batch fixes

13 files changed, 89 insertions, 115 deletions

diff --git a/src/objective-c/GRPCClient/GRPCCall.h b/src/objective-c/GRPCClient/GRPCCall.h
index 6d8b9c1b12..be63de1af9 100644
--- a/src/objective-c/GRPCClient/GRPCCall.h
+++ b/src/objective-c/GRPCClient/GRPCCall.h
@@ -206,7 +206,7 @@ extern NSString *const kGRPCTrailersKey;
 @property(copy, readonly) NSString *path;
 /**
  * Specify whether the call is idempotent or cachable. gRPC may select different HTTP verbs for the
- * call based on this information.
+ * call based on this information. The default verb used by gRPC is POST.
  */
 @property(readonly) GRPCCallSafety safety;
 
diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index e75ca7193a..e56cc72149 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -35,7 +35,6 @@
 #import "private/NSData+GRPC.h"
 #import "private/NSDictionary+GRPC.h"
 #import "private/NSError+GRPC.h"
-#import "private/utilities.h"
 #import "private/GRPCChannelPool.h"
 #import "private/GRPCCompletionQueue.h"
 
@@ -277,7 +276,7 @@ const char *kCFStreamVarName = "grpc_cfstream";
 - (void)writeData:(NSData *)data {
   GRXBufferedPipe *copiedPipe = nil;
   @synchronized(self) {
-    NSAssert(!_canceled, @"Call arleady canceled.");
+    NSAssert(!_canceled, @"Call already canceled.");
     NSAssert(!_finished, @"Call is half-closed before sending data.");
     if (_canceled) {
       return;
@@ -297,7 +296,7 @@ const char *kCFStreamVarName = "grpc_cfstream";
   GRXBufferedPipe *copiedPipe = nil;
   @synchronized(self) {
     NSAssert(_started, @"Call not started.");
-    NSAssert(!_canceled, @"Call arleady canceled.");
+    NSAssert(!_canceled, @"Call already canceled.");
     NSAssert(!_finished, @"Call already half-closed.");
     if (!_started) {
       return;
diff --git a/src/objective-c/GRPCClient/GRPCCallOptions.h b/src/objective-c/GRPCClient/GRPCCallOptions.h
index 158a4745d2..85786c7417 100644
--- a/src/objective-c/GRPCClient/GRPCCallOptions.h
+++ b/src/objective-c/GRPCClient/GRPCCallOptions.h
@@ -170,7 +170,7 @@ typedef NS_ENUM(NSUInteger, GRPCTransportType) {
 /**
  * PEM format certificate chain for client authentication, if required by the server.
  */
-@property(copy, readonly, nullable) NSString *PEMCertChain;
+@property(copy, readonly, nullable) NSString *PEMCertificateChain;
 
 /**
  * Select the transport type to be used for this call.
@@ -314,7 +314,7 @@ typedef NS_ENUM(NSUInteger, GRPCTransportType) {
 /**
  * PEM format certificate chain for client authentication, if required by the server.
  */
-@property(copy, readwrite, nullable) NSString *PEMCertChain;
+@property(copy, readwrite, nullable) NSString *PEMCertificateChain;
 
