add basic backup support to block driver

[qemu.git] / main-loop.c

diff --git a/main-loop.c b/main-loop.c
index e43c7c8e8d4355794540063da0f6be92c73e8bdc..6f52ac39bc7f6bfede652230bbad4a80ce44b6c5 100644 (file)
--- a/main-loop.c
+++ b/main-loop.c
@@ -23,14 +23,14 @@
  */
 
 #include "qemu-common.h"
-#include "qemu-timer.h"
+#include "qemu/timer.h"
 #include "slirp/slirp.h"
-#include "main-loop.h"
-#include "qemu-aio.h"
+#include "qemu/main-loop.h"
+#include "block/aio.h"
 
 #ifndef _WIN32
 
-#include "compatfd.h"
+#include "qemu/compatfd.h"
 
 /* If we have signalfd, we mask out the signals we want to handle and then
  * use signalfd to listen for them.  We rely on whatever the current signal
@@ -123,9 +123,11 @@ int qemu_init_main_loop(void)
     GSource *src;
 
     init_clocks();
-    init_timer_alarm();
+    if (init_timer_alarm() < 0) {
+        fprintf(stderr, "could not initialize alarm timer\n");
+        exit(1);
+    }
 
-    qemu_mutex_lock_iothread();
     ret = qemu_signal_init();
     if (ret) {
         return ret;
@@ -328,7 +330,7 @@ void qemu_fd_register(int fd)
 static int os_host_main_loop_wait(uint32_t timeout)
 {
     GMainContext *context = g_main_context_default();
-    int ret, i;
+    int select_ret, g_poll_ret, ret, i;
     PollingEntry *pe;
     WaitObjects *w = &wait_objects;
     gint poll_timeout;
@@ -343,13 +345,6 @@ static int os_host_main_loop_wait(uint32_t timeout)
         return ret;
     }
 
-    if (nfds >= 0) {
-        ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
-        if (ret != 0) {
-            timeout = 0;
-        }
-    }
-
     g_main_context_prepare(context, &max_priority);
     n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
                                       poll_fds, ARRAY_SIZE(poll_fds));
@@ -365,9 +360,9 @@ static int os_host_main_loop_wait(uint32_t timeout)
     }
 
     qemu_mutex_unlock_iothread();
-    ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout);
+    g_poll_ret = g_poll(poll_fds, n_poll_fds + w->num, poll_timeout);
     qemu_mutex_lock_iothread();
-    if (ret > 0) {
+    if (g_poll_ret > 0) {
         for (i = 0; i < w->num; i++) {
             w->revents[i] = poll_fds[n_poll_fds + i].revents;
         }
@@ -382,12 +377,18 @@ static int os_host_main_loop_wait(uint32_t timeout)
         g_main_context_dispatch(context);
     }
 
-    /* If an edge-triggered socket event occurred, select will return a
-     * positive result on the next iteration.  We do not need to do anything
-     * here.
+    /* Call select after g_poll to avoid a useless iteration and therefore
+     * improve socket latency.
      */
 
-    return ret;
+    if (nfds >= 0) {
+        select_ret = select(nfds + 1, &rfds, &wfds, &xfds, &tv0);
+        if (select_ret != 0) {
+            timeout = 0;
+        }
+    }
+
+    return select_ret || g_poll_ret;
 }
 #endif
 
@@ -430,11 +431,6 @@ QEMUBH *qemu_bh_new(QEMUBHFunc *cb, void *opaque)
     return aio_bh_new(qemu_aio_context, cb, opaque);
 }
 
-void qemu_aio_flush(void)
-{
-    aio_flush(qemu_aio_context);
-}
-
 bool qemu_aio_wait(void)
 {
     return aio_poll(qemu_aio_context, true);