WebSVN – HelenOS – Diff – /trunk/uspace/lib/libc/generic/fibril_sync.c


/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * Copyright (c) 2007 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
/** @addtogroup libc
 * @{
 */
/** @file
 */
 
#include <adt/list.h>
#include <fibril.h>
#include <thread.h>
#include <tls.h>
#include <malloc.h>
#include <unistd.h>
#include <stdio.h>
#include <libarch/faddr.h>
#include <futex.h>
#include <assert.h>
#include <async.h>
 
#ifndef FIBRIL_INITIAL_STACK_PAGES_NO
#define FIBRIL_INITIAL_STACK_PAGES_NO   1
#endif
 
/**
 * This futex serializes access to ready_list, serialized_list and manager_list.
 */
static atomic_t fibril_futex = FUTEX_INITIALIZER;
 
static LIST_INITIALIZE(ready_list);
static LIST_INITIALIZE(serialized_list);
static LIST_INITIALIZE(manager_list);
 
static void fibril_main(void);
 
/** Number of threads that are executing a manager fibril. */
static int threads_in_manager;
/** Number of threads that are executing a manager fibril and are serialized. */
static int serialized_threads;  /* Protected by async_futex */
/** Thread-local count of serialization. If > 0, we must not preempt */
static __thread int serialization_count;
 
/** Setup fibril information into TCB structure */
fibril_t *fibril_setup(void)
{
    fibril_t *f;
    tcb_t *tcb;
 
    tcb = __make_tls();
    if (!tcb)
        return NULL;
 
    f = malloc(sizeof(fibril_t));
    if (!f) {
        __free_tls(tcb);
        return NULL;
    }
 
    tcb->fibril_data = f;
    f->tcb = tcb;
 
    f->func = NULL;
    f->arg = NULL;
    f->stack = NULL;
    f->clean_after_me = NULL;
    f->retval = 0;
    f->flags = 0;
 
    return f;
}
 
void fibril_teardown(fibril_t *f)
{
    __free_tls(f->tcb);
    free(f);
}
 
/** Function that spans the whole life-cycle of a fibril.
 *
 * Each fibril begins execution in this function. Then the function implementing
 * the fibril logic is called.  After its return, the return value is saved.
 * The fibril then switches to another fibril, which cleans up after it.
 */
void fibril_main(void)
{
    fibril_t *f = __tcb_get()->fibril_data;
 
    /* Call the implementing function. */
    f->retval = f->func(f->arg);
 
    fibril_switch(FIBRIL_FROM_DEAD);
    /* not reached */
}
 
/** Switch from the current fibril.
 *
 * If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be
 * held.
 *
 * @param stype     Switch type. One of FIBRIL_PREEMPT, FIBRIL_TO_MANAGER,
 *          FIBRIL_FROM_MANAGER, FIBRIL_FROM_DEAD. The parameter
 *          describes the circumstances of the switch.
 * @return      Return 0 if there is no ready fibril,
 *          return 1 otherwise.
 */
int fibril_switch(fibril_switch_type_t stype)
{
    fibril_t *srcf, *dstf;
    int retval = 0;
   
    futex_down(&fibril_futex);
 
    if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))
        goto ret_0;
 
    if (stype == FIBRIL_FROM_MANAGER) {
        if (list_empty(&ready_list) && list_empty(&serialized_list))
            goto ret_0;
        /*
         * Do not preempt if there is not enough threads to run the
         * ready fibrils which are not serialized.
         */
        if (list_empty(&serialized_list) &&
            threads_in_manager <= serialized_threads) {
            goto ret_0;
        }
    }
    /* If we are going to manager and none exists, create it */
    if (stype == FIBRIL_TO_MANAGER || stype == FIBRIL_FROM_DEAD) {
        while (list_empty(&manager_list)) {
            futex_up(&fibril_futex);
            async_create_manager();
            futex_down(&fibril_futex);
        }
    }
   
    srcf = __tcb_get()->fibril_data;
    if (stype != FIBRIL_FROM_DEAD) {
        /* Save current state */
        if (!context_save(&srcf->ctx)) {
            if (serialization_count)
                srcf->flags &= ~FIBRIL_SERIALIZED;
            if (srcf->clean_after_me) {
                /*
                 * Cleanup after the dead fibril from which we
                 * restored context here.
                 */
                void *stack = srcf->clean_after_me->stack;
                if (stack) {
                    /*
                     * This check is necessary because a
                     * thread could have exited like a
                     * normal fibril using the
                     * FIBRIL_FROM_DEAD switch type. In that
                     * case, its fibril will not have the
                     * stack member filled.
                     */
                    free(stack);
                }
                fibril_teardown(srcf->clean_after_me);
                srcf->clean_after_me = NULL;
            }
            return 1;   /* futex_up already done here */
        }
 
