Simplified some batch code, resolved comments

src/objective-c/GRPCClient/private/GRPCCompletionQueue.m

@@ -71,11 +71,14 @@
           case GRPC_OP_COMPLETE:
             handler = (__bridge_transfer GRPCQueueCompletionHandler)event->tag;
             handler(event->data.op_complete);
+            grpc_event_finish(event);
             break;
           case GRPC_QUEUE_SHUTDOWN:
+            grpc_event_finish(event);
             grpc_completion_queue_destroy(unmanagedQueue);
             return;
           default:
+            grpc_event_finish(event);
             [NSException raise:@"Unrecognized completion type" format:@""];
         }
       };

src/objective-c/GRPCClient/private/GRPCWrappedCall.m

@@ -53,13 +53,8 @@
 
 - (instancetype)initWithMetadata:(NSDictionary *)metadata handler:(void (^)(void))handler {
   if (self = [super init]) {
-    if (metadata) {
-      [metadata grpc_getMetadataArray:&_send_metadata];
-      _count = metadata.count;
-    } else {
-      _send_metadata = NULL;
-      _count = 0;
-    }
+    _send_metadata = [metadata grpc_getMetadataArray];
+    _count = metadata.count;
     _handler = handler;
   }
   return self;
@@ -68,6 +63,7 @@
 - (void)getOp:(grpc_op *)op {
   op->op = GRPC_OP_SEND_INITIAL_METADATA;
   op->data.send_initial_metadata.count = _count;
+  op->data.send_initial_metadata.metadata = _send_metadata;
 }
 
 - (void (^)(void))opProcessor {
@@ -148,7 +144,7 @@
 
 @implementation GRPCOpRecvMetadata{
   void(^_handler)(NSDictionary *);
-  grpc_metadata_array *_recv_initial_metadata;
+  grpc_metadata_array _recv_initial_metadata;
 }
 
 - (instancetype) init {
@@ -158,23 +154,22 @@
 - (instancetype) initWithHandler:(void (^)(NSDictionary *))handler {
   if (self = [super init]) {
     _handler = handler;
-    _recv_initial_metadata = gpr_malloc(sizeof(grpc_metadata_array));
-    grpc_metadata_array_init(_recv_initial_metadata);
+    grpc_metadata_array_init(&_recv_initial_metadata);
   }
   return self;
 }
 
 - (void)getOp:(grpc_op *)op {
   op->op = GRPC_OP_RECV_INITIAL_METADATA;
-  op->data.recv_initial_metadata = _recv_initial_metadata;
+  op->data.recv_initial_metadata = &_recv_initial_metadata;
 }
 
 - (void (^)(void))opProcessor {
   return ^{
     NSDictionary *metadata = [NSDictionary
-                              grpc_dictionaryFromMetadata:_recv_initial_metadata->metadata
-                              count:_recv_initial_metadata->count];
-    grpc_metadata_array_destroy(_recv_initial_metadata);
+                              grpc_dictionaryFromMetadata:_recv_initial_metadata.metadata
+                              count:_recv_initial_metadata.count];
+    grpc_metadata_array_destroy(&_recv_initial_metadata);
     if (_handler) {
       _handler(metadata);
     }
@@ -185,7 +180,7 @@
 
 @implementation GRPCOpRecvMessage{
   void(^_handler)(grpc_byte_buffer *);
-  grpc_byte_buffer **_recv_message;
+  grpc_byte_buffer *_recv_message;
 }
 
 - (instancetype)init {
@@ -195,21 +190,19 @@
 - (instancetype)initWithHandler:(void (^)(grpc_byte_buffer *))handler {
   if (self = [super init]) {
     _handler = handler;
-    _recv_message = gpr_malloc(sizeof(grpc_byte_buffer*));
   }
   return self;
 }
 
 - (void)getOp:(grpc_op *)op {
   op->op = GRPC_OP_RECV_MESSAGE;
-  op->data.recv_message = _recv_message;
+  op->data.recv_message = &_recv_message;
 }
 
 - (void (^)(void))opProcessor {
   return ^{
     if (_handler) {
-      _handler(*_recv_message);
-      gpr_free(_recv_message);
+      _handler(_recv_message);
     }
   };
 }
@@ -218,10 +211,8 @@
 
 @implementation GRPCOpRecvStatus{
   void(^_handler)(NSError *);
-  grpc_status_code *_code;
-  char **_details;
-  size_t *_details_capacity;
-  grpc_metadata_array *_recv_trailing_metadata;
+  size_t _details_capacity;
+  grpc_status _status;
 }
 
