WebSVN – HelenOS – Diff – /trunk/uspace/lib/libc/generic/fibril.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 <libadt/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 manage_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 fibrils that are in async_serialized mode */
static int serialized_fibrils;  /* Protected by async_futex */
/** Thread-local count of serialization. If >0, we must not preempt */
static __thread int serialization_count;
/** Counter for fibrils residing in async_manager */
static int fibrils_in_manager;
 
/** 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 sufficient count of fibril
         * managers.
         */
        if (list_empty(&serialized_list) &&
            fibrils_in_manager <= serialized_fibrils) {
            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);
            fibrils_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_fibrils++;
            srcf->flags |= FIBRIL_SERIALIZED;
        }
        fibrils_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_fibrils--;
        } 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       Pinter 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       Pinter 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 pseudo thread.
 */
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 2568	Rev 2586
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 <libadt/list.h>	36	#include <libadt/list.h>
37	#include <fibril.h>	37	#include <fibril.h>
-		38	#include <thread.h>
-		39	#include <tls.h>
38	#include <malloc.h>	40	#include <malloc.h>
39	#include <unistd.h>	41	#include <unistd.h>
40	#include <thread.h>	-
41	#include <stdio.h>	42	#include <stdio.h>
42	#include <libarch/faddr.h>	43	#include <libarch/faddr.h>
43	#include <futex.h>	44	#include <futex.h>
44	#include <assert.h>	45	#include <assert.h>
45	#include <async.h>	46	#include <async.h>
46		47
47	#ifndef FIBRIL_INITIAL_STACK_PAGES_NO	48	#ifndef FIBRIL_INITIAL_STACK_PAGES_NO
48	#define FIBRIL_INITIAL_STACK_PAGES_NO 1	49	#define FIBRIL_INITIAL_STACK_PAGES_NO 1
49	#endif	50	#endif
50		51
51	/** This futex serializes access to ready_list, serialized_list and manage_list.	52	/** This futex serializes access to ready_list, serialized_list and manage_list.
52	*/	53	*/
53	static atomic_t fibril_futex = FUTEX_INITIALIZER;	54	static atomic_t fibril_futex = FUTEX_INITIALIZER;
54		55
55	static LIST_INITIALIZE(ready_list);	56	static LIST_INITIALIZE(ready_list);
56	static LIST_INITIALIZE(serialized_list);	57	static LIST_INITIALIZE(serialized_list);
57	static LIST_INITIALIZE(manager_list);	58	static LIST_INITIALIZE(manager_list);
58		59
59	static void fibril_main(void);	60	static void fibril_main(void);
60		61
61	/** Number of fibrils that are in async_serialized mode */	62	/** Number of fibrils that are in async_serialized mode */
62	static int serialized_fibrils; /* Protected by async_futex */	63	static int serialized_fibrils; /* Protected by async_futex */
63	/** Thread-local count of serialization. If >0, we must not preempt */	64	/** Thread-local count of serialization. If >0, we must not preempt */
64	static __thread int serialization_count;	65	static __thread int serialization_count;
65	/** Counter for fibrils residing in async_manager */	66	/** Counter for fibrils residing in async_manager */
66	static int fibrils_in_manager;	67	static int fibrils_in_manager;
67		68
68	/** Setup fibril information into TCB structure */	69	/** Setup fibril information into TCB structure */
69	fibril_t *fibril_setup(void)	70	fibril_t *fibril_setup(void)
70	{	71	{
71	fibril_t *f;	72	fibril_t *f;
72	tcb_t *tcb;	73	tcb_t *tcb;
73		74
74	tcb = __make_tls();	75	tcb = __make_tls();
75	if (!tcb)	76	if (!tcb)
76	return NULL;	77	return NULL;
77		78
78	f = malloc(sizeof(fibril_t));	79	f = malloc(sizeof(fibril_t));
79	if (!f) {	80	if (!f) {
80	__free_tls(tcb);	81	__free_tls(tcb);
81	return NULL;	82	return NULL;
82	}	83	}
83		84
84	tcb->fibril_data = f;	85	tcb->fibril_data = f;
85	f->tcb = tcb;	86	f->tcb = tcb;
86		87
87	f->func = NULL;	88	f->func = NULL;
88	f->arg = NULL;	89	f->arg = NULL;
89	f->stack = NULL;	90	f->stack = NULL;
90	f->clean_after_me = NULL;	91	f->clean_after_me = NULL;
91	f->retval = 0;	92	f->retval = 0;
92	f->flags = 0;	93	f->flags = 0;
93		94
94	return f;	95	return f;
95	}	96	}
96		97
97	void fibril_teardown(fibril_t *f)	98	void fibril_teardown(fibril_t *f)
98	{	99	{
99	__free_tls(f->tcb);	100	__free_tls(f->tcb);
100	free(f);	101	free(f);
101	}	102	}
102		103
103	/** Function that spans the whole life-cycle of a fibril.	104	/** Function that spans the whole life-cycle of a fibril.
