Allow udp_server to create multiple listeners for each port via SO_REUSEPORT

1 files changed, 24 insertions, 0 deletions

diff --git a/src/core/lib/iomgr/socket_utils_common_posix.cc b/src/core/lib/iomgr/socket_utils_common_posix.cc
index c52e237fa8..8ef1f4f4a2 100644
--- a/src/core/lib/iomgr/socket_utils_common_posix.cc
+++ b/src/core/lib/iomgr/socket_utils_common_posix.cc
@@ -181,6 +181,30 @@ grpc_error* grpc_set_socket_reuse_port(int fd, int reuse) {
 #endif
 }
 
+static gpr_once g_probe_so_reuesport_once = GPR_ONCE_INIT;
+static int g_support_so_reuseport = false;
+
+void probe_so_reuseport_once(void) {
+#ifndef GPR_MANYLINUX1
+  int s = socket(AF_INET, SOCK_STREAM, 0);
+  if (s < 0) {
+    /* This might be an ipv6-only environment in which case 'socket(AF_INET,..)'
+       call would fail. Try creating IPv6 socket in that case */
+    s = socket(AF_INET6, SOCK_STREAM, 0);
+  }
+  if (s >= 0) {
+    g_support_so_reuseport = GRPC_LOG_IF_ERROR("check for SO_REUSEPORT",
+                                         grpc_set_socket_reuse_port(s, 1));
+    close(s);
+  }
+#endif
+}
+
+bool grpc_is_socket_reuse_port_supported() {
+  gpr_once_init(&g_probe_so_reuesport_once, probe_so_reuseport_once);
+  return g_support_so_reuseport;
+}
+
 /* disable nagle */
 grpc_error* grpc_set_socket_low_latency(int fd, int low_latency) {
   int val = (low_latency != 0);