        /* Save myself to the correct run list */
        if (stype == FIBRIL_PREEMPT)
            list_append(&srcf->link, &ready_list);
        else if (stype == FIBRIL_FROM_MANAGER) {
            list_append(&srcf->link, &manager_list);
            threads_in_manager--;
        } else {   
            /*
             * If stype == FIBRIL_TO_MANAGER, don't put ourselves to
             * any list, we should already be somewhere, or we will
             * be lost.
             */
        }
    }
   
    /* Choose a new fibril to run */
    if (stype == FIBRIL_TO_MANAGER || stype == FIBRIL_FROM_DEAD) {
        dstf = list_get_instance(manager_list.next, fibril_t, link);
        if (serialization_count && stype == FIBRIL_TO_MANAGER) {
            serialized_threads++;
            srcf->flags |= FIBRIL_SERIALIZED;
        }
        threads_in_manager++;
 
        if (stype == FIBRIL_FROM_DEAD)
            dstf->clean_after_me = srcf;
    } else {
        if (!list_empty(&serialized_list)) {
            dstf = list_get_instance(serialized_list.next, fibril_t,
                link);
            serialized_threads--;
        } else {
            dstf = list_get_instance(ready_list.next, fibril_t,
                link);
        }
    }
    list_remove(&dstf->link);
 
    futex_up(&fibril_futex);
    context_restore(&dstf->ctx);
    /* not reached */
 
ret_0:
    futex_up(&fibril_futex);
    return retval;
}
 
/** Create a new fibril.
 *
 * @param func      Implementing function of the new fibril.
 * @param arg       Argument to pass to func.
 *
 * @return      Return 0 on failure or TLS of the new fibril.
 */
fid_t fibril_create(int (*func)(void *), void *arg)
{
    fibril_t *f;
 
    f = fibril_setup();
    if (!f)
        return 0;
    f->stack = (char *) malloc(FIBRIL_INITIAL_STACK_PAGES_NO *
        getpagesize());
    if (!f->stack) {
        fibril_teardown(f);
        return 0;
    }
   
    f->func = func;
    f->arg = arg;
 
    context_save(&f->ctx);
    context_set(&f->ctx, FADDR(fibril_main), f->stack,
        FIBRIL_INITIAL_STACK_PAGES_NO * getpagesize(), f->tcb);
 
    return (fid_t) f;
}
 
/** Add a fibril to the ready list.
 *
 * @param fid       Pointer to the fibril structure of the fibril to be
 *          added.
 */
void fibril_add_ready(fid_t fid)
{
    fibril_t *f;
 
    f = (fibril_t *) fid;
    futex_down(&fibril_futex);
    if ((f->flags & FIBRIL_SERIALIZED))
        list_append(&f->link, &serialized_list);
    else
        list_append(&f->link, &ready_list);
    futex_up(&fibril_futex);
}
 
/** Add a fibril to the manager list.
 *
 * @param fid       Pointer to the fibril structure of the fibril to be
 *          added.
 */
void fibril_add_manager(fid_t fid)
{
    fibril_t *f;
 
    f = (fibril_t *) fid;
 
    futex_down(&fibril_futex);
    list_append(&f->link, &manager_list);
    futex_up(&fibril_futex);
}
 
/** Remove one manager from the manager list. */
void fibril_remove_manager(void)
{
    futex_down(&fibril_futex);
    if (list_empty(&manager_list)) {
        futex_up(&fibril_futex);
        return;
    }
    list_remove(manager_list.next);
    futex_up(&fibril_futex);
}
 
/** Return fibril id of the currently running fibril.
 *
 * @return      Fibril ID of the currently running fibril.
 */
fid_t fibril_get_id(void)
{
    return (fid_t) __tcb_get()->fibril_data;
}
 
