avoid UDS conflict between tests in local bazel test run

test/core/end2end/fixtures/h2_local_uds.cc

@@ -16,6 +16,7 @@
  *
  */
 
+#include <inttypes.h>
 #include <unistd.h>
 
 #include "absl/strings/str_format.h"
@@ -32,9 +33,11 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack_uds(
     grpc_channel_args* /*client_args*/, grpc_channel_args* /*server_args*/) {
   grpc_end2end_test_fixture f =
       grpc_end2end_local_chttp2_create_fixture_fullstack();
+  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   static_cast<grpc_end2end_local_fullstack_fixture_data*>(f.fixture_data)
-      ->localaddr = absl::StrFormat("unix:/tmp/grpc_fullstack_test.%d.%d",
-                                    getpid(), unique++);
+      ->localaddr = absl::StrFormat(
+      "unix:/tmp/grpc_fullstack_test.%d.%" PRId64 ".%" PRId32 ".%d", getpid(),
+      now.tv_sec, now.tv_nsec, unique++);
   return f;
 }
 

test/core/end2end/fixtures/h2_uds.cc

@@ -18,6 +18,7 @@
 
 #include "test/core/end2end/end2end_tests.h"
 
+#include <inttypes.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -62,16 +63,20 @@ static grpc_end2end_test_fixture chttp2_create_fixture_fullstack_base(
 
 static grpc_end2end_test_fixture chttp2_create_fixture_fullstack(
     grpc_channel_args* /*client_args*/, grpc_channel_args* /*server_args*/) {
+  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   const std::string localaddr = absl::StrFormat(
-      "unix:/tmp/grpc_fullstack_test.%d.%d", getpid(), unique++);
+      "unix:/tmp/grpc_fullstack_test.%d.%" PRId64 ".%" PRId32 ".%d", getpid(),
+      now.tv_sec, now.tv_nsec, unique++);
   return chttp2_create_fixture_fullstack_base(localaddr);
 }
 
 static grpc_end2end_test_fixture
 chttp2_create_fixture_fullstack_abstract_namespace(
     grpc_channel_args* /*client_args*/, grpc_channel_args* /*server_args*/) {
+  gpr_timespec now = gpr_now(GPR_CLOCK_REALTIME);
   const std::string localaddr = absl::StrFormat(
-      "unix-abstract:grpc_fullstack_test.%d.%d", getpid(), unique++);
+      "unix-abstract:grpc_fullstack_test.%d.%" PRId64 ".%" PRId32 ".%d",
+      getpid(), now.tv_sec, now.tv_nsec, unique++);
   return chttp2_create_fixture_fullstack_base(localaddr);
 }