 /**
  * Select the transport type to be used for this call.
diff --git a/src/objective-c/GRPCClient/GRPCCallOptions.m b/src/objective-c/GRPCClient/GRPCCallOptions.m
index 9a36ee547c..1962ad8956 100644
--- a/src/objective-c/GRPCClient/GRPCCallOptions.m
+++ b/src/objective-c/GRPCClient/GRPCCallOptions.m
@@ -35,7 +35,7 @@ static const NSTimeInterval kDefaultConnectMaxBackoff = 0;
 static NSDictionary *const kDefaultAdditionalChannelArgs = nil;
 static NSString *const kDefaultPEMRootCertificates = nil;
 static NSString *const kDefaultPEMPrivateKey = nil;
-static NSString *const kDefaultPEMCertChain = nil;
+static NSString *const kDefaultPEMCertificateChain = nil;
 static NSString *const kDefaultOauth2AccessToken = nil;
 static const id<GRPCAuthorizationProtocol> kDefaultAuthTokenProvider = nil;
 static const GRPCTransportType kDefaultTransportType = GRPCTransportTypeChttp2BoringSSL;
@@ -74,7 +74,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   NSDictionary *_additionalChannelArgs;
   NSString *_PEMRootCertificates;
   NSString *_PEMPrivateKey;
-  NSString *_PEMCertChain;
+  NSString *_PEMCertificateChain;
   GRPCTransportType _transportType;
   NSString *_hostNameOverride;
   id<NSObject> _logContext;
@@ -99,7 +99,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
 @synthesize additionalChannelArgs = _additionalChannelArgs;
 @synthesize PEMRootCertificates = _PEMRootCertificates;
 @synthesize PEMPrivateKey = _PEMPrivateKey;
-@synthesize PEMCertChain = _PEMCertChain;
+@synthesize PEMCertificateChain = _PEMCertificateChain;
 @synthesize transportType = _transportType;
 @synthesize hostNameOverride = _hostNameOverride;
 @synthesize logContext = _logContext;
@@ -124,7 +124,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                  additionalChannelArgs:kDefaultAdditionalChannelArgs
                    PEMRootCertificates:kDefaultPEMRootCertificates
                          PEMPrivateKey:kDefaultPEMPrivateKey
-                          PEMCertChain:kDefaultPEMCertChain
+                   PEMCertificateChain:kDefaultPEMCertificateChain
                          transportType:kDefaultTransportType
                       hostNameOverride:kDefaultHostNameOverride
                             logContext:kDefaultLogContext
@@ -149,7 +149,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                   additionalChannelArgs:(NSDictionary *)additionalChannelArgs
                     PEMRootCertificates:(NSString *)PEMRootCertificates
                           PEMPrivateKey:(NSString *)PEMPrivateKey
-                           PEMCertChain:(NSString *)PEMCertChain
+                    PEMCertificateChain:(NSString *)PEMCertificateChain
                           transportType:(GRPCTransportType)transportType
                        hostNameOverride:(NSString *)hostNameOverride
                              logContext:(id)logContext
@@ -174,7 +174,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
         [[NSDictionary alloc] initWithDictionary:additionalChannelArgs copyItems:YES];
     _PEMRootCertificates = [PEMRootCertificates copy];
     _PEMPrivateKey = [PEMPrivateKey copy];
-    _PEMCertChain = [PEMCertChain copy];
+    _PEMCertificateChain = [PEMCertificateChain copy];
     _transportType = transportType;
     _hostNameOverride = [hostNameOverride copy];
     _logContext = logContext;
@@ -203,7 +203,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                                               additionalChannelArgs:_additionalChannelArgs
                                                 PEMRootCertificates:_PEMRootCertificates
                                                       PEMPrivateKey:_PEMPrivateKey
-                                                       PEMCertChain:_PEMCertChain
+                                                PEMCertificateChain:_PEMCertificateChain
                                                       transportType:_transportType
                                                    hostNameOverride:_hostNameOverride
                                                          logContext:_logContext
@@ -233,7 +233,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                                                              copyItems:YES]
           PEMRootCertificates:[_PEMRootCertificates copy]
                 PEMPrivateKey:[_PEMPrivateKey copy]
-                 PEMCertChain:[_PEMCertChain copy]
+                 PEMCertificateChain:[_PEMCertificateChain copy]
                 transportType:_transportType
              hostNameOverride:[_hostNameOverride copy]
                    logContext:_logContext
@@ -256,7 +256,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   if (!areObjectsEqual(callOptions.additionalChannelArgs, _additionalChannelArgs)) return NO;
   if (!areObjectsEqual(callOptions.PEMRootCertificates, _PEMRootCertificates)) return NO;
   if (!areObjectsEqual(callOptions.PEMPrivateKey, _PEMPrivateKey)) return NO;
-  if (!areObjectsEqual(callOptions.PEMCertChain, _PEMCertChain)) return NO;
+  if (!areObjectsEqual(callOptions.PEMCertificateChain, _PEMCertificateChain)) return NO;
   if (!areObjectsEqual(callOptions.hostNameOverride, _hostNameOverride)) return NO;
   if (!(callOptions.transportType == _transportType)) return NO;
   if (!areObjectsEqual(callOptions.logContext, _logContext)) return NO;
@@ -280,7 +280,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   result ^= _additionalChannelArgs.hash;
   result ^= _PEMRootCertificates.hash;
   result ^= _PEMPrivateKey.hash;
-  result ^= _PEMCertChain.hash;
+  result ^= _PEMCertificateChain.hash;
   result ^= _hostNameOverride.hash;
   result ^= _transportType;
   result ^= _logContext.hash;
@@ -311,7 +311,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
 @dynamic additionalChannelArgs;
 @dynamic PEMRootCertificates;
 @dynamic PEMPrivateKey;
-@dynamic PEMCertChain;
+@dynamic PEMCertificateChain;
 @dynamic transportType;
 @dynamic hostNameOverride;
 @dynamic logContext;
@@ -336,7 +336,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                  additionalChannelArgs:kDefaultAdditionalChannelArgs
                    PEMRootCertificates:kDefaultPEMRootCertificates
                          PEMPrivateKey:kDefaultPEMPrivateKey
-                          PEMCertChain:kDefaultPEMCertChain
+                          PEMCertificateChain:kDefaultPEMCertificateChain
                          transportType:kDefaultTransportType
                       hostNameOverride:kDefaultHostNameOverride
                             logContext:kDefaultLogContext
@@ -363,7 +363,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
                                               additionalChannelArgs:_additionalChannelArgs
                                                 PEMRootCertificates:_PEMRootCertificates
                                                       PEMPrivateKey:_PEMPrivateKey
-                                                       PEMCertChain:_PEMCertChain
+                                                       PEMCertificateChain:_PEMCertificateChain
                                                       transportType:_transportType
                                                    hostNameOverride:_hostNameOverride
                                                          logContext:_logContext
@@ -391,7 +391,7 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
         additionalChannelArgs:[_additionalChannelArgs copy]
           PEMRootCertificates:_PEMRootCertificates
                 PEMPrivateKey:_PEMPrivateKey
-                 PEMCertChain:_PEMCertChain
+                 PEMCertificateChain:_PEMCertificateChain
                 transportType:_transportType
              hostNameOverride:_hostNameOverride
                    logContext:_logContext
@@ -493,8 +493,8 @@ static BOOL areObjectsEqual(id obj1, id obj2) {
   _PEMPrivateKey = [PEMPrivateKey copy];
 }
 
