1 619085f0 2004-12-25 devnull #include "threadimpl.h"
  2 619085f0 2004-12-25 devnull 
  3 619085f0 2004-12-25 devnull /*
  4 619085f0 2004-12-25 devnull  * One can go through a lot of effort to avoid this global lock.
  5 619085f0 2004-12-25 devnull  * You have to put locks in all the channels and all the Alt
  6 619085f0 2004-12-25 devnull  * structures.  At the beginning of an alt you have to lock all
  7 619085f0 2004-12-25 devnull  * the channels, but then to try to actually exec an op you
  8 fa325e9b 2020-01-10 cross  * have to lock the other guy's alt structure, so that other
  9 619085f0 2004-12-25 devnull  * people aren't trying to use him in some other op at the
 10 619085f0 2004-12-25 devnull  * same time.
 11 fa325e9b 2020-01-10 cross  *
 12 619085f0 2004-12-25 devnull  * For Plan 9 apps, it's just not worth the extra effort.
 13 619085f0 2004-12-25 devnull  */
 14 619085f0 2004-12-25 devnull static QLock chanlock;
 15 619085f0 2004-12-25 devnull 
 16 619085f0 2004-12-25 devnull Channel*
 17 619085f0 2004-12-25 devnull chancreate(int elemsize, int bufsize)
 18 619085f0 2004-12-25 devnull {
 19 619085f0 2004-12-25 devnull 	Channel *c;
 20 619085f0 2004-12-25 devnull 
 21 619085f0 2004-12-25 devnull 	c = malloc(sizeof *c+bufsize*elemsize);
 22 73722a8b 2004-12-27 devnull 	if(c == nil)
 23 73722a8b 2004-12-27 devnull 		sysfatal("chancreate malloc: %r");
 24 619085f0 2004-12-25 devnull 	memset(c, 0, sizeof *c);
 25 619085f0 2004-12-25 devnull 	c->elemsize = elemsize;
 26 619085f0 2004-12-25 devnull 	c->bufsize = bufsize;
 27 619085f0 2004-12-25 devnull 	c->nbuf = 0;
 28 619085f0 2004-12-25 devnull 	c->buf = (uchar*)(c+1);
 29 619085f0 2004-12-25 devnull 	return c;
 30 619085f0 2004-12-25 devnull }
 31 619085f0 2004-12-25 devnull 
 32 619085f0 2004-12-25 devnull void
 33 619085f0 2004-12-25 devnull chansetname(Channel *c, char *fmt, ...)
 34 619085f0 2004-12-25 devnull {
 35 619085f0 2004-12-25 devnull 	char *name;
 36 619085f0 2004-12-25 devnull 	va_list arg;
 37 619085f0 2004-12-25 devnull 
 38 619085f0 2004-12-25 devnull 	va_start(arg, fmt);
 39 619085f0 2004-12-25 devnull 	name = vsmprint(fmt, arg);
 40 619085f0 2004-12-25 devnull 	va_end(arg);
 41 619085f0 2004-12-25 devnull 	free(c->name);
 42 619085f0 2004-12-25 devnull 	c->name = name;
 43 619085f0 2004-12-25 devnull }
 44 619085f0 2004-12-25 devnull 
 45 619085f0 2004-12-25 devnull /* bug - work out races */
 46 619085f0 2004-12-25 devnull void
 47 619085f0 2004-12-25 devnull chanfree(Channel *c)
 48 619085f0 2004-12-25 devnull {
 49 619085f0 2004-12-25 devnull 	if(c == nil)
 50 619085f0 2004-12-25 devnull 		return;
 51 619085f0 2004-12-25 devnull 	free(c->name);
 52 619085f0 2004-12-25 devnull 	free(c->arecv.a);
 53 619085f0 2004-12-25 devnull 	free(c->asend.a);
 54 619085f0 2004-12-25 devnull 	free(c);
 55 619085f0 2004-12-25 devnull }
 56 619085f0 2004-12-25 devnull 
