Make all async I/O object referenced.
Since it's hard to control lifespan of an object in asynchronous environment, we
should make all AsyncXxx objects a referenced objecst, that will self-destruct
when its reference count drops to zero, indicating that the last client that
used the object has abandoned it.
Change-Id: I6f8194aa14e52a23a8772d827583782989654504
diff --git a/android/async-socket-connector.c b/android/async-socket-connector.c
index 41a13e0..80ec5bb 100644
--- a/android/async-socket-connector.c
+++ b/android/async-socket-connector.c
@@ -55,6 +55,8 @@
int retry_to;
/* Socket descriptor for the connection. */
int fd;
+ /* Number of outstanding references to the connector. */
+ int ref_count;
};
/* Asynchronous I/O looper callback invoked by the connector.
@@ -79,11 +81,20 @@
_async_socket_connector_free(AsyncSocketConnector* connector)
{
if (connector != NULL) {
+ D("%s: Connector is destroyed.", _asc_socket_string(connector));
+ if (asyncConnector_stop(connector->connector) == 0) {
+ /* Connection was in progress. We need to destroy I/O descriptor for
+ * that connection. */
+ D("%s: Stopped async connection in progress.",
+ _asc_socket_string(connector));
+ loopIo_done(connector->connector_io);
+ }
if (connector->fd >= 0) {
socket_close(connector->fd);
}
if (connector->looper != NULL) {
+ loopTimer_stop(connector->connector_timer);
loopTimer_done(connector->connector_timer);
looper_free(connector->looper);
}
@@ -106,15 +117,13 @@
/* Open socket. */
connector->fd = socket_create_inet(SOCKET_STREAM);
if (connector->fd < 0) {
- D("Unable to create AsyncSocketConnector socket for '%s'. Error: %d -> %s",
+ D("%s: Unable to create socket: %d -> %s",
_asc_socket_string(connector), errno, strerror(errno));
return -1;
}
/* Prepare for async I/O on the connector. */
socket_set_nonblock(connector->fd);
- loopIo_init(connector->connector_io, connector->looper, connector->fd,
- _on_async_socket_connector_io, connector);
return 0;
}
@@ -136,12 +145,11 @@
/* Asynchronous connector (AsyncConnector instance) has completed connection
* attempt.
- *
- * NOTE: Upon exit from this routine AsyncSocketConnector instance might be
- * destroyed. So, once this routine is called, there must be no further
- * references to AsyncSocketConnector instance passed to this routine.
* Param:
- * connector - Initialized AsyncSocketConnector instance.
+ * connector - Initialized AsyncSocketConnector instance. Note: When this
+ * callback is called, the caller has referenced passed connector object,
+ * So, it's guaranteed that this connector is not going to be destroyed
+ * while this routine executes.
* status - Status of the connection attempt.
*/
static void
@@ -173,14 +181,11 @@
}
if (action == ASIO_ACTION_RETRY) {
- D("Retrying connection to socket '%s'", _asc_socket_string(connector));
+ D("%s: Retrying connection", _asc_socket_string(connector));
loopTimer_startRelative(connector->connector_timer, connector->retry_to);
- } else {
- if (action == ASIO_ACTION_ABORT) {
- D("%s: AsyncSocketConnector client for socket '%s' has aborted connection",
- __FUNCTION__, _asc_socket_string(connector));
- }
- _async_socket_connector_free(connector);
+ } else if (action == ASIO_ACTION_ABORT) {
+ D("%s: AsyncSocketConnector client for socket '%s' has aborted connection",
+ __FUNCTION__, _asc_socket_string(connector));
}
}
@@ -189,6 +194,9 @@
{
AsyncSocketConnector* const connector = (AsyncSocketConnector*)opaque;
+ /* Reference the connector while we're handing I/O. */
+ async_socket_connector_reference(connector);
+
/* Notify the client that another connection attempt is about to start. */
const AsyncIOAction action =
connector->on_connected_cb(connector->on_connected_cb_opaque,
@@ -200,8 +208,10 @@
} else {
D("%s: AsyncSocketConnector client for socket '%s' has aborted connection",
__FUNCTION__, _asc_socket_string(connector));
- _async_socket_connector_free(connector);
}
+
+ /* Release the connector after we're done with handing I/O. */
+ async_socket_connector_release(connector);
}
/* Retry connection timer callback.