104	*	105	*
105	* Each fibril begins execution in this function. Then the function implementing	106	* Each fibril begins execution in this function. Then the function implementing
106	* the fibril logic is called. After its return, the return value is saved.	107	* the fibril logic is called. After its return, the return value is saved.
107	* The fibril then switches to another fibril, which cleans up after it.	108	* The fibril then switches to another fibril, which cleans up after it.
108	*/	109	*/
109	void fibril_main(void)	110	void fibril_main(void)
110	{	111	{
111	fibril_t *f = __tcb_get()->fibril_data;	112	fibril_t *f = __tcb_get()->fibril_data;
112		113
113	/* Call the implementing function. */	114	/* Call the implementing function. */
114	f->retval = f->func(f->arg);	115	f->retval = f->func(f->arg);
115		116
116	fibril_switch(FIBRIL_FROM_DEAD);	117	fibril_switch(FIBRIL_FROM_DEAD);
117	/* not reached */	118	/* not reached */
118	}	119	}
119		120
120	/** Switch from the current fibril.	121	/** Switch from the current fibril.
121	*	122	*
122	* If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be	123	* If calling with FIBRIL_TO_MANAGER parameter, the async_futex should be
123	* held.	124	* held.
124	*	125	*
125	* @param stype Switch type. One of FIBRIL_PREEMPT, FIBRIL_TO_MANAGER,	126	* @param stype Switch type. One of FIBRIL_PREEMPT, FIBRIL_TO_MANAGER,
126	* FIBRIL_FROM_MANAGER, FIBRIL_FROM_DEAD. The parameter	127	* FIBRIL_FROM_MANAGER, FIBRIL_FROM_DEAD. The parameter
127	* describes the circumstances of the switch.	128	* describes the circumstances of the switch.
128	* @return Return 0 if there is no ready fibril,	129	* @return Return 0 if there is no ready fibril,
129	* return 1 otherwise.	130	* return 1 otherwise.
130	*/	131	*/
131	int fibril_switch(fibril_switch_type_t stype)	132	int fibril_switch(fibril_switch_type_t stype)
132	{	133	{
133	fibril_t srcf, dstf;	134	fibril_t srcf, dstf;
134	int retval = 0;	135	int retval = 0;
135		136
136	futex_down(&fibril_futex);	137	futex_down(&fibril_futex);
137		138
138	if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))	139	if (stype == FIBRIL_PREEMPT && list_empty(&ready_list))
139	goto ret_0;	140	goto ret_0;
140		141
141	if (stype == FIBRIL_FROM_MANAGER) {	142	if (stype == FIBRIL_FROM_MANAGER) {
142	if (list_empty(&ready_list) && list_empty(&serialized_list))	143	if (list_empty(&ready_list) && list_empty(&serialized_list))
143	goto ret_0;	144	goto ret_0;
144	/*	145	/*
145	* Do not preempt if there is not sufficient count of fibril	146	* Do not preempt if there is not sufficient count of fibril
146	* managers.	147	* managers.
