1 /*
2 +----------------------------------------------------------------------+
3 | Copyright (c) The PHP Group |
4 +----------------------------------------------------------------------+
5 | This source file is subject to version 3.01 of the PHP license, |
6 | that is bundled with this package in the file LICENSE, and is |
7 | available through the world-wide-web at the following url: |
8 | http://www.php.net/license/3_01.txt |
9 | If you did not receive a copy of the PHP license and are unable to |
10 | obtain it through the world-wide-web, please send a note to |
11 | license@php.net so we can mail you a copy immediately. |
12 +----------------------------------------------------------------------+
13 | Authors: Kalle Sommer Nielsen <kalle@php.net> |
14 +----------------------------------------------------------------------+
15 */
16
17 #include <php.h>
18 #include "nice.h"
19
20 /*
21 * Basic Windows implementation for the nice() function.
22 *
23 * This implementation uses SetPriorityClass() as a backend for defining
24 * a process priority.
25 *
26 * The following values of inc, defines the value sent to SetPriorityClass():
27 *
28 * +-----------------------+-----------------------------+
29 * | Expression | Priority type |
30 * +-----------------------+-----------------------------+
31 * | priority < -9 | HIGH_PRIORITY_CLASS |
32 * +-----------------------+-----------------------------+
33 * | priority < -4 | ABOVE_NORMAL_PRIORITY_CLASS |
34 * +-----------------------+-----------------------------+
35 * | priority > 4 | BELOW_NORMAL_PRIORITY_CLASS |
36 * +-----------------------+-----------------------------+
37 * | priority > 9 | IDLE_PRIORITY_CLASS |
38 * +-----------------------+-----------------------------+
39 *
40 * If a value is between -4 and 4 (inclusive), then the priority will be set
41 * to NORMAL_PRIORITY_CLASS.
42 *
43 * These values tries to mimic that of the UNIX version of nice().
44 *
45 * This is applied to the main process, not per thread, although this could
46 * be implemented using SetThreadPriority() at one point.
47 *
48 * Note, the following priority classes are left out with intention:
49 *
50 * . REALTIME_PRIORITY_CLASS
51 * Realtime priority class requires special system permissions to set, and
52 * can be dangerous in certain cases.
53 *
54 * . PROCESS_MODE_BACKGROUND_BEGIN
55 * . PROCESS_MODE_BACKGROUND_END
56 * Process mode is not covered because it can easily forgotten to be changed
57 * back and can cause unforeseen side effects that is hard to debug. Besides
58 * that, these do generally not really fit into making a Windows somewhat
59 * compatible nice() function.
60 */
61
nice(zend_long p)62 PHPAPI int nice(zend_long p)
63 {
64 DWORD dwFlag = NORMAL_PRIORITY_CLASS;
65
66 if (p < -9) {
67 dwFlag = HIGH_PRIORITY_CLASS;
68 } else if (p < -4) {
69 dwFlag = ABOVE_NORMAL_PRIORITY_CLASS;
70 } else if (p > 9) {
71 dwFlag = IDLE_PRIORITY_CLASS;
72 } else if (p > 4) {
73 dwFlag = BELOW_NORMAL_PRIORITY_CLASS;
74 }
75
76 if (!SetPriorityClass(GetCurrentProcess(), dwFlag)) {
77 return -1;
78 }
79
80 return 0;
81 }
82
