sched-linux.cpp@ 28800

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1	/* $Id: sched-linux.cpp 28800 2010-04-27 08:22:32Z vboxsync $ */
2	/** @file
3	* IPRT - Scheduling, POSIX.
4	*/
5
6	/*
7	* Copyright (C) 2006-2007 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27	/*
28	* !WARNING!
29	*
30	* When talking about lowering and raising priority, we do NOT refere to
31	* the common direction priority values takes on unix systems (lower means
32	* higher). So, when we raise the priority of a linux thread the nice
33	* value will decrease, and when we lower the priority the nice value
34	* will increase. Confusing, right?
35	*
36	* !WARNING!
37	*/
38
39
40
41	/** @def THREAD_LOGGING
42	* Be very careful with enabling this, it may cause deadlocks when combined
43	* with the 'thread' logging prefix.
44	*/
45	#ifdef DOXYGEN_RUNNING
46	# define THREAD_LOGGING
47	#endif
48
49
50	/*******************************************************************************
51	* Header Files *
52	*******************************************************************************/
53	#define LOG_GROUP RTLOGGROUP_THREAD
54	#include <errno.h>
55	#include <pthread.h>
56	#include <sched.h>
57	#include <unistd.h>
58	#include <sys/resource.h>
59
60	#include <iprt/thread.h>
61	#include <iprt/process.h>
62	#include <iprt/semaphore.h>
63	#include <iprt/string.h>
64	#include <iprt/assert.h>
65	#include <iprt/log.h>
66	#include <iprt/err.h>
67	#include "internal/sched.h"
68	#include "internal/thread.h"
69
70
71	/*******************************************************************************
72	* Structures and Typedefs *
73	*******************************************************************************/
74
75	/** Array scheduler attributes corresponding to each of the thread types.
76	* @internal */
77	typedef struct PROCPRIORITYTYPE
78	{
79	/** For sanity include the array index. */
80	RTTHREADTYPE enmType;
81	/** The thread priority or nice delta - depends on which priority type. */
82	int iPriority;
83	} PROCPRIORITYTYPE;
84
85
86	/**
87	* Configuration of one priority.
88	* @internal
89	*/
90	typedef struct
91	{
92	/** The priority. */
93	RTPROCPRIORITY enmPriority;
94	/** The name of this priority. */
95	const char *pszName;
96	/** The process nice value. */
97	int iNice;
98	/** The delta applied to the iPriority value. */
99	int iDelta;
100	/** Array scheduler attributes corresponding to each of the thread types. */
101	const PROCPRIORITYTYPE *paTypes;
102	} PROCPRIORITY;
103
104
105	/**
106	* Saved priority settings
107	* @internal
108	*/
109	typedef struct
110	{
111	/** Process priority. */
112	int iPriority;
113	/** Process level. */
114	struct sched_param SchedParam;
115	/** Process level. */
116	int iPolicy;
117	/** pthread level. */
118	struct sched_param PthreadSchedParam;
119	/** pthread level. */
120	int iPthreadPolicy;
121	} SAVEDPRIORITY, *PSAVEDPRIORITY;
122
123
124	/*******************************************************************************
125	* Global Variables *
126	*******************************************************************************/
127	/**
128	* Deltas for a process in which we are not restricted
129	* to only be lowering the priority.
130	*/
131	static const PROCPRIORITYTYPE g_aTypesLinuxFree[RTTHREADTYPE_END] =
132	{
133	{ RTTHREADTYPE_INVALID, -999999999 },
134	{ RTTHREADTYPE_INFREQUENT_POLLER, +3 },
135	{ RTTHREADTYPE_MAIN_HEAVY_WORKER, +2 },
136	{ RTTHREADTYPE_EMULATION, +1 },
137	{ RTTHREADTYPE_DEFAULT, 0 },
138	{ RTTHREADTYPE_GUI, 0 },
139	{ RTTHREADTYPE_MAIN_WORKER, 0 },
140	{ RTTHREADTYPE_VRDP_IO, -1 },
141	{ RTTHREADTYPE_DEBUGGER, -1 },
142	{ RTTHREADTYPE_MSG_PUMP, -2 },
143	{ RTTHREADTYPE_IO, -3 },
144	{ RTTHREADTYPE_TIMER, -4 }
145	};
146
147	/**
148	* Deltas for a process in which we are restricted and can only lower the priority.