 - (instancetype) init {
@@ -231,34 +222,27 @@
 - (instancetype) initWithHandler:(void (^)(NSError *))handler {
   if (self = [super init]) {
     _handler = handler;
-    _code = gpr_malloc(sizeof(grpc_status_code));
-    _details = gpr_malloc(sizeof(char*));
-    _details_capacity = gpr_malloc(sizeof(size_t));
-    *_details_capacity = 0;
-    _recv_trailing_metadata = gpr_malloc(sizeof(grpc_metadata_array));
+    _status.details = NULL;
+    _details_capacity = 0;
+    grpc_metadata_array_init(&_status.metadata);
   }
   return self;
 }
 
 - (void)getOp:(grpc_op *)op {
   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
-  op->data.recv_status_on_client.status = _code;
-  op->data.recv_status_on_client.status_details = _details;
-  op->data.recv_status_on_client.status_details_capacity = _details_capacity;
-  op->data.recv_status_on_client.trailing_metadata = _recv_trailing_metadata;
+  op->data.recv_status_on_client.status = &_status.status;
+  op->data.recv_status_on_client.status_details = &_status.details;
+  op->data.recv_status_on_client.status_details_capacity = &_details_capacity;
+  op->data.recv_status_on_client.trailing_metadata = &_status.metadata;
 }
 
 - (void (^)(void))opProcessor {
   return ^{
-    grpc_status status;
-    status.status = *_code;
-    status.details = *_details;
-    status.metadata = _recv_trailing_metadata;
-    gpr_free(_code);
-    gpr_free(_details);
-    gpr_free(_details_capacity);
     if (_handler) {
-      _handler([NSError grpc_errorFromStatus:&status]);
+      NSError *error = [NSError grpc_errorFromStatus:&_status];
+      grpc_metadata_array_destroy(&_status.metadata);
+      _handler(error);
     }
   };
 }
@@ -326,7 +310,8 @@
   }));
   
   if (error != GRPC_CALL_OK) {
-    [NSException raise:NSInvalidArgumentException format:@"The batch did not start successfully"];
+    [NSException raise:NSInternalInconsistencyException
+                format:@"A precondition for calling grpc_call_start_batch wasn't met"];
   }
 }
 

src/objective-c/GRPCClient/private/NSDictionary+GRPC.h

@@ -36,5 +36,5 @@
 
 @interface NSDictionary (GRPC)
 + (instancetype)grpc_dictionaryFromMetadata:(struct grpc_metadata *)entries count:(size_t)count;
-- (void)grpc_getMetadataArray:(grpc_metadata **)metadata;
+- (grpc_metadata *)grpc_getMetadataArray;
 @end

src/objective-c/GRPCClient/private/NSDictionary+GRPC.m

@@ -33,7 +33,6 @@
 
 #import "NSDictionary+GRPC.h"
 
-#include <grpc/grpc.h>
 #include <grpc/support/alloc.h>
 
 @implementation NSDictionary (GRPC)
@@ -55,12 +54,12 @@
   return metadata;
 }
 
-- (void)grpc_getMetadataArray:(grpc_metadata **)metadata {
-  *metadata = gpr_malloc([self count] * sizeof(grpc_metadata));
+- (grpc_metadata *)grpc_getMetadataArray {
+  grpc_metadata *metadata = gpr_malloc([self count] * sizeof(grpc_metadata));
   int i = 0;
   for (id key in self) {
     id value = self[key];
-    grpc_metadata *current = &(*metadata)[i];
+    grpc_metadata *current = &metadata[i];
     current->key = [key UTF8String];
     if ([value isKindOfClass:[NSData class]]) {
       current->value = [value bytes];
@@ -70,8 +69,8 @@
       [NSException raise:NSInvalidArgumentException
                   format:@"Metadata values must be NSString or NSData."];
     }
-    current->value = [value UTF8String];
     i += 1;
   }
+  return metadata;
 }
 @end

src/objective-c/GRPCClient/private/NSError+GRPC.h

@@ -62,7 +62,7 @@ typedef NS_ENUM(NSInteger, GRPCErrorCode) {
 typedef struct grpc_status {
     grpc_status_code status;
     const char *details;
-    grpc_metadata_array *metadata;
+    grpc_metadata_array metadata;
 } grpc_status;
 
 @interface NSError (GRPC)