/** Disable preemption
 *
 * If the fibril wants to send several message in a row and does not want to be
 * preempted, it should start async_serialize_start() in the beginning of
 * communication and async_serialize_end() in the end. If it is a true
 * multithreaded application, it should protect the communication channel by a
 * futex as well. Interrupt messages can still be preempted.
 */
void fibril_inc_sercount(void)
{
    serialization_count++;
}
 
/** Restore the preemption counter to the previous state. */
void fibril_dec_sercount(void)
{
    serialization_count--;
}
 
/** @}
 */
 

Rev 4510	Rev 4513
1	/*	1	/*
2	* Copyright (c) 2006 Ondrej Palkovsky	2	* Copyright (c) 2006 Ondrej Palkovsky
3	* Copyright (c) 2007 Jakub Jermar	3	* Copyright (c) 2007 Jakub Jermar
4	* All rights reserved.	4	* All rights reserved.
5	*	5	*
6	* Redistribution and use in source and binary forms, with or without	6	* Redistribution and use in source and binary forms, with or without
7	* modification, are permitted provided that the following conditions	7	* modification, are permitted provided that the following conditions
8	* are met:	8	* are met:
9	*	9	*
10	* - Redistributions of source code must retain the above copyright	10	* - Redistributions of source code must retain the above copyright
11	* notice, this list of conditions and the following disclaimer.	11	* notice, this list of conditions and the following disclaimer.
12	* - Redistributions in binary form must reproduce the above copyright	12	* - Redistributions in binary form must reproduce the above copyright
13	* notice, this list of conditions and the following disclaimer in the	13	* notice, this list of conditions and the following disclaimer in the
14	* documentation and/or other materials provided with the distribution.	14	* documentation and/or other materials provided with the distribution.
15	* - The name of the author may not be used to endorse or promote products	15	* - The name of the author may not be used to endorse or promote products
16	* derived from this software without specific prior written permission.	16	* derived from this software without specific prior written permission.
17	*	17	*
18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28	*/	28	*/
29		29
30	/** @addtogroup libc	30	/** @addtogroup libc
31	* @{	31	* @{
32	*/	32	*/
33	/** @file	33	/** @file
34	*/	34	*/
35		35
36	#include <adt/list.h>	36	#include <adt/list.h>
37	#include <fibril.h>	37	#include <fibril.h>
38	#include <thread.h>	38	#include <thread.h>
39	#include <tls.h>	39	#include <tls.h>
40	#include <malloc.h>	40	#include <malloc.h>
41	#include <unistd.h>	41	#include <unistd.h>
42	#include <stdio.h>	42	#include <stdio.h>
43	#include <libarch/faddr.h>	43	#include <libarch/faddr.h>
44	#include <futex.h>	44	#include <futex.h>
45	#include <assert.h>	45	#include <assert.h>
46	#include <async.h>	46	#include <async.h>
47		47
48	#ifndef FIBRIL_INITIAL_STACK_PAGES_NO	48	#ifndef FIBRIL_INITIAL_STACK_PAGES_NO
49	#define FIBRIL_INITIAL_STACK_PAGES_NO 1	49	#define FIBRIL_INITIAL_STACK_PAGES_NO 1
50	#endif	50	#endif
51		51
52	/**	52	/**
53	* This futex serializes access to ready_list, serialized_list and manager_list.	53	* This futex serializes access to ready_list, serialized_list and manager_list.
54	*/	54	*/
55	static atomic_t fibril_futex = FUTEX_INITIALIZER;	55	static atomic_t fibril_futex = FUTEX_INITIALIZER;
56		56
57	static LIST_INITIALIZE(ready_list);	57	static LIST_INITIALIZE(ready_list);
58	static LIST_INITIALIZE(serialized_list);	58	static LIST_INITIALIZE(serialized_list);
59	static LIST_INITIALIZE(manager_list);	59	static LIST_INITIALIZE(manager_list);
60		60
61	static void fibril_main(void);	61	static void fibril_main(void);
62		62
