.c:161: error: invalid operands to binary ==

Use of pthread_equal suggested by Filip Navara.
Signed-off-by: NSebastian Herbszt <herbszt@gmx.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@7237 c046a42c-6fe2-441c-8c8c-71466251a162