2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 #include <afsconfig.h>
11 #include "afs/param.h"
16 #include "afs/sysincludes.h" /* Standard vendor system headers */
17 #include "afsincludes.h" /* Afs-based standard headers */
18 #include "afs/afs_stats.h" /* afs statistics */
20 static int osi_TimedSleep(char *event, afs_int32 ams, int aintok);
22 static char waitV, dummyV;
25 afs_osi_InitWaitHandle(struct afs_osi_WaitHandle *achandle)
27 AFS_STATCNT(osi_InitWaitHandle);
28 achandle->proc = (caddr_t) 0;
33 afs_osi_CancelWait(struct afs_osi_WaitHandle *achandle)
37 AFS_STATCNT(osi_CancelWait);
38 proc = achandle->proc;
41 achandle->proc = (caddr_t) 0; /* so dude can figure out he was signalled */
42 afs_osi_Wakeup(&waitV);
46 * Waits for data on ahandle, or ams ms later. ahandle may be null.
47 * Returns 0 if timeout and EINTR if signalled.
50 afs_osi_Wait(afs_int32 ams, struct afs_osi_WaitHandle *ahandle, int aintok)
55 AFS_STATCNT(osi_Wait);
56 endTime = osi_Time() + (ams / 1000);
58 ahandle->proc = (caddr_t) current;
62 code = osi_TimedSleep(&waitV, ams, 1);
65 if (ahandle && (ahandle->proc == (caddr_t) 0)) {
66 /* we've been signalled */
69 } while (osi_Time() < endTime);
76 typedef struct afs_event {
77 struct afs_event *next; /* next in hash chain */
78 char *event; /* lwp event: an address */
79 int refcount; /* Is it in use? */
80 int seq; /* Sequence number: this is incremented
81 * by wakeup calls; wait will not return until
83 #if defined(AFS_LINUX24_ENV)
84 wait_queue_head_t cond;
86 struct wait_queue *cond;
91 afs_event_t *afs_evhasht[HASHSIZE]; /* Hash table for events */
92 #define afs_evhash(event) (afs_uint32) ((((long)event)>>2) & (HASHSIZE-1));
93 int afs_evhashcnt = 0;
95 /* Get and initialize event structure corresponding to lwp event (i.e. address)
98 afs_getevent(char *event)
100 afs_event_t *evp, *newp = 0;
104 hashcode = afs_evhash(event);
105 evp = afs_evhasht[hashcode];
107 if (evp->event == event) {
111 if (evp->refcount == 0)
123 /* afs_addevent -- allocates a new event for the address. It isn't returned;
124 * instead, afs_getevent should be called again. Thus, the real effect of
125 * this routine is to add another event to the hash bucket for this
129 * Called with GLOCK held. However the function might drop
130 * GLOCK when it calls osi_AllocSmallSpace for allocating
131 * a new event (In Linux, the allocator drops GLOCK to avoid
136 afs_addevent(char *event)
142 hashcode = afs_evhash(event);
143 newp = osi_linux_alloc(sizeof(afs_event_t), 0);
145 newp->next = afs_evhasht[hashcode];
146 afs_evhasht[hashcode] = newp;
147 #if defined(AFS_LINUX24_ENV)
148 init_waitqueue_head(&newp->cond);
150 init_waitqueue(&newp->cond);
153 newp->event = &dummyV; /* Dummy address for new events */
157 #ifndef set_current_state
158 #define set_current_state(x) current->state = (x);
161 /* Release the specified event */
162 #define relevent(evp) ((evp)->refcount--)
166 * Waits for an event to be notified, returning early if a signal
167 * is received. Returns EINTR if signaled, and 0 otherwise.
170 afs_osi_SleepSig(void *event)
172 struct afs_event *evp;
174 #ifdef DECLARE_WAITQUEUE
175 DECLARE_WAITQUEUE(wait, current);
177 struct wait_queue wait = { current, NULL };
180 evp = afs_getevent(event);
183 evp = afs_getevent(event);
189 add_wait_queue(&evp->cond, &wait);
190 while (seq == evp->seq) {
191 set_current_state(TASK_INTERRUPTIBLE);
195 #ifdef AFS_LINUX26_ENV
197 if (current->flags & PF_FREEZE)
198 refrigerator(PF_FREEZE);
202 if (signal_pending(current)) {
207 remove_wait_queue(&evp->cond, &wait);
208 set_current_state(TASK_RUNNING);
214 /* afs_osi_Sleep -- waits for an event to be notified, ignoring signals.
215 * - NOTE: that on Linux, there are circumstances in which TASK_INTERRUPTIBLE
216 * can wake up, even if all signals are blocked
217 * - TODO: handle signals correctly by passing an indication back to the
218 * caller that the wait has been interrupted and the stack should be cleaned
219 * up preparatory to signal delivery
222 afs_osi_Sleep(void *event)
227 saved_set = current->blocked;
228 sigfillset(¤t->blocked);
229 RECALC_SIGPENDING(current);
232 afs_osi_SleepSig(event);
235 current->blocked = saved_set;
236 RECALC_SIGPENDING(current);
243 * event - event to sleep on
244 * ams --- max sleep time in milliseconds
245 * aintok - 1 if should sleep interruptibly
247 * Returns 0 if timeout, EINTR if signalled, and EGAIN if it might
251 osi_TimedSleep(char *event, afs_int32 ams, int aintok)
254 long ticks = (ams * HZ / 1000) + 1;
255 struct afs_event *evp;
256 #ifdef DECLARE_WAITQUEUE
257 DECLARE_WAITQUEUE(wait, current);
259 struct wait_queue wait = { current, NULL };
262 evp = afs_getevent(event);
265 evp = afs_getevent(event);
268 add_wait_queue(&evp->cond, &wait);
269 set_current_state(TASK_INTERRUPTIBLE);
270 /* always sleep TASK_INTERRUPTIBLE to keep load average
271 * from artifically increasing. */
275 if (schedule_timeout(ticks))
278 schedule_timeout(ticks);
279 #ifdef AFS_LINUX26_ENV
281 if (current->flags & PF_FREEZE)
282 refrigerator(PF_FREEZE);
287 remove_wait_queue(&evp->cond, &wait);
288 set_current_state(TASK_RUNNING);
297 afs_osi_Wakeup(void *event)
300 struct afs_event *evp;
302 evp = afs_getevent(event);
303 if (!evp) /* No sleepers */
306 if (evp->refcount > 1) {