 57 619085f0 2004-12-25 devnull static void
 58 619085f0 2004-12-25 devnull addarray(_Altarray *a, Alt *alt)
 59 619085f0 2004-12-25 devnull {
 60 619085f0 2004-12-25 devnull 	if(a->n == a->m){
 61 619085f0 2004-12-25 devnull 		a->m += 16;
 62 619085f0 2004-12-25 devnull 		a->a = realloc(a->a, a->m*sizeof a->a[0]);
 63 619085f0 2004-12-25 devnull 	}
 64 619085f0 2004-12-25 devnull 	a->a[a->n++] = alt;
 65 619085f0 2004-12-25 devnull }
 66 619085f0 2004-12-25 devnull 
 67 619085f0 2004-12-25 devnull static void
 68 619085f0 2004-12-25 devnull delarray(_Altarray *a, int i)
 69 619085f0 2004-12-25 devnull {
 70 619085f0 2004-12-25 devnull 	--a->n;
 71 619085f0 2004-12-25 devnull 	a->a[i] = a->a[a->n];
 72 619085f0 2004-12-25 devnull }
 73 619085f0 2004-12-25 devnull 
 74 619085f0 2004-12-25 devnull /*
 75 619085f0 2004-12-25 devnull  * doesn't really work for things other than CHANSND and CHANRCV
 76 619085f0 2004-12-25 devnull  * but is only used as arg to chanarray, which can handle it
 77 619085f0 2004-12-25 devnull  */
 78 619085f0 2004-12-25 devnull #define otherop(op)	(CHANSND+CHANRCV-(op))
 79 619085f0 2004-12-25 devnull 
 80 619085f0 2004-12-25 devnull static _Altarray*
 81 619085f0 2004-12-25 devnull chanarray(Channel *c, uint op)
 82 619085f0 2004-12-25 devnull {
 83 619085f0 2004-12-25 devnull 	switch(op){
 84 619085f0 2004-12-25 devnull 	default:
 85 619085f0 2004-12-25 devnull 		return nil;
 86 619085f0 2004-12-25 devnull 	case CHANSND:
 87 619085f0 2004-12-25 devnull 		return &c->asend;
 88 619085f0 2004-12-25 devnull 	case CHANRCV:
 89 619085f0 2004-12-25 devnull 		return &c->arecv;
 90 619085f0 2004-12-25 devnull 	}
 91 619085f0 2004-12-25 devnull }
 92 619085f0 2004-12-25 devnull 
 93 619085f0 2004-12-25 devnull static int
 94 619085f0 2004-12-25 devnull altcanexec(Alt *a)
 95 619085f0 2004-12-25 devnull {
 96 619085f0 2004-12-25 devnull 	_Altarray *ar;
 97 619085f0 2004-12-25 devnull 	Channel *c;
 98 619085f0 2004-12-25 devnull 
 99 80f2165d 2008-05-06 rsc 	if(a->op == CHANNOP || (c=a->c) == nil)
100 619085f0 2004-12-25 devnull 		return 0;
101 619085f0 2004-12-25 devnull 	if(c->bufsize == 0){
102 619085f0 2004-12-25 devnull 		ar = chanarray(c, otherop(a->op));
103 619085f0 2004-12-25 devnull 		return ar && ar->n;
104 619085f0 2004-12-25 devnull 	}else{
105 619085f0 2004-12-25 devnull 		switch(a->op){
106 619085f0 2004-12-25 devnull 		default:
107 619085f0 2004-12-25 devnull 			return 0;
108 619085f0 2004-12-25 devnull 		case CHANSND:
109 619085f0 2004-12-25 devnull 			return c->nbuf < c->bufsize;
110 619085f0 2004-12-25 devnull 		case CHANRCV:
111 619085f0 2004-12-25 devnull 			return c->nbuf > 0;
112 619085f0 2004-12-25 devnull 		}
113 619085f0 2004-12-25 devnull 	}
114 619085f0 2004-12-25 devnull }
115 619085f0 2004-12-25 devnull 
116 619085f0 2004-12-25 devnull static void
117 619085f0 2004-12-25 devnull altqueue(Alt *a)
