1/* thr_lwp.c - wrappers around SunOS LWP threads */
2/* $OpenLDAP: pkg/ldap/libraries/libldap_r/thr_lwp.c,v 1.20.2.5 2010/04/13 20:23:02 kurt Exp $ */
3/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
4 *
5 * Copyright 1998-2010 The OpenLDAP Foundation.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted only as authorized by the OpenLDAP
10 * Public License.
11 *
12 * A copy of this license is available in file LICENSE in the
13 * top-level directory of the distribution or, alternatively, at
14 * <http://www.OpenLDAP.org/license.html>.
15 */
16
17/* BUGS:
18 * - slurpd calls the get_stack/free_stack functions. Should be fixed, so
19 *   they can become static.
20 */
21
22#include "portable.h"
23
24#if defined( HAVE_LWP )
25
26/*************
27 *           *
28 * SunOS LWP *
29 *           *
30 *************/
31
32/* This implementation NEEDS WORK.   It currently does not compile */
33
34#include <stdio.h>
35
36#include <ac/time.h>
37#include <ac/socket.h>
38
39#include "ldap-int.h"
40
41#include "ldap_pvt_thread.h" /* Get the thread interface */
42#define LDAP_THREAD_IMPLEMENTATION
43#include "ldap_thr_debug.h"	 /* May rename the symbols defined below */
44
45#include <lwp/lwp.h>
46#include <lwp/stackdep.h>
47
48#define MAX_STACK	51200
49#define MAX_THREADS	20
50
51/*
52 * Initialize LWP by spinning of a schedular
53 */
54int
55ldap_int_thread_initialize( void )
56{
57	thread_t		tid;
58	stkalign_t		*stack;
59	int			stackno;
60
61	if (( stack = get_stack( &stackno )) == NULL ) {
62		return -1;
63	}
64
65	lwp_create( &tid, lwp_scheduler, MINPRIO, 0, stack, 1, stackno );
66	return 0;
67}
68
69int
70ldap_int_thread_destroy( void )
71{
72	/* need to destroy lwp_scheduler thread and clean up private
73		variables */
74	return 0;
75}
76
77struct stackinfo {
78	int		stk_inuse;
79	stkalign_t	*stk_stack;
80};
81
82static struct stackinfo	*stacks;
83
84static stkalign_t * ldap_int_thread_get_stack( int *stacknop )
85{
86	int	i;
87
88	if ( stacks == NULL ) {
89		stacks = (struct stackinfo *) LDAP_CALLOC( 1, MAX_THREADS *
90		    sizeof(struct stackinfo) );
91
92		if( stacks == NULL ) {
93			Debug( LDAP_DEBUG_ANY, "stacks allocation failed",
94				0, 0, 0 );
95			return NULL;
96		}
97	}
98
99	for ( i = 0; i < MAX_THREADS; i++ ) {
100		if ( stacks[i].stk_inuse == 0 ) {
101			break;
102		}
103	}
104
105	if ( i == MAX_THREADS ) {
106		Debug( LDAP_DEBUG_ANY,
107		    "no more stacks (max %d) - increase MAX_THREADS for more",
108		    MAX_THREADS, 0, 0 );
109		return( NULL );
110	}
111
112	if ( stacks[i].stk_stack == NULL ) {
113		stacks[i].stk_stack = (stkalign_t *) LDAP_MALLOC(
114		    (MAX_STACK / sizeof(stkalign_t) + 1 )
115		    * sizeof(stkalign_t) );
116
117		if( stacks[i].stk_stack == NULL ) {
118			Debug( LDAP_DEBUG_ANY, "stack allocation failed",
119				0, 0, 0 );
120			return( NULL );
121		}
122	}
123
124	*stacknop = i;
125	stacks[i].stk_inuse = 1;
126	return( stacks[i].stk_stack + MAX_STACK / sizeof(stkalign_t) );
127}
128
129static void
130ldap_int_thread_free_stack( int	stackno )
131{
132	if ( stackno < 0 || stackno > MAX_THREADS ) {
133		Debug( LDAP_DEBUG_ANY, "free_stack of bogus stack %d\n",
134		    stackno, 0, 0 );
135	}
136
137	stacks[stackno].stk_inuse = 0;
138}
139
140static void
141lwp_create_stack( void *(*func)(), void *arg, int stackno )
142{
143	(*func)( arg );
144
145	ldap_int_thread_free_stack( stackno );
146}
147
148int
149ldap_pvt_thread_create( ldap_pvt_thread_t * thread,
150	int detach,
151	void *(*start_routine)( void *),
152	void *arg)
153{
154	stkalign_t	*stack;
155	int		stackno;
156
157	if ( (stack = ldap_int_thread_get_stack( &stackno )) == NULL ) {
158		return( -1 );
159	}
160	return( lwp_create( thread, lwp_create_stack, MINPRIO, 0,
161			   stack, 3, start_routine, arg, stackno ) );
162}
163
164void
165ldap_pvt_thread_exit( void *retval )
166{
167	lwp_destroy( SELF );
168}
169
170unsigned int
171ldap_pvt_thread_sleep(
172	unsigned int interval
173)
174{
175	thread_t		mylwp;
176	tl_t		*t, *nt;
177	time_t		now;
178
179
180	if ( lwp_self( &mylwp ) < 0 ) {
181		return -1;
182	}
183
184	time( &now );
185
186	mon_enter( &sglob->tsl_mon );
187
188	if ( sglob->tsl_list != NULL ) {
189		for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
190			if ( SAMETHREAD( t->tl_tid, mylwp )) {
191				/* We're already sleeping? */
192				t->tl_wake = now + interval;
193				mon_exit( &sglob->tsl_mon );
194				lwp_suspend( mylwp );
195				return 0;
196			}
197		}
198	}
199
200	nt = (tl_t *) LDAP_MALLOC( sizeof( tl_t ));
201
202	if( nt == NULL ) return -1;
203
204	nt->tl_next = sglob->tsl_list;
205	nt->tl_wake = now + interval;
206	nt->tl_tid = mylwp;
207	sglob->tsl_list = nt;
208
209	mon_exit( &sglob->tsl_mon );
210
211	lwp_suspend( mylwp );
212	return 0;
213}
214
215/*
216 * The lwp_scheduler thread periodically checks to see if any threads
217 * are due to be resumed.  If there are, it resumes them.  Otherwise,
218 * it computes the lesser of ( 1 second ) or ( the minimum time until
219 * a thread need to be resumed ) and puts itself to sleep for that amount
220 * of time.