63	/** Number of threads that are executing a manager fibril. */	63	/** Number of threads that are executing a manager fibril. */
64	static int threads_in_manager;	64	static int threads_in_manager;
65	/** Number of threads that are executing a manager fibril and are serialized. */	65	/** Number of threads that are executing a manager fibril and are serialized. */
66	static int serialized_threads; /* Protected by async_futex */	66	static int serialized_threads; /* Protected by async_futex */
67	/** Thread-local count of serialization. If > 0, we must not preempt */	67	/** Thread-local count of serialization. If > 0, we must not preempt */
68	static __thread int serialization_count;	68	static __thread int serialization_count;
69		69
70	/** Setup fibril information into TCB structure */	70	/** Setup fibril information into TCB structure */
71	fibril_t *fibril_setup(void)	71	fibril_t *fibril_setup(void)
72	{	72	{
73	fibril_t *f;	73	fibril_t *f;
74	tcb_t *tcb;	74	tcb_t *tcb;
75		75
76	tcb = __make_tls();	76	tcb = __make_tls();
77	if (!tcb)	77	if (!tcb)
78	return NULL;	78	return NULL;
79		79
80	f = malloc(sizeof(fibril_t));	80	f = malloc(sizeof(fibril_t));
81	if (!f) {	81	if (!f) {
82	__free_tls(tcb);	82	__free_tls(tcb);
83	return NULL;	83	return NULL;
84	}	84	}
85		85
86	tcb->fibril_data = f;	86	tcb->fibril_data = f;
87	f->tcb = tcb;	87	f->tcb = tcb;
88		88
89	f->func = NULL;	89	f->func = NULL;
90	f->arg = NULL;	90	f->arg = NULL;
91	f->stack = NULL;	91	f->stack = NULL;
92	f->clean_after_me = NULL;	92	f->clean_after_me = NULL;
93	f->retval = 0;	93	f->retval = 0;
94	f->flags = 0;	94	f->flags = 0;
95		95
96	return f;	96	return f;
97	}	97	}
98		98
99	void fibril_teardown(fibril_t *f)	99	void fibril_teardown(fibril_t *f)
100	{	100	{
101	__free_tls(f->tcb);	101	__free_tls(f->tcb);
102	free(f);	102	free(f);
103	}	103	}
104		104
105	/** Function that spans the whole life-cycle of a fibril.	105	/** Function that spans the whole life-cycle of a fibril.
106	*	106	*
107	* Each fibril begins execution in this function. Then the function implementing	107	* Each fibril begins execution in this function. Then the function implementing
108	* the fibril logic is called. After its return, the return value is saved.	108	* the fibril logic is called. After its return, the return value is saved.
109	* The fibril then switches to another fibril, which cleans up after it.	109	* The fibril then switches to another fibril, which cleans up after it.
110	*/	110	*/
111	void fibril_main(void)	111	void fibril_main(void)
112	{	112	{
113	fibril_t *f = __tcb_get()->fibril_data;	113	fibril_t *f = __tcb_get()->fibril_data;
114		114
115	/* Call the implementing function. */	115	/* Call the implementing function. */
116	f->retval = f->func(f->arg);	116	f->retval = f->func(f->arg);
117		117
118	fibril_switch(FIBRIL_FROM_DEAD);	118	fibril_switch(FIBRIL_FROM_DEAD);
119	/* not reached */	119	/* not reached */
120	}	120	}
121		121
122	/** Switch from the current fibril.	122	/** Switch from the current fibril.
123	*	123	*
124	* If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be	124	* If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be
125	* held.	125	* held.
126	*	126	*
127	* @param stype Switch type. One of FIBRIL_PREEMPT, FIBRIL_TO_MANAGER,	127	* @param stype Switch type. One of FIBRIL_PREEMPT, FIBRIL_TO_MANAGER,
128	* FIBRIL_FROM_MANAGER, FIBRIL_FROM_DEAD. The parameter	128	* FIBRIL_FROM_MANAGER, FIBRIL_FROM_DEAD. The parameter
129	* describes the circumstances of the switch.	129	* describes the circumstances of the switch.
130	* @return Return 0 if there is no ready fibril,	130	* @return Return 0 if there is no ready fibril,
131	* return 1 otherwise.	131	* return 1 otherwise.
132	*/	132	*/
