Recognize EMSGSIZE as non-fatal on OS X.

ipc/ipc_channel_posix.cc

 // Copyright (c) 2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ipc/ipc_channel_posix.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stddef.h>
 #include <sys/types.h>
@@ skipping 223 matching lines @@
   if (HANDLE_EINTR(connect(fd, reinterpret_cast<sockaddr*>(&server_unix_addr),
                            server_unix_addr_len)) != 0) {
     HANDLE_EINTR(close(fd));
     return false;
   }
 
   *client_socket = fd;
   return true;
 }
 
+bool SocketWriteErrorIsRecoverable() {
+#if defined(OS_MACOSX)
+  // On OS X if sendmsg() is trying to send fds between processes and there
+  // isn't enough room in the output buffer to send the fd structure over
+  // atomically then EMSGSIZE is returned.
+  return errno == EAGAIN || errno == EMSGSIZE;
+#else
+  return errno == EAGAIN;
+#endif
+}
+
 }  // namespace
 //------------------------------------------------------------------------------
 
 Channel::ChannelImpl::ChannelImpl(const std::string& channel_id, Mode mode,
                                   Listener* listener)
     : mode_(mode),
       is_blocked_on_write_(false),
       message_send_bytes_written_(0),
       uses_fifo_(CommandLine::ForCurrentProcess()->HasSwitch(
                      switches::kIPCUseFIFO)),
@@ skipping 554 matching lines @@
         bytes_written = HANDLE_EINTR(write(pipe_, out_bytes, amt_to_write));
       } else
 #endif
       {
         bytes_written = HANDLE_EINTR(sendmsg(pipe_, &msgh, MSG_DONTWAIT));
       }
     }
     if (bytes_written > 0)
       msg->file_descriptor_set()->CommitAll();
 
-    if (bytes_written < 0 && errno != EAGAIN) {
+    if (bytes_written < 0 && !SocketWriteErrorIsRecoverable()) {
 #if defined(OS_MACOSX)
       // On OSX writing to a pipe with no listener returns EPERM.
       if (errno == EPERM) {
         Close();
         return false;
       }
 #endif  // OS_MACOSX
       if (errno == EPIPE) {
         Close();
         return false;
       }
       PLOG(ERROR) << "pipe error on "
                   << fd_written
                   << " Currently writing message of size:"
-                  << msg->size()
-                  << " msgh.msg_iovlen:"
-                  << msgh.msg_iovlen
-                  << " amt_to_write: "
-                  << amt_to_write
-                  << " num FDs to send:"
-                  << msg->file_descriptor_set()->size();
+                  << msg->size();
       return false;
     }
 
     if (static_cast<size_t>(bytes_written) != amt_to_write) {
       if (bytes_written > 0) {
         // If write() fails with EAGAIN then bytes_written will be -1.
         message_send_bytes_written_ += bytes_written;
       }
 
       // Tell libevent to call us back once things are unblocked.
@@ skipping 180 matching lines @@
 
 bool Channel::Send(Message* message) {
   return channel_impl_->Send(message);
 }
 
 int Channel::GetClientFileDescriptor() const {
   return channel_impl_->GetClientFileDescriptor();
 }
 
 }  // namespace IPC