[Spice-commits] Branch '0.8' - 2 commits - server/main_dispatcher.c server/main_dispatcher.h server/Makefile.am server/reds.c server/tests

Alon Levy alon at kemper.freedesktop.org
Tue Oct 25 00:24:04 PDT 2011


 server/Makefile.am                 |    2 
 server/main_dispatcher.c           |  145 +++++++++++++++++++++++++++++++++++++
 server/main_dispatcher.h           |    9 ++
 server/reds.c                      |    4 -
 server/tests/basic_event_loop.c    |    6 +
 server/tests/test_display_no_ssl.c |    1 
 6 files changed, 164 insertions(+), 3 deletions(-)

New commits:
commit 80caf07e09efe14c67f89a3c01501a6a39681167
Author: Alon Levy <alevy at redhat.com>
Date:   Thu Sep 8 02:16:24 2011 +0300

    [0.8 branch] server: add main_dispatcher
    
    add main_dispatcher, a message passing mechanism for sending messages to
    the main thread. The main thread is the thread that implements
    SpiceCoreInterface, which is assumed to be a single thread.
    
    Similar to the async operation of red_worker, a socket pair is created
    and used to pass messages. The messages are a fixed size to ease
    parsing. A single message is defined to pass a channel_event.
    
    RHBZ: 746950
    FDBZ: 41858
    
    This patch is 0.8 branch only, for the master branch there should be a
    better approach to share code with red_dispatcher and ready the way for
    later adding more threads.

diff --git a/server/Makefile.am b/server/Makefile.am
index 93ed312..ebb0d3f 100644
--- a/server/Makefile.am
+++ b/server/Makefile.am
@@ -114,6 +114,8 @@ libspice_server_la_SOURCES =			\
 	red_common.h				\
 	red_dispatcher.c			\
 	red_dispatcher.h			\
+	main_dispatcher.c			\
+	main_dispatcher.h			\
 	red_memslots.c				\
 	red_memslots.h				\
 	red_parse_qxl.c				\
diff --git a/server/main_dispatcher.c b/server/main_dispatcher.c
new file mode 100644
index 0000000..73856bf
--- /dev/null
+++ b/server/main_dispatcher.c
@@ -0,0 +1,145 @@
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <pthread.h>
+#include <assert.h>
+
+#include "red_common.h"
+#include "main_dispatcher.h"
+
+/*
+ * Main Dispatcher
+ * ===============
+ *
+ * Communication channel between any non main thread and the main thread.
+ *
+ * The main thread is that from which spice_server_init is called.
+ *
+ * Messages are single sized, sent from the non-main thread to the main-thread.
+ * No acknowledge is sent back. This prevents a possible deadlock with the main
+ * thread already waiting on a response for the existing red_dispatcher used
+ * by the worker thread.
+ *
+ * All events have three functions:
+ * main_dispatcher_<event_name> - non static, public function
+ * main_dispatcher_self_<event_name> - handler for main thread
+ * main_dispatcher_handle_<event_name> - handler for callback from main thread
+ *   seperate from self because it may send an ack or do other work in the future.
+ */
+
+typedef struct {
+    SpiceCoreInterface *core;
+    int main_fd;
+    int other_fd;
+    pthread_t self;
+    pthread_mutex_t lock;
+} MainDispatcher;
+
+MainDispatcher main_dispatcher;
+
+enum {
+    MAIN_DISPATCHER_CHANNEL_EVENT = 0,
+
+    MAIN_DISPATCHER_NUM_MESSAGES
+};
+
+typedef struct MainDispatcherMessage {
+    uint32_t type;
+    union {
+        struct {
+            int event;
+            SpiceChannelEventInfo *info;
+        } channel_event;
+    } data;
+} MainDispatcherMessage;
+
+/* channel_event - calls core->channel_event, must be done in main thread */
+static void main_dispatcher_self_handle_channel_event(
+                                                int event,
+                                                SpiceChannelEventInfo *info)
+{
+    main_dispatcher.core->channel_event(event, info);
+}
+
+static void main_dispatcher_handle_channel_event(MainDispatcherMessage *msg)
+{
+    main_dispatcher_self_handle_channel_event(msg->data.channel_event.event,
+                                              msg->data.channel_event.info);
+}
+
+void main_dispatcher_channel_event(int event, SpiceChannelEventInfo *info)
+{
+    MainDispatcherMessage msg;
+    ssize_t written = 0;
+    ssize_t ret;
+
+    if (pthread_self() == main_dispatcher.self) {
+        main_dispatcher_self_handle_channel_event(event, info);
+        return;
+    }
+    msg.type = MAIN_DISPATCHER_CHANNEL_EVENT;
+    msg.data.channel_event.event = event;
+    msg.data.channel_event.info = info;
+    pthread_mutex_lock(&main_dispatcher.lock);
+    while (written < sizeof(msg)) {
+        ret = write(main_dispatcher.other_fd, &msg + written,
+                    sizeof(msg) - written);
+        if (ret == -1) {
+            assert(errno == EINTR);
+            continue;
+        }
+        written += ret;
+    }
+    pthread_mutex_unlock(&main_dispatcher.lock);
+}
+
+
+static void main_dispatcher_handle_read(int fd, int event, void *opaque)
+{
+    int ret;
+    MainDispatcher *md = opaque;
+    MainDispatcherMessage msg;
+    int read_size = 0;
+
+    while (read_size < sizeof(msg)) {
+        /* blocks until sizeof(msg) is read */
+        ret = read(md->main_fd, &msg + read_size, sizeof(msg) - read_size);
+        if (ret == -1) {
+            if (errno != EINTR) {
+                red_printf("error reading from main dispatcher: %d\n", errno);
+                /* TODO: close channel? */
+                return;
+            }
+            continue;
+        }
+        read_size += ret;
+    }
+    switch (msg.type) {
+        case MAIN_DISPATCHER_CHANNEL_EVENT:
+            main_dispatcher_handle_channel_event(&msg);
+            break;
+        default:
+            red_printf("error: unhandled main dispatcher message type %d\n",
+                       msg.type);
+    }
+}
+
+void main_dispatcher_init(SpiceCoreInterface *core)
+{
+    int channels[2];
+
+    memset(&main_dispatcher, 0, sizeof(main_dispatcher));
+    main_dispatcher.core = core;
+
+    if (socketpair(AF_LOCAL, SOCK_STREAM, 0, channels) == -1) {
+        red_error("socketpair failed %s", strerror(errno));
+        return;
+    }
+    pthread_mutex_init(&main_dispatcher.lock, NULL);
+    main_dispatcher.main_fd = channels[0];
+    main_dispatcher.other_fd = channels[1];
+    main_dispatcher.self = pthread_self();
+
+    core->watch_add(main_dispatcher.main_fd, SPICE_WATCH_EVENT_READ,
+                    main_dispatcher_handle_read, &main_dispatcher);
+}
diff --git a/server/main_dispatcher.h b/server/main_dispatcher.h
new file mode 100644
index 0000000..2c201c7
--- /dev/null
+++ b/server/main_dispatcher.h
@@ -0,0 +1,9 @@
+#ifndef MAIN_DISPATCHER_H
+#define MAIN_DISPATCHER_H
+
+#include <spice.h>
+
+void main_dispatcher_channel_event(int event, SpiceChannelEventInfo *info);
+void main_dispatcher_init(SpiceCoreInterface *core);
+
+#endif //MAIN_DISPATCHER_H
diff --git a/server/reds.c b/server/reds.c
index 8e83b99..0bb7e96 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -53,6 +53,7 @@
 
