Support for suspending on character device open and on drivers that need to

be restarted.
This commit is contained in:
Philip Homburg 2008-02-22 14:47:40 +00:00
parent ca91b3b5be
commit 7387449b23

View File

@ -245,11 +245,14 @@ int task; /* who is proc waiting for? (PIPE = pipe) */
if (task == XPOPEN) susp_count++;/* #procs susp'ed on pipe*/
fp->fp_suspended = SUSPENDED;
assert(!GRANT_VALID(fp->fp_grant));
assert(fp->fp_grant == GRANT_INVALID || !GRANT_VALID(fp->fp_grant));
fp->fp_fd = m_in.fd << 8 | call_nr;
if(task == NONE)
panic(__FILE__,"suspend on NONE",NO_NUM);
fp->fp_task = -task;
fp->fp_flags &= ~SUSP_REOPEN; /* Clear this flag. The caller
* can set it when needed.
*/
if (task == XLOCK) {
fp->fp_buffer = (char *) m_in.name1; /* third arg to fcntl() */
fp->fp_nbytes = m_in.request; /* second arg to fcntl() */
@ -371,10 +374,10 @@ int returned; /* if hanging on task, how many bytes read */
/* Revive a previously blocked process. When a process hangs on tty, this
* is the way it is eventually released.
*/
register struct fproc *rfp;
register int task;
int proc_nr;
int fd_nr, proc_nr;
struct filp *fil_ptr;
if(isokendpt(proc_nr_e, &proc_nr) != OK)
return;
@ -392,13 +395,37 @@ int returned; /* if hanging on task, how many bytes read */
/* Revive a process suspended on a pipe or lock. */
rfp->fp_revived = REVIVING;
reviving++; /* process was waiting on pipe or lock */
} else {
}
else if (task == XDOPEN)
{
rfp->fp_suspended = NOT_SUSPENDED;
fd_nr= rfp->fp_fd>>8;
if (returned < 0)
{
fil_ptr= rfp->fp_filp[fd_nr];
rfp->fp_filp[fd_nr] = NIL_FILP;
FD_CLR(fd_nr, &rfp->fp_filp_inuse);
if (fil_ptr->filp_count != 1)
{
panic(__FILE__, "revive: bad count in filp",
fil_ptr->filp_count);
}
fil_ptr->filp_count= 0;
put_vnode(fil_ptr->filp_vno);
fil_ptr->filp_vno = NIL_VNODE;
reply(proc_nr_e, returned);
}
else
reply(proc_nr_e, fd_nr);
}
else {
rfp->fp_suspended = NOT_SUSPENDED;
if (task == XPOPEN) /* process blocked in open or create */
reply(proc_nr_e, rfp->fp_fd>>8);
else if (task == XSELECT) {
reply(proc_nr_e, returned);
} else {
}
else {
/* Revive a process suspended on TTY or other device.
* Pretend it wants only what there is.
*/
@ -419,25 +446,10 @@ int returned; /* if hanging on task, how many bytes read */
}
/*===========================================================================*
* do_unpause *
*===========================================================================*/
PUBLIC int do_unpause()
{
/* A signal has been sent to a user who is paused on the file system.
* Abort the system call with the EINTR error message.
*/
int proc_nr_e;
if (who_e != PM_PROC_NR) return(EPERM);
proc_nr_e = m_in.ENDPT;
return unpause(proc_nr_e);
}
/*===========================================================================*
* unpause *
*===========================================================================*/
PUBLIC int unpause(proc_nr_e)
PUBLIC void unpause(proc_nr_e)
int proc_nr_e;
{
/* A signal has been sent to a user who is paused on the file system.
@ -452,7 +464,8 @@ int proc_nr_e;
okendpt(proc_nr_e, &proc_nr_p);
rfp = &fproc[proc_nr_p];
if (rfp->fp_suspended == NOT_SUSPENDED) return(OK);
if (rfp->fp_suspended == NOT_SUSPENDED)
return;
task = -rfp->fp_task;
if (rfp->fp_revived == REVIVING)
@ -475,7 +488,21 @@ int proc_nr_e;
case XPOPEN: /* process trying to open a fifo */
break;
case XDOPEN: /* process trying to open a device */
/* Don't cancel OPEN. Just wait until the open completes. */
return;
default: /* process trying to do device I/O (e.g. tty)*/
if (rfp->fp_flags & SUSP_REOPEN)
{
/* Process is suspended while waiting for a reopen.
* Just reply EINTR.
*/
rfp->fp_flags &= ~SUSP_REOPEN;
status= EINTR;
break;
}
fild = (rfp->fp_fd >> 8) & BYTE;/* extract file descriptor */
if (fild < 0 || fild >= OPEN_MAX)
panic(__FILE__,"unpause err 2",NO_NUM);
@ -491,6 +518,11 @@ int proc_nr_e;
fp = rfp; /* hack - ctty_io uses fp */
(*dmap[(dev >> MAJOR) & BYTE].dmap_io)(task, &mess);
status = mess.REP_STATUS;
if (status == SUSPEND)
return; /* Process will be revived at a
* later time.
*/
if(status == EAGAIN) status = EINTR;
if(GRANT_VALID(rfp->fp_grant)) {
if(cpf_revoke(rfp->fp_grant)) {
@ -503,7 +535,6 @@ int proc_nr_e;
rfp->fp_suspended = NOT_SUSPENDED;
reply(proc_nr_e, status); /* signal interrupted call */
return(OK);
}