147	*/	148	*/
148	if (list_empty(&serialized_list) &&	149	if (list_empty(&serialized_list) &&
149	fibrils_in_manager <= serialized_fibrils) {	150	fibrils_in_manager <= serialized_fibrils) {
150	goto ret_0;	151	goto ret_0;
151	}	152	}
152	}	153	}
153	/* If we are going to manager and none exists, create it */	154	/* If we are going to manager and none exists, create it */
154	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {	155	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {
155	while (list_empty(&manager_list)) {	156	while (list_empty(&manager_list)) {
156	futex_up(&fibril_futex);	157	futex_up(&fibril_futex);
157	async_create_manager();	158	async_create_manager();
158	futex_down(&fibril_futex);	159	futex_down(&fibril_futex);
159	}	160	}
160	}	161	}
161		162
162	srcf = __tcb_get()->fibril_data;	163	srcf = __tcb_get()->fibril_data;
163	if (stype != FIBRIL_FROM_DEAD) {	164	if (stype != FIBRIL_FROM_DEAD) {
164	/* Save current state */	165	/* Save current state */
165	if (!context_save(&srcf->ctx)) {	166	if (!context_save(&srcf->ctx)) {
166	if (serialization_count)	167	if (serialization_count)
167	srcf->flags &= ~FIBRIL_SERIALIZED;	168	srcf->flags &= ~FIBRIL_SERIALIZED;
168	if (srcf->clean_after_me) {	169	if (srcf->clean_after_me) {
169	/*	170	/*
170	* Cleanup after the dead fibril from which we	171	* Cleanup after the dead fibril from which we
171	* restored context here.	172	* restored context here.
172	*/	173	*/
173	void *stack = srcf->clean_after_me->stack;	174	void *stack = srcf->clean_after_me->stack;
174	if (stack) {	175	if (stack) {
175	/*	176	/*
176	* This check is necessary because a	177	* This check is necessary because a
177	* thread could have exited like a	178	* thread could have exited like a
178	* normal fibril using the	179	* normal fibril using the
179	* FIBRIL_FROM_DEAD switch type. In that	180	* FIBRIL_FROM_DEAD switch type. In that
180	* case, its fibril will not have the	181	* case, its fibril will not have the
181	* stack member filled.	182	* stack member filled.
182	*/	183	*/
183	free(stack);	184	free(stack);
184	}	185	}
185	fibril_teardown(srcf->clean_after_me);	186	fibril_teardown(srcf->clean_after_me);
186	srcf->clean_after_me = NULL;	187	srcf->clean_after_me = NULL;
187	}	188	}
188	return 1; /* futex_up already done here */	189	return 1; /* futex_up already done here */
189	}	190	}
190		191
191	/* Save myself to the correct run list */	192	/* Save myself to the correct run list */
192	if (stype == FIBRIL_PREEMPT)	193	if (stype == FIBRIL_PREEMPT)
193	list_append(&srcf->link, &ready_list);	194	list_append(&srcf->link, &ready_list);
194	else if (stype == FIBRIL_FROM_MANAGER) {	195	else if (stype == FIBRIL_FROM_MANAGER) {
195	list_append(&srcf->link, &manager_list);	196	list_append(&srcf->link, &manager_list);
196	fibrils_in_manager--;	197	fibrils_in_manager--;
197	} else {	198	} else {
198	/*	199	/*
199	* If stype == FIBRIL_TO_MANAGER, don't put ourselves to	200	* If stype == FIBRIL_TO_MANAGER, don't put ourselves to
200	* any list, we should already be somewhere, or we will	201	* any list, we should already be somewhere, or we will
201	* be lost.	202	* be lost.
