ru_php/win32/nice.c

80 lines
3 KiB
C

/*
+----------------------------------------------------------------------+
| Copyright © The PHP Group and Contributors. |
+----------------------------------------------------------------------+
| This source file is subject to the Modified BSD License that is |
| bundled with this package in the file LICENSE, and is available |
| through the World Wide Web at <https://www.php.net/license/>. |
| |
| SPDX-License-Identifier: BSD-3-Clause |
+----------------------------------------------------------------------+
| Authors: Kalle Sommer Nielsen <kalle@php.net> |
+----------------------------------------------------------------------+
*/
#include <php.h>
#include "nice.h"
/*
* Basic Windows implementation for the nice() function.
*
* This implementation uses SetPriorityClass() as a backend for defining
* a process priority.
*
* The following values of inc, defines the value sent to SetPriorityClass():
*
* +-----------------------+-----------------------------+
* | Expression | Priority type |
* +-----------------------+-----------------------------+
* | priority < -9 | HIGH_PRIORITY_CLASS |
* +-----------------------+-----------------------------+
* | priority < -4 | ABOVE_NORMAL_PRIORITY_CLASS |
* +-----------------------+-----------------------------+
* | priority > 4 | BELOW_NORMAL_PRIORITY_CLASS |
* +-----------------------+-----------------------------+
* | priority > 9 | IDLE_PRIORITY_CLASS |
* +-----------------------+-----------------------------+
*
* If a value is between -4 and 4 (inclusive), then the priority will be set
* to NORMAL_PRIORITY_CLASS.
*
* These values tries to mimic that of the UNIX version of nice().
*
* This is applied to the main process, not per thread, although this could
* be implemented using SetThreadPriority() at one point.
*
* Note, the following priority classes are left out with intention:
*
* . REALTIME_PRIORITY_CLASS
* Realtime priority class requires special system permissions to set, and
* can be dangerous in certain cases.
*
* . PROCESS_MODE_BACKGROUND_BEGIN
* . PROCESS_MODE_BACKGROUND_END
* Process mode is not covered because it can easily forgotten to be changed
* back and can cause unforeseen side effects that is hard to debug. Besides
* that, these do generally not really fit into making a Windows somewhat
* compatible nice() function.
*/
PHPAPI int nice(zend_long p)
{
DWORD dwFlag = NORMAL_PRIORITY_CLASS;
if (p < -9) {
dwFlag = HIGH_PRIORITY_CLASS;
} else if (p < -4) {
dwFlag = ABOVE_NORMAL_PRIORITY_CLASS;
} else if (p > 9) {
dwFlag = IDLE_PRIORITY_CLASS;
} else if (p > 4) {
dwFlag = BELOW_NORMAL_PRIORITY_CLASS;
}
if (!SetPriorityClass(GetCurrentProcess(), dwFlag)) {
return -1;
}
return 0;
}