Fix tests on Mac

test/core/iomgr/ev_epollsig_linux_test.c

@@ -403,6 +403,7 @@ int main(int argc, char **argv) {
   const char *poll_strategy = NULL;
   grpc_test_init(argc, argv);
   grpc_iomgr_init();
+  grpc_iomgr_start();
 
   poll_strategy = grpc_get_poll_strategy_name();
   if (poll_strategy != NULL && strcmp(poll_strategy, "epollsig") == 0) {

test/core/iomgr/fd_conservation_posix_test.c

@@ -46,6 +46,7 @@ int main(int argc, char **argv) {
 
   grpc_test_init(argc, argv);
   grpc_iomgr_init();
+  grpc_iomgr_start();
 
   /* set max # of file descriptors to a low value, and
      verify we can create and destroy many more than this number

test/core/iomgr/fd_posix_test.c

@@ -543,6 +543,7 @@ int main(int argc, char **argv) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_test_init(argc, argv);
   grpc_iomgr_init();
+  grpc_iomgr_start();
   g_pollset = gpr_zalloc(grpc_pollset_size());
   grpc_pollset_init(g_pollset, &g_mu);
   test_grpc_fd();

test/core/iomgr/pollset_set_test.c

@@ -448,6 +448,7 @@ int main(int argc, char **argv) {
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
   grpc_test_init(argc, argv);
   grpc_iomgr_init();
+  grpc_iomgr_start();
 
   if (poll_strategy != NULL &&
       (strcmp(poll_strategy, "epoll") == 0 ||

test/core/iomgr/resolve_address_posix_test.c

@@ -176,6 +176,7 @@ int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_executor_init();
   grpc_iomgr_init();
+  grpc_iomgr_start();
   test_unix_socket();
   test_unix_socket_path_name_too_long();
   {

test/core/iomgr/resolve_address_test.c

@@ -265,6 +265,7 @@ int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
   grpc_executor_init();
   grpc_iomgr_init();
+  grpc_iomgr_start();
   test_localhost();
   test_default_port();
   test_non_numeric_default_port();