[apple/xnu.git] / osfmk / kern / syscall_subr.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */

#include <mach/boolean.h>
#include <mach/thread_switch.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_space.h>
#include <kern/counters.h>
#include <kern/etap_macros.h>
#include <kern/ipc_kobject.h>
#include <kern/processor.h>
#include <kern/sched.h>
#include <kern/sched_prim.h>
#include <kern/spl.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/ast.h>
#include <mach/policy.h>

#include <kern/syscall_subr.h>
#include <mach/mach_host_server.h>
#include <mach/mach_syscalls.h>

#include <kern/mk_sp.h>

/*
 *	swtch and swtch_pri both attempt to context switch (logic in
 *	thread_block no-ops the context switch if nothing would happen).
 *	A boolean is returned that indicates whether there is anything
 *	else runnable.
 *
 *	This boolean can be used by a thread waiting on a
 *	lock or condition:  If FALSE is returned, the thread is justified
 *	in becoming a resource hog by continuing to spin because there's
 *	nothing else useful that the processor could do.  If TRUE is
 *	returned, the thread should make one more check on the
 *	lock and then be a good citizen and really suspend.
 */

void
swtch_continue(void)
{
	register processor_t	myprocessor;
    boolean_t				result;

    mp_disable_preemption();
	myprocessor = current_processor();
	result =		myprocessor->runq.count > 0					||
				myprocessor->processor_set->runq.count > 0;
	mp_enable_preemption();

	thread_syscall_return(result);
	/*NOTREACHED*/
}

boolean_t
swtch(void)
{
	register processor_t	myprocessor;
	boolean_t				result;

	mp_disable_preemption();
	myprocessor = current_processor();
	if (		myprocessor->runq.count == 0				&&
			myprocessor->processor_set->runq.count == 0			) {
		mp_enable_preemption();

		return (FALSE);
	}
	mp_enable_preemption();

	counter(c_swtch_block++);

	thread_block_reason(swtch_continue, AST_YIELD);

	mp_disable_preemption();
	myprocessor = current_processor();
	result =		myprocessor->runq.count > 0					||
				myprocessor->processor_set->runq.count > 0;
	mp_enable_preemption();

	return (result);
}

void
swtch_pri_continue(void)
{
	register processor_t	myprocessor;
    boolean_t				result;

	_mk_sp_thread_depress_abort(current_thread(), FALSE);

    mp_disable_preemption();
	myprocessor = current_processor();
	result =		myprocessor->runq.count > 0					||
				myprocessor->processor_set->runq.count > 0;
	mp_enable_preemption();

	thread_syscall_return(result);
	/*NOTREACHED*/
}

boolean_t
swtch_pri(
	int				pri)
{
	register processor_t	myprocessor;
	boolean_t				result;

	mp_disable_preemption();
	myprocessor = current_processor();
	if (	myprocessor->runq.count == 0					&&
			myprocessor->processor_set->runq.count == 0			) {
		mp_enable_preemption();

		return (FALSE);
	}
	mp_enable_preemption();

	counter(c_swtch_pri_block++);

	_mk_sp_thread_depress_abstime(std_quantum);

	thread_block_reason(swtch_pri_continue, AST_YIELD);

	_mk_sp_thread_depress_abort(current_thread(), FALSE);

	mp_disable_preemption();
	myprocessor = current_processor();
	result =	myprocessor->runq.count > 0						||
				myprocessor->processor_set->runq.count > 0;
	mp_enable_preemption();

	return (result);
}

/*
 *	thread_switch:
 *
 *	Context switch.  User may supply thread hint.
 */
kern_return_t
thread_switch(
	mach_port_name_t		thread_name,
	int						option,
	mach_msg_timeout_t		option_time)
{
    register thread_t		self = current_thread();
    register thread_act_t 	hint_act = THR_ACT_NULL;