149	*/
150	static const PROCPRIORITYTYPE g_aTypesLinuxRestricted[RTTHREADTYPE_END] =
151	{
152	{ RTTHREADTYPE_INVALID, -999999999 },
153	{ RTTHREADTYPE_INFREQUENT_POLLER, +3 },
154	{ RTTHREADTYPE_MAIN_HEAVY_WORKER, +2 },
155	{ RTTHREADTYPE_EMULATION, +1 },
156	{ RTTHREADTYPE_DEFAULT, 0 },
157	{ RTTHREADTYPE_GUI, 0 },
158	{ RTTHREADTYPE_MAIN_WORKER, 0 },
159	{ RTTHREADTYPE_VRDP_IO, 0 },
160	{ RTTHREADTYPE_DEBUGGER, 0 },
161	{ RTTHREADTYPE_MSG_PUMP, 0 },
162	{ RTTHREADTYPE_IO, 0 },
163	{ RTTHREADTYPE_TIMER, 0 }
164	};
165
166	/**
167	* All threads have the same priority.
168	*
169	* This is typically choosen when we find that we can't raise the priority
170	* to the process default of a thread created by a low priority thread.
171	*/
172	static const PROCPRIORITYTYPE g_aTypesLinuxFlat[RTTHREADTYPE_END] =
173	{
174	{ RTTHREADTYPE_INVALID, -999999999 },
175	{ RTTHREADTYPE_INFREQUENT_POLLER, 0 },
176	{ RTTHREADTYPE_MAIN_HEAVY_WORKER, 0 },
177	{ RTTHREADTYPE_EMULATION, 0 },
178	{ RTTHREADTYPE_DEFAULT, 0 },
179	{ RTTHREADTYPE_GUI, 0 },
180	{ RTTHREADTYPE_MAIN_WORKER, 0 },
181	{ RTTHREADTYPE_VRDP_IO, 0 },
182	{ RTTHREADTYPE_DEBUGGER, 0 },
183	{ RTTHREADTYPE_MSG_PUMP, 0 },
184	{ RTTHREADTYPE_IO, 0 },
185	{ RTTHREADTYPE_TIMER, 0 }
186	};
187
188	/**
189	* Process and thread level priority, full access at thread level.
190	*/
191	static const PROCPRIORITY g_aUnixConfigs[] =
192	{
193	{ RTPROCPRIORITY_FLAT, "Flat", 0, 0, g_aTypesLinuxFlat },
194	{ RTPROCPRIORITY_LOW, "Low", 9, 9, g_aTypesLinuxFree },
195	{ RTPROCPRIORITY_LOW, "Low", 9, 9, g_aTypesLinuxFlat },
196	{ RTPROCPRIORITY_LOW, "Low", 15, 15, g_aTypesLinuxFree },
197	{ RTPROCPRIORITY_LOW, "Low", 15, 15, g_aTypesLinuxFlat },
198	{ RTPROCPRIORITY_LOW, "Low", 17, 17, g_aTypesLinuxFree },
199	{ RTPROCPRIORITY_LOW, "Low", 17, 17, g_aTypesLinuxFlat },
200	{ RTPROCPRIORITY_LOW, "Low", 19, 19, g_aTypesLinuxFlat },
201	{ RTPROCPRIORITY_LOW, "Low", 9, 9, g_aTypesLinuxRestricted },
202	{ RTPROCPRIORITY_LOW, "Low", 15, 15, g_aTypesLinuxRestricted },
203	{ RTPROCPRIORITY_LOW, "Low", 17, 17, g_aTypesLinuxRestricted },
204	{ RTPROCPRIORITY_NORMAL, "Normal", 0, 0, g_aTypesLinuxFree },
205	{ RTPROCPRIORITY_NORMAL, "Normal", 0, 0, g_aTypesLinuxRestricted },
206	{ RTPROCPRIORITY_NORMAL, "Normal", 0, 0, g_aTypesLinuxFlat },
207	{ RTPROCPRIORITY_HIGH, "High", -9, -9, g_aTypesLinuxFree },
208	{ RTPROCPRIORITY_HIGH, "High", -7, -7, g_aTypesLinuxFree },
209	{ RTPROCPRIORITY_HIGH, "High", -5, -5, g_aTypesLinuxFree },
210	{ RTPROCPRIORITY_HIGH, "High", -3, -3, g_aTypesLinuxFree },
211	{ RTPROCPRIORITY_HIGH, "High", -1, -1, g_aTypesLinuxFree },
212	{ RTPROCPRIORITY_HIGH, "High", -9, -9, g_aTypesLinuxRestricted },
213	{ RTPROCPRIORITY_HIGH, "High", -7, -7, g_aTypesLinuxRestricted },
214	{ RTPROCPRIORITY_HIGH, "High", -5, -5, g_aTypesLinuxRestricted },
