POSIX: Add code for shuffling file descriptors.

base/process_util.h

 // Copyright (c) 2009 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.
 
 // This file/namespace contains utility functions for enumerating, ending and
 // computing statistics of processes.
 
 #ifndef BASE_PROCESS_UTIL_H_
 #define BASE_PROCESS_UTIL_H_
 
@@ skipping 26 matching lines @@
 };
 
 struct IoCounters {
   unsigned long long ReadOperationCount;
   unsigned long long WriteOperationCount;
   unsigned long long OtherOperationCount;
   unsigned long long ReadTransferCount;
   unsigned long long WriteTransferCount;
   unsigned long long OtherTransferCount;
 };
+
+#include "base/file_descriptor_shuffle.h"
 #endif
 
 #if defined(OS_MACOSX)
 struct kinfo_proc;
 #endif
 
 namespace base {
 
 // A minimalistic but hopefully cross-platform set of exit codes.
 // Do not change the enumeration values or you will break third-party
@@ skipping 18 matching lines @@
 void CloseProcessHandle(ProcessHandle process);
 
 // Returns the unique ID for the specified process. This is functionally the
 // same as Windows' GetProcessId(), but works on versions of Windows before
 // Win XP SP1 as well.
 ProcessId GetProcId(ProcessHandle process);
 
 #if defined(OS_POSIX)
 // Sets all file descriptors to close on exec except for stdin, stdout
 // and stderr.
+// TODO(agl): remove this function
+// WARNING: do not use. It's inherently race-prone in the face of
+// multi-threading.
 void SetAllFDsToCloseOnExec();
+// Close all file descriptors, expect those which are a destination in the
+// given multimap. Only call this function in a child process where you know
+// that there aren't any other threads.
+void CloseSuperfluousFds(const base::InjectiveMultimap& saved_map);
 #endif
 
 #if defined(OS_WIN)
 // Runs the given application name with the given command line. Normally, the
 // first command line argument should be the path to the process, and don't
 // forget to quote it.
 //
 // If wait is true, it will block and wait for the other process to finish,
 // otherwise, it will just continue asynchronously.
 //
@@ skipping 276 matching lines @@
 // overflow. Has no effect if the OS doesn't provide the necessary facility.
 void EnableTerminationOnHeapCorruption();
 
 // If supported on the platform, and the user has sufficent rights, increase
 // the current process's scheduling priority to a high priority.
 void RaiseProcessToHighPriority();
 
 }  // namespace base
 
 #endif  // BASE_PROCESS_UTIL_H_