221 */
222static void
223lwp_scheduler(
224	int		stackno
225)
226{
227	time_t			now, min;
228	struct timeval		interval;
229	tl_t			*t;
230
231	while ( !sglob->slurpd_shutdown ) {
232		mon_enter( &sglob->tsl_mon );
233
234		time( &now );
235		min = 0L;
236		if ( sglob->tsl_list != NULL ) {
237			for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
238				if (( t->tl_wake  > 0L ) && ( t->tl_wake < now )) {
239					lwp_resume( t->tl_tid );
240					t->tl_wake = 0L;
241				}
242
243				if (( t->tl_wake > now ) && ( t->tl_wake < min )) {
244					min =  t->tl_wake;
245				}
246			}
247		}
248
249		mon_exit( &sglob->tsl_mon );
250
251		interval.tv_usec = 0L;
252		if ( min == 0L ) {
253			interval.tv_sec = 1L;
254		} else {
255			interval.tv_sec = min;
256		}
257
258		lwp_sleep( &interval );
259	}
260
261	mon_enter( &sglob->tsl_mon );
262
263	for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
264		lwp_resume( t->tl_tid );
265	}
266
267	mon_exit( &sglob->tsl_mon );
268
269	free_stack( stackno );
270}
271
272int
273ldap_pvt_thread_join( ldap_pvt_thread_t thread, void **thread_return )
274{
275	lwp_join( thread );
276	return 0;
277}
278
279int
280ldap_pvt_thread_kill( ldap_pvt_thread_t thread, int signo )
281{
282	return 0;
283}
284
285int
286ldap_pvt_thread_yield( void )
287{
288	lwp_yield( SELF );
289	return 0;
290}
291
292int
293ldap_pvt_thread_cond_init( ldap_pvt_thread_cond_t *cond )
294{
295	/*
296	 * lwp cv_create requires the monitor id be passed in
297	 * when the cv is created, pthreads passes it when the
298	 * condition is waited for.  so, we fake the creation
299	 * here and actually do it when the cv is waited for
300	 * later.
301	 */
302
303	cond->lcv_created = 0;
304
305	return( 0 );
306}
307
308int
309ldap_pvt_thread_cond_signal( ldap_pvt_thread_cond_t *cond )
310{
311	return( cond->lcv_created ? cv_notify( cv->lcv_cv ) : 0 );
312}
313
314int
315ldap_pvt_thread_cond_wait( ldap_pvt_thread_cond_t *cond,
316	ldap_pvt_thread_mutex_t *mutex )
317{
318	if ( ! cond->lcv_created ) {
319		cv_create( &cond->lcv_cv, *mutex );
320		cond->lcv_created = 1;
321	}
322
323	return( cv_wait( cond->lcv_cv ) );
324}
325
326int
327ldap_pvt_thread_mutex_init( ldap_pvt_thread_mutex_t *mutex )
328{
329	return( mon_create( mutex ) );
330}
331
332int
333ldap_pvt_thread_mutex_destroy( ldap_pvt_thread_mutex_t *mutex )
334{
335	return( mon_destroy( *mutex ) );
336}
337
338int
339ldap_pvt_thread_mutex_lock( ldap_pvt_thread_mutex_t *mutex )
340{
341	return( mon_enter( *mutex ) );
342}
343
344int
345ldap_pvt_thread_mutex_unlock( ldap_pvt_thread_mutex_t *mutex )
346{
347	return( mon_exit( *mutex ) );
348}
349
350int
351ldap_pvt_thread_mutex_trylock( ldap_pvt_thread_mutex_t *mp )
352{
353	return( mon_cond_enter( *mp ) );
354}
355
356int
357ldap_pvt_thread_cond_destroy( ldap_pvt_thread_cond_t *cv )
358{
359	return( cv->lcv_created ? cv_destroy( cv->lcv_cv ) : 0 );
360}
361
362int
363ldap_pvt_thread_cond_broadcast( ldap_pvt_thread_cond_t *cv )
364{
365	return( cv->lcv_created ? cv_broadcast( cv->lcv_cv ) : 0 );
366}
367
368ldap_pvt_thread_t
369ldap_pvt_thread_self( void )
370{
371	thread_t		mylwp;
372
373	lwp_self( &mylwp );
374
375	return mylwp;
376}
377
378#endif /* HAVE_LWP */
379