118 619085f0 2004-12-25 devnull {
119 619085f0 2004-12-25 devnull 	_Altarray *ar;
120 619085f0 2004-12-25 devnull 
121 80f2165d 2008-05-06 rsc 	if(a->c == nil)
122 80f2165d 2008-05-06 rsc 		return;
123 619085f0 2004-12-25 devnull 	ar = chanarray(a->c, a->op);
124 619085f0 2004-12-25 devnull 	addarray(ar, a);
125 619085f0 2004-12-25 devnull }
126 619085f0 2004-12-25 devnull 
127 619085f0 2004-12-25 devnull static void
128 619085f0 2004-12-25 devnull altdequeue(Alt *a)
129 619085f0 2004-12-25 devnull {
130 619085f0 2004-12-25 devnull 	int i;
131 619085f0 2004-12-25 devnull 	_Altarray *ar;
132 619085f0 2004-12-25 devnull 
133 619085f0 2004-12-25 devnull 	ar = chanarray(a->c, a->op);
134 619085f0 2004-12-25 devnull 	if(ar == nil){
135 619085f0 2004-12-25 devnull 		fprint(2, "bad use of altdequeue op=%d\n", a->op);
136 619085f0 2004-12-25 devnull 		abort();
137 619085f0 2004-12-25 devnull 	}
138 619085f0 2004-12-25 devnull 
139 619085f0 2004-12-25 devnull 	for(i=0; i<ar->n; i++)
140 619085f0 2004-12-25 devnull 		if(ar->a[i] == a){
141 619085f0 2004-12-25 devnull 			delarray(ar, i);
142 619085f0 2004-12-25 devnull 			return;
143 619085f0 2004-12-25 devnull 		}
144 baef953d 2020-05-18 rsc 	fprint(2, "cannot find self in altdequeue\n");
145 619085f0 2004-12-25 devnull 	abort();
146 619085f0 2004-12-25 devnull }
147 619085f0 2004-12-25 devnull 
148 619085f0 2004-12-25 devnull static void
149 619085f0 2004-12-25 devnull altalldequeue(Alt *a)
150 619085f0 2004-12-25 devnull {
151 619085f0 2004-12-25 devnull 	int i;
152 619085f0 2004-12-25 devnull 
153 619085f0 2004-12-25 devnull 	for(i=0; a[i].op!=CHANEND && a[i].op!=CHANNOBLK; i++)
154 619085f0 2004-12-25 devnull 		if(a[i].op != CHANNOP)
155 619085f0 2004-12-25 devnull 			altdequeue(&a[i]);
156 619085f0 2004-12-25 devnull }
157 619085f0 2004-12-25 devnull 
158 619085f0 2004-12-25 devnull static void
159 619085f0 2004-12-25 devnull amove(void *dst, void *src, uint n)
160 619085f0 2004-12-25 devnull {
161 619085f0 2004-12-25 devnull 	if(dst){
162 619085f0 2004-12-25 devnull 		if(src == nil)
163 619085f0 2004-12-25 devnull 			memset(dst, 0, n);
164 619085f0 2004-12-25 devnull 		else
165 619085f0 2004-12-25 devnull 			memmove(dst, src, n);
166 619085f0 2004-12-25 devnull 	}
167 619085f0 2004-12-25 devnull }
168 619085f0 2004-12-25 devnull 
169 619085f0 2004-12-25 devnull /*
170 619085f0 2004-12-25 devnull  * Actually move the data around.  There are up to three
171 619085f0 2004-12-25 devnull  * players: the sender, the receiver, and the channel itself.
172 619085f0 2004-12-25 devnull  * If the channel is unbuffered or the buffer is empty,
173 619085f0 2004-12-25 devnull  * data goes from sender to receiver.  If the channel is full,
174 619085f0 2004-12-25 devnull  * the receiver removes some from the channel and the sender
175 619085f0 2004-12-25 devnull  * gets to put some in.