215	{ RTPROCPRIORITY_HIGH, "High", -3, -3, g_aTypesLinuxRestricted },
216	{ RTPROCPRIORITY_HIGH, "High", -1, -1, g_aTypesLinuxRestricted },
217	{ RTPROCPRIORITY_HIGH, "High", -9, -9, g_aTypesLinuxFlat },
218	{ RTPROCPRIORITY_HIGH, "High", -7, -7, g_aTypesLinuxFlat },
219	{ RTPROCPRIORITY_HIGH, "High", -5, -5, g_aTypesLinuxFlat },
220	{ RTPROCPRIORITY_HIGH, "High", -3, -3, g_aTypesLinuxFlat },
221	{ RTPROCPRIORITY_HIGH, "High", -1, -1, g_aTypesLinuxFlat }
222	};
223
224	/**
225	* The dynamic default priority configuration.
226	*
227	* This will be recalulated at runtime depending on what the
228	* system allow us to do and what the current priority is.
229	*/
230	static PROCPRIORITY g_aDefaultPriority =
231	{
232	RTPROCPRIORITY_LOW, "Default", 0, 0, g_aTypesLinuxRestricted
233	};
234
235	/** Pointer to the current priority configuration. */
236	static const PROCPRIORITY *g_pProcessPriority = &g_aDefaultPriority;
237
238	/** Set if we can raise the priority of a thread beyond the default.
239	*
240	* It might mean we have the CAP_SYS_NICE capability or that the
241	* process's RLIMIT_NICE is higher than the priority of the thread
242	* calculating the defaults.
243	*/
244	static bool g_fCanRaisePriority = false;
245
246	/** Set if we can restore the priority after having temporarily lowered or raised it. */
247	static bool g_fCanRestorePriority = false;
248
249	/** Set if we can NOT raise the priority to the process default in a thread
250	* created by a thread running below the process default.
251	*/
252	static bool g_fScrewedUpMaxPriorityLimitInheritance = true;
253
254	/** The highest priority we can set. */
255	static int g_iMaxPriority = 0;
256
257	/** The lower priority we can set. */
258	static int g_iMinPriority = 19;
259
260	/** Set when we've successfully determined the capabilities of the process and kernel. */
261	static bool g_fInitialized = false;
262
263
264
265	/*******************************************************************************
266	* Internal Functions *
267	*******************************************************************************/
268
269
270	/**
271	* Saves all the scheduling attributes we can think of.
272	*/
273	static void rtSchedNativeSave(PSAVEDPRIORITY pSave)
274	{
275	memset(pSave, 0xff, sizeof(*pSave));
276
277	errno = 0;
278	pSave->iPriority = getpriority(PRIO_PROCESS, 0 /* current process */);
279	Assert(errno == 0);
280
281	errno = 0;
282	sched_getparam(0 /* current process */, &pSave->SchedParam);
283	Assert(errno == 0);
284
285	errno = 0;
286	pSave->iPolicy = sched_getscheduler(0 /* current process */);
287	Assert(errno == 0);
288
289	int rc = pthread_getschedparam(pthread_self(), &pSave->iPthreadPolicy, &pSave->PthreadSchedParam);
290	Assert(rc == 0); NOREF(rc);
291	}
292
293
294	/**
295	* Restores scheduling attributes.
