Make the call retain cycle explicit and encapsulated within GRPCCall.m
diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index 0bfc864..9435bf2 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -81,6 +81,10 @@
GRXConcurrentWriteable *_responseWriteable;
GRXWriter *_requestWriter;
+ // To create a retain cycle when a call is started, up until it finishes. See
+ // |startWithWriteable:| and |finishWithError:|.
+ GRPCCall *_self;
+
NSMutableDictionary *_requestMetadata;
NSMutableDictionary *_responseMetadata;
}
@@ -143,8 +147,13 @@
#pragma mark Finish
- (void)finishWithError:(NSError *)errorOrNil {
+ // If the call isn't retained anywhere else, it can be deallocated now.
+ _self = nil;
+
+ // If there were still request messages coming, stop them.
_requestWriter.state = GRXWriterStateFinished;
_requestWriter = nil;
+
if (errorOrNil) {
[_responseWriteable cancelWithError:errorOrNil];
} else {
@@ -276,6 +285,7 @@
}
- (void)writesFinishedWithError:(NSError *)errorOrNil {
+ _requestWriter = nil;
if (errorOrNil) {
[self cancel];
} else {
@@ -335,12 +345,14 @@
#pragma mark GRXWriter implementation
- (void)startWithWriteable:(id<GRXWriteable>)writeable {
- // The following produces a retain cycle self:_responseWriteable:self, which is only
- // broken when writesFinishedWithError: is sent to the wrapped writeable.
- // Care is taken not to retain self strongly in any of the blocks used in
- // the implementation of GRPCCall, so that the life of the instance is
- // determined by this retain cycle.
- _responseWriteable = [[GRXConcurrentWriteable alloc] initWithWriteable:writeable writer:self];
+ // Create a retain cycle so that this instance lives until the RPC finishes (or is cancelled).
+ // This makes RPCs in which the call isn't externally retained possible (as long as it is started
+ // before being autoreleased).
+ // Care is taken not to retain self strongly in any of the blocks used in this implementation, so
+ // that the life of the instance is determined by this retain cycle.
+ _self = self;
+
+ _responseWriteable = [[GRXConcurrentWriteable alloc] initWithWriteable:writeable];
[self sendHeaders:_requestMetadata];
[self invokeCall];
}