176 619085f0 2004-12-25 devnull  */
177 619085f0 2004-12-25 devnull static void
178 619085f0 2004-12-25 devnull altcopy(Alt *s, Alt *r)
179 619085f0 2004-12-25 devnull {
180 619085f0 2004-12-25 devnull 	Alt *t;
181 619085f0 2004-12-25 devnull 	Channel *c;
182 619085f0 2004-12-25 devnull 	uchar *cp;
183 619085f0 2004-12-25 devnull 
184 619085f0 2004-12-25 devnull 	/*
185 619085f0 2004-12-25 devnull 	 * Work out who is sender and who is receiver
186 619085f0 2004-12-25 devnull 	 */
187 619085f0 2004-12-25 devnull 	if(s == nil && r == nil)
188 619085f0 2004-12-25 devnull 		return;
189 619085f0 2004-12-25 devnull 	assert(s != nil);
190 619085f0 2004-12-25 devnull 	c = s->c;
191 619085f0 2004-12-25 devnull 	if(s->op == CHANRCV){
192 619085f0 2004-12-25 devnull 		t = s;
193 619085f0 2004-12-25 devnull 		s = r;
194 619085f0 2004-12-25 devnull 		r = t;
195 619085f0 2004-12-25 devnull 	}
196 619085f0 2004-12-25 devnull 	assert(s==nil || s->op == CHANSND);
197 619085f0 2004-12-25 devnull 	assert(r==nil || r->op == CHANRCV);
198 619085f0 2004-12-25 devnull 
199 619085f0 2004-12-25 devnull 	/*
200 619085f0 2004-12-25 devnull 	 * Channel is empty (or unbuffered) - copy directly.
201 619085f0 2004-12-25 devnull 	 */
202 619085f0 2004-12-25 devnull 	if(s && r && c->nbuf == 0){
203 619085f0 2004-12-25 devnull 		amove(r->v, s->v, c->elemsize);
204 619085f0 2004-12-25 devnull 		return;
205 619085f0 2004-12-25 devnull 	}
206 619085f0 2004-12-25 devnull 
207 619085f0 2004-12-25 devnull 	/*
208 619085f0 2004-12-25 devnull 	 * Otherwise it's always okay to receive and then send.
209 619085f0 2004-12-25 devnull 	 */
210 619085f0 2004-12-25 devnull 	if(r){
211 619085f0 2004-12-25 devnull 		cp = c->buf + c->off*c->elemsize;
212 619085f0 2004-12-25 devnull 		amove(r->v, cp, c->elemsize);
213 619085f0 2004-12-25 devnull 		--c->nbuf;
214 619085f0 2004-12-25 devnull 		if(++c->off == c->bufsize)
215 619085f0 2004-12-25 devnull 			c->off = 0;
216 619085f0 2004-12-25 devnull 	}
217 619085f0 2004-12-25 devnull 	if(s){
218 619085f0 2004-12-25 devnull 		cp = c->buf + (c->off+c->nbuf)%c->bufsize*c->elemsize;
219 619085f0 2004-12-25 devnull 		amove(cp, s->v, c->elemsize);
220 619085f0 2004-12-25 devnull 		++c->nbuf;
221 619085f0 2004-12-25 devnull 	}
222 619085f0 2004-12-25 devnull }
223 619085f0 2004-12-25 devnull 
224 619085f0 2004-12-25 devnull static void
225 619085f0 2004-12-25 devnull altexec(Alt *a)
226 619085f0 2004-12-25 devnull {
227 619085f0 2004-12-25 devnull 	int i;
228 619085f0 2004-12-25 devnull 	_Altarray *ar;
229 619085f0 2004-12-25 devnull 	Alt *other;
230 619085f0 2004-12-25 devnull 	Channel *c;
231 619085f0 2004-12-25 devnull 
232 619085f0 2004-12-25 devnull 	c = a->c;
233 619085f0 2004-12-25 devnull 	ar = chanarray(c, otherop(a->op));
234 619085f0 2004-12-25 devnull 	if(ar && ar->n){
