Disable SIGPIPE for sockets created on iOS.

webrtc/base/physicalsocketserver.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include "webrtc/base/physicalsocketserver.h"
@@ skipping 591 matching lines @@
 
 bool SocketDispatcher::Initialize() {
   RTC_DCHECK(s_ != INVALID_SOCKET);
   // Must be a non-blocking
 #if defined(WEBRTC_WIN)
   u_long argp = 1;
   ioctlsocket(s_, FIONBIO, &argp);
 #elif defined(WEBRTC_POSIX)
   fcntl(s_, F_SETFL, fcntl(s_, F_GETFL, 0) | O_NONBLOCK);
 #endif
+#if defined(WEBRTC_IOS)
+  // iOS may kill sockets when the app is moved to the background
+  // (specifically, if the app doesn't use the "voip" UIBackgroundMode). When
+  // we attempt to write to such a socket, SIGPIPE will be raised, which by
+  // default will terminate the process, which we don't want. By specifying
+  // this socket option, SIGPIPE will be disabled for the socket.
+  int value = 1;
+  ::setsockopt(s_, SOL_SOCKET, SO_NOSIGPIPE, &value, sizeof(value));
+#endif
   ss_->Add(this);
   return true;
 }
 
 bool SocketDispatcher::Create(int type) {
   return Create(AF_INET, type);
 }
 
 bool SocketDispatcher::Create(int family, int type) {
   // Change the socket to be non-blocking.
@@ skipping 964 matching lines @@
        break;
     }
   }
 
   // Done
   return true;
 }
 #endif  // WEBRTC_WIN
 
 }  // namespace rtc