1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1997-2018 The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Kalle Sommer Nielsen <kalle@php.net> |
16 +----------------------------------------------------------------------+
17 */
18
19 #include <php.h>
20 #include "nice.h"
21
22 /*
23 * Basic Windows implementation for the nice() function.
24 *
25 * This implementation uses SetPriorityClass() as a backend for defining
26 * a process priority.
27 *
28 * The following values of inc, defines the value sent to SetPriorityClass():
29 *
30 * +-----------------------+-----------------------------+
31 * | Expression | Priority type |
32 * +-----------------------+-----------------------------+
33 * | priority < -9 | HIGH_PRIORITY_CLASS |
34 * +-----------------------+-----------------------------+
35 * | priority < -4 | ABOVE_NORMAL_PRIORITY_CLASS |
36 * +-----------------------+-----------------------------+
37 * | priority > 4 | BELOW_NORMAL_PRIORITY_CLASS |
38 * +-----------------------+-----------------------------+
39 * | priority > 9 | IDLE_PRIORITY_CLASS |
40 * +-----------------------+-----------------------------+
41 *
42 * If a value is between -4 and 4 (inclusive), then the priority will be set
43 * to NORMAL_PRIORITY_CLASS.
44 *
45 * These values tries to mimic that of the UNIX version of nice().
46 *
47 * This is applied to the main process, not per thread, although this could
48 * be implemented using SetThreadPriority() at one point.
49 *
50 * Note, the following priority classes are left out with intention:
51 *
52 * . REALTIME_PRIORITY_CLASS
53 * Realtime priority class requires special system permissions to set, and
54 * can be dangerous in certain cases.
55 *
56 * . PROCESS_MODE_BACKGROUND_BEGIN
57 * . PROCESS_MODE_BACKGROUND_END
58 * Process mode is not covered because it can easily forgotten to be changed
59 * back and can cause unforseen side effects that is hard to debug. Besides
60 * that, these do generally not really fit into making a Windows somewhat
61 * compatible nice() function.
62 */
63
nice(zend_long p)64 PHPAPI int nice(zend_long p)
65 {
66 DWORD dwFlag = NORMAL_PRIORITY_CLASS;
67
68 if (p < -9) {
69 dwFlag = HIGH_PRIORITY_CLASS;
70 } else if (p < -4) {
71 dwFlag = ABOVE_NORMAL_PRIORITY_CLASS;
72 } else if (p > 9) {
73 dwFlag = IDLE_PRIORITY_CLASS;
74 } else if (p > 4) {
75 dwFlag = BELOW_NORMAL_PRIORITY_CLASS;
76 }
77
78 if (!SetPriorityClass(GetCurrentProcess(), dwFlag)) {
79 return -1;
80 }
81
82 return 0;
83 }
84
85 /*
86 * Local variables:
87 * tab-width: 4
88 * c-basic-offset: 4
89 * End:
90 * vim600: sw=4 ts=4 fdm=marker
91 * vim<600: sw=4 ts=4
92 */
93
