• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // Copyright (c) 2006-2008 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/basictypes.h"
9 #include "build/build_config.h"
10 
11 #include <sys/types.h>
12 #ifdef OS_WIN
13 #include <windows.h>
14 #endif
15 
16 namespace base {
17 
18 // ProcessHandle is a platform specific type which represents the underlying OS
19 // handle to a process.
20 // ProcessId is a number which identifies the process in the OS.
21 #if defined(OS_WIN)
22 typedef HANDLE ProcessHandle;
23 typedef DWORD ProcessId;
24 typedef HANDLE UserTokenHandle;
25 const ProcessHandle kNullProcessHandle = NULL;
26 #elif defined(OS_POSIX)
27 // On POSIX, our ProcessHandle will just be the PID.
28 typedef pid_t ProcessHandle;
29 typedef pid_t ProcessId;
30 const ProcessHandle kNullProcessHandle = 0;
31 #endif
32 
33 #if defined(OS_POSIX) && !defined(OS_MACOSX)
34 // saved_priority_ will be set to this to indicate that it's not holding
35 // a valid value. -20 to 19 are valid process priorities.
36 const int kUnsetProcessPriority = 256;
37 #endif
38 
39 class Process {
40  public:
Process()41   Process() : process_(kNullProcessHandle) {
42 #if defined(OS_POSIX) && !defined(OS_MACOSX)
43     saved_priority_ = kUnsetProcessPriority;
44 #endif
45   }
46 
Process(ProcessHandle handle)47   explicit Process(ProcessHandle handle) : process_(handle) {
48 #if defined(OS_POSIX) && !defined(OS_MACOSX)
49     saved_priority_ = kUnsetProcessPriority;
50 #endif
51   }
52 
53   // A handle to the current process.
54   static Process Current();
55 
56   // Get/Set the handle for this process. The handle will be 0 if the process
57   // is no longer running.
handle()58   ProcessHandle handle() const { return process_; }
set_handle(ProcessHandle handle)59   void set_handle(ProcessHandle handle) {
60     process_ = handle;
61 #if defined(OS_POSIX) && !defined(OS_MACOSX)
62     saved_priority_ = kUnsetProcessPriority;
63 #endif
64   }
65 
66   // Get the PID for this process.
67   ProcessId pid() const;
68 
69   // Is the this process the current process.
70   bool is_current() const;
71 
72   // Close the process handle. This will not terminate the process.
73   void Close();
74 
75   // Terminates the process with extreme prejudice. The given result code will
76   // be the exit code of the process. If the process has already exited, this
77   // will do nothing.
78   void Terminate(int result_code);
79 
80   // A process is backgrounded when it's priority is lower than normal.
81   // Return true if this process is backgrounded, false otherwise.
82   bool IsProcessBackgrounded() const;
83 
84   // Set a process as backgrounded. If value is true, the priority
85   // of the process will be lowered. If value is false, the priority
86   // of the process will be made "normal" - equivalent to default
87   // process priority.
88   // Returns true if the priority was changed, false otherwise.
89   bool SetProcessBackgrounded(bool value);
90 
91   // Returns an integer representing the priority of a process. The meaning
92   // of this value is OS dependent.
93   int GetPriority() const;
94 
95  private:
96   ProcessHandle process_;
97 #if defined(OS_POSIX) && !defined(OS_MACOSX)
98   // Holds the priority that the process was set to when it was backgrounded.
99   // If the process wasn't backgrounded it will be kUnsetProcessPriority.
100   int saved_priority_;
101 #endif
102 };
103 
104 }  // namespace base
105 
106 #endif  // BASE_PROCESS_H_
107