-- (void)setPEMCertChain:(NSString *)PEMCertChain {
-  _PEMCertChain = [PEMCertChain copy];
+- (void)setPEMCertificateChain:(NSString *)PEMCertificateChain {
+  _PEMCertificateChain = [PEMCertificateChain copy];
 }
 
 - (void)setTransportType:(GRPCTransportType)transportType {
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.h b/src/objective-c/GRPCClient/private/GRPCChannel.h
index c01aeccf81..bbada0d8cb 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.h
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.h
@@ -29,7 +29,10 @@ struct grpc_channel_credentials;
 
 NS_ASSUME_NONNULL_BEGIN
 
-/** Caching signature of a channel. */
+/**
+ * Signature for the channel. If two channel's signatures are the same and connect to the same
+ * remote, they share the same underlying \a GRPCChannel object.
+ */
 @interface GRPCChannelConfiguration : NSObject<NSCopying>
 
 - (instancetype)init NS_UNAVAILABLE;
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.m b/src/objective-c/GRPCClient/private/GRPCChannel.m
index 9432e7ab39..edcedf6e24 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.m
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.m
@@ -28,7 +28,6 @@
 #import "GRPCCronetChannelFactory.h"
 #import "GRPCInsecureChannelFactory.h"
 #import "GRPCSecureChannelFactory.h"
-#import "utilities.h"
 #import "version.h"
 
