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