Make blocking_resolve_address overridable

src/core/iomgr/resolve_address.h

@@ -66,7 +66,7 @@ void grpc_resolved_addresses_destroy(grpc_resolved_addresses *addresses);
 
 /* Resolve addr in a blocking fashion. Returns NULL on failure. On success,
    result must be freed with grpc_resolved_addresses_destroy. */
-grpc_resolved_addresses *grpc_blocking_resolve_address(
+extern grpc_resolved_addresses *(*grpc_blocking_resolve_address)(
-    const char *addr, const char *default_port);
+    const char *name, const char *default_port);
 
 #endif /* GRPC_INTERNAL_CORE_IOMGR_RESOLVE_ADDRESS_H */

src/core/iomgr/resolve_address_posix.c

@@ -34,18 +34,13 @@
 #include <grpc/support/port_platform.h>
 #ifdef GPR_POSIX_SOCKET
 
-#include "src/core/iomgr/sockaddr.h"
 #include "src/core/iomgr/resolve_address.h"
+#include "src/core/iomgr/sockaddr.h"
 
+#include <string.h>
 #include <sys/types.h>
 #include <sys/un.h>
-#include <string.h>
 
-#include "src/core/iomgr/executor.h"
-#include "src/core/iomgr/iomgr_internal.h"
-#include "src/core/iomgr/sockaddr_utils.h"
-#include "src/core/support/block_annotate.h"
-#include "src/core/support/string.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
 #include <grpc/support/log.h>
@@ -53,6 +48,11 @@
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
 #include <grpc/support/useful.h>
+#include "src/core/iomgr/executor.h"
+#include "src/core/iomgr/iomgr_internal.h"
+#include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/support/block_annotate.h"
+#include "src/core/support/string.h"
 
 typedef struct {
   char *name;
@@ -62,7 +62,7 @@ typedef struct {
   void *arg;
 } request;
 
-grpc_resolved_addresses *grpc_blocking_resolve_address(
+static grpc_resolved_addresses *blocking_resolve_address_impl(
     const char *name, const char *default_port) {
   struct addrinfo hints;
   struct addrinfo *result = NULL, *resp;
@@ -150,6 +150,9 @@ done:
   return addrs;
 }
 
+grpc_resolved_addresses *(*grpc_blocking_resolve_address)(
+    const char *name, const char *default_port) = blocking_resolve_address_impl;
+
 /* Callback to be passed to grpc_executor to asynch-ify
  * grpc_blocking_resolve_address */
 static void do_request_thread(grpc_exec_ctx *exec_ctx, void *rp, bool success) {

src/core/iomgr/resolve_address_windows.c

@@ -34,17 +34,12 @@
 #include <grpc/support/port_platform.h>
 #ifdef GPR_WINSOCK_SOCKET
 
-#include "src/core/iomgr/sockaddr.h"
 #include "src/core/iomgr/resolve_address.h"
+#include "src/core/iomgr/sockaddr.h"
 
-#include <sys/types.h>
 #include <string.h>
+#include <sys/types.h>
 
-#include "src/core/iomgr/executor.h"
-#include "src/core/iomgr/iomgr_internal.h"
-#include "src/core/iomgr/sockaddr_utils.h"
-#include "src/core/support/block_annotate.h"
-#include "src/core/support/string.h"
 #include <grpc/support/alloc.h>
 #include <grpc/support/host_port.h>
 #include <grpc/support/log.h>
@@ -52,6 +47,11 @@
 #include <grpc/support/string_util.h>
 #include <grpc/support/thd.h>
 #include <grpc/support/time.h>
+#include "src/core/iomgr/executor.h"
+#include "src/core/iomgr/iomgr_internal.h"
+#include "src/core/iomgr/sockaddr_utils.h"
+#include "src/core/support/block_annotate.h"
+#include "src/core/support/string.h"
 
 typedef struct {
   char *name;
@@ -61,7 +61,7 @@ typedef struct {
   void *arg;
 } request;
 
-grpc_resolved_addresses *grpc_blocking_resolve_address(
+static grpc_resolved_addresses *blocking_resolve_address_impl(
     const char *name, const char *default_port) {
   struct addrinfo hints;
   struct addrinfo *result = NULL, *resp;
@@ -133,6 +133,9 @@ done:
   return addrs;
 }
 
+grpc_resolved_addresses *(*grpc_blocking_resolve_address)(
+    const char *name, const char *default_port) = blocking_resolve_address_impl;
+
 /* Callback to be passed to grpc_executor to asynch-ify
  * grpc_blocking_resolve_address */
 static void do_request_thread(grpc_exec_ctx *exec_ctx, void *rp, bool success) {