Don't use select() in SyncSocket when handle > FD_SETSIZE.

base/sync_socket_posix.cc

 // Copyright (c) 2012 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 "base/sync_socket.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
@@ skipping 107 matching lines @@
   return 0;
 }
 
 size_t SyncSocket::ReceiveWithTimeout(void* buffer,
                                       size_t length,
                                       TimeDelta timeout) {
   ThreadRestrictions::AssertIOAllowed();
   DCHECK_GT(length, 0u);
   DCHECK_LE(length, kMaxMessageLength);
   DCHECK_NE(handle_, kInvalidHandle);
-  CHECK_LT(handle_, FD_SETSIZE);
+
+  // TODO(dalecurtis): There's an undiagnosed issue on OSX where we're seeing
+  // extremely high numbers of open files which prevents select() from being
+  // used.  When this is true, the best we can do is Peek() to see if we can
+  // Receive() now and return an error if not.  See http://crbug.com/314364.

[awong, 2013/11/04 23:25:23]

Please clarify why returning 0 doesn't turn into degenerate behavior. :)

[DaleCurtis, 2013/11/04 23:32:25]

Clarified that the 0 return value is a timeout error.

+  if (handle_ >= FD_SETSIZE)
+    return Peek() < length ? 0 : Receive(buffer, length);
 
   // Only timeouts greater than zero and less than one second are allowed.
   DCHECK_GT(timeout.InMicroseconds(), 0);
   DCHECK_LT(timeout.InMicroseconds(),
             base::TimeDelta::FromSeconds(1).InMicroseconds());
 
   // Track the start time so we can reduce the timeout as data is read.
   TimeTicks start_time = TimeTicks::Now();
   const TimeTicks finish_time = start_time + timeout;
 
@@ skipping 78 matching lines @@
   return len;
 }
 
 // static
 bool CancelableSyncSocket::CreatePair(CancelableSyncSocket* socket_a,
                                       CancelableSyncSocket* socket_b) {
   return SyncSocket::CreatePair(socket_a, socket_b);
 }
 
 }  // namespace base