235 619085f0 2004-12-25 devnull 		i = rand()%ar->n;
236 619085f0 2004-12-25 devnull 		other = ar->a[i];
237 619085f0 2004-12-25 devnull 		altcopy(a, other);
238 47ede89e 2007-08-22 rsc 		altalldequeue(other->thread->alt);
239 47ede89e 2007-08-22 rsc 		other->thread->alt = other;
240 619085f0 2004-12-25 devnull 		_threadready(other->thread);
241 619085f0 2004-12-25 devnull 	}else
242 619085f0 2004-12-25 devnull 		altcopy(a, nil);
243 619085f0 2004-12-25 devnull }
244 619085f0 2004-12-25 devnull 
245 619085f0 2004-12-25 devnull #define dbgalt 0
246 619085f0 2004-12-25 devnull int
247 619085f0 2004-12-25 devnull chanalt(Alt *a)
248 619085f0 2004-12-25 devnull {
249 619085f0 2004-12-25 devnull 	int i, j, ncan, n, canblock;
250 619085f0 2004-12-25 devnull 	Channel *c;
251 619085f0 2004-12-25 devnull 	_Thread *t;
252 619085f0 2004-12-25 devnull 
253 c8b6342d 2005-01-13 devnull 	needstack(512);
254 619085f0 2004-12-25 devnull 	for(i=0; a[i].op != CHANEND && a[i].op != CHANNOBLK; i++)
255 619085f0 2004-12-25 devnull 		;
256 619085f0 2004-12-25 devnull 	n = i;
257 619085f0 2004-12-25 devnull 	canblock = a[i].op == CHANEND;
258 619085f0 2004-12-25 devnull 
259 619085f0 2004-12-25 devnull 	t = proc()->thread;
260 47ede89e 2007-08-22 rsc 	for(i=0; i<n; i++)
261 619085f0 2004-12-25 devnull 		a[i].thread = t;
262 47ede89e 2007-08-22 rsc 	t->alt = a;
263 619085f0 2004-12-25 devnull 	qlock(&chanlock);
264 619085f0 2004-12-25 devnull if(dbgalt) print("alt ");
265 619085f0 2004-12-25 devnull 	ncan = 0;
266 619085f0 2004-12-25 devnull 	for(i=0; i<n; i++){
267 619085f0 2004-12-25 devnull 		c = a[i].c;
268 619085f0 2004-12-25 devnull if(dbgalt) print(" %c:", "esrnb"[a[i].op]);
269 619085f0 2004-12-25 devnull if(dbgalt) if(c->name) print("%s", c->name); else print("%p", c);
270 619085f0 2004-12-25 devnull 		if(altcanexec(&a[i])){
271 619085f0 2004-12-25 devnull if(dbgalt) print("*");
272 619085f0 2004-12-25 devnull 			ncan++;
273 619085f0 2004-12-25 devnull 		}
274 619085f0 2004-12-25 devnull 	}
275 619085f0 2004-12-25 devnull 	if(ncan){
276 619085f0 2004-12-25 devnull 		j = rand()%ncan;
277 619085f0 2004-12-25 devnull 		for(i=0; i<n; i++){
278 619085f0 2004-12-25 devnull 			if(altcanexec(&a[i])){
279 619085f0 2004-12-25 devnull 				if(j-- == 0){
280 619085f0 2004-12-25 devnull if(dbgalt){
281 619085f0 2004-12-25 devnull c = a[i].c;
282 619085f0 2004-12-25 devnull print(" => %c:", "esrnb"[a[i].op]);
283 619085f0 2004-12-25 devnull if(c->name) print("%s", c->name); else print("%p", c);
284 619085f0 2004-12-25 devnull print("\n");
285 619085f0 2004-12-25 devnull }
286 619085f0 2004-12-25 devnull 					altexec(&a[i]);
287 619085f0 2004-12-25 devnull 					qunlock(&chanlock);
288 619085f0 2004-12-25 devnull 					return i;
289 619085f0 2004-12-25 devnull 				}
290 619085f0 2004-12-25 devnull 			}
291 619085f0 2004-12-25 devnull 		}