 #import <GRPCClient/GRPCCall+Cronet.h>
@@ -63,8 +62,9 @@
         factory = [GRPCSecureChannelFactory
             factoryWithPEMRootCertificates:_callOptions.PEMRootCertificates
                                 privateKey:_callOptions.PEMPrivateKey
-                                 certChain:_callOptions.PEMCertChain
+                                 certChain:_callOptions.PEMCertificateChain
                                      error:&error];
+        NSAssert(factory != nil, @"Failed to create secure channel factory");
         if (factory == nil) {
           NSLog(@"Error creating secure channel factory: %@", error);
         }
@@ -114,8 +114,8 @@
         [NSNumber numberWithUnsignedInteger:(NSUInteger)(_callOptions.keepaliveTimeout * 1000)];
   }
 
-  if (_callOptions.retryEnabled == NO) {
-    args[@GRPC_ARG_ENABLE_RETRIES] = [NSNumber numberWithInt:_callOptions.retryEnabled];
+  if (!_callOptions.retryEnabled) {
+    args[@GRPC_ARG_ENABLE_RETRIES] = [NSNumber numberWithInt:_callOptions.retryEnabled ? 1 : 0];
   }
 
   if (_callOptions.connectMinTimeout > 0) {
diff --git a/src/objective-c/GRPCClient/private/GRPCChannelPool.h b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
index d1f28ec9bf..19ef4c93ac 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannelPool.h
+++ b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
@@ -16,11 +16,6 @@
  *
  */
 
-/**
- * Signature for the channel. If two channel's signatures are the same, they share the same
- * underlying \a GRPCChannel object.
- */
-
 #import <GRPCClient/GRPCCallOptions.h>
 
 #import "GRPCChannelFactory.h"
@@ -35,10 +30,10 @@ NS_ASSUME_NONNULL_BEGIN
 @class GRPCWrappedCall;
 
 /**
- * A proxied channel object that can be retained and creates GRPCWrappedCall object from. If a
- * raw channel is not present (i.e. no tcp connection to the server) when a GRPCWrappedCall object
- * is requested, it issues a connection/reconnection. The behavior of this object is to mimic that
- * of gRPC core's channel object.
+ * A proxied channel object that can be retained and used to create GRPCWrappedCall object
+ * regardless of the current connection status. If a connection is not established when a
+ * GRPCWrappedCall object is requested, it issues a connection/reconnection. This behavior is to
+ * follow that of gRPC core's channel object.
  */
 @interface GRPCPooledChannel : NSObject
 
diff --git a/src/objective-c/GRPCClient/private/GRPCChannelPool.m b/src/objective-c/GRPCClient/private/GRPCChannelPool.m
index 349bdd44a6..17c74e558b 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannelPool.m
+++ b/src/objective-c/GRPCClient/private/GRPCChannelPool.m
@@ -27,7 +27,6 @@
 #import "GRPCCronetChannelFactory.h"
 #import "GRPCInsecureChannelFactory.h"
 #import "GRPCSecureChannelFactory.h"
-#import "utilities.h"
 #import "version.h"
 #import "GRPCWrappedCall.h"
 #import "GRPCCompletionQueue.h"
@@ -57,6 +56,34 @@ static const NSTimeInterval kDefaultChannelDestroyDelay = 30;
   return [self initWithChannelConfiguration:channelConfiguration destroyDelay:kDefaultChannelDestroyDelay];
 }
 
