1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 #include "umem_base.h"
28 #include "vmem_base.h"
29
30 #include <sys/ccompile.h>
31
32 #include <signal.h>
33
34 /*ARGSUSED*/
35 static void * __NORETURN
umem_update_thread(void * arg)36 umem_update_thread(void *arg)
37 {
38 struct timeval now;
39 int in_update = 0;
40
41 (void) mutex_lock(&umem_update_lock);
42
43 ASSERT(umem_update_thr == thr_self());
44 ASSERT(umem_st_update_thr == 0);
45
46 for (;;) {
47 umem_process_updates();
48
49 if (in_update) {
50 in_update = 0;
51 /*
52 * we wait until now to set the next update time
53 * so that the updates are self-throttling
54 */
55 (void) gettimeofday(&umem_update_next, NULL);
56 umem_update_next.tv_sec += umem_reap_interval;
57 }
58
59 switch (umem_reaping) {
60 case UMEM_REAP_DONE:
61 case UMEM_REAP_ADDING:
62 break;
63
64 case UMEM_REAP_ACTIVE:
65 umem_reap_next = gethrtime() +
66 (hrtime_t)umem_reap_interval * NANOSEC;
67 umem_reaping = UMEM_REAP_DONE;
68 break;
69
70 default:
71 ASSERT(umem_reaping == UMEM_REAP_DONE ||
72 umem_reaping == UMEM_REAP_ADDING ||
73 umem_reaping == UMEM_REAP_ACTIVE);
74 break;
75 }
76
77 (void) gettimeofday(&now, NULL);
78 if (now.tv_sec > umem_update_next.tv_sec ||
79 (now.tv_sec == umem_update_next.tv_sec &&
80 now.tv_usec >= umem_update_next.tv_usec)) {
81 /*
82 * Time to run an update
83 */
84 (void) mutex_unlock(&umem_update_lock);
85
86 vmem_update(NULL);
87 /*
88 * umem_cache_update can use umem_add_update to
89 * request further work. The update is not complete
90 * until all such work is finished.
91 */
92 umem_cache_applyall(umem_cache_update);
93
94 (void) mutex_lock(&umem_update_lock);
95 in_update = 1;
96 continue; /* start processing immediately */
97 }
98
99 /*
100 * if there is no work to do, we wait until it is time for
101 * next update, or someone wakes us.
102 */
103 if (umem_null_cache.cache_unext == &umem_null_cache) {
104 int cancel_state;
105 timespec_t abs_time;
106 abs_time.tv_sec = umem_update_next.tv_sec;
107 abs_time.tv_nsec = umem_update_next.tv_usec * 1000;
108
109 (void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE,
110 &cancel_state);
111 (void) cond_timedwait(&umem_update_cv,
112 &umem_update_lock, &abs_time);
113 (void) pthread_setcancelstate(cancel_state, NULL);
114 }
115 }
116 /* LINTED no return statement */
117 }
118
119 int
umem_create_update_thread(void)120 umem_create_update_thread(void)
121 {
122 sigset_t sigmask, oldmask;
123 thread_t newthread;
124
125 ASSERT(MUTEX_HELD(&umem_update_lock));
126 ASSERT(umem_update_thr == 0);
127
128 /*
129 * The update thread handles no signals
130 */
131 (void) sigfillset(&sigmask);
132 (void) thr_sigsetmask(SIG_BLOCK, &sigmask, &oldmask);
133
134 /*
135 * drop the umem_update_lock; we cannot hold locks acquired in
136 * pre-fork handler while calling thr_create or thr_continue().
137 */
138
139 (void) mutex_unlock(&umem_update_lock);
140
141 if (thr_create(NULL, NULL, umem_update_thread, NULL,
142 THR_BOUND | THR_DAEMON | THR_DETACHED | THR_SUSPENDED,
143 &newthread) == 0) {
144 (void) thr_sigsetmask(SIG_SETMASK, &oldmask, NULL);
145
146 (void) mutex_lock(&umem_update_lock);
147 /*
148 * due to the locking in umem_reap(), only one thread can
149 * ever call umem_create_update_thread() at a time. This
150 * must be the case for this code to work.
151 */
152
153 ASSERT(umem_update_thr == 0);
154 umem_update_thr = newthread;
155 (void) mutex_unlock(&umem_update_lock);
156 (void) thr_continue(newthread);
157 (void) mutex_lock(&umem_update_lock);
158
159 return (1);
160 } else { /* thr_create failed */
161 (void) thr_sigsetmask(SIG_SETMASK, &oldmask, NULL);
162 (void) mutex_lock(&umem_update_lock);
163 }
164 return (0);
165 }
166