296	* Most of this won't work right, but anyway...
297	*/
298	static void rtSchedNativeRestore(PSAVEDPRIORITY pSave)
299	{
300	setpriority(PRIO_PROCESS, 0, pSave->iPriority);
301	sched_setscheduler(0, pSave->iPolicy, &pSave->SchedParam);
302	sched_setparam(0, &pSave->SchedParam);
303	pthread_setschedparam(pthread_self(), pSave->iPthreadPolicy, &pSave->PthreadSchedParam);
304	}
305
306
307	/**
308	* Starts a worker thread and wait for it to complete.
309	* We cannot use RTThreadCreate since we're already owner of the RW lock.
310	*/
311	static int rtSchedRunThread(void (pfnThread)(void pvArg), void pvArg)
312	{
313	/*
314	* Setup thread attributes.
315	*/
316	pthread_attr_t ThreadAttr;
317	int rc = pthread_attr_init(&ThreadAttr);
318	if (!rc)
319	{
320	rc = pthread_attr_setdetachstate(&ThreadAttr, PTHREAD_CREATE_JOINABLE);
321	if (!rc)
322	{
323	rc = pthread_attr_setstacksize(&ThreadAttr, 128*1024);
324	if (!rc)
325	{
326	/*
327	* Create the thread.
328	*/
329	pthread_t Thread;
330	rc = pthread_create(&Thread, &ThreadAttr, pfnThread, pvArg);
331	if (!rc)
332	{
333	/*
334	* Wait for the thread to finish.
335	*/
336	void pvRet = (void )-1;
337	do
338	{
339	rc = pthread_join(Thread, &pvRet);
340	} while (errno == EINTR);
341	if (rc)
342	return RTErrConvertFromErrno(rc);
343	return (int)(uintptr_t)pvRet;
344	}
345	}
346	}
347	pthread_attr_destroy(&ThreadAttr);
348	}
349	return RTErrConvertFromErrno(rc);
350	}
351
352
353	static void rtSchedDumpPriority(void)
354	{
355	#ifdef THREAD_LOGGING
356	Log(("Priority: g_fCanRaisePriority=%RTbool g_fCanRestorePriority=%RTbool g_fScrewedUpMaxPriorityLimitInheritance=%RTbool\n",
357	g_fCanRaisePriority, g_fCanRestorePriority, g_fScrewedUpMaxPriorityLimitInheritance));
358	Log(("Priority: g_iMaxPriority=%d g_iMinPriority=%d\n", g_iMaxPriority, g_iMinPriority));
359	Log(("Priority: enmPriority=%d \"%s\" iNice=%d iDelta=%d\n",
360	g_pProcessPriority->enmPriority,
361	g_pProcessPriority->pszName,
362	g_pProcessPriority->iNice,
363	g_pProcessPriority->iDelta));
364	Log(("Priority: %2d INFREQUENT_POLLER = %d\n", RTTHREADTYPE_INFREQUENT_POLLER, g_pProcessPriority->paTypes[RTTHREADTYPE_INFREQUENT_POLLER].iPriority));
365	Log(("Priority: %2d MAIN_HEAVY_WORKER = %d\n", RTTHREADTYPE_MAIN_HEAVY_WORKER, g_pProcessPriority->paTypes[RTTHREADTYPE_MAIN_HEAVY_WORKER].iPriority));
366	Log(("Priority: %2d EMULATION = %d\n", RTTHREADTYPE_EMULATION , g_pProcessPriority->paTypes[RTTHREADTYPE_EMULATION ].iPriority));
367	Log(("Priority: %2d DEFAULT = %d\n", RTTHREADTYPE_DEFAULT , g_pProcessPriority->paTypes[RTTHREADTYPE_DEFAULT ].iPriority));
368	Log(("Priority: %2d GUI = %d\n", RTTHREADTYPE_GUI , g_pProcessPriority->paTypes[RTTHREADTYPE_GUI ].iPriority));
369	Log(("Priority: %2d MAIN_WORKER = %d\n", RTTHREADTYPE_MAIN_WORKER , g_pProcessPriority->paTypes[RTTHREADTYPE_MAIN_WORKER ].iPriority));