+- (nullable instancetype)initWithChannelConfiguration:(GRPCChannelConfiguration *)channelConfiguration
+                                         destroyDelay:(NSTimeInterval)destroyDelay {
+  NSAssert(channelConfiguration != nil, @"channelConfiguration cannot be empty.");
+  if (channelConfiguration == nil) {
+    return nil;
+  }
+
+  if ((self = [super init])) {
+    _channelConfiguration = [channelConfiguration copy];
+    _destroyDelay = destroyDelay;
+    _wrappedCalls = [NSHashTable weakObjectsHashTable];
+    _wrappedChannel = nil;
+    _lastTimedDestroy = nil;
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 110000 || __MAC_OS_X_VERSION_MAX_ALLOWED >= 101300
+    if (@available(iOS 8.0, macOS 10.10, *)) {
+      _timerQueue = dispatch_queue_create(NULL,
+                                          dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_DEFAULT, 0));
+    } else {
+#else
+    {
+#endif
+      _timerQueue = dispatch_queue_create(NULL, DISPATCH_QUEUE_SERIAL);
+    }
+  }
+
+  return self;
+}
+
 - (void)dealloc {
   // Disconnect GRPCWrappedCall objects created but not yet removed
   if (_wrappedCalls.allObjects.count != 0) {
@@ -67,12 +94,14 @@ static const NSTimeInterval kDefaultChannelDestroyDelay = 30;
 }
 
 - (GRPCWrappedCall *)wrappedCallWithPath:(NSString *)path
-completionQueue:(GRPCCompletionQueue *)queue
-callOptions:(GRPCCallOptions *)callOptions {
+                         completionQueue:(GRPCCompletionQueue *)queue
+                             callOptions:(GRPCCallOptions *)callOptions {
   NSAssert(path.length > 0, @"path must not be empty.");
   NSAssert(queue != nil, @"completionQueue must not be empty.");
   NSAssert(callOptions, @"callOptions must not be empty.");
-  if (path.length == 0 || queue == nil || callOptions == nil) return nil;
+  if (path.length == 0 || queue == nil || callOptions == nil) {
+    return nil;
+  }
 
   GRPCWrappedCall *call = nil;
 
@@ -97,6 +126,7 @@ callOptions:(GRPCCallOptions *)callOptions {
     call = [[GRPCWrappedCall alloc] initWithUnmanagedCall:unmanagedCall pooledChannel:self];
     if (call == nil) {
       NSAssert(call != nil, @"Unable to create GRPCWrappedCall object");
+      grpc_call_unref(unmanagedCall);
       return nil;
     }
 
@@ -111,16 +141,22 @@ callOptions:(GRPCCallOptions *)callOptions {
     return;
   }
   @synchronized(self) {
-    // Detect if all objects weakly referenced in _wrappedCalls are (implicitly) removed. In such
-    // case the channel is no longer referenced by a grpc_call object and can be destroyed after
-    // a certain delay.
+    // Detect if all objects weakly referenced in _wrappedCalls are (implicitly) removed.
+    // _wrappedCalls.count does not work here since the hash table may include deallocated weak
+    // references. _wrappedCalls.allObjects forces removal of those objects.
     if (_wrappedCalls.allObjects.count == 0) {
+      // No more call has reference to this channel. We may start the timer for destroying the
+      // channel now.
       NSDate *now = [NSDate date];
       NSAssert(now != nil, @"Unable to create NSDate object 'now'.");
       _lastTimedDestroy = now;
       dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)_destroyDelay * NSEC_PER_SEC),
                      _timerQueue, ^{
                        @synchronized(self) {
+                         // Check _lastTimedDestroy against now in case more calls are created (and
+                         // maybe destroyed) after this dispatch_async. In that case the current
+                         // dispatch_after block should be discarded; the channel should be
+                         // destroyed in a later dispatch_after block.
                          if (now != nil && self->_lastTimedDestroy == now) {
                            self->_wrappedChannel = nil;
                            self->_lastTimedDestroy = nil;
@@ -145,38 +181,6 @@ callOptions:(GRPCCallOptions *)callOptions {
   }
 }
 
