Avoid RMQConnection leaks by adopting weak refs, take 2 (on behalf of @BarryDuggan)

for some important dependencies of allocated channels and
RMQConnection itself.

In this client, RMQConnection auto-allocates a channel for
the purpose of special "channel zero" (system communication
in the protocol) purposes, and that leads to a loop
of strong references that prevent RMQConnection instances
from being released.

Contributed by @BarryDuggan in #194.

Author: michaelklishin

Makefile

@@ -1,4 +1,4 @@
-iOS_VERSION := 14.4
+iOS_VERSION := 15.4
 
 SCHEME := "RMQClient"
 
@@ -16,7 +16,7 @@ tests_iOS: test_dependencies
 		xcodebuild test \
 		-project RMQClient.xcodeproj \
 		-scheme "${SCHEME}" \
-		-destination 'platform=iOS Simulator,name=iPhone 12,OS=$(iOS_VERSION)' | \
+		-destination 'platform=iOS Simulator,name=iPhone 13,OS=$(iOS_VERSION)' | \
 		xcpretty
 
 tests_MacOS: test_dependencies

RMQClient/RMQAllocatedChannel.m

@@ -49,7 +49,6 @@
 @interface RMQAllocatedChannel ()
 @property (nonatomic, copy, readwrite) NSNumber *channelNumber;
 @property (nonatomic, readwrite) NSNumber *contentBodySize;
-@property (nonatomic, readwrite) id <RMQDispatcher> dispatcher;
 @property (nonatomic, readwrite) NSMutableDictionary *consumers;
 @property (nonatomic, readwrite) NSMutableDictionary *exchanges;
 @property (nonatomic, readwrite) NSMutableDictionary *exchangeBindings;
@@ -60,7 +59,8 @@ @interface RMQAllocatedChannel ()
 @property (nonatomic, readwrite) NSNumber *prefetchCountPerChannel;
 @property (nonatomic, readwrite) id<RMQConnectionDelegate> delegate;
 @property (nonatomic, readwrite) id<RMQNameGenerator> nameGenerator;
-@property (nonatomic, readwrite) id<RMQChannelAllocator> allocator;
+@property (nonatomic, weak, readwrite) id<RMQChannelAllocator> allocator;
+@property (nonatomic, weak, readwrite) id <RMQDispatcher> dispatcher;
 @end
 
 @implementation RMQAllocatedChannel

RMQClient/RMQChannel.h

@@ -215,7 +215,7 @@ typedef void (^RMQChannelCompletionHandler)(void);
                               options:(RMQBasicConsumeOptions)options
                             arguments:(RMQTable * _Nonnull)arguments
                               handler:(RMQConsumerDeliveryHandler _Nonnull)handler;
-                              
+
 /// @brief Internal method used by a consumer object
 - (nonnull NSString *)generateConsumerTag;
 

RMQClient/RMQConnection.m

@@ -61,16 +61,16 @@
 #import <RMQProcessInfoNameGenerator.h>
 
 @interface RMQConnection ()
-@property (strong, nonatomic, readwrite) id <RMQTransport> transport;
+@property ( nonatomic, readwrite) id <RMQTransport> transport;
 @property (nonatomic, readwrite) RMQReader *reader;
-@property (nonatomic, readwrite) id <RMQChannelAllocator> channelAllocator;
-@property (nonatomic, readwrite) id <RMQFrameHandler> frameHandler;
-@property (nonatomic, readwrite) id<RMQLocalSerialQueue> commandQueue;
-@property (nonatomic, readwrite) id<RMQWaiterFactory> waiterFactory;
-@property (nonatomic, readwrite) id<RMQHeartbeatSender> heartbeatSender;
 @property (nonatomic, weak, readwrite) id<RMQConnectionDelegate> delegate;
+@property (nonatomic, weak, readwrite) id <RMQChannelAllocator> channelAllocator;
+@property (nonatomic, weak, readwrite) id <RMQFrameHandler> frameHandler;
+@property (nonatomic, readwrite) id<RMQHeartbeatSender> heartbeatSender;
 @property (nonatomic, readwrite) id <RMQChannel> channelZero;
 @property (nonatomic, readwrite) RMQConnectionConfig *config;
+@property (nonatomic, readwrite) id<RMQLocalSerialQueue> commandQueue;
+@property (nonatomic, readwrite) id<RMQWaiterFactory> waiterFactory;
 @property (nonatomic, readwrite) NSMutableDictionary *userChannels;
 @property (nonatomic, readwrite) NSNumber *frameMax;
 @property (nonatomic, readwrite) BOOL handshakeComplete;