fix live migration

[qemu.git] / qemu-thread-posix.c

diff --git a/qemu-thread-posix.c b/qemu-thread-posix.c
index ac3c0c9d14b81024b470a2f6ee4af14fbbcc2c1a..4ef9c7b3f83469c87d09b66751ceb2e67e7877e1 100644 (file)
--- a/qemu-thread-posix.c
+++ b/qemu-thread-posix.c
@@ -17,6 +17,9 @@
 #include <signal.h>
 #include <stdint.h>
 #include <string.h>
+#include <limits.h>
+#include <unistd.h>
+#include <sys/time.h>
 #include "qemu-thread.h"
 
 static void error_exit(int err, const char *msg)
@@ -115,22 +118,184 @@ void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
         error_exit(err, __func__);
 }
 
+void qemu_sem_init(QemuSemaphore *sem, int init)
+{
+    int rc;
+
+#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
+    rc = pthread_mutex_init(&sem->lock, NULL);
+    if (rc != 0) {
+        error_exit(rc, __func__);
+    }
+    rc = pthread_cond_init(&sem->cond, NULL);
+    if (rc != 0) {
+        error_exit(rc, __func__);
+    }
+    if (init < 0) {
+        error_exit(EINVAL, __func__);
+    }
+    sem->count = init;
+#else
+    rc = sem_init(&sem->sem, 0, init);
+    if (rc < 0) {
+        error_exit(errno, __func__);
+    }
+#endif
+}
+
+void qemu_sem_destroy(QemuSemaphore *sem)
+{
+    int rc;
+
+#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
+    rc = pthread_cond_destroy(&sem->cond);
+    if (rc < 0) {
+        error_exit(rc, __func__);
+    }
+    rc = pthread_mutex_destroy(&sem->lock);
+    if (rc < 0) {
+        error_exit(rc, __func__);
+    }
+#else
+    rc = sem_destroy(&sem->sem);
+    if (rc < 0) {
+        error_exit(errno, __func__);
+    }
+#endif
+}
+
+void qemu_sem_post(QemuSemaphore *sem)
+{
+    int rc;
+
+#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
+    pthread_mutex_lock(&sem->lock);
+    if (sem->count == INT_MAX) {
+        rc = EINVAL;
+    } else if (sem->count++ < 0) {
+        rc = pthread_cond_signal(&sem->cond);
+    } else {
+        rc = 0;
+    }
+    pthread_mutex_unlock(&sem->lock);
+    if (rc != 0) {
+        error_exit(rc, __func__);
+    }
+#else
+    rc = sem_post(&sem->sem);
+    if (rc < 0) {
+        error_exit(errno, __func__);
+    }
+#endif
+}
+
+static void compute_abs_deadline(struct timespec *ts, int ms)
+{
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    ts->tv_nsec = tv.tv_usec * 1000 + (ms % 1000) * 1000000;
+    ts->tv_sec = tv.tv_sec + ms / 1000;
+    if (ts->tv_nsec >= 1000000000) {
+        ts->tv_sec++;
+        ts->tv_nsec -= 1000000000;
+    }
+}
+
+int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
+{
+    int rc;
+    struct timespec ts;
+
+#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
+    compute_abs_deadline(&ts, ms);
+    pthread_mutex_lock(&sem->lock);
+    --sem->count;
+    while (sem->count < 0) {
+        rc = pthread_cond_timedwait(&sem->cond, &sem->lock, &ts);
+        if (rc == ETIMEDOUT) {
+            break;
+        }
+        if (rc != 0) {
+            error_exit(rc, __func__);
+        }
+    }
+    pthread_mutex_unlock(&sem->lock);
+    return (rc == ETIMEDOUT ? -1 : 0);
+#else
+    if (ms <= 0) {
+        /* This is cheaper than sem_timedwait.  */
+        do {
+            rc = sem_trywait(&sem->sem);
+        } while (rc == -1 && errno == EINTR);
+        if (rc == -1 && errno == EAGAIN) {
+            return -1;
+        }
+    } else {
+        compute_abs_deadline(&ts, ms);
+        do {
+            rc = sem_timedwait(&sem->sem, &ts);
+        } while (rc == -1 && errno == EINTR);
+        if (rc == -1 && errno == ETIMEDOUT) {
+            return -1;
+        }
+    }
+    if (rc < 0) {
+        error_exit(errno, __func__);
+    }
+    return 0;
+#endif
+}
+
+void qemu_sem_wait(QemuSemaphore *sem)
+{
+#if defined(__OpenBSD__) || defined(__APPLE__) || defined(__NetBSD__)
+    pthread_mutex_lock(&sem->lock);
+    --sem->count;
+    while (sem->count < 0) {
+        pthread_cond_wait(&sem->cond, &sem->lock);
+    }
+    pthread_mutex_unlock(&sem->lock);
+#else
+    int rc;
+
+    do {
+        rc = sem_wait(&sem->sem);
+    } while (rc == -1 && errno == EINTR);
+    if (rc < 0) {
+        error_exit(errno, __func__);
+    }
+#endif
+}
+
 void qemu_thread_create(QemuThread *thread,
                        void *(*start_routine)(void*),
-                       void *arg)
+                       void *arg, int mode)
 {
+    sigset_t set, oldset;
     int err;
+    pthread_attr_t attr;
 
-    /* Leave signal handling to the iothread.  */
-    sigset_t set, oldset;
+    err = pthread_attr_init(&attr);
+    if (err) {
+        error_exit(err, __func__);
+    }
+    if (mode == QEMU_THREAD_DETACHED) {
+        err = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+        if (err) {
+            error_exit(err, __func__);
+        }
+    }
 
+    /* Leave signal handling to the iothread.  */
     sigfillset(&set);
     pthread_sigmask(SIG_SETMASK, &set, &oldset);
-    err = pthread_create(&thread->thread, NULL, start_routine, arg);
+    err = pthread_create(&thread->thread, &attr, start_routine, arg);
     if (err)
         error_exit(err, __func__);
 
     pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+
+    pthread_attr_destroy(&attr);
 }
 
 void qemu_thread_get_self(QemuThread *thread)
@@ -138,7 +303,7 @@ void qemu_thread_get_self(QemuThread *thread)
     thread->thread = pthread_self();
 }
 
-int qemu_thread_is_self(QemuThread *thread)
+bool qemu_thread_is_self(QemuThread *thread)
 {
    return pthread_equal(pthread_self(), thread->thread);
 }
@@ -147,3 +312,15 @@ void qemu_thread_exit(void *retval)
 {
     pthread_exit(retval);
 }
+
+void *qemu_thread_join(QemuThread *thread)
+{
+    int err;
+    void *ret;
+
+    err = pthread_join(thread->thread, &ret);
+    if (err) {
+        error_exit(err, __func__);
+    }
+    return ret;
+}