133	int fibril_switch(fibril_switch_type_t stype)	133	int fibril_switch(fibril_switch_type_t stype)
134	{	134	{
135	fibril_t srcf, dstf;	135	fibril_t srcf, dstf;
136	int retval = 0;	136	int retval = 0;
137		137
138	futex_down(&fibril_futex);	138	futex_down(&fibril_futex);
139		139
140	if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))	140	if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))
141	goto ret_0;	141	goto ret_0;
142		142
143	if (stype == FIBRIL_FROM_MANAGER) {	143	if (stype == FIBRIL_FROM_MANAGER) {
144	if (list_empty(&ready_list) && list_empty(&serialized_list))	144	if (list_empty(&ready_list) && list_empty(&serialized_list))
145	goto ret_0;	145	goto ret_0;
146	/*	146	/*
147	* Do not preempt if there is not enough threads to run the	147	* Do not preempt if there is not enough threads to run the
148	* ready fibrils, which are not serialized.	148	* ready fibrils which are not serialized.
149	*/	149	*/
150	if (list_empty(&serialized_list) &&	150	if (list_empty(&serialized_list) &&
151	threads_in_manager <= serialized_threads) {	151	threads_in_manager <= serialized_threads) {
152	goto ret_0;	152	goto ret_0;
153	}	153	}
154	}	154	}
155	/* If we are going to manager and none exists, create it */	155	/* If we are going to manager and none exists, create it */
156	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {	156	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {
157	while (list_empty(&manager_list)) {	157	while (list_empty(&manager_list)) {
158	futex_up(&fibril_futex);	158	futex_up(&fibril_futex);
159	async_create_manager();	159	async_create_manager();
160	futex_down(&fibril_futex);	160	futex_down(&fibril_futex);
161	}	161	}
162	}	162	}
163		163
164	srcf = __tcb_get()->fibril_data;	164	srcf = __tcb_get()->fibril_data;
165	if (stype != FIBRIL_FROM_DEAD) {	165	if (stype != FIBRIL_FROM_DEAD) {
166	/* Save current state */	166	/* Save current state */
167	if (!context_save(&srcf->ctx)) {	167	if (!context_save(&srcf->ctx)) {
168	if (serialization_count)	168	if (serialization_count)
169	srcf->flags &= ~FIBRIL_SERIALIZED;	169	srcf->flags &= ~FIBRIL_SERIALIZED;
170	if (srcf->clean_after_me) {	170	if (srcf->clean_after_me) {
171	/*	171	/*
172	* Cleanup after the dead fibril from which we	172	* Cleanup after the dead fibril from which we
173	* restored context here.	173	* restored context here.
174	*/	174	*/
175	void *stack = srcf->clean_after_me->stack;	175	void *stack = srcf->clean_after_me->stack;
176	if (stack) {	176	if (stack) {
177	/*	177	/*
178	* This check is necessary because a	178	* This check is necessary because a
179	* thread could have exited like a	179	* thread could have exited like a
180	* normal fibril using the	180	* normal fibril using the
181	* FIBRIL_FROM_DEAD switch type. In that	181	* FIBRIL_FROM_DEAD switch type. In that
182	* case, its fibril will not have the	182	* case, its fibril will not have the
183	* stack member filled.	183	* stack member filled.
184	*/	184	*/
185	free(stack);	185	free(stack);
186	}	186	}
187	fibril_teardown(srcf->clean_after_me);	187	fibril_teardown(srcf->clean_after_me);
188	srcf->clean_after_me = NULL;	188	srcf->clean_after_me = NULL;
189	}	189	}
190	return 1; /* futex_up already done here */	190	return 1; /* futex_up already done here */
191	}	191	}
192		192
193	/* Save myself to the correct run list */	193	/* Save myself to the correct run list */
194	if (stype == FIBRIL_PREEMPT)	194	if (stype == FIBRIL_PREEMPT)
195	list_append(&srcf->link, &ready_list);	195	list_append(&srcf->link, &ready_list);
196	else if (stype == FIBRIL_FROM_MANAGER) {	196	else if (stype == FIBRIL_FROM_MANAGER) {
197	list_append(&srcf->link, &manager_list);	197	list_append(&srcf->link, &manager_list);
198	threads_in_manager--;	198	threads_in_manager--;
