1 76193d7c 2003-09-30 devnull #include "threadimpl.h"
 2 76193d7c 2003-09-30 devnull 
 3 76193d7c 2003-09-30 devnull enum
 4 76193d7c 2003-09-30 devnull {
 5 76193d7c 2003-09-30 devnull 	STACK = 8192,
 6 76193d7c 2003-09-30 devnull };
 7 76193d7c 2003-09-30 devnull 
 8 76193d7c 2003-09-30 devnull void
 9 76193d7c 2003-09-30 devnull iointerrupt(Ioproc *io)
10 76193d7c 2003-09-30 devnull {
11 76193d7c 2003-09-30 devnull 	if(!io->inuse)
12 76193d7c 2003-09-30 devnull 		return;
13 76193d7c 2003-09-30 devnull 	threadint(io->tid);
14 76193d7c 2003-09-30 devnull }
15 76193d7c 2003-09-30 devnull 
16 76193d7c 2003-09-30 devnull static void
17 76193d7c 2003-09-30 devnull xioproc(void *a)
18 76193d7c 2003-09-30 devnull {
19 76193d7c 2003-09-30 devnull 	Ioproc *io, *x;
20 76193d7c 2003-09-30 devnull 	io = a;
21 76193d7c 2003-09-30 devnull 	/*
22 76193d7c 2003-09-30 devnull 	 * first recvp acquires the ioproc.
23 76193d7c 2003-09-30 devnull 	 * second tells us that the data is ready.
24 76193d7c 2003-09-30 devnull 	 */
25 76193d7c 2003-09-30 devnull 	for(;;){
26 76193d7c 2003-09-30 devnull 		while(recv(io->c, &x) == -1)
27 76193d7c 2003-09-30 devnull 			;
28 76193d7c 2003-09-30 devnull 		if(x == 0)	/* our cue to leave */
29 76193d7c 2003-09-30 devnull 			break;
30 76193d7c 2003-09-30 devnull 		assert(x == io);
31 76193d7c 2003-09-30 devnull 
32 76193d7c 2003-09-30 devnull 		/* caller is now committed -- even if interrupted he'll return */
33 76193d7c 2003-09-30 devnull 		while(recv(io->creply, &x) == -1)
34 76193d7c 2003-09-30 devnull 			;
35 76193d7c 2003-09-30 devnull 		if(x == 0)	/* caller backed out */
36 76193d7c 2003-09-30 devnull 			continue;
37 76193d7c 2003-09-30 devnull 		assert(x == io);
38 76193d7c 2003-09-30 devnull 
39 76193d7c 2003-09-30 devnull 		io->ret = io->op(&io->arg);
40 76193d7c 2003-09-30 devnull 		if(io->ret < 0)
41 76193d7c 2003-09-30 devnull 			rerrstr(io->err, sizeof io->err);
42 76193d7c 2003-09-30 devnull 		while(send(io->creply, &io) == -1)
43 76193d7c 2003-09-30 devnull 			;
44 76193d7c 2003-09-30 devnull 		while(recv(io->creply, &x) == -1)
45 76193d7c 2003-09-30 devnull 			;
46 76193d7c 2003-09-30 devnull 	}
47 76193d7c 2003-09-30 devnull }
48 76193d7c 2003-09-30 devnull 
49 76193d7c 2003-09-30 devnull Ioproc*
50 76193d7c 2003-09-30 devnull ioproc(void)
51 76193d7c 2003-09-30 devnull {
52 76193d7c 2003-09-30 devnull 	Ioproc *io;
53 76193d7c 2003-09-30 devnull 
54 76193d7c 2003-09-30 devnull 	io = mallocz(sizeof(*io), 1);
55 76193d7c 2003-09-30 devnull 	if(io == nil)
56 76193d7c 2003-09-30 devnull 		sysfatal("ioproc malloc: %r");
57 76193d7c 2003-09-30 devnull 	io->c = chancreate(sizeof(void*), 0);
58 76193d7c 2003-09-30 devnull 	io->creply = chancreate(sizeof(void*), 0);
59 76193d7c 2003-09-30 devnull 	io->tid = proccreate(xioproc, io, STACK);
60 76193d7c 2003-09-30 devnull 	return io;
61 76193d7c 2003-09-30 devnull }
62 76193d7c 2003-09-30 devnull 
63 76193d7c 2003-09-30 devnull void
64 76193d7c 2003-09-30 devnull closeioproc(Ioproc *io)
65 76193d7c 2003-09-30 devnull {
66 76193d7c 2003-09-30 devnull 	if(io == nil)
67 76193d7c 2003-09-30 devnull 		return;
68 76193d7c 2003-09-30 devnull 	iointerrupt(io);
69 76193d7c 2003-09-30 devnull 	while(send(io->c, 0) == -1)
70 76193d7c 2003-09-30 devnull 		;
71 76193d7c 2003-09-30 devnull 	chanfree(io->c);
72 76193d7c 2003-09-30 devnull 	chanfree(io->creply);
73 76193d7c 2003-09-30 devnull 	free(io);
74 76193d7c 2003-09-30 devnull }