292 619085f0 2004-12-25 devnull 	}
293 619085f0 2004-12-25 devnull if(dbgalt)print("\n");
294 619085f0 2004-12-25 devnull 
295 619085f0 2004-12-25 devnull 	if(!canblock){
296 619085f0 2004-12-25 devnull 		qunlock(&chanlock);
297 619085f0 2004-12-25 devnull 		return -1;
298 619085f0 2004-12-25 devnull 	}
299 619085f0 2004-12-25 devnull 
300 619085f0 2004-12-25 devnull 	for(i=0; i<n; i++){
301 619085f0 2004-12-25 devnull 		if(a[i].op != CHANNOP)
302 619085f0 2004-12-25 devnull 			altqueue(&a[i]);
303 619085f0 2004-12-25 devnull 	}
304 619085f0 2004-12-25 devnull 	qunlock(&chanlock);
305 619085f0 2004-12-25 devnull 
306 619085f0 2004-12-25 devnull 	_threadswitch();
307 619085f0 2004-12-25 devnull 
308 619085f0 2004-12-25 devnull 	/*
309 619085f0 2004-12-25 devnull 	 * the guy who ran the op took care of dequeueing us
310 47ede89e 2007-08-22 rsc 	 * and then set t->alt to the one that was executed.
311 619085f0 2004-12-25 devnull 	 */
312 47ede89e 2007-08-22 rsc 	if(t->alt < a || t->alt >= a+n)
313 47ede89e 2007-08-22 rsc 		sysfatal("channel bad alt");
314 47ede89e 2007-08-22 rsc 	return t->alt - a;
315 619085f0 2004-12-25 devnull }
316 619085f0 2004-12-25 devnull 
317 619085f0 2004-12-25 devnull static int
318 619085f0 2004-12-25 devnull _chanop(Channel *c, int op, void *p, int canblock)
319 619085f0 2004-12-25 devnull {
320 619085f0 2004-12-25 devnull 	Alt a[2];
321 619085f0 2004-12-25 devnull 
322 619085f0 2004-12-25 devnull 	a[0].c = c;
323 619085f0 2004-12-25 devnull 	a[0].op = op;
324 619085f0 2004-12-25 devnull 	a[0].v = p;
325 619085f0 2004-12-25 devnull 	a[1].op = canblock ? CHANEND : CHANNOBLK;
326 619085f0 2004-12-25 devnull 	if(chanalt(a) < 0)
327 619085f0 2004-12-25 devnull 		return -1;
328 619085f0 2004-12-25 devnull 	return 1;
329 619085f0 2004-12-25 devnull }
330 619085f0 2004-12-25 devnull 
331 619085f0 2004-12-25 devnull int
332 619085f0 2004-12-25 devnull chansend(Channel *c, void *v)
333 619085f0 2004-12-25 devnull {
334 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, v, 1);
335 619085f0 2004-12-25 devnull }
336 619085f0 2004-12-25 devnull 
337 619085f0 2004-12-25 devnull int
338 619085f0 2004-12-25 devnull channbsend(Channel *c, void *v)
339 619085f0 2004-12-25 devnull {
340 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, v, 0);
341 619085f0 2004-12-25 devnull }
342 619085f0 2004-12-25 devnull 
343 619085f0 2004-12-25 devnull int
344 619085f0 2004-12-25 devnull chanrecv(Channel *c, void *v)
345 619085f0 2004-12-25 devnull {
346 619085f0 2004-12-25 devnull 	return _chanop(c, CHANRCV, v, 1);
347 619085f0 2004-12-25 devnull }
348 619085f0 2004-12-25 devnull 
349 619085f0 2004-12-25 devnull int
350 619085f0 2004-12-25 devnull channbrecv(Channel *c, void *v)
351 619085f0 2004-12-25 devnull {
352 619085f0 2004-12-25 devnull 	return _chanop(c, CHANRCV, v, 0);