202	*/	203	*/
203	}	204	}
204	}	205	}
205		206
206	/* Choose a new fibril to run */	207	/* Choose a new fibril to run */
207	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {	208	if (stype == FIBRIL_TO_MANAGER \|\| stype == FIBRIL_FROM_DEAD) {
208	dstf = list_get_instance(manager_list.next, fibril_t, link);	209	dstf = list_get_instance(manager_list.next, fibril_t, link);
209	if (serialization_count && stype == FIBRIL_TO_MANAGER) {	210	if (serialization_count && stype == FIBRIL_TO_MANAGER) {
210	serialized_fibrils++;	211	serialized_fibrils++;
211	srcf->flags \|= FIBRIL_SERIALIZED;	212	srcf->flags \|= FIBRIL_SERIALIZED;
212	}	213	}
213	fibrils_in_manager++;	214	fibrils_in_manager++;
214		215
215	if (stype == FIBRIL_FROM_DEAD)	216	if (stype == FIBRIL_FROM_DEAD)
216	dstf->clean_after_me = srcf;	217	dstf->clean_after_me = srcf;
217	} else {	218	} else {
218	if (!list_empty(&serialized_list)) {	219	if (!list_empty(&serialized_list)) {
219	dstf = list_get_instance(serialized_list.next, fibril_t,	220	dstf = list_get_instance(serialized_list.next, fibril_t,
220	link);	221	link);
221	serialized_fibrils--;	222	serialized_fibrils--;
222	} else {	223	} else {
223	dstf = list_get_instance(ready_list.next, fibril_t,	224	dstf = list_get_instance(ready_list.next, fibril_t,
224	link);	225	link);
225	}	226	}
226	}	227	}
227	list_remove(&dstf->link);	228	list_remove(&dstf->link);
228		229
229	futex_up(&fibril_futex);	230	futex_up(&fibril_futex);
230	context_restore(&dstf->ctx);	231	context_restore(&dstf->ctx);
231	/* not reached */	232	/* not reached */
232		233
233	ret_0:	234	ret_0:
234	futex_up(&fibril_futex);	235	futex_up(&fibril_futex);
235	return retval;	236	return retval;
236	}	237	}
237		238
238	/** Create a new fibril.	239	/** Create a new fibril.
239	*	240	*
240	* @param func Implementing function of the new fibril.	241	* @param func Implementing function of the new fibril.
241	* @param arg Argument to pass to func.	242	* @param arg Argument to pass to func.
242	*	243	*
243	* @return Return 0 on failure or TLS of the new fibril.	244	* @return Return 0 on failure or TLS of the new fibril.
244	*/	245	*/
245	fid_t fibril_create(int (func)(void ), void *arg)	246	fid_t fibril_create(int (func)(void ), void *arg)
246	{	247	{
247	fibril_t *f;	248	fibril_t *f;
248		249
249	f = fibril_setup();	250	f = fibril_setup();
250	if (!f)	251	if (!f)
251	return 0;	252	return 0;
252	f->stack = (char ) malloc(FIBRIL_INITIAL_STACK_PAGES_NO	253	f->stack = (char ) malloc(FIBRIL_INITIAL_STACK_PAGES_NO
253	getpagesize());	254	getpagesize());
254	if (!f->stack) {	255	if (!f->stack) {
255	fibril_teardown(f);	256	fibril_teardown(f);
256	return 0;	257	return 0;
257	}	258	}
258		259
259	f->func = func;	260	f->func = func;
260	f->arg = arg;	261	f->arg = arg;
261		262
262	context_save(&f->ctx);	263	context_save(&f->ctx);
263	context_set(&f->ctx, FADDR(fibril_main), f->stack,	264	context_set(&f->ctx, FADDR(fibril_main), f->stack,
264	FIBRIL_INITIAL_STACK_PAGES_NO * getpagesize(), f->tcb);	265	FIBRIL_INITIAL_STACK_PAGES_NO * getpagesize(), f->tcb);
265		266
266	return (fid_t) f;	267	return (fid_t) f;
267	}	268	}
268		269
269	/** Add a fibril to the ready list.	270	/** Add a fibril to the ready list.
270	*	271	*
271	* @param fid Pinter to the fibril structure of the fibril to be	272	* @param fid Pinter to the fibril structure of the fibril to be
272	* added.	273	* added.