    /*
     *	Process option.
     */
    switch (option) {

	case SWITCH_OPTION_NONE:
	case SWITCH_OPTION_DEPRESS:
	case SWITCH_OPTION_WAIT:
	    break;

	default:
	    return (KERN_INVALID_ARGUMENT);
    }

    if (thread_name != MACH_PORT_NULL) {
		ipc_port_t			port;

		if (ipc_port_translate_send(self->top_act->task->itk_space,
									thread_name, &port) == KERN_SUCCESS) {
			ip_reference(port);
			ip_unlock(port);

			hint_act = convert_port_to_act(port);
			ipc_port_release(port);
		}
	}

    return _mk_sp_thread_switch(hint_act, option, option_time);
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* The contents of this file constitute Original Code as defined in and
	7	* are subject to the Apple Public Source License Version 1.1 (the
	8	* "License"). You may not use this file except in compliance with the
	9	* License. Please obtain a copy of the License at
	10	* http://www.apple.com/publicsource and read it before using this file.
	11	*
	12	* This Original Code and all software distributed under the License are
	13	* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	14	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	15	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	16	* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
	17	* License for the specific language governing rights and limitations
	18	* under the License.
	19	*
	20	* @APPLE_LICENSE_HEADER_END@
	21	*/
	22	/*
	23	* @OSF_COPYRIGHT@
	24	*/
	25	/*
	26	* Mach Operating System
	27	* Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University
	28	* All Rights Reserved.
	29	*
	30	* Permission to use, copy, modify and distribute this software and its
	31	* documentation is hereby granted, provided that both the copyright
	32	* notice and this permission notice appear in all copies of the
	33	* software, derivative works or modified versions, and any portions
	34	* thereof, and that both notices appear in supporting documentation.
	35	*
	36	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	37	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	38	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	39	*
	40	* Carnegie Mellon requests users of this software to return to
	41	*
	42	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	43	* School of Computer Science
	44	* Carnegie Mellon University
	45	* Pittsburgh PA 15213-3890
	46	*
	47	* any improvements or extensions that they make and grant Carnegie Mellon
	48	* the rights to redistribute these changes.
	49	*/
	50	/*
	51	*/
	52
1c79356b A	53	#include <mach/boolean.h>
	54	#include <mach/thread_switch.h>
	55	#include <ipc/ipc_port.h>
	56	#include <ipc/ipc_space.h>
	57	#include <kern/counters.h>
	58	#include <kern/etap_macros.h>
	59	#include <kern/ipc_kobject.h>
	60	#include <kern/processor.h>
	61	#include <kern/sched.h>
	62	#include <kern/sched_prim.h>
	63	#include <kern/spl.h>
	64	#include <kern/task.h>
	65	#include <kern/thread.h>
	66	#include <kern/ast.h>
	67	#include <mach/policy.h>
	68
	69	#include <kern/syscall_subr.h>
	70	#include <mach/mach_host_server.h>
	71	#include <mach/mach_syscalls.h>
	72
0b4e3aa0	73	#include <kern/mk_sp.h>
1c79356b A	74
	75	/*
	76	* swtch and swtch_pri both attempt to context switch (logic in
	77	* thread_block no-ops the context switch if nothing would happen).
	78	* A boolean is returned that indicates whether there is anything
	79	* else runnable.
	80	*
	81	* This boolean can be used by a thread waiting on a
	82	* lock or condition: If FALSE is returned, the thread is justified
	83	* in becoming a resource hog by continuing to spin because there's
	84	* nothing else useful that the processor could do. If TRUE is
	85	* returned, the thread should make one more check on the