-@end
-
-@implementation GRPCPooledChannel (Test)
-
-- (nullable instancetype)initWithChannelConfiguration:(GRPCChannelConfiguration *)channelConfiguration
-                                         destroyDelay:(NSTimeInterval)destroyDelay {
-  NSAssert(channelConfiguration != nil, @"channelConfiguration cannot be empty.");
-  if (channelConfiguration == nil) {
-    return nil;
-  }
-
-  if ((self = [super init])) {
-    _channelConfiguration = [channelConfiguration copy];
-    _destroyDelay = destroyDelay;
-    _wrappedCalls = [NSHashTable weakObjectsHashTable];
-    _wrappedChannel = nil;
-    _lastTimedDestroy = nil;
-#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 110000 || __MAC_OS_X_VERSION_MAX_ALLOWED >= 101300
-    if (@available(iOS 8.0, macOS 10.10, *)) {
-      _timerQueue = dispatch_queue_create(NULL,
-                                          dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_DEFAULT, 0));
-    } else {
-#else
-    {
-#endif
-      _timerQueue = dispatch_queue_create(NULL, DISPATCH_QUEUE_SERIAL);
-    }
-  }
-
-  return self;
-}
-
 - (GRPCChannel *)wrappedChannel {
   GRPCChannel *channel = nil;
   @synchronized(self) {
diff --git a/src/objective-c/GRPCClient/private/GRPCCronetChannelFactory.m b/src/objective-c/GRPCClient/private/GRPCCronetChannelFactory.m
index 0aeb67b142..5bcb021dc4 100644
--- a/src/objective-c/GRPCClient/private/GRPCCronetChannelFactory.m
+++ b/src/objective-c/GRPCClient/private/GRPCCronetChannelFactory.m
@@ -40,8 +40,8 @@
 }
 
 - (instancetype)initWithEngine:(stream_engine *)engine {
+  NSAssert(engine != NULL, @"Cronet engine cannot be empty.");
   if (!engine) {
-    [NSException raise:NSInvalidArgumentException format:@"Cronet engine is NULL. Set it first."];
     return nil;
   }
   if ((self = [super init])) {
@@ -65,14 +65,12 @@
 @implementation GRPCCronetChannelFactory
 
 + (instancetype)sharedInstance {
-  [NSException raise:NSInvalidArgumentException
-              format:@"Must enable macro GRPC_COMPILE_WITH_CRONET to build Cronet channel."];
+  NSAssert(NO, @"Must enable macro GRPC_COMPILE_WITH_CRONET to build Cronet channel.");
   return nil;
 }
 
 - (grpc_channel *)createChannelWithHost:(NSString *)host channelArgs:(NSDictionary *)args {
-  [NSException raise:NSInvalidArgumentException
-              format:@"Must enable macro GRPC_COMPILE_WITH_CRONET to build Cronet channel."];
+  NSAssert(NO, @"Must enable macro GRPC_COMPILE_WITH_CRONET to build Cronet channel.");
   return NULL;
 }
 
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.m b/src/objective-c/GRPCClient/private/GRPCHost.m
index 0f2281ede8..e7a7460221 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.m
+++ b/src/objective-c/GRPCClient/private/GRPCHost.m
@@ -32,7 +32,6 @@
 #import "GRPCCronetChannelFactory.h"
 #import "GRPCSecureChannelFactory.h"
 #import "NSDictionary+GRPC.h"
-#import "utilities.h"
 #import "version.h"
 
 NS_ASSUME_NONNULL_BEGIN
@@ -42,7 +41,7 @@ static NSMutableDictionary *gHostCache;
 @implementation GRPCHost {
   NSString *_PEMRootCertificates;
   NSString *_PEMPrivateKey;
-  NSString *_pemCertChain;
+  NSString *_PEMCertificateChain;
 }
 
 + (nullable instancetype)hostWithAddress:(NSString *)address {
@@ -96,7 +95,7 @@ static NSMutableDictionary *gHostCache;
                      error:(NSError **)errorPtr {
   _PEMRootCertificates = [pemRootCerts copy];
   _PEMPrivateKey = [pemPrivateKey copy];
-  _pemCertChain = [pemCertChain copy];
+  _PEMCertificateChain = [pemCertChain copy];
   return YES;
 }
 