353 619085f0 2004-12-25 devnull }
354 619085f0 2004-12-25 devnull 
355 619085f0 2004-12-25 devnull int
356 619085f0 2004-12-25 devnull chansendp(Channel *c, void *v)
357 619085f0 2004-12-25 devnull {
358 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, (void*)&v, 1);
359 619085f0 2004-12-25 devnull }
360 619085f0 2004-12-25 devnull 
361 619085f0 2004-12-25 devnull void*
362 619085f0 2004-12-25 devnull chanrecvp(Channel *c)
363 619085f0 2004-12-25 devnull {
364 619085f0 2004-12-25 devnull 	void *v;
365 619085f0 2004-12-25 devnull 
366 0215811d 2008-05-06 rsc 	if(_chanop(c, CHANRCV, (void*)&v, 1) > 0)
367 0215811d 2008-05-06 rsc 		return v;
368 0215811d 2008-05-06 rsc 	return nil;
369 619085f0 2004-12-25 devnull }
370 619085f0 2004-12-25 devnull 
371 619085f0 2004-12-25 devnull int
372 619085f0 2004-12-25 devnull channbsendp(Channel *c, void *v)
373 619085f0 2004-12-25 devnull {
374 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, (void*)&v, 0);
375 619085f0 2004-12-25 devnull }
376 619085f0 2004-12-25 devnull 
377 619085f0 2004-12-25 devnull void*
378 619085f0 2004-12-25 devnull channbrecvp(Channel *c)
379 619085f0 2004-12-25 devnull {
380 619085f0 2004-12-25 devnull 	void *v;
381 619085f0 2004-12-25 devnull 
382 0215811d 2008-05-06 rsc 	if(_chanop(c, CHANRCV, (void*)&v, 0) > 0)
383 0215811d 2008-05-06 rsc 		return v;
384 0215811d 2008-05-06 rsc 	return nil;
385 619085f0 2004-12-25 devnull }
386 619085f0 2004-12-25 devnull 
387 619085f0 2004-12-25 devnull int
388 619085f0 2004-12-25 devnull chansendul(Channel *c, ulong val)
389 619085f0 2004-12-25 devnull {
390 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, &val, 1);
391 619085f0 2004-12-25 devnull }
392 619085f0 2004-12-25 devnull 
393 619085f0 2004-12-25 devnull ulong
394 619085f0 2004-12-25 devnull chanrecvul(Channel *c)
395 619085f0 2004-12-25 devnull {
396 619085f0 2004-12-25 devnull 	ulong val;
397 619085f0 2004-12-25 devnull 
398 0215811d 2008-05-06 rsc 	if(_chanop(c, CHANRCV, &val, 1) > 0)
399 0215811d 2008-05-06 rsc 		return val;
400 369923f6 2020-01-13 rsc 	return 0;
401 619085f0 2004-12-25 devnull }
402 619085f0 2004-12-25 devnull 
403 619085f0 2004-12-25 devnull int
404 619085f0 2004-12-25 devnull channbsendul(Channel *c, ulong val)
405 619085f0 2004-12-25 devnull {
406 619085f0 2004-12-25 devnull 	return _chanop(c, CHANSND, &val, 0);
407 619085f0 2004-12-25 devnull }
408 619085f0 2004-12-25 devnull 
409 619085f0 2004-12-25 devnull ulong
410 619085f0 2004-12-25 devnull channbrecvul(Channel *c)
411 619085f0 2004-12-25 devnull {
412 619085f0 2004-12-25 devnull 	ulong val;
413 619085f0 2004-12-25 devnull 
414 0215811d 2008-05-06 rsc 	if(_chanop(c, CHANRCV, &val, 0) > 0)
415 0215811d 2008-05-06 rsc 		return val;
416 369923f6 2020-01-13 rsc 	return 0;
417 619085f0 2004-12-25 devnull }