	86	* lock and then be a good citizen and really suspend.
	87	*/
	88
0b4e3aa0 A	89	void
0b4e3aa0 A	90	swtch_continue(void)
1c79356b	91	{
0b4e3aa0 A	92	register processor_t myprocessor;
0b4e3aa0 A	93	boolean_t result;
1c79356b A	94
	95	mp_disable_preemption();
	96	myprocessor = current_processor();
0b4e3aa0 A	97	result = myprocessor->runq.count > 0 \|\|
0b4e3aa0 A	98	myprocessor->processor_set->runq.count > 0;
1c79356b	99	mp_enable_preemption();
1c79356b	100
0b4e3aa0 A	101	thread_syscall_return(result);
	102	/NOTREACHED/
	103	}
1c79356b A	104
	105	boolean_t
	106	swtch(void)
	107	{
	108	register processor_t myprocessor;
	109	boolean_t result;
	110
	111	mp_disable_preemption();
	112	myprocessor = current_processor();
0b4e3aa0	113	if ( myprocessor->runq.count == 0 &&
1c79356b A	114	myprocessor->processor_set->runq.count == 0 ) {
	115	mp_enable_preemption();
	116
	117	return (FALSE);
	118	}
	119	mp_enable_preemption();
	120
	121	counter(c_swtch_block++);
	122
9bccf70c	123	thread_block_reason(swtch_continue, AST_YIELD);
1c79356b A	124
	125	mp_disable_preemption();
	126	myprocessor = current_processor();
0b4e3aa0 A	127	result = myprocessor->runq.count > 0 \|\|
0b4e3aa0 A	128	myprocessor->processor_set->runq.count > 0;
1c79356b A	129	mp_enable_preemption();
	130
	131	return (result);
	132	}
	133
0b4e3aa0 A	134	void
	135	swtch_pri_continue(void)
	136	{
	137	register processor_t myprocessor;
	138	boolean_t result;
	139
	140	_mk_sp_thread_depress_abort(current_thread(), FALSE);
	141
	142	mp_disable_preemption();
	143	myprocessor = current_processor();
	144	result = myprocessor->runq.count > 0 \|\|
	145	myprocessor->processor_set->runq.count > 0;
	146	mp_enable_preemption();
	147
	148	thread_syscall_return(result);
	149	/NOTREACHED/
	150	}
	151
1c79356b A	152	boolean_t
	153	swtch_pri(
	154	int pri)
	155	{
1c79356b A	156	register processor_t myprocessor;
1c79356b A	157	boolean_t result;
1c79356b	158
0b4e3aa0	159	mp_disable_preemption();
1c79356b	160	myprocessor = current_processor();
0b4e3aa0	161	if ( myprocessor->runq.count == 0 &&
1c79356b	162	myprocessor->processor_set->runq.count == 0 ) {
0b4e3aa0	163	mp_enable_preemption();
1c79356b A	164
	165	return (FALSE);
	166	}
0b4e3aa0 A	167	mp_enable_preemption();
	168
	169	counter(c_swtch_pri_block++);
	170
	171	_mk_sp_thread_depress_abstime(std_quantum);
1c79356b	172
9bccf70c	173	thread_block_reason(swtch_pri_continue, AST_YIELD);
1c79356b	174
0b4e3aa0	175	_mk_sp_thread_depress_abort(current_thread(), FALSE);
1c79356b A	176
	177	mp_disable_preemption();
	178	myprocessor = current_processor();
0b4e3aa0 A	179	result = myprocessor->runq.count > 0 \|\|
0b4e3aa0 A	180	myprocessor->processor_set->runq.count > 0;
1c79356b A	181	mp_enable_preemption();
	182
	183	return (result);
	184	}
	185
	186	/*
	187	* thread_switch:
	188	*
	189	* Context switch. User may supply thread hint.
	190	*/
	191	kern_return_t
	192	thread_switch(
	193	mach_port_name_t thread_name,
	194	int option,
	195	mach_msg_timeout_t option_time)
	196	{
	197	register thread_t self = current_thread();
	198	register thread_act_t hint_act = THR_ACT_NULL;
1c79356b A	199
	200	/*
	201	* Process option.
	202	*/
	203	switch (option) {
	204
	205	case SWITCH_OPTION_NONE:
	206	case SWITCH_OPTION_DEPRESS:
	207	case SWITCH_OPTION_WAIT:
	208	break;
	209
	210	default:
	211	return (KERN_INVALID_ARGUMENT);
	212	}
	213
	214	if (thread_name != MACH_PORT_NULL) {
	215	ipc_port_t port;
	216
	217	if (ipc_port_translate_send(self->top_act->task->itk_space,
	218	thread_name, &port) == KERN_SUCCESS) {
	219	ip_reference(port);
	220	ip_unlock(port);
	221
	222	hint_act = convert_port_to_act(port);
	223	ipc_port_release(port);
	224	}
	225	}
	226
0b4e3aa0	227	return _mk_sp_thread_switch(hint_act, option, option_time);
1c79356b	228	}