@@ -113,7 +112,7 @@ static NSMutableDictionary *gHostCache;
   options.connectMaxBackoff = (NSTimeInterval)_maxConnectBackoff / 1000;
   options.PEMRootCertificates = _PEMRootCertificates;
   options.PEMPrivateKey = _PEMPrivateKey;
-  options.PEMCertChain = _pemCertChain;
+  options.PEMCertificateChain = _PEMCertificateChain;
   options.hostNameOverride = _hostNameOverride;
 #ifdef GRPC_COMPILE_WITH_CRONET
   // By old API logic, insecure channel precedes Cronet channel; Cronet channel preceeds default
diff --git a/src/objective-c/GRPCClient/private/GRPCSecureChannelFactory.m b/src/objective-c/GRPCClient/private/GRPCSecureChannelFactory.m
index 69f70de17d..3ccc70a744 100644
--- a/src/objective-c/GRPCClient/private/GRPCSecureChannelFactory.m
+++ b/src/objective-c/GRPCClient/private/GRPCSecureChannelFactory.m
@@ -22,7 +22,6 @@
 
 #import "ChannelArgsUtil.h"
 #import "GRPCChannel.h"
-#import "utilities.h"
 
 @implementation GRPCSecureChannelFactory {
   grpc_channel_credentials *_channelCreds;
@@ -116,6 +115,10 @@
 }
 
 - (grpc_channel *)createChannelWithHost:(NSString *)host channelArgs:(NSDictionary *)args {
+  NSAssert(host.length != 0, @"host cannot be empty");
+  if (host.length == 0) {
+    return NULL;
+  }
   grpc_channel_args *coreChannelArgs = GRPCBuildChannelArgs([args copy]);
   grpc_channel *unmanagedChannel =
       grpc_secure_channel_create(_channelCreds, host.UTF8String, coreChannelArgs, NULL);
diff --git a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
index 727c9e0a88..82149e3dba 100644
--- a/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
+++ b/src/objective-c/GRPCClient/private/GRPCWrappedCall.m
@@ -30,7 +30,6 @@
 #import "NSData+GRPC.h"
 #import "NSDictionary+GRPC.h"
 #import "NSError+GRPC.h"
-#import "utilities.h"
 
 #import "GRPCOpBatchLog.h"
 
@@ -237,6 +236,7 @@
 #pragma mark GRPCWrappedCall
 
 @implementation GRPCWrappedCall {
+  // pooledChannel holds weak reference to this object so this is ok
   GRPCPooledChannel *_pooledChannel;
   grpc_call *_call;
 }
@@ -275,8 +275,7 @@
       for (GRPCOperation *operation in operations) {
         ops_array[i++] = operation.op;
       }
-      grpc_call_error error;
-      error = grpc_call_start_batch(_call, ops_array, nops, (__bridge_retained void *)(^(bool success) {
+      grpc_call_error error = grpc_call_start_batch(_call, ops_array, nops, (__bridge_retained void *)(^(bool success) {
         if (!success) {
           if (errorHandler) {
             errorHandler();
@@ -291,11 +290,7 @@
                                     NULL);
       gpr_free(ops_array);
 
-      if (error != GRPC_CALL_OK) {
-        [NSException
-         raise:NSInternalInconsistencyException
-         format:@"A precondition for calling grpc_call_start_batch wasn't met. Error %i", error];
-      }
+      NSAssert(error == GRPC_CALL_OK, @"Error starting a batch of operations: %i", error);
     }
   }
 }
diff --git a/src/objective-c/GRPCClient/private/utilities.h b/src/objective-c/GRPCClient/private/utilities.h
deleted file mode 100644
index 8e3dd79358..0000000000
--- a/src/objective-c/GRPCClient/private/utilities.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- *
- * Copyright 2018 gRPC authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *
- */
-
-#import <Foundation/Foundation.h>
-
-/** Raise exception when condition not met. */
-#define GRPCAssert(condition, errorString) NSAssert(condition, errorString)