1 7c709434 2005-03-18 devnull #include <u.h>
  2 7c709434 2005-03-18 devnull #include <libc.h>
  3 7c709434 2005-03-18 devnull #include <thread.h>
  4 7c709434 2005-03-18 devnull #include <9pclient.h>
  5 7c709434 2005-03-18 devnull #include "acme.h"
  6 7c709434 2005-03-18 devnull 
  7 7c709434 2005-03-18 devnull extern int debug;
  8 7c709434 2005-03-18 devnull 
  9 590c5b34 2005-03-21 devnull #define dprint if(debug>1)print
 10 7c709434 2005-03-18 devnull 
 11 7c709434 2005-03-18 devnull typedef struct Waitreq Waitreq;
 12 7c709434 2005-03-18 devnull struct Waitreq
 13 7c709434 2005-03-18 devnull {
 14 7c709434 2005-03-18 devnull 	int pid;
 15 7c709434 2005-03-18 devnull 	Channel *c;
 16 7c709434 2005-03-18 devnull };
 17 7c709434 2005-03-18 devnull 
 18 7c709434 2005-03-18 devnull /*
 19 7c709434 2005-03-18 devnull  * watch the exiting children
 20 7c709434 2005-03-18 devnull  */
 21 7c709434 2005-03-18 devnull Channel *twaitchan;	/* chan(Waitreq) */
 22 7c709434 2005-03-18 devnull void
 23 7c709434 2005-03-18 devnull waitthread(void *v)
 24 7c709434 2005-03-18 devnull {
 25 7c709434 2005-03-18 devnull 	Alt a[3];
 26 7c709434 2005-03-18 devnull 	Waitmsg *w, **wq;
 27 7c709434 2005-03-18 devnull 	Waitreq *rq, r;
 28 7c709434 2005-03-18 devnull 	int i, nrq, nwq;
 29 7c709434 2005-03-18 devnull 
 30 7c709434 2005-03-18 devnull 	threadsetname("waitthread");
 31 7c709434 2005-03-18 devnull 	a[0].c = threadwaitchan();
 32 7c709434 2005-03-18 devnull 	a[0].v = &w;
 33 7c709434 2005-03-18 devnull 	a[0].op = CHANRCV;
 34 7c709434 2005-03-18 devnull 	a[1].c = twaitchan;
 35 7c709434 2005-03-18 devnull 	a[1].v = &r;
 36 7c709434 2005-03-18 devnull 	a[1].op = CHANRCV;
 37 7c709434 2005-03-18 devnull 	a[2].op = CHANEND;
 38 7c709434 2005-03-18 devnull 
 39 7c709434 2005-03-18 devnull 	nrq = 0;
 40 7c709434 2005-03-18 devnull 	nwq = 0;
 41 7c709434 2005-03-18 devnull 	rq = nil;
 42 7c709434 2005-03-18 devnull 	wq = nil;
 43 7c709434 2005-03-18 devnull 	dprint("wait: start\n");
 44 7c709434 2005-03-18 devnull 	for(;;){
 45 7c709434 2005-03-18 devnull 	cont2:;
 46 7c709434 2005-03-18 devnull 		dprint("wait: alt\n");
 47 7c709434 2005-03-18 devnull 		switch(alt(a)){
 48 7c709434 2005-03-18 devnull 		case 0:
 49 7c709434 2005-03-18 devnull 			dprint("wait: pid %d exited\n", w->pid);
 50 7c709434 2005-03-18 devnull 			for(i=0; i<nrq; i++){
 51 7c709434 2005-03-18 devnull 				if(rq[i].pid == w->pid){
 52 7c709434 2005-03-18 devnull 					dprint("wait: match with rq chan %p\n", rq[i].c);
 53 7c709434 2005-03-18 devnull 					sendp(rq[i].c, w);
 54 7c709434 2005-03-18 devnull 					rq[i] = rq[--nrq];
 55 7c709434 2005-03-18 devnull 					goto cont2;
 56 7c709434 2005-03-18 devnull 				}
 57 7c709434 2005-03-18 devnull 			}
 58 7c709434 2005-03-18 devnull 			if(i == nrq){
 59 7c709434 2005-03-18 devnull 				dprint("wait: queueing waitmsg\n");