370	Log(("Priority: %2d VRDP_IO = %d\n", RTTHREADTYPE_VRDP_IO , g_pProcessPriority->paTypes[RTTHREADTYPE_VRDP_IO ].iPriority));
371	Log(("Priority: %2d DEBUGGER = %d\n", RTTHREADTYPE_DEBUGGER , g_pProcessPriority->paTypes[RTTHREADTYPE_DEBUGGER ].iPriority));
372	Log(("Priority: %2d MSG_PUMP = %d\n", RTTHREADTYPE_MSG_PUMP , g_pProcessPriority->paTypes[RTTHREADTYPE_MSG_PUMP ].iPriority));
373	Log(("Priority: %2d IO = %d\n", RTTHREADTYPE_IO , g_pProcessPriority->paTypes[RTTHREADTYPE_IO ].iPriority));
374	Log(("Priority: %2d TIMER = %d\n", RTTHREADTYPE_TIMER , g_pProcessPriority->paTypes[RTTHREADTYPE_TIMER ].iPriority));
375	#endif
376	}
377
378
379	/**
380	* This just checks if it can raise the priority after having been
381	* created by a thread with a low priority.
382	*
383	* @returns zero on success, non-zero on failure.
384	* @param pvUser The priority of the parent before it was lowered (cast to int).
385	*/
386	static void rtSchedNativeSubProberThread(void pvUser)
387	{
388	int iPriority = getpriority(PRIO_PROCESS, 0);
389	Assert(iPriority == g_iMinPriority);
390
391	if (setpriority(PRIO_PROCESS, 0, iPriority + 1))
392	return (void *)-1;
393	if (setpriority(PRIO_PROCESS, 0, (int)(intptr_t)pvUser))
394	return (void *)-1;
395	return (void *)0;
396	}
397
398
399	/**
400	* The prober thread.
401	* We don't want to mess with the priority of the calling thread.
402	*
403	* @remark This is pretty presumptive stuff, but if it works on Linux and
404	* FreeBSD it does what I want.
405	*/
406	static void rtSchedNativeProberThread(void pvUser)
407	{
408	SAVEDPRIORITY SavedPriority;
409	rtSchedNativeSave(&SavedPriority);
410
411	/*
412	* Check if we can get higher priority (typically only root can do this).
413	* (Won't work right if our priority is -19 to start with, but what the heck.)
414	*
415	* We assume that the priority range is -19 to 19. Should probably find the right
416	* define for this.
417	*/
418	int iStart = getpriority(PRIO_PROCESS, 0);
419	int i = iStart;
420	while (i-- > -20)
421	if (setpriority(PRIO_PROCESS, 0, i))
422	break;
423	g_iMaxPriority = getpriority(PRIO_PROCESS, 0);
424	g_fCanRaisePriority = g_iMaxPriority < iStart;
425	g_fCanRestorePriority = setpriority(PRIO_PROCESS, 0, iStart) == 0;
426
427	/*
428	* Check if we temporarily lower the thread priority.
429	* Again, we assume we're not at the extreme end of the priority scale.
430	*/
431	iStart = getpriority(PRIO_PROCESS, 0);
432	i = iStart;
433	while (i++ < 19)
434	if (setpriority(PRIO_PROCESS, 0, i))
435	break;
436	g_iMinPriority = getpriority(PRIO_PROCESS, 0);
437	if ( setpriority(PRIO_PROCESS, 0, iStart)
438	\|\| getpriority(PRIO_PROCESS, 0) != iStart)
439	g_fCanRestorePriority = false;
440	if (g_iMinPriority == g_iMaxPriority)
441	g_fCanRestorePriority = g_fCanRaisePriority = false;
442
443	/*
444	* Check what happens to child threads when the parent lowers the
445	* priority when it's being created.
