Merge remote-tracking branch 'remotes/elmarco/tags/chardev-pull-request' into staging

Chardev fixes

# gpg: Signature made Wed 13 Feb 2019 16:18:36 GMT
# gpg:                using RSA key DAE8E10975969CE5
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>" [full]
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>" [full]
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/elmarco/tags/chardev-pull-request: (25 commits)
  char-pty: remove write_lock usage
  char-pty: remove the check for connection on write
  chardev: add a note about frontend sources and context switch
  terminal3270: do not use backend timer sources
  char: update the mux handlers in class callback
  chardev/wctablet: Fix a typo
  char: allow specifying a GMainContext at opening time
  chardev: ensure termios is fully initialized
  tests: expand coverage of socket chardev test
  chardev: fix race with client connections in tcp_chr_wait_connected
  chardev: disallow TLS/telnet/websocket with tcp_chr_wait_connected
  chardev: honour the reconnect setting in tcp_chr_wait_connected
  chardev: use a state machine for socket connection state
  chardev: split up qmp_chardev_open_socket connection code
  chardev: split tcp_chr_wait_connected into two methods
  chardev: remove unused 'sioc' variable & cleanup paths
  chardev: ensure qemu_chr_parse_compat reports missing driver error
  chardev: remove many local variables in qemu_chr_parse_socket
  chardev: forbid 'wait' option with client sockets
  chardev: forbid 'reconnect' option with server sockets
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 69 insertions, 32 deletions

diff --git a/io/task.c b/io/task.c
index 2886a2c1bc..64c4c7126a 100644
--- a/io/task.c
+++ b/io/task.c
@@ -24,6 +24,15 @@
 #include "qemu/thread.h"
 #include "trace.h"
 
+struct QIOTaskThreadData {
+    QIOTaskWorker worker;
+    gpointer opaque;
+    GDestroyNotify destroy;
+    GMainContext *context;
+    GSource *completion;
+};
+
+
 struct QIOTask {
     Object *source;
     QIOTaskFunc func;
@@ -32,6 +41,9 @@ struct QIOTask {
     Error *err;
     gpointer result;
     GDestroyNotify destroyResult;
+    QemuMutex thread_lock;
+    QemuCond thread_cond;
+    struct QIOTaskThreadData *thread;
 };
 
 
@@ -49,6 +61,8 @@ QIOTask *qio_task_new(Object *source,
     task->func = func;
     task->opaque = opaque;
     task->destroy = destroy;
+    qemu_mutex_init(&task->thread_lock);
+    qemu_cond_init(&task->thread_cond);
 
     trace_qio_task_new(task, source, func, opaque);
 
@@ -57,6 +71,19 @@ QIOTask *qio_task_new(Object *source,
 
 static void qio_task_free(QIOTask *task)
 {
+    qemu_mutex_lock(&task->thread_lock);
+    if (task->thread) {
+        if (task->thread->destroy) {
+            task->thread->destroy(task->thread->opaque);
+        }
+
+        if (task->thread->context) {
+            g_main_context_unref(task->thread->context);
+        }
+
+        g_free(task->thread);
+    }
+
     if (task->destroy) {
         task->destroy(task->opaque);
     }
@@ -68,35 +95,20 @@ static void qio_task_free(QIOTask *task)
     }
     object_unref(task->source);
 
+    qemu_mutex_unlock(&task->thread_lock);
+    qemu_mutex_destroy(&task->thread_lock);
+    qemu_cond_destroy(&task->thread_cond);
+
     g_free(task);
 }
 
 
-struct QIOTaskThreadData {
-    QIOTask *task;
-    QIOTaskWorker worker;
-    gpointer opaque;
-    GDestroyNotify destroy;
-    GMainContext *context;
-};
-
-
 static gboolean qio_task_thread_result(gpointer opaque)
 {
-    struct QIOTaskThreadData *data = opaque;
-
-    trace_qio_task_thread_result(data->task);
-    qio_task_complete(data->task);
-
-    if (data->destroy) {
-        data->destroy(data->opaque);
-    }
-
-    if (data->context) {
-        g_main_context_unref(data->context);
-    }
+    QIOTask *task = opaque;
 
-    g_free(data);
+    trace_qio_task_thread_result(task);
+    qio_task_complete(task);
 
     return FALSE;
 }
@@ -104,22 +116,30 @@ static gboolean qio_task_thread_result(gpointer opaque)
 
 static gpointer qio_task_thread_worker(gpointer opaque)
 {
-    struct QIOTaskThreadData *data = opaque;
-    GSource *idle;
+    QIOTask *task = opaque;
 
-    trace_qio_task_thread_run(data->task);
-    data->worker(data->task, data->opaque);
+    trace_qio_task_thread_run(task);
+
+    task->thread->worker(task, task->thread->opaque);
 
     /* We're running in the background thread, and must only
      * ever report the task results in the main event loop
      * thread. So we schedule an idle callback to report
      * the worker results
      */
-    trace_qio_task_thread_exit(data->task);
+    trace_qio_task_thread_exit(task);
+
+    qemu_mutex_lock(&task->thread_lock);
 
-    idle = g_idle_source_new();
-    g_source_set_callback(idle, qio_task_thread_result, data, NULL);
-    g_source_attach(idle, data->context);
+    task->thread->completion = g_idle_source_new();
+    g_source_set_callback(task->thread->completion,
+                          qio_task_thread_result, task, NULL);
+    g_source_attach(task->thread->completion,
+                    task->thread->context);
+    trace_qio_task_thread_source_attach(task, task->thread->completion);
+
+    qemu_cond_signal(&task->thread_cond);
+    qemu_mutex_unlock(&task->thread_lock);
 
     return NULL;
 }
@@ -138,21 +158,38 @@ void qio_task_run_in_thread(QIOTask *task,
         g_main_context_ref(context);
     }
 
-    data->task = task;
     data->worker = worker;
     data->opaque = opaque;
     data->destroy = destroy;
     data->context = context;
 
+    task->thread = data;
+
     trace_qio_task_thread_start(task, worker, opaque);
     qemu_thread_create(&thread,
                        "io-task-worker",
                        qio_task_thread_worker,
-                       data,
+                       task,
                        QEMU_THREAD_DETACHED);
 }
 
 
+void qio_task_wait_thread(QIOTask *task)
+{
+    qemu_mutex_lock(&task->thread_lock);
+    g_assert(task->thread != NULL);
+    while (task->thread->completion == NULL) {
+        qemu_cond_wait(&task->thread_cond, &task->thread_lock);
+    }
+
+    trace_qio_task_thread_source_cancel(task, task->thread->completion);
+    g_source_destroy(task->thread->completion);
+    qemu_mutex_unlock(&task->thread_lock);
+
+    qio_task_thread_result(task);
+}
+
+
 void qio_task_complete(QIOTask *task)
 {
     task->func(task, task->opaque);