199	} else {	199	} else {
200	/*	200	/*
201	* If stype == FIBRIL_TO_MANAGER, don't put ourselves to	201	* If stype == FIBRIL_TO_MANAGER, don't put ourselves to
202	* any list, we should already be somewhere, or we will	202	* any list, we should already be somewhere, or we will
203	* be lost.	203	* be lost.
204	*/	204	*/
205	}	205	}
206	}	206	}
207		207
208	/* Choose a new fibril to run */	208	/* Choose a new fibril to run */
209	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {	209	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {
210	dstf = list_get_instance(manager_list.next, fibril_t, link);	210	dstf = list_get_instance(manager_list.next, fibril_t, link);
211	if (serialization_count && stype == FIBRIL_TO_MANAGER) {	211	if (serialization_count && stype == FIBRIL_TO_MANAGER) {
212	serialized_threads++;	212	serialized_threads++;
213	srcf->flags \|= FIBRIL_SERIALIZED;	213	srcf->flags \|= FIBRIL_SERIALIZED;
214	}	214	}
215	threads_in_manager++;	215	threads_in_manager++;
216		216
217	if (stype == FIBRIL_FROM_DEAD)	217	if (stype == FIBRIL_FROM_DEAD)
218	dstf->clean_after_me = srcf;	218	dstf->clean_after_me = srcf;
219	} else {	219	} else {
220	if (!list_empty(&serialized_list)) {	220	if (!list_empty(&serialized_list)) {
221	dstf = list_get_instance(serialized_list.next, fibril_t,	221	dstf = list_get_instance(serialized_list.next, fibril_t,
222	link);	222	link);
223	serialized_threads--;	223	serialized_threads--;
224	} else {	224	} else {
225	dstf = list_get_instance(ready_list.next, fibril_t,	225	dstf = list_get_instance(ready_list.next, fibril_t,
226	link);	226	link);
227	}	227	}
228	}	228	}
229	list_remove(&dstf->link);	229	list_remove(&dstf->link);
230		230
231	futex_up(&fibril_futex);	231	futex_up(&fibril_futex);
232	context_restore(&dstf->ctx);	232	context_restore(&dstf->ctx);
233	/* not reached */	233	/* not reached */
234		234
235	ret_0:	235	ret_0:
236	futex_up(&fibril_futex);	236	futex_up(&fibril_futex);
237	return retval;	237	return retval;
238	}	238	}
239		239
240	/** Create a new fibril.	240	/** Create a new fibril.
241	*	241	*
242	* @param func Implementing function of the new fibril.	242	* @param func Implementing function of the new fibril.
243	* @param arg Argument to pass to func.	243	* @param arg Argument to pass to func.
244	*	244	*
245	* @return Return 0 on failure or TLS of the new fibril.	245	* @return Return 0 on failure or TLS of the new fibril.
246	*/	246	*/
247	fid_t fibril_create(int (func)(void ), void *arg)	247	fid_t fibril_create(int (func)(void ), void *arg)
248	{	248	{
249	fibril_t *f;	249	fibril_t *f;
250		250
251	f = fibril_setup();	251	f = fibril_setup();
252	if (!f)	252	if (!f)
253	return 0;	253	return 0;
254	f->stack = (char ) malloc(FIBRIL_INITIAL_STACK_PAGES_NO	254	f->stack = (char ) malloc(FIBRIL_INITIAL_STACK_PAGES_NO
255	getpagesize());	255	getpagesize());
256	if (!f->stack) {	256	if (!f->stack) {
257	fibril_teardown(f);	257	fibril_teardown(f);
258	return 0;	258	return 0;
259	}	259	}
260		260
261	f->func = func;	261	f->func = func;
262	f->arg = arg;	262	f->arg = arg;
263		263
264	context_save(&f->ctx);	264	context_save(&f->ctx);
265	context_set(&f->ctx, FADDR(fibril_main), f->stack,	265	context_set(&f->ctx, FADDR(fibril_main), f->stack,
266	FIBRIL_INITIAL_STACK_PAGES_NO * getpagesize(), f->tcb);	266	FIBRIL_INITIAL_STACK_PAGES_NO * getpagesize(), f->tcb);
267		267
268	return (fid_t) f;	268	return (fid_t) f;
269	}	269	}
270		270
271	/** Add a fibril to the ready list.	271	/** Add a fibril to the ready list.
272	*	272	*
273	* @param fid Pointer to the fibril structure of the fibril to be	273	* @param fid Pointer to the fibril structure of the fibril to be
274	* added.	274	* added.
275	*/	275	*/
