[Qemu-devel] [PATCH 2/6] Introduce qemu_cond_timedwait

[Jan Kiszka]

First user will be posix compat aio.

Signed-off-by: Jan Kiszka <address@hidden>
---
 qemu-thread-posix.c |   22 ++++++++++++++++++++++
 qemu-thread-win32.c |   16 +++++++++++++++-
 qemu-thread.h       |    2 ++
 3 files changed, 39 insertions(+), 1 deletions(-)

diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c
index f76427e..1d970fb 100644
--- a/qemu-thread-posix.c
+++ b/qemu-thread-posix.c
@@ -17,6 +17,7 @@
 #include <signal.h>
 #include <stdint.h>
 #include <string.h>
+#include <sys/time.h>
 #include "qemu-thread.h"
 
 static void error_exit(int err, const char *msg)
@@ -115,6 +116,27 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
         error_exit(err, __func__);
 }
 
+int qemu_cond_timedwait(QemuCond *cond, QemuMutex *mutex,
+                        unsigned int timeout_ms)
+{
+    struct timespec ts;
+    struct timeval tv;
+    int err;
+
+    gettimeofday(&tv, NULL);
+    ts.tv_sec = tv.tv_sec + timeout_ms / 1000;
+    ts.tv_nsec = tv.tv_usec * 1000 + timeout_ms % 1000;
+    if (ts.tv_nsec > 1000000000) {
+        ts.tv_sec++;
+        ts.tv_nsec -= 1000000000;
+    }
+    err = pthread_cond_timedwait(&cond->cond, &mutex->lock, &ts);
+    if (err && err != ETIMEDOUT) {
+        error_exit(err, __func__);
+    }
+    return err == 0;
+}
+
 void qemu_thread_create(QemuThread *thread,
                        void *(*start_routine)(void*),
                        void *arg, int mode)
diff --git a/qemu-thread-win32.c b/qemu-thread-win32.c
index 4819ff4..1b01a8b 100644
--- a/qemu-thread-win32.c
+++ b/qemu-thread-win32.c
@@ -158,6 +158,14 @@ void qemu_cond_broadcast(QemuCond *cond)
 
 void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
 {
+    qemu_cond_timedwait(cond, mutex, INFINITE);
+}
+
+int qemu_cond_timedwait(QemuCond *cond, QemuMutex *mutex,
+                        unsigned int timeout_ms)
+{
+    DWORD result;
+
     /*
      * This access is protected under the mutex.
      */
@@ -170,7 +178,11 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
      * leaving mutex unlocked before we wait on semaphore.
      */
     qemu_mutex_unlock(mutex);
-    WaitForSingleObject(cond->sema, INFINITE);
+    result = WaitForSingleObject(cond->sema, timeout_ms);
+
+    if (result != WAIT_OBJECT_0 && result != WAIT_TIMEOUT) {
+        error_exit(GetLastError(), __func__);
+    }
 
     /* Now waiters must rendez-vous with the signaling thread and
      * let it continue.  For cond_broadcast this has heavy contention
@@ -190,6 +202,8 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
     }
 
     qemu_mutex_lock(mutex);
+
+    return result == WAIT_OBJECT_0;
 }
 
 struct QemuThreadData {
diff --git a/qemu-thread.h b/qemu-thread.h
index aa1ae55..8be48e4 100644
--- a/qemu-thread.h
+++ b/qemu-thread.h
@@ -33,6 +33,8 @@ void qemu_cond_destroy(QemuCond *cond);
 void qemu_cond_signal(QemuCond *cond);
 void qemu_cond_broadcast(QemuCond *cond);
 void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex);
+int qemu_cond_timedwait(QemuCond *cond, QemuMutex *mutex,
+                        unsigned int timeout_ms);
 
 void qemu_thread_create(QemuThread *thread,
                         void *(*start_routine)(void *),
-- 
1.7.3.4