273	*/	274	*/
274	void fibril_add_ready(fid_t fid)	275	void fibril_add_ready(fid_t fid)
275	{	276	{
276	fibril_t *f;	277	fibril_t *f;
277		278
278	f = (fibril_t *) fid;	279	f = (fibril_t *) fid;
279	futex_down(&fibril_futex);	280	futex_down(&fibril_futex);
280	if ((f->flags & FIBRIL_SERIALIZED))	281	if ((f->flags & FIBRIL_SERIALIZED))
281	list_append(&f->link, &serialized_list);	282	list_append(&f->link, &serialized_list);
282	else	283	else
283	list_append(&f->link, &ready_list);	284	list_append(&f->link, &ready_list);
284	futex_up(&fibril_futex);	285	futex_up(&fibril_futex);
285	}	286	}
286		287
287	/** Add a fibril to the manager list.	288	/** Add a fibril to the manager list.
288	*	289	*
289	* @param fid Pinter to the fibril structure of the fibril to be added.	290	* @param fid Pinter to the fibril structure of the fibril to be added.
290	*/	291	*/
291	void fibril_add_manager(fid_t fid)	292	void fibril_add_manager(fid_t fid)
292	{	293	{
293	fibril_t *f;	294	fibril_t *f;
294		295
295	f = (fibril_t *) fid;	296	f = (fibril_t *) fid;
296		297
297	futex_down(&fibril_futex);	298	futex_down(&fibril_futex);
298	list_append(&f->link, &manager_list);	299	list_append(&f->link, &manager_list);
299	futex_up(&fibril_futex);	300	futex_up(&fibril_futex);
300	}	301	}
301		302
302	/** Remove one manager from the manager list. */	303	/** Remove one manager from the manager list. */
303	void fibril_remove_manager(void)	304	void fibril_remove_manager(void)
304	{	305	{
305	futex_down(&fibril_futex);	306	futex_down(&fibril_futex);
306	if (list_empty(&manager_list)) {	307	if (list_empty(&manager_list)) {
307	futex_up(&fibril_futex);	308	futex_up(&fibril_futex);
308	return;	309	return;
309	}	310	}
310	list_remove(manager_list.next);	311	list_remove(manager_list.next);
311	futex_up(&fibril_futex);	312	futex_up(&fibril_futex);
312	}	313	}
313		314
314	/** Return fibril id of the currently running fibril.	315	/** Return fibril id of the currently running fibril.
315	*	316	*
316	* @return Fibril ID of the currently running pseudo thread.	317	* @return Fibril ID of the currently running pseudo thread.
317	*/	318	*/
318	fid_t fibril_get_id(void)	319	fid_t fibril_get_id(void)
319	{	320	{
320	return (fid_t) __tcb_get()->fibril_data;	321	return (fid_t) __tcb_get()->fibril_data;
321	}	322	}
322		323
323	/** Disable preemption	324	/** Disable preemption
324	*	325	*
325	* If the fibril wants to send several message in a row and does not want to be	326	* If the fibril wants to send several message in a row and does not want to be
326	* preempted, it should start async_serialize_start() in the beginning of	327	* preempted, it should start async_serialize_start() in the beginning of
327	* communication and async_serialize_end() in the end. If it is a true	328	* communication and async_serialize_end() in the end. If it is a true
328	* multithreaded application, it should protect the communication channel by a	329	* multithreaded application, it should protect the communication channel by a
329	* futex as well. Interrupt messages can still be preempted.	330	* futex as well. Interrupt messages can still be preempted.
330	*/	331	*/
331	void fibril_inc_sercount(void)	332	void fibril_inc_sercount(void)
332	{	333	{
333	serialization_count++;	334	serialization_count++;
334	}	335	}
335		336
336	/** Restore the preemption counter to the previous state. */	337	/** Restore the preemption counter to the previous state. */
337	void fibril_dec_sercount(void)	338	void fibril_dec_sercount(void)
338	{	339	{
339	serialization_count--;	340	serialization_count--;
340	}	341	}
341		342
342	/** @}	343	/** @}
343	*/	344	*/
344		345
345		346

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(root)/trunk/uspace/lib/libc/generic/fibril.c – Rev 2568 → 2586