base/process.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_PROCESS_H_
   6 #define BASE_PROCESS_H_
   7 #pragma once
   8
   9 #include "base/base_export.h"
  10 #include "base/basictypes.h"
  11 #include "build/build_config.h"
  12
  13 #include <sys/types.h>
  14 #if defined(OS_WIN)
  15 #include <windows.h>
  16 #endif
  17
  18 namespace base {
  19
  20 // ProcessHandle is a platform specific type which represents the underlying OS
  21 // handle to a process.
  22 // ProcessId is a number which identifies the process in the OS.
  23 #if defined(OS_WIN)
  24 typedef HANDLE ProcessHandle;
  25 typedef DWORD ProcessId;
  26 typedef HANDLE UserTokenHandle;
  27 const ProcessHandle kNullProcessHandle = NULL;
  28 const ProcessId kNullProcessId = 0;
  29 #elif defined(OS_POSIX)
  30 // On POSIX, our ProcessHandle will just be the PID.
  31 typedef pid_t ProcessHandle;
  32 typedef pid_t ProcessId;
  33 const ProcessHandle kNullProcessHandle = 0;
  34 const ProcessId kNullProcessId = 0;
  35 #endif  // defined(OS_WIN)
  36
  37 class BASE_EXPORT Process {
  38  public:
  39   Process() : process_(kNullProcessHandle) {
  40   }
  41
  42   explicit Process(ProcessHandle handle) : process_(handle) {
  43   }
  44
  45   // A handle to the current process.
  46   static Process Current();
  47
  48   static bool CanBackgroundProcesses();
  49
  50   // Get/Set the handle for this process. The handle will be 0 if the process
  51   // is no longer running.
  52   ProcessHandle handle() const { return process_; }
  53   void set_handle(ProcessHandle handle) {
  54     process_ = handle;
  55   }
  56
  57   // Get the PID for this process.
  58   ProcessId pid() const;
  59
  60   // Is the this process the current process.
  61   bool is_current() const;
  62
  63   // Close the process handle. This will not terminate the process.
  64   void Close();
  65
  66   // Terminates the process with extreme prejudice. The given result code will
  67   // be the exit code of the process. If the process has already exited, this
  68   // will do nothing.
  69   void Terminate(int result_code);
  70
  71   // A process is backgrounded when it's priority is lower than normal.
  72   // Return true if this process is backgrounded, false otherwise.
  73   bool IsProcessBackgrounded() const;
  74
  75   // Set a process as backgrounded. If value is true, the priority
  76   // of the process will be lowered. If value is false, the priority
  77   // of the process will be made "normal" - equivalent to default
  78   // process priority.
  79   // Returns true if the priority was changed, false otherwise.
  80   bool SetProcessBackgrounded(bool value);
  81
  82   // Returns an integer representing the priority of a process. The meaning
  83   // of this value is OS dependent.
  84   int GetPriority() const;
  85
  86  private:
  87   ProcessHandle process_;
  88 };
  89
  90 }  // namespace base
  91
  92 #endif  // BASE_PROCESS_H_