Blame


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