276	void fibril_add_ready(fid_t fid)	276	void fibril_add_ready(fid_t fid)
277	{	277	{
278	fibril_t *f;	278	fibril_t *f;
279		279
280	f = (fibril_t *) fid;	280	f = (fibril_t *) fid;
281	futex_down(&fibril_futex);	281	futex_down(&fibril_futex);
282	if ((f->flags & FIBRIL_SERIALIZED))	282	if ((f->flags & FIBRIL_SERIALIZED))
283	list_append(&f->link, &serialized_list);	283	list_append(&f->link, &serialized_list);
284	else	284	else
285	list_append(&f->link, &ready_list);	285	list_append(&f->link, &ready_list);
286	futex_up(&fibril_futex);	286	futex_up(&fibril_futex);
287	}	287	}
288		288
289	/** Add a fibril to the manager list.	289	/** Add a fibril to the manager list.
290	*	290	*
291	* @param fid Pointer to the fibril structure of the fibril to be	291	* @param fid Pointer to the fibril structure of the fibril to be
292	* added.	292	* added.
293	*/	293	*/
294	void fibril_add_manager(fid_t fid)	294	void fibril_add_manager(fid_t fid)
295	{	295	{
296	fibril_t *f;	296	fibril_t *f;
297		297
298	f = (fibril_t *) fid;	298	f = (fibril_t *) fid;
299		299
300	futex_down(&fibril_futex);	300	futex_down(&fibril_futex);
301	list_append(&f->link, &manager_list);	301	list_append(&f->link, &manager_list);
302	futex_up(&fibril_futex);	302	futex_up(&fibril_futex);
303	}	303	}
304		304
305	/** Remove one manager from the manager list. */	305	/** Remove one manager from the manager list. */
306	void fibril_remove_manager(void)	306	void fibril_remove_manager(void)
307	{	307	{
308	futex_down(&fibril_futex);	308	futex_down(&fibril_futex);
309	if (list_empty(&manager_list)) {	309	if (list_empty(&manager_list)) {
310	futex_up(&fibril_futex);	310	futex_up(&fibril_futex);
311	return;	311	return;
312	}	312	}
313	list_remove(manager_list.next);	313	list_remove(manager_list.next);
314	futex_up(&fibril_futex);	314	futex_up(&fibril_futex);
315	}	315	}
316		316
317	/** Return fibril id of the currently running fibril.	317	/** Return fibril id of the currently running fibril.
318	*	318	*
319	* @return Fibril ID of the currently running fibril.	319	* @return Fibril ID of the currently running fibril.
320	*/	320	*/
321	fid_t fibril_get_id(void)	321	fid_t fibril_get_id(void)
322	{	322	{
323	return (fid_t) __tcb_get()->fibril_data;	323	return (fid_t) __tcb_get()->fibril_data;
324	}	324	}
325		325
326	/** Disable preemption	326	/** Disable preemption
327	*	327	*
328	* If the fibril wants to send several message in a row and does not want to be	328	* If the fibril wants to send several message in a row and does not want to be
329	* preempted, it should start async_serialize_start() in the beginning of	329	* preempted, it should start async_serialize_start() in the beginning of
330	* communication and async_serialize_end() in the end. If it is a true	330	* communication and async_serialize_end() in the end. If it is a true
331	* multithreaded application, it should protect the communication channel by a	331	* multithreaded application, it should protect the communication channel by a
332	* futex as well. Interrupt messages can still be preempted.	332	* futex as well. Interrupt messages can still be preempted.
333	*/	333	*/
334	void fibril_inc_sercount(void)	334	void fibril_inc_sercount(void)
335	{	335	{
336	serialization_count++;	336	serialization_count++;
337	}	337	}
338		338
339	/** Restore the preemption counter to the previous state. */	339	/** Restore the preemption counter to the previous state. */
340	void fibril_dec_sercount(void)	340	void fibril_dec_sercount(void)
341	{	341	{
342	serialization_count--;	342	serialization_count--;
343	}	343	}
344		344
345	/** @}	345	/** @}
346	*/	346	*/
347		347

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(root)/trunk/uspace/lib/libc/generic/fibril_sync.c @ 4537 – Rev 4510 → 4513