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- /*
- * This file is part of the UCB release of Plan 9. It is subject to the license
- * terms in the LICENSE file found in the top-level directory of this
- * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
- * part of the UCB release of Plan 9, including this file, may be copied,
- * modified, propagated, or distributed except according to the terms contained
- * in the LICENSE file.
- */
- #include <u.h>
- #include <libc.h>
- #include <thread.h>
- #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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