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#include "threadimpl.h"
enum
{
STACK = 8192,
};
void
iointerrupt(Ioproc *io)
{
if(!io->inuse)
return;
threadint(io->tid);
}
static void
xioproc(void *a)
{
Ioproc *io, *x;
io = a;
/*
* first recvp acquires the ioproc.
* second tells us that the data is ready.
*/
for(;;){
while(recv(io->c, &x) == -1)
;
if(x == 0) /* our cue to leave */
break;
assert(x == io);
/* caller is now committed -- even if interrupted he'll return */
while(recv(io->creply, &x) == -1)
;
if(x == 0) /* caller backed out */
continue;
assert(x == io);
io->ret = io->op(&io->arg);
if(io->ret < 0)
rerrstr(io->err, sizeof io->err);
while(send(io->creply, &io) == -1)
;
while(recv(io->creply, &x) == -1)
;
}
}
Ioproc*
ioproc(void)
{
Ioproc *io;
io = mallocz(sizeof(*io), 1);
if(io == nil)
sysfatal("ioproc malloc: %r");
io->c = chancreate(sizeof(void*), 0);
io->creply = chancreate(sizeof(void*), 0);
io->tid = proccreate(xioproc, io, STACK);
return io;
}
void
closeioproc(Ioproc *io)
{
if(io == nil)
return;
iointerrupt(io);
while(send(io->c, 0) == -1)
;
chanfree(io->c);
chanfree(io->creply);
free(io);
}
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