Don’t set the request writer to nil, as @synchr(nil) is undefined behavior.
Also clarify in GRXWriter.h that the writeable is released whenever the
writer finishes.
diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index 405f033..6836d34 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -150,7 +150,6 @@
// If there were still request messages coming, stop them.
@synchronized(_requestWriter) {
_requestWriter.state = GRXWriterStateFinished;
- _requestWriter = nil;
}
if (errorOrNil) {
@@ -288,9 +287,6 @@
}
- (void)writesFinishedWithError:(NSError *)errorOrNil {
- @synchronized(_requestWriter) {
- _requestWriter = nil;
- }
if (errorOrNil) {
[self cancel];
} else {
diff --git a/src/objective-c/RxLibrary/GRXWriter.h b/src/objective-c/RxLibrary/GRXWriter.h
index 65c8806..b1c994a 100644
--- a/src/objective-c/RxLibrary/GRXWriter.h
+++ b/src/objective-c/RxLibrary/GRXWriter.h
@@ -35,33 +35,28 @@
#import "GRXWriteable.h"
+// States of a writer.
typedef NS_ENUM(NSInteger, GRXWriterState) {
- // The writer has not yet been given a writeable to which it can push its
- // values. To have an writer transition to the Started state, send it a
- // startWithWriteable: message.
+ // The writer has not yet been given a writeable to which it can push its values. To have a writer
+ // transition to the Started state, send it a startWithWriteable: message.
//
- // An writer's state cannot be manually set to this value.
+ // A writer's state cannot be manually set to this value.
GRXWriterStateNotStarted,
// The writer might push values to the writeable at any moment.
GRXWriterStateStarted,
- // The writer is temporarily paused, and won't send any more values to the
- // writeable unless its state is set back to Started. The writer might still
- // transition to the Finished state at any moment, and is allowed to send
- // writesFinishedWithError: to its writeable.
- //
- // Not all implementations of writer have to support pausing, and thus
- // trying to set an writer's state to this value might have no effect.
+ // The writer is temporarily paused, and won't send any more values to the writeable unless its
+ // state is set back to Started. The writer might still transition to the Finished state at any
+ // moment, and is allowed to send writesFinishedWithError: to its writeable.
GRXWriterStatePaused,
// The writer has released its writeable and won't interact with it anymore.
//
- // One seldomly wants to set an writer's state to this value, as its
- // writeable isn't notified with a writesFinishedWithError: message. Instead, sending
- // finishWithError: to the writer will make it notify the writeable and then
- // transition to this state.
+ // One seldomly wants to set a writer's state to this value, as its writeable isn't notified with
+ // a writesFinishedWithError: message. Instead, sending finishWithError: to the writer will make
+ // it notify the writeable and then transition to this state.
GRXWriterStateFinished
};
@@ -88,28 +83,25 @@
// GRXWriter. I.e., conforming classes aren't required to be thread-safe.
@interface GRXWriter : NSObject
-// This property can be used to query the current state of the writer, which
-// determines how it might currently use its writeable. Some state transitions can
-// be triggered by setting this property to the corresponding value, and that's
-// useful for advanced use cases like pausing an writer. For more details,
-// see the documentation of the enum.
+// This property can be used to query the current state of the writer, which determines how it might
+// currently use its writeable. Some state transitions can be triggered by setting this property to
+// the corresponding value, and that's useful for advanced use cases like pausing an writer. For
+// more details, see the documentation of the enum further down.
@property(nonatomic) GRXWriterState state;
-// Start sending messages to the writeable. Messages may be sent before the method
-// returns, or they may be sent later in the future. See GRXWriteable.h for the
-// different messages a writeable can receive.
+// Transition to the Started state, and start sending messages to the writeable (a reference to it
+// is retained). Messages to the writeable may be sent before the method returns, or they may be
+// sent later in the future. See GRXWriteable.h for the different messages a writeable can receive.
//
-// If this writer draws its values from an external source (e.g. from the
-// filesystem or from a server), calling this method will commonly trigger side
-// effects (like network connections).
+// If this writer draws its values from an external source (e.g. from the filesystem or from a
+// server), calling this method will commonly trigger side effects (like network connections).
//
// This method might only be called on writers in the NotStarted state.
- (void)startWithWriteable:(id<GRXWriteable>)writeable;
-// Send writesFinishedWithError:errorOrNil immediately to the writeable, and don't send
-// any more messages to it.
+// Send writesFinishedWithError:errorOrNil to the writeable. Then release the reference to it and
+// transition to the Finished state.
//
-// This method might only be called on writers in the Started or Paused
-// state.
+// This method might only be called on writers in the Started or Paused state.
- (void)finishWithError:(NSError *)errorOrNil;
@end