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, 28 insertions, 1 deletions

diff --git a/include/io/task.h b/include/io/task.h
index 9e09b95b2e..57d8ba835e 100644
--- a/include/io/task.h
+++ b/include/io/task.h
@@ -232,7 +232,8 @@ QIOTask *qio_task_new(Object *source,
  *
  * Run a task in a background thread. When @worker
  * returns it will call qio_task_complete() in
- * the event thread context that provided.
+ * the thread that is running the main loop associated
+ * with @context.
  */
 void qio_task_run_in_thread(QIOTask *task,
                             QIOTaskWorker worker,
@@ -240,6 +241,32 @@ void qio_task_run_in_thread(QIOTask *task,
                             GDestroyNotify destroy,
                             GMainContext *context);
 
+
+/**
+ * qio_task_wait_thread:
+ * @task: the task struct
+ *
+ * Wait for completion of a task that was previously
+ * invoked using qio_task_run_in_thread. This MUST
+ * ONLY be invoked if the task has not already
+ * completed, since after the completion callback
+ * is invoked, @task will have been freed.
+ *
+ * To avoid racing with execution of the completion
+ * callback provided with qio_task_new, this method
+ * MUST ONLY be invoked from the thread that is
+ * running the main loop associated with @context
+ * parameter to qio_task_run_in_thread.
+ *
+ * When the thread has completed, the completion
+ * callback provided to qio_task_new will be invoked.
+ * When that callback returns @task will be freed,
+ * so @task must not be referenced after this
+ * method completes.
+ */
+void qio_task_wait_thread(QIOTask *task);
+
+
 /**
  * qio_task_complete:
  * @task: the task struct