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 "ioproc.h"
  5 619085f0 2004-12-25 devnull 
  6 619085f0 2004-12-25 devnull enum
  7 619085f0 2004-12-25 devnull {
  8 cbeb0b26 2006-04-01 devnull 	STACK = 32768
  9 619085f0 2004-12-25 devnull };
 10 619085f0 2004-12-25 devnull 
 11 619085f0 2004-12-25 devnull void
 12 619085f0 2004-12-25 devnull iointerrupt(Ioproc *io)
 13 619085f0 2004-12-25 devnull {
 14 619085f0 2004-12-25 devnull 	if(!io->inuse)
 15 619085f0 2004-12-25 devnull 		return;
 16 af89fc10 2005-01-06 devnull 	fprint(2, "bug: cannot iointerrupt %p yet\n", io);
 17 619085f0 2004-12-25 devnull }
 18 619085f0 2004-12-25 devnull 
 19 619085f0 2004-12-25 devnull static void
 20 619085f0 2004-12-25 devnull xioproc(void *a)
 21 619085f0 2004-12-25 devnull {
 22 619085f0 2004-12-25 devnull 	Ioproc *io, *x;
 23 2c87dda8 2004-12-28 devnull 
 24 2c87dda8 2004-12-28 devnull 	threadsetname("ioproc");
 25 619085f0 2004-12-25 devnull 	io = a;
 26 619085f0 2004-12-25 devnull 	/*
 27 619085f0 2004-12-25 devnull 	 * first recvp acquires the ioproc.
 28 619085f0 2004-12-25 devnull 	 * second tells us that the data is ready.
 29 619085f0 2004-12-25 devnull 	 */
 30 619085f0 2004-12-25 devnull 	for(;;){
 31 619085f0 2004-12-25 devnull 		while(recv(io->c, &x) == -1)
 32 619085f0 2004-12-25 devnull 			;
 33 619085f0 2004-12-25 devnull 		if(x == 0)	/* our cue to leave */
 34 619085f0 2004-12-25 devnull 			break;
 35 619085f0 2004-12-25 devnull 		assert(x == io);
 36 619085f0 2004-12-25 devnull 
 37 619085f0 2004-12-25 devnull 		/* caller is now committed -- even if interrupted he'll return */
 38 619085f0 2004-12-25 devnull 		while(recv(io->creply, &x) == -1)
 39 619085f0 2004-12-25 devnull 			;
 40 619085f0 2004-12-25 devnull 		if(x == 0)	/* caller backed out */
 41 619085f0 2004-12-25 devnull 			continue;
 42 619085f0 2004-12-25 devnull 		assert(x == io);
 43 619085f0 2004-12-25 devnull 
 44 619085f0 2004-12-25 devnull 		io->ret = io->op(&io->arg);
 45 619085f0 2004-12-25 devnull 		if(io->ret < 0)
 46 619085f0 2004-12-25 devnull 			rerrstr(io->err, sizeof io->err);
 47 619085f0 2004-12-25 devnull 		while(send(io->creply, &io) == -1)
 48 619085f0 2004-12-25 devnull 			;
 49 619085f0 2004-12-25 devnull 		while(recv(io->creply, &x) == -1)
 50 619085f0 2004-12-25 devnull 			;
 51 619085f0 2004-12-25 devnull 	}
 52 619085f0 2004-12-25 devnull }
 53 619085f0 2004-12-25 devnull 
 54 619085f0 2004-12-25 devnull Ioproc*
 55 619085f0 2004-12-25 devnull ioproc(void)
 56 619085f0 2004-12-25 devnull {
 57 619085f0 2004-12-25 devnull 	Ioproc *io;
 58 619085f0 2004-12-25 devnull 
 59 619085f0 2004-12-25 devnull 	io = mallocz(sizeof(*io), 1);
 60 619085f0 2004-12-25 devnull 	if(io == nil)
 61 619085f0 2004-12-25 devnull 		sysfatal("ioproc malloc: %r");
 62 619085f0 2004-12-25 devnull 	io->c = chancreate(sizeof(void*), 0);
 63 619085f0 2004-12-25 devnull 	chansetname(io->c, "ioc%p", io->c);
 64 619085f0 2004-12-25 devnull 	io->creply = chancreate(sizeof(void*), 0);
 65 619085f0 2004-12-25 devnull 	chansetname(io->creply, "ior%p", io->c);
 66 619085f0 2004-12-25 devnull 	io->tid = proccreate(xioproc, io, STACK);
 67 619085f0 2004-12-25 devnull 	return io;
 68 619085f0 2004-12-25 devnull }
 69 619085f0 2004-12-25 devnull 
 70 619085f0 2004-12-25 devnull void
 71 619085f0 2004-12-25 devnull closeioproc(Ioproc *io)
 72 619085f0 2004-12-25 devnull {
 73 619085f0 2004-12-25 devnull 	if(io == nil)
 74 619085f0 2004-12-25 devnull 		return;
 75 619085f0 2004-12-25 devnull 	iointerrupt(io);
 76 619085f0 2004-12-25 devnull 	while(send(io->c, 0) == -1)
 77 619085f0 2004-12-25 devnull 		;
 78 619085f0 2004-12-25 devnull 	chanfree(io->c);
 79 619085f0 2004-12-25 devnull 	chanfree(io->creply);
 80 619085f0 2004-12-25 devnull 	free(io);
 81 619085f0 2004-12-25 devnull }
 82 619085f0 2004-12-25 devnull 
 83 619085f0 2004-12-25 devnull long
 84 619085f0 2004-12-25 devnull iocall(Ioproc *io, long (*op)(va_list*), ...)