 #include "red_common.h"
 #include "red_dispatcher.h"
+#include "main_dispatcher.h"
 #include "snd_worker.h"
 #include <spice/stats.h>
 #include "stat.h"
@@ -415,7 +416,7 @@ static void reds_channel_event(RedsStream *stream, int event)
 {
     if (core->base.minor_version < 3 || core->channel_event == NULL)
         return;
-    core->channel_event(event, &stream->info);
+    main_dispatcher_channel_event(event, &stream->info);
 }
 
 static ssize_t stream_write_cb(RedsStream *s, const void *buf, size_t size)
@@ -4685,6 +4686,7 @@ static int do_spice_init(SpiceCoreInterface *core_interface)
     reds->outgoing.vec = reds->outgoing.vec_buf;
 
     init_vd_agent_resources();
+    main_dispatcher_init(core);
 
     if (!(reds->mig_timer = core->timer_add(migrate_timeout, NULL))) {
         red_error("migration timer create failed");
commit 691afbbab56cb7b42bafd97b80221b8486d6cc10
Author: Alon Levy <alevy at redhat.com>
Date:   Wed Sep 7 20:37:29 2011 +0300

    server/tests: print pthread id on channel_event

diff --git a/server/tests/basic_event_loop.c b/server/tests/basic_event_loop.c
index 1d54ed0..5f0b7ce 100644
--- a/server/tests/basic_event_loop.c
+++ b/server/tests/basic_event_loop.c
@@ -1,6 +1,10 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <sys/time.h>
+#include <strings.h>
+#include <signal.h>
+#include <string.h>
+#include <pthread.h>
 
 #include "test_util.h"
 #include "basic_event_loop.h"
@@ -221,7 +225,7 @@ static void watch_remove(SpiceWatch *watch)
 
 static void channel_event(int event, SpiceChannelEventInfo *info)
 {
-    NOT_IMPLEMENTED
+    printf("got event %d, pthreadid %x\n", event, pthread_self());
 }
 
 SpiceTimer *get_next_timer(void)
diff --git a/server/tests/test_display_no_ssl.c b/server/tests/test_display_no_ssl.c
index 7edc8dc..a7fa4c5 100644
--- a/server/tests/test_display_no_ssl.c
+++ b/server/tests/test_display_no_ssl.c
@@ -288,4 +288,3 @@ int main()
 
     return 0;
 }
-


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