ref: dac5756766be04f303bceaea49eba4f6ffc4e25e
dir: /sys/src/libthread/ioproc.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "threadimpl.h" enum { STACK = 8192, }; void iointerrupt(Ioproc *io) { if(io->ctl < 0) return; qlock(io); if(++io->intr == 1) write(io->ctl, "interrupt", 9); qunlock(io); } static void xioproc(void *a) { Channel *c; Ioproc *io; Iocall *r; c = a; if(io = mallocz(sizeof(*io), 1)){ char buf[128]; /* * open might fail, ignore it for programs like factotum * that don't use iointerrupt() anyway. */ snprint(buf, sizeof(buf), "/proc/%d/ctl", getpid()); io->ctl = open(buf, OWRITE); if((io->creply = chancreate(sizeof(void*), 0)) == nil){ if(io->ctl >= 0) close(io->ctl); free(io); io = nil; } else io->c = c; } while(send(c, &io) < 0) ; if(io == nil) return; for(;;){ while(recv(io->c, &r) < 0) ; if(r == 0) break; if(io->intr){ r->ret = -1; strcpy(r->err, "interrupted"); } else if((r->ret = r->op(&r->arg)) < 0) rerrstr(r->err, sizeof r->err); qlock(io); if(io->intr){ io->intr = 0; if(io->ctl >= 0) write(io->ctl, "nointerrupt", 11); } while(send(io->creply, &r) < 0) ; qunlock(io); } if(io->ctl >= 0) close(io->ctl); chanfree(io->c); chanfree(io->creply); free(io); } Ioproc* ioproc(void) { Channel *c; Ioproc *io; if((c = chancreate(sizeof(void*), 0)) == nil) sysfatal("ioproc chancreate"); proccreate(xioproc, c, STACK); while(recv(c, &io) < 0) ; if(io == nil) sysfatal("ioproc alloc"); return io; } void closeioproc(Ioproc *io) { if(io == nil) return; iointerrupt(io); while(sendp(io->c, nil) < 0) ; }