[Qemu-devel] [patch 05/14] qemu: factor out special event notification

[mtosatti@redhat.com]

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Special events that have no particular event descriptor (either fd for UNIX
or HANDLE for Windows) associated with make use of an artificial one.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: trunk/vl.c
===================================================================
--- trunk.orig/vl.c
+++ trunk/vl.c
@@ -921,15 +921,11 @@ static void qemu_rearm_alarm_timer(struc
 #define MIN_TIMER_REARM_US 250
 
 static struct qemu_alarm_timer *alarm_timer;
-#ifndef _WIN32
-static int alarm_timer_rfd, alarm_timer_wfd;
-#endif
 
 #ifdef _WIN32
 
 struct qemu_alarm_win32 {
     MMRESULT timerId;
-    HANDLE host_alarm;
     unsigned int period;
 } alarm_win32_data = {0, NULL, -1};
 
@@ -1343,10 +1339,6 @@ static void host_alarm_handler(int host_
                            qemu_get_clock(rt_clock))) {
         CPUState *env = next_cpu;
 
-#ifdef _WIN32
-        struct qemu_alarm_win32 *data = ((struct qemu_alarm_timer*)dwUser)->priv;
-        SetEvent(data->host_alarm);
-#endif
         alarm_timer->flags |= ALARM_FLAG_EXPIRED;
 
         if (env) {
@@ -1638,9 +1630,6 @@ static void unix_stop_timer(struct qemu_
 
 #ifdef _WIN32
 
-static void dummy_event_handler(void *opaque)
-{
-}
 
 static int win32_start_timer(struct qemu_alarm_timer *t)
 {
@@ -1648,12 +1637,6 @@ static int win32_start_timer(struct qemu
     struct qemu_alarm_win32 *data = t->priv;
     UINT flags;
 
-    data->host_alarm = CreateEvent(NULL, FALSE, FALSE, NULL);
-    if (!data->host_alarm) {
-        perror("Failed CreateEvent");
-        return -1;
-    }
-
     memset(&tc, 0, sizeof(tc));
     timeGetDevCaps(&tc, sizeof(tc));
 
@@ -1682,8 +1665,6 @@ static int win32_start_timer(struct qemu
         return -1;
     }
 
-    qemu_add_wait_object(data->host_alarm, dummy_event_handler, t);
-
     return 0;
 }
 
@@ -1733,25 +1714,6 @@ static int init_timer_alarm(void)
     struct qemu_alarm_timer *t = NULL;
     int i, err = -1;
 
-#ifndef _WIN32
-    int fds[2];
-
-    err = pipe(fds);
-    if (err == -1)
-        return -errno;
-
-    err = fcntl_setfl(fds[0], O_NONBLOCK);
-    if (err < 0)
-        goto fail;
-
-    err = fcntl_setfl(fds[1], O_NONBLOCK);
-    if (err < 0)
-        goto fail;
-
-    alarm_timer_rfd = fds[0];
-    alarm_timer_wfd = fds[1];
-#endif
-
     for (i = 0; alarm_timers[i].name; i++) {
         t = &alarm_timers[i];
 
@@ -1770,10 +1732,6 @@ static int init_timer_alarm(void)
     return 0;
 
 fail:
-#ifndef _WIN32
-    close(fds[0]);
-    close(fds[1]);
-#endif
     return err;
 }
 
@@ -3629,6 +3587,82 @@ void qemu_notify_event(void)
      }
 }
 
+#ifdef CONFIG_IOTHREAD
+#ifndef _WIN32
+static int io_thread_fd = -1;
+
+static void qemu_event_increment(void)
+{
+    static const char byte = 0;
+
+    if (io_thread_fd == -1)
+        return;
+
+    write(io_thread_fd, &byte, sizeof(byte));
+}
+
+static void qemu_event_read(void *opaque)
+{
+    int fd = (unsigned long)opaque;
+    ssize_t len;
+
+    /* Drain the notify pipe */
+    do {
+        char buffer[512];
+        len = read(fd, buffer, sizeof(buffer));
+    } while ((len == -1 && errno == EINTR) || len > 0);
+}
+
+static int qemu_event_init(void)
+{
+    int err;
+    int fds[2];
+
+    err = pipe(fds);
+    if (err == -1)
+        return -errno;
+
+    err = fcntl_setfl(fds[0], O_NONBLOCK);
+    if (err < 0)
+        goto fail;
+
+    err = fcntl_setfl(fds[1], O_NONBLOCK);
+    if (err < 0)
+        goto fail;
+
+    qemu_set_fd_handler2(fds[0], NULL, qemu_event_read, NULL,
+                         (void *)(unsigned long)fds[0]);
+
+    io_thread_fd = fds[1];
+fail:
+    close(fds[0]);
+    close(fds[1]);
+    return err;
+}
+#else
+HANDLE qemu_event_handle;
+
+static void dummy_event_handler(void *opaque)
+{
+}
+
+static int qemu_event_init(void)
+{
+    qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
+    if (!qemu_event_handle) {
+        perror("Failed CreateEvent");
+        return -1;
+    }
+    qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
+}
+
+static void qemu_event_increment(void)
+{
+    SetEvent(qemu_event_handle);
+}
+#endif
+#endif
+
 #ifdef _WIN32
 static void host_main_loop_wait(int *timeout)
 {

--