446	*/
447	iStart = getpriority(PRIO_PROCESS, 0);
448	g_fScrewedUpMaxPriorityLimitInheritance = true;
449	if ( g_fCanRestorePriority
450	&& !setpriority(PRIO_PROCESS, 0, g_iMinPriority)
451	&& iStart != g_iMinPriority)
452	{
453	if (rtSchedRunThread(rtSchedNativeSubProberThread, (void *)iStart) == 0)
454	g_fScrewedUpMaxPriorityLimitInheritance = false;
455	}
456
457	/* done */
458	rtSchedNativeRestore(&SavedPriority);
459	return (void *)VINF_SUCCESS;
460	}
461
462
463	/**
464	* Calculate the scheduling properties for all the threads in the default
465	* process priority, assuming the current thread have the type enmType.
466	*
467	* @returns iprt status code.
468	* @param enmType The thread type to be assumed for the current thread.
469	*/
470	int rtSchedNativeCalcDefaultPriority(RTTHREADTYPE enmType)
471	{
472	Assert(enmType > RTTHREADTYPE_INVALID && enmType < RTTHREADTYPE_END);
473
474	/*
475	* First figure out what's we're allowed to do in this process.
476	*/
477	if (!g_fInitialized)
478	{
479	int iPriority = getpriority(PRIO_PROCESS, 0);
480	#ifdef RLIMIT_RTPRIO
481	/** @todo */
482	#endif
483	int rc = rtSchedRunThread(rtSchedNativeProberThread, NULL);
484	if (RT_FAILURE(rc))
485	return rc;
486	Assert(getpriority(PRIO_PROCESS, 0) == iPriority); NOREF(iPriority);
487	g_fInitialized = true;
488	}
489
490	/*
491	* Select the right priority type table and update the default
492	* process priority structure.
493	*/
494	if (g_fCanRaisePriority && g_fCanRestorePriority && !g_fScrewedUpMaxPriorityLimitInheritance)
495	g_aDefaultPriority.paTypes = &g_aTypesLinuxFree[0];
496	else if (!g_fCanRaisePriority && g_fCanRestorePriority && !g_fScrewedUpMaxPriorityLimitInheritance)
497	g_aDefaultPriority.paTypes = &g_aTypesLinuxRestricted[0];
498	else
499	g_aDefaultPriority.paTypes = &g_aTypesLinuxFlat[0];
500	Assert(enmType == g_aDefaultPriority.paTypes[enmType].enmType);
501
502	int iPriority = getpriority(PRIO_PROCESS, 0 /* current process */);
503	g_aDefaultPriority.iNice = iPriority - g_aDefaultPriority.paTypes[enmType].iPriority;
504	g_aDefaultPriority.iDelta = g_aDefaultPriority.iNice;
505
506	rtSchedDumpPriority();
507	return VINF_SUCCESS;
508	}
509
510
511	/**
512	* The process priority validator thread.
513	* (We don't want to mess with the priority of the calling thread.)
514	*/
515	static void rtSchedNativeValidatorThread(void pvUser)
516	{
517	const PROCPRIORITY pCfg = (const PROCPRIORITY )pvUser;
518	SAVEDPRIORITY SavedPriority;
519	rtSchedNativeSave(&SavedPriority);
520
521	/*
522	* Try out the priorities from the top and down.
523	*/
524	int rc = VINF_SUCCESS;
525	int i = RTTHREADTYPE_END;
526	while (--i > RTTHREADTYPE_INVALID)
527	{
528	int iPriority = pCfg->paTypes[i].iPriority + pCfg->iDelta;
529	if (setpriority(PRIO_PROCESS, 0, iPriority))
530	{
531	rc = RTErrConvertFromErrno(errno);
532	break;
533	}
534	}
535
536	/* done */
537	rtSchedNativeRestore(&SavedPriority);
538	return (void *)rc;
539	}
540
541
542	/**
543	* Validates and sets the process priority.
