Make some global variables static

They do not need to be extern.

src/ruby/ext/grpc/rb_call.c

@@ -42,6 +42,18 @@
 #include "rb_completion_queue.h"
 #include "rb_grpc.h"
 
+/* grpc_rb_cCall is the Call class whose instances proxy grpc_call. */
+static VALUE grpc_rb_cCall;
+
+/* grpc_rb_eCallError is the ruby class of the exception thrown during call
+   operations; */
+VALUE grpc_rb_eCallError = Qnil;
+
+/* grpc_rb_eOutOfTime is the ruby class of the exception thrown to indicate
+   a timeout. */
+static VALUE grpc_rb_eOutOfTime = Qnil;
+
+
 /* grpc_rb_sBatchResult is struct class used to hold the results of a batch
  * call. */
 static VALUE grpc_rb_sBatchResult;
@@ -582,17 +594,6 @@ static VALUE grpc_rb_call_run_batch(VALUE self, VALUE cqueue, VALUE tag,
   return result;
 }
 
-/* grpc_rb_cCall is the ruby class that proxies grpc_call. */
-VALUE grpc_rb_cCall = Qnil;
-
-/* grpc_rb_eCallError is the ruby class of the exception thrown during call
-   operations; */
-VALUE grpc_rb_eCallError = Qnil;
-
-/* grpc_rb_eOutOfTime is the ruby class of the exception thrown to indicate
-   a timeout. */
-VALUE grpc_rb_eOutOfTime = Qnil;
-
 void Init_grpc_error_codes() {
   /* Constants representing the error codes of grpc_call_error in grpc.h */
   VALUE grpc_rb_mRpcErrors =

src/ruby/ext/grpc/rb_call.h

@@ -49,17 +49,10 @@ const char* grpc_call_error_detail_of(grpc_call_error err);
 /* Converts a metadata array to a hash. */
 VALUE grpc_rb_md_ary_to_h(grpc_metadata_array *md_ary);
 
-/* grpc_rb_cCall is the Call class whose instances proxy grpc_call. */
-extern VALUE grpc_rb_cCall;
-
 /* grpc_rb_eCallError is the ruby class of the exception thrown during call
    operations. */
 extern VALUE grpc_rb_eCallError;
 
-/* grpc_rb_eOutOfTime is the ruby class of the exception thrown to indicate
-   a timeout. */
-extern VALUE grpc_rb_eOutOfTime;
-
 /* Initializes the Call class. */
 void Init_grpc_call();
 

src/ruby/ext/grpc/rb_channel.c

@@ -58,6 +58,8 @@ static ID id_target;
  * GCed before the channel */
 static ID id_cqueue;
 
+/* grpc_rb_cChannel is the ruby class that proxies grpc_channel. */
+static VALUE grpc_rb_cChannel = Qnil;
 
 /* Used during the conversion of a hash to channel args during channel setup */
 static VALUE grpc_rb_cChannelArgs;
@@ -240,9 +242,6 @@ static VALUE grpc_rb_channel_destroy(VALUE self) {
   return Qnil;
 }
 
-/* grpc_rb_cChannel is the ruby class that proxies grpc_channel. */
-VALUE grpc_rb_cChannel = Qnil;
-
 void Init_grpc_channel() {
   grpc_rb_cChannelArgs = rb_define_class("TmpChannelArgs", rb_cObject);
   grpc_rb_cChannel =

src/ruby/ext/grpc/rb_channel.h

@@ -37,9 +37,6 @@
 #include <ruby.h>
 #include <grpc/grpc.h>
 
-/* grpc_rb_cChannel is the Channel class whose instances proxy grpc_channel. */
-extern VALUE grpc_rb_cChannel;
-
 /* Initializes the Channel class. */
 void Init_grpc_channel();
 

src/ruby/ext/grpc/rb_completion_queue.c

@@ -39,6 +39,10 @@
 #include <grpc/support/time.h>
 #include "rb_grpc.h"
 
+/* grpc_rb_cCompletionQueue is the ruby class that proxies
+ * grpc_completion_queue. */
+static VALUE grpc_rb_cCompletionQueue = Qnil;
+
 /* Used to allow grpc_completion_queue_next call to release the GIL */
 typedef struct next_call_stack {
   grpc_completion_queue *cq;
@@ -166,10 +170,6 @@ grpc_event* grpc_rb_completion_queue_pluck_event(VALUE self, VALUE tag,
   return next_call.event;
 }
 
-/* grpc_rb_cCompletionQueue is the ruby class that proxies
- * grpc_completion_queue. */
-VALUE grpc_rb_cCompletionQueue = Qnil;
-
 void Init_grpc_completion_queue() {
   grpc_rb_cCompletionQueue =
       rb_define_class_under(grpc_rb_mGrpcCore, "CompletionQueue", rb_cObject);

src/ruby/ext/grpc/rb_completion_queue.h

@@ -48,10 +48,6 @@ grpc_completion_queue *grpc_rb_get_wrapped_completion_queue(VALUE v);
 grpc_event* grpc_rb_completion_queue_pluck_event(VALUE cqueue, VALUE tag,
                                                  VALUE timeout);
 
