[Qemu-devel] [PATCH v2 03/12] main-loop: use event notifiers

[Paolo Bonzini <pbonzini@redhat.com>]

Reviewed-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 Makefile.objs |   4 +--
 main-loop.c   | 106 +++++++++-------------------------------------------------
 oslib-posix.c |  31 -----------------
 qemu-common.h |   1 -
 4 file modificati, 17 inserzioni(+), 125 rimozioni(-)

diff --git a/Makefile.objs b/Makefile.objs
index 2d9d0ce..e6d40da 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -20,8 +20,8 @@ universal-obj-y += $(qom-obj-y)
 #######################################################################
 # oslib-obj-y is code depending on the OS (win32 vs posix)
 oslib-obj-y = osdep.o
-oslib-obj-$(CONFIG_WIN32) += oslib-win32.o qemu-thread-win32.o
-oslib-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o
+oslib-obj-$(CONFIG_WIN32) += oslib-win32.o qemu-thread-win32.o event_notifier-win32.o
+oslib-obj-$(CONFIG_POSIX) += oslib-posix.o qemu-thread-posix.o event_notifier-posix.o
 
 #######################################################################
 # coroutines
diff --git a/main-loop.c b/main-loop.c
index eb3b6e6..81f49b3 100644
--- a/main-loop.c
+++ b/main-loop.c
@@ -26,75 +26,12 @@
 #include "qemu-timer.h"
 #include "slirp/slirp.h"
 #include "main-loop.h"
+#include "event_notifier.h"
 
 #ifndef _WIN32
 
 #include "compatfd.h"
 
-static int io_thread_fd = -1;
-
-void qemu_notify_event(void)
-{
-    /* Write 8 bytes to be compatible with eventfd.  */
-    static const uint64_t val = 1;
-    ssize_t ret;
-
-    if (io_thread_fd == -1) {
-        return;
-    }
-    do {
-        ret = write(io_thread_fd, &val, sizeof(val));
-    } while (ret < 0 && errno == EINTR);
-
-    /* EAGAIN is fine, a read must be pending.  */
-    if (ret < 0 && errno != EAGAIN) {
-        fprintf(stderr, "qemu_notify_event: write() failed: %s\n",
-                strerror(errno));
-        exit(1);
-    }
-}
-
-static void qemu_event_read(void *opaque)
-{
-    int fd = (intptr_t)opaque;
-    ssize_t len;
-    char buffer[512];
-
-    /* Drain the notify pipe.  For eventfd, only 8 bytes will be read.  */
-    do {
-        len = read(fd, buffer, sizeof(buffer));
-    } while ((len == -1 && errno == EINTR) || len == sizeof(buffer));
-}
-
-static int qemu_event_init(void)
-{
-    int err;
-    int fds[2];
-
-    err = qemu_eventfd(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 *)(intptr_t)fds[0]);
-
-    io_thread_fd = fds[1];
-    return 0;
-
-fail:
-    close(fds[0]);
-    close(fds[1]);
-    return err;
-}
-
 /* 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
  * handler is to dispatch the signals when we receive them.
@@ -164,40 +101,22 @@ static int qemu_signal_init(void)
 
 #else /* _WIN32 */
 
-static HANDLE qemu_event_handle = NULL;
-
-static void dummy_event_handler(void *opaque)
-{
-}
-
-static int qemu_event_init(void)
+static int qemu_signal_init(void)
 {
-    qemu_event_handle = CreateEvent(NULL, FALSE, FALSE, NULL);
-    if (!qemu_event_handle) {
-        fprintf(stderr, "Failed CreateEvent: %ld\n", GetLastError());
-        return -1;
-    }
-    qemu_add_wait_object(qemu_event_handle, dummy_event_handler, NULL);
     return 0;
 }
+#endif
+
+static EventNotifier io_thread_notifier;
+static int io_thread_initialized;
 
 void qemu_notify_event(void)
 {
-    if (!qemu_event_handle) {
+    if (!io_thread_initialized) {
         return;
     }
-    if (!SetEvent(qemu_event_handle)) {
-        fprintf(stderr, "qemu_notify_event: SetEvent failed: %ld\n",
-                GetLastError());
-        exit(1);
-    }
-}
-
-static int qemu_signal_init(void)
-{
-    return 0;
+    event_notifier_set(&io_thread_notifier);
 }
-#endif
 
 int main_loop_init(void)
 {
@@ -210,11 +129,15 @@ int main_loop_init(void)
     }
 
     /* Note eventfd must be drained before signalfd handlers run */
-    ret = qemu_event_init();
+    ret = event_notifier_init(&io_thread_notifier, 0);
     if (ret) {
         return ret;
     }
 
+    io_thread_initialized = true;
+    event_notifier_set_handler(&io_thread_notifier,
+                               (EventNotifierHandler *)
+                               event_notifier_test_and_clear);
     return 0;
 }
 
@@ -400,7 +323,8 @@ void qemu_del_wait_object(HANDLE handle, WaitObjectFunc *func, void *opaque)
 
 void qemu_fd_register(int fd)
 {
-    WSAEventSelect(fd, qemu_event_handle, FD_READ | FD_ACCEPT | FD_CLOSE |
+    WSAEventSelect(fd, event_notifier_get_handle(&io_thread_notifier),
+                   FD_READ | FD_ACCEPT | FD_CLOSE |
                    FD_CONNECT | FD_WRITE | FD_OOB);
 }
 
diff --git a/oslib-posix.c b/oslib-posix.c
index dbeb627..9db9c3d 100644
--- a/oslib-posix.c
+++ b/oslib-posix.c
@@ -61,9 +61,6 @@ static int running_on_valgrind = -1;
 #ifdef CONFIG_LINUX
 #include <sys/syscall.h>
 #endif
-#ifdef CONFIG_EVENTFD
-#include <sys/eventfd.h>
-#endif
 
 int qemu_get_thread_id(void)
 {
@@ -183,34 +180,6 @@ int qemu_pipe(int pipefd[2])
     return ret;
 }
 
-/*
- * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
- */
-int qemu_eventfd(int fds[2])
-{
-#ifdef CONFIG_EVENTFD
-    int ret;
-
-    ret = eventfd(0, 0);
-    if (ret >= 0) {
-        fds[0] = ret;
-        fds[1] = dup(ret);
-        if (fds[1] == -1) {
-            close(ret);
-            return -1;
-        }
-        qemu_set_cloexec(ret);
-        qemu_set_cloexec(fds[1]);
-        return 0;
-    }
-    if (errno != ENOSYS) {
-        return -1;
-    }
-#endif
-
-    return qemu_pipe(fds);
-}
-
 int qemu_utimens(const char *path, const struct timespec *times)
 {
     struct timeval tv[2], tv_now;
diff --git a/qemu-common.h b/qemu-common.h
index f16079f..162591b 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -215,7 +215,6 @@ ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
     QEMU_WARN_UNUSED_RESULT;
 
 #ifndef _WIN32
-int qemu_eventfd(int pipefd[2]);
 int qemu_pipe(int pipefd[2]);
 #endif
 
-- 
1.7.11.2