544	*
545	* This will check that all rtThreadNativeSetPriority() will success for all the
546	* thread types when applied to the current thread.
547	*
548	* @returns iprt status code.
549	* @param enmPriority The priority to validate and set.
550	*/
551	int rtProcNativeSetPriority(RTPROCPRIORITY enmPriority)
552	{
553	Assert(enmPriority > RTPROCPRIORITY_INVALID && enmPriority < RTPROCPRIORITY_LAST);
554
555	int rc = VINF_SUCCESS;
556	if (enmPriority == RTPROCPRIORITY_DEFAULT)
557	g_pProcessPriority = &g_aDefaultPriority;
558	else
559	{
560	/*
561	* Find a configuration which matches and can be applied.
562	*/
563	rc = VERR_FILE_NOT_FOUND;
564	for (unsigned i = 0; i < RT_ELEMENTS(g_aUnixConfigs); i++)
565	{
566	if (g_aUnixConfigs[i].enmPriority == enmPriority)
567	{
568	int iPriority = getpriority(PRIO_PROCESS, 0);
569	int rc3 = rtSchedRunThread(rtSchedNativeValidatorThread, (void *)&g_aUnixConfigs[i]);
570	Assert(getpriority(PRIO_PROCESS, 0) == iPriority); NOREF(iPriority);
571	if (RT_SUCCESS(rc3))
572	{
573	g_pProcessPriority = &g_aUnixConfigs[i];
574	rc = VINF_SUCCESS;
575	break;
576	}
577	if (rc == VERR_FILE_NOT_FOUND)
578	rc = rc3;
579	}
580	}
581	}
582
583	#ifdef THREAD_LOGGING
584	LogFlow(("rtProcNativeSetPriority: returns %Rrc enmPriority=%d\n", rc, enmPriority));
585	rtSchedDumpPriority();
586	#endif
587	return rc;
588	}
589
590
591	/**
592	* Sets the priority of the thread according to the thread type
593	* and current process priority.
594	*
595	* The RTTHREADINT::enmType member has not yet been updated and will be updated by
596	* the caller on a successful return.
597	*
598	* @returns iprt status code.
599	* @param pThread The thread in question.
600	* @param enmType The thread type.
601	*/
602	int rtThreadNativeSetPriority(PRTTHREADINT pThread, RTTHREADTYPE enmType)
603	{
604	/* sanity */
605	Assert(enmType > RTTHREADTYPE_INVALID && enmType < RTTHREADTYPE_END);
606	Assert(enmType == g_pProcessPriority->paTypes[enmType].enmType);
607	Assert((pthread_t)pThread->Core.Key == pthread_self());
608
609	/*
610	* Calculate the thread priority and apply it.
611	*/
612	int rc = VINF_SUCCESS;
613	int iPriority = g_pProcessPriority->paTypes[enmType].iPriority + g_pProcessPriority->iDelta;
614	if (!setpriority(PRIO_PROCESS, 0, iPriority))
615	{
616	AssertMsg(iPriority == getpriority(PRIO_PROCESS, 0), ("iPriority=%d getpriority()=%d\n", iPriority, getpriority(PRIO_PROCESS, 0)));
617	#ifdef THREAD_LOGGING
618	Log(("rtThreadNativeSetPriority: Thread=%p enmType=%d iPriority=%d pid=%d\n", pThread->Core.Key, enmType, iPriority, getpid()));
619	#endif
620	}
621	else
622	{
623	rc = RTErrConvertFromErrno(errno);
624	AssertMsgFailed(("setpriority(,, %d) -> errno=%d rc=%Rrc\n", iPriority, errno, rc));
625	rc = VINF_SUCCESS; //non-fatal for now.
626	}
627
628	return rc;
629	}
630

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source: vbox/trunk/src/VBox/Runtime/r3/linux/sched-linux.cpp@ 28800

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