-/* grpc_rb_cCompletionQueue is the CompletionQueue class whose instances proxy
-   grpc_completion_queue. */
-extern VALUE grpc_rb_cCompletionQueue;
-
 /* Initializes the CompletionQueue class. */
 void Init_grpc_completion_queue();
 

src/ruby/ext/grpc/rb_credentials.c

@@ -40,6 +40,9 @@
 
 #include "rb_grpc.h"
 
+/* grpc_rb_cCredentials is the ruby class that proxies grpc_credentials. */
+static VALUE grpc_rb_cCredentials = Qnil;
+
 /* grpc_rb_credentials wraps a grpc_credentials.  It provides a
  * peer ruby object, 'mark' to minimize copying when a credential is
  * created from ruby. */
@@ -242,9 +245,6 @@ static VALUE grpc_rb_credentials_init(int argc, VALUE *argv, VALUE self) {
   return self;
 }
 
-/* grpc_rb_cCredentials is the ruby class that proxies grpc_credentials. */
-VALUE grpc_rb_cCredentials = Qnil;
-
 void Init_grpc_credentials() {
   grpc_rb_cCredentials =
       rb_define_class_under(grpc_rb_mGrpcCore, "Credentials", rb_cObject);

src/ruby/ext/grpc/rb_credentials.h

@@ -37,10 +37,6 @@
 #include <ruby.h>
 #include <grpc/grpc_security.h>
 
-/* grpc_rb_cCredentials is the ruby class whose instances proxy
-   grpc_credentials. */
-extern VALUE grpc_rb_cCredentials;
-
 /* Initializes the ruby Credentials class. */
 void Init_grpc_credentials();
 

src/ruby/ext/grpc/rb_grpc.c

@@ -50,7 +50,7 @@
 const RUBY_DATA_FUNC GC_NOT_MARKED = NULL;
 const RUBY_DATA_FUNC GC_DONT_FREE = NULL;
 
-VALUE grpc_rb_cTimeVal = Qnil;
+static VALUE grpc_rb_cTimeVal = Qnil;
 
 /* Alloc func that blocks allocation of a given object by raising an
  * exception. */

src/ruby/ext/grpc/rb_grpc.h

@@ -41,9 +41,6 @@
 /* grpc_rb_mGrpcCore is the module containing the ruby wrapper GRPC classes. */
 extern VALUE grpc_rb_mGrpcCore;
 
-/* Class used to wrap timeval structs. */
-extern VALUE grpc_rb_cTimeVal;
-
 /* grpc_rb_sNewServerRpc is the struct that holds new server rpc details. */
 extern VALUE grpc_rb_sNewServerRpc;
 

src/ruby/ext/grpc/rb_server.c

@@ -44,7 +44,7 @@
 #include "rb_grpc.h"
 
 /* grpc_rb_cServer is the ruby class that proxies grpc_server. */
-VALUE grpc_rb_cServer = Qnil;
+static VALUE grpc_rb_cServer = Qnil;
 
 /* id_at is the constructor method of the ruby standard Time class. */
 static ID id_at;

src/ruby/ext/grpc/rb_server.h

@@ -37,10 +37,6 @@
 #include <ruby.h>
 #include <grpc/grpc.h>
 
-/* grpc_rb_cServer is the Server class whose instances proxy
-   grpc_byte_buffer. */
-extern VALUE grpc_rb_cServer;
-
 /* Initializes the Server class. */
 void Init_grpc_server();
 

src/ruby/ext/grpc/rb_server_credentials.c

@@ -40,6 +40,10 @@
 
 #include "rb_grpc.h"
 
+/* grpc_rb_cServerCredentials is the ruby class that proxies
+   grpc_server_credentials. */
+static VALUE grpc_rb_cServerCredentials = Qnil;
+
 /* grpc_rb_server_credentials wraps a grpc_server_credentials.  It provides a
    peer ruby object, 'mark' to minimize copying when a server credential is
    created from ruby. */
@@ -180,10 +184,6 @@ static VALUE grpc_rb_server_credentials_init(VALUE self, VALUE pem_root_certs,
   return self;
 }
 
-/* grpc_rb_cServerCredentials is the ruby class that proxies
-   grpc_server_credentials. */
-VALUE grpc_rb_cServerCredentials = Qnil;
-
 void Init_grpc_server_credentials() {
   grpc_rb_cServerCredentials =
       rb_define_class_under(grpc_rb_mGrpcCore, "ServerCredentials", rb_cObject);

src/ruby/ext/grpc/rb_server_credentials.h

@@ -37,10 +37,6 @@
 #include <ruby.h>
 #include <grpc/grpc_security.h>
 
-/* grpc_rb_cServerCredentials is the ruby class whose instances proxy
-   grpc_server_credentials. */
-extern VALUE grpc_rb_cServerCredentials;
-
 /* Initializes the ruby ServerCredentials class. */
 void Init_grpc_server_credentials();