Store read_cb in one place

src/core/iomgr/udp_server.c

@@ -84,9 +84,6 @@ struct grpc_udp_server {
   /* shutdown callback */
   void (*shutdown_complete)(void *);
   void *shutdown_complete_arg;
-
-  /* Called when there is data to read from the underlying FD. */
-  grpc_udp_server_read_cb read_cb;
 };
 
 grpc_udp_server *grpc_udp_server_create(void) {
@@ -233,7 +230,8 @@ static void on_read(void *arg, int success) {
   server_port *sp = arg;
 
   /* Tell the registered callback that data is available to read. */
-  sp->server->read_cb(sp->fd, sp->server->cb, sp->server->cb_arg);
+  GPR_ASSERT(sp->read_cb);
+  sp->read_cb(sp->fd, sp->server->cb, sp->server->cb_arg);
 
   /* Re-arm the notification event so we get another chance to read. */
   grpc_fd_notify_on_read(sp->emfd, &sp->read_closure);

test/core/iomgr/udp_server_test.c

@@ -0,0 +1,152 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/iomgr/udp_server.h"
+#include "src/core/iomgr/iomgr.h"
+#include <grpc/support/log.h>
+#include <grpc/support/sync.h>
+#include <grpc/support/time.h>
+#include "test/core/util/test_config.h"
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <unistd.h>
+
+#define LOG_TEST(x) gpr_log(GPR_INFO, "%s", #x)
+
+static grpc_pollset g_pollset;
+static int g_number_of_reads = 0;
+
+static void on_connect(void *arg, grpc_endpoint *tcp) {
+}
+
+static void on_read(int fd, grpc_udp_server_cb new_transport_cb, void *cb_arg) {
+  g_number_of_reads++;
+}
+
+static void test_no_op(void) {
+  grpc_udp_server *s = grpc_udp_server_create();
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_start(void) {
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_start");
+  grpc_udp_server_start(s, NULL, 0, on_connect, NULL);
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_port(void) {
+  struct sockaddr_in addr;
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_port");
+
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, sizeof(addr),
+                                      on_read));
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_no_op_with_port_and_start(void) {
+  struct sockaddr_in addr;
+  grpc_udp_server *s = grpc_udp_server_create();
+  LOG_TEST("test_no_op_with_port_and_start");
+
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, sizeof(addr),
+                                      on_read));
+
+  grpc_udp_server_start(s, NULL, 0, on_connect, NULL);
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void test_receive(int n) {
+  struct sockaddr_storage addr;
+  socklen_t addr_len = sizeof(addr);
+  int clifd;
+  grpc_udp_server *s = grpc_udp_server_create();
+  int i;
+  int number_of_reads_before;
+  gpr_timespec deadline;
+  grpc_pollset *pollsets[1];
+  LOG_TEST("test_receive");
+  gpr_log(GPR_INFO, "clients=%d", n);
+
+  memset(&addr, 0, sizeof(addr));
+  addr.ss_family = AF_INET;
+  GPR_ASSERT(grpc_udp_server_add_port(s, (struct sockaddr *)&addr, addr_len, on_read));
+  pollsets[0] = &g_pollset;
+  grpc_udp_server_start(s, pollsets, 1, on_connect, NULL);
+
+  for (i = 0; i < n; i++) {
+    deadline = GRPC_TIMEOUT_SECONDS_TO_DEADLINE(4000);
+
+    number_of_reads_before = g_number_of_reads;
+    /* Create a socket, send a packet to the UDP server. */
+    clifd = socket(addr.ss_family, SOCK_DGRAM, 0);
+    GPR_ASSERT(clifd >= 0);
+    GPR_ASSERT(connect(clifd, (struct sockaddr *)&addr, addr_len) == 0);
+    GPR_ASSERT(write(clifd, "hello", 5));
+    while (g_number_of_reads == number_of_reads_before &&
+           gpr_time_cmp(deadline, gpr_now()) > 0) {
+      grpc_pollset_work(&g_pollset, deadline);
+    }
+    GPR_ASSERT(g_number_of_reads == number_of_reads_before + 1);
+    close(clifd);
+  }
+
+  grpc_udp_server_destroy(s, NULL, NULL);
+}
+
+static void destroy_pollset(void *p) { grpc_pollset_destroy(p); }
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  grpc_iomgr_init();
+  grpc_pollset_init(&g_pollset);
+
+  test_no_op();
+  test_no_op_with_start();
+  test_no_op_with_port();
+  test_no_op_with_port_and_start();
+  test_receive(1);
+
+  grpc_pollset_shutdown(&g_pollset, destroy_pollset, &g_pollset);
+  grpc_iomgr_shutdown();
+  return 0;
+}