@@ -214,30 +224,37 @@
AsyncStatus status;
AsyncSocketConnector* const connector = (AsyncSocketConnector*)opaque;
+ /* Reference the connector while we're in callback. */
+ async_socket_connector_reference(connector);
+
/* Invoke the callback to notify about a connection retry attempt. */
AsyncIOAction action =
connector->on_connected_cb(connector->on_connected_cb_opaque,
connector, ASIO_STATE_RETRYING);
- if (action == ASIO_ACTION_ABORT) {
+ if (action != ASIO_ACTION_ABORT) {
+ /* Close handle opened for the previous (failed) attempt. */
+ _async_socket_connector_close_socket(connector);
+
+ /* Retry connection attempt. */
+ if (_async_socket_connector_open_socket(connector) == 0) {
+ loopIo_init(connector->connector_io, connector->looper,
+ connector->fd, _on_async_socket_connector_io, connector);
+ status = asyncConnector_init(connector->connector,
+ &connector->address,
+ connector->connector_io);
+ } else {
+ status = ASYNC_ERROR;
+ }
+
+ _on_async_socket_connector_connecting(connector, status);
+ } else {
D("%s: AsyncSocketConnector client for socket '%s' has aborted connection",
__FUNCTION__, _asc_socket_string(connector));
- _async_socket_connector_free(connector);
- return;
}
- /* Close handle opened for the previous (failed) attempt. */
- _async_socket_connector_close_socket(connector);
-
- /* Retry connection attempt. */
- if (_async_socket_connector_open_socket(connector) == 0) {
- status = asyncConnector_init(connector->connector, &connector->address,
- connector->connector_io);
- } else {
- status = ASYNC_ERROR;
- }
-
- _on_async_socket_connector_connecting(connector, status);
+ /* Release the connector after we're done with the callback. */
+ async_socket_connector_release(connector);
}
/********************************************************************************
@@ -265,6 +282,7 @@
connector->retry_to = retry_to;
connector->on_connected_cb = cb;
connector->on_connected_cb_opaque = cb_opaque;
+ connector->ref_count = 1;
/* Copy socket address. */
if (sock_address_get_family(address) == SOCKET_UNIX) {
@@ -275,11 +293,7 @@
/* Create a looper for asynchronous I/O. */
connector->looper = looper_newCore();
- if (connector->looper != NULL) {
- /* Create a timer that will be used for connection retries. */
- loopTimer_init(connector->connector_timer, connector->looper,
- _on_async_socket_connector_retry, connector);
- } else {
+ if (connector->looper == NULL) {
E("Unable to create I/O looper for AsyncSocketConnector for socket '%s'",
_asc_socket_string(connector));
cb(cb_opaque, connector, ASIO_STATE_FAILED);
@@ -287,9 +301,34 @@
return NULL;
}
+ /* Create a timer that will be used for connection retries. */
+ loopTimer_init(connector->connector_timer, connector->looper,
+ _on_async_socket_connector_retry, connector);
+
return connector;
}
+int
+async_socket_connector_reference(AsyncSocketConnector* connector)
+{
+ assert(connector->ref_count > 0);
+ connector->ref_count++;
+ return connector->ref_count;
+}
+
+int
+async_socket_connector_release(AsyncSocketConnector* connector)
+{
+ assert(connector->ref_count > 0);
+ connector->ref_count--;
+ if (connector->ref_count == 0) {
+ /* Last reference has been dropped. Destroy this object. */
+ _async_socket_connector_free(connector);
+ return 0;
+ }
+ return connector->ref_count;
+}
+
void
async_socket_connector_connect(AsyncSocketConnector* connector)
{
@@ -302,9 +341,10 @@
if (action == ASIO_ACTION_ABORT) {
D("%s: AsyncSocketConnector client for socket '%s' has aborted connection",
__FUNCTION__, _asc_socket_string(connector));
- _async_socket_connector_free(connector);
return;
} else {
+ loopIo_init(connector->connector_io, connector->looper,
+ connector->fd, _on_async_socket_connector_io, connector);
status = asyncConnector_init(connector->connector,
&connector->address,
connector->connector_io);