 85 619085f0 2004-12-25 devnull {
 86 619085f0 2004-12-25 devnull 	char e[ERRMAX];
 87 619085f0 2004-12-25 devnull 	int ret, inted;
 88 619085f0 2004-12-25 devnull 	Ioproc *msg;
 89 619085f0 2004-12-25 devnull 
 90 619085f0 2004-12-25 devnull 	if(send(io->c, &io) == -1){
 91 619085f0 2004-12-25 devnull 		werrstr("interrupted");
 92 619085f0 2004-12-25 devnull 		return -1;
 93 619085f0 2004-12-25 devnull 	}
 94 619085f0 2004-12-25 devnull 	assert(!io->inuse);
 95 619085f0 2004-12-25 devnull 	io->inuse = 1;
 96 619085f0 2004-12-25 devnull 	io->op = op;
 97 619085f0 2004-12-25 devnull 	va_start(io->arg, op);
 98 619085f0 2004-12-25 devnull 	msg = io;
 99 619085f0 2004-12-25 devnull 	inted = 0;
100 619085f0 2004-12-25 devnull 	while(send(io->creply, &msg) == -1){
101 619085f0 2004-12-25 devnull 		msg = nil;
102 619085f0 2004-12-25 devnull 		inted = 1;
103 619085f0 2004-12-25 devnull 	}
104 619085f0 2004-12-25 devnull 	if(inted){
105 619085f0 2004-12-25 devnull 		werrstr("interrupted");
106 619085f0 2004-12-25 devnull 		return -1;
107 619085f0 2004-12-25 devnull 	}
108 619085f0 2004-12-25 devnull 
109 619085f0 2004-12-25 devnull 	/*
110 619085f0 2004-12-25 devnull 	 * If we get interrupted, we have stick around so that
111 619085f0 2004-12-25 devnull 	 * the IO proc has someone to talk to.  Send it an interrupt
112 619085f0 2004-12-25 devnull 	 * and try again.
113 619085f0 2004-12-25 devnull 	 */
114 619085f0 2004-12-25 devnull 	inted = 0;
115 619085f0 2004-12-25 devnull 	while(recv(io->creply, nil) == -1){
116 619085f0 2004-12-25 devnull 		inted = 1;
117 619085f0 2004-12-25 devnull 		iointerrupt(io);
118 619085f0 2004-12-25 devnull 	}
119 619085f0 2004-12-25 devnull 	USED(inted);
120 619085f0 2004-12-25 devnull 	va_end(io->arg);
121 619085f0 2004-12-25 devnull 	ret = io->ret;
122 619085f0 2004-12-25 devnull 	if(ret < 0)
123 619085f0 2004-12-25 devnull 		strecpy(e, e+sizeof e, io->err);
124 619085f0 2004-12-25 devnull 	io->inuse = 0;
125 619085f0 2004-12-25 devnull 
126 619085f0 2004-12-25 devnull 	/* release resources */
127 619085f0 2004-12-25 devnull 	while(send(io->creply, &io) == -1)
128 619085f0 2004-12-25 devnull 		;
129 619085f0 2004-12-25 devnull 	if(ret < 0)
130 619085f0 2004-12-25 devnull 		errstr(e, sizeof e);
131 619085f0 2004-12-25 devnull 	return ret;
132 619085f0 2004-12-25 devnull }