 60 7c709434 2005-03-18 devnull 				wq = erealloc(wq, (nwq+1)*sizeof(wq[0]));
 61 7c709434 2005-03-18 devnull 				wq[nwq++] = w;
 62 7c709434 2005-03-18 devnull 			}
 63 7c709434 2005-03-18 devnull 			break;
 64 fa325e9b 2020-01-10 cross 
 65 7c709434 2005-03-18 devnull 		case 1:
 66 7c709434 2005-03-18 devnull 			dprint("wait: req for pid %d chan %p\n", r.pid, r.c);
 67 7c709434 2005-03-18 devnull 			for(i=0; i<nwq; i++){
 68 7c709434 2005-03-18 devnull 				if(w->pid == r.pid){
 69 7c709434 2005-03-18 devnull 					dprint("wait: match with waitmsg\n");
 70 7c709434 2005-03-18 devnull 					sendp(r.c, w);
 71 7c709434 2005-03-18 devnull 					wq[i] = wq[--nwq];
 72 7c709434 2005-03-18 devnull 					goto cont2;
 73 7c709434 2005-03-18 devnull 				}
 74 7c709434 2005-03-18 devnull 			}
 75 7c709434 2005-03-18 devnull 			if(i == nwq){
 76 7c709434 2005-03-18 devnull 				dprint("wait: queueing req\n");
 77 7c709434 2005-03-18 devnull 				rq = erealloc(rq, (nrq+1)*sizeof(rq[0]));
 78 7c709434 2005-03-18 devnull 				rq[nrq] = r;
 79 7c709434 2005-03-18 devnull 				dprint("wait: queueing req pid %d chan %p\n", rq[nrq].pid, rq[nrq].c);
 80 7c709434 2005-03-18 devnull 				nrq++;
 81 7c709434 2005-03-18 devnull 			}
 82 7c709434 2005-03-18 devnull 			break;
 83 7c709434 2005-03-18 devnull 		}
 84 7c709434 2005-03-18 devnull 	}
 85 7c709434 2005-03-18 devnull }
 86 7c709434 2005-03-18 devnull 
 87 7c709434 2005-03-18 devnull Waitmsg*
 88 7c709434 2005-03-18 devnull twaitfor(int pid)
 89 7c709434 2005-03-18 devnull {
 90 7c709434 2005-03-18 devnull 	Waitreq r;
 91 7c709434 2005-03-18 devnull 	Waitmsg *w;
 92 fa325e9b 2020-01-10 cross 
 93 7c709434 2005-03-18 devnull 	r.pid = pid;
 94 7c709434 2005-03-18 devnull 	r.c = chancreate(sizeof(Waitmsg*), 1);
 95 7c709434 2005-03-18 devnull 	send(twaitchan, &r);
 96 7c709434 2005-03-18 devnull 	w = recvp(r.c);
 97 7c709434 2005-03-18 devnull 	chanfree(r.c);
 98 7c709434 2005-03-18 devnull 	return w;
 99 7c709434 2005-03-18 devnull }
100 7c709434 2005-03-18 devnull 
101 7c709434 2005-03-18 devnull int
102 7c709434 2005-03-18 devnull twait(int pid)
103 7c709434 2005-03-18 devnull {
104 7c709434 2005-03-18 devnull 	int x;
105 7c709434 2005-03-18 devnull 	Waitmsg *w;
106 fa325e9b 2020-01-10 cross 
107 7c709434 2005-03-18 devnull 	w = twaitfor(pid);
108 7c709434 2005-03-18 devnull 	x = w->msg[0] != 0 ? -1 : 0;
109 7c709434 2005-03-18 devnull 	free(w);
110 7c709434 2005-03-18 devnull 	return x;
111 7c709434 2005-03-18 devnull }
112 7c709434 2005-03-18 devnull 
113 7c709434 2005-03-18 devnull void
114 7c709434 2005-03-18 devnull twaitinit(void)
115 7c709434 2005-03-18 devnull {
116 7c709434 2005-03-18 devnull 	threadwaitchan();	/* allocate it before returning */
117 7c709434 2005-03-18 devnull 	twaitchan = chancreate(sizeof(Waitreq), 10);
118 7c709434 2005-03-18 devnull 	threadcreate(waitthread, nil, 128*1024);
119 7c709434 2005-03-18 devnull }