sleep() ...

[Kay Roemer <roemer@informatik.uni-frankfurt.de>]

The following patches make sleep() return whether
or not it was interrupted by delivery of signals.
It returns nonzero if it was interrupted by signals.

The diffs are relative to 1.09.

These changes should make it easy to change pipefs
(to Eric ...) so that it does NOT touch objects
that could have been kfree()'ed by a signal handler
while sleep()ing:

Simply change
	sleep(IO_Q, cond);
into
	if (sleep(IO_Q, cond)) {
		/* Handle interrupted system call */
	}
where appropriate.

My next message contains diffs to change Fselect()
so that it really works for multiple processes
select()ing the same file. I posted that already
some time ago, but this version makes use of the
new sleep(), thus giving somewhat cleaner code :-).

Cheers -- Kay.

*** file.h.orig	Fri Oct 22 18:50:52 1993
--- file.h	Fri Oct 22 18:52:08 1993
***************
*** 232,238 ****
   * to sleep
   */
  	void	ARGS_ON_STACK (*nap) P_((unsigned));
! 	void	ARGS_ON_STACK (*sleep) P_((int que, long cond));
  	void	ARGS_ON_STACK (*wake) P_((int que, long cond));
  	void	ARGS_ON_STACK (*wakeselect) P_((long param));
  
--- 232,238 ----
   * to sleep
   */
  	void	ARGS_ON_STACK (*nap) P_((unsigned));
! 	short	ARGS_ON_STACK (*sleep) P_((int que, long cond));
  	void	ARGS_ON_STACK (*wake) P_((int que, long cond));
  	void	ARGS_ON_STACK (*wakeselect) P_((long param));
  
*** proc.c.orig	Mon Sep 13 21:22:00 1993
--- proc.c	Fri Oct 22 19:58:24 1993
***************
*** 107,112 ****
--- 107,113 ----
  	p->ppid = curproc->pid;
  	p->pid = newpid();
  	p->sigpending = 0;
+ 	p->nsigs = 0;
  	p->sysstack = (long)(p->stack + STKSIZE - 12);
  	p->ctxt[CURRENT].ssp = p->sysstack;
  	p->ctxt[SYSCALL].ssp = (long)(p->stack + ISTKSIZE);
***************
*** 451,463 ****
  	p->slices = SLICES(p->curpri);
  }
  
! void ARGS_ON_STACK 
  sleep(que, cond)
  	int que;
  	long cond;
  {
  	PROC *p;
  	short sr;
  	extern short kintr;	/* in bios.c */
  #ifndef MULTITOS
  #ifdef FASTTEXT
--- 452,465 ----
  	p->slices = SLICES(p->curpri);
  }
  
! short ARGS_ON_STACK 
  sleep(que, cond)
  	int que;
  	long cond;
  {
  	PROC *p;
  	short sr;
+ 	ulong onsigs = curproc->nsigs;
  	extern short kintr;	/* in bios.c */
  #ifndef MULTITOS
  #ifdef FASTTEXT
***************
*** 478,484 ****
  	if (que == READY_Q && !sys_q[READY_Q]) {
  /* we're just going to wake up again right away! */
  		do_wakeup_things();
! 		return;
  	}
  
  	sr = spl7();
--- 480,486 ----
  	if (que == READY_Q && !sys_q[READY_Q]) {
  /* we're just going to wake up again right away! */
  		do_wakeup_things();
! 		return (onsigs != curproc->nsigs);
  	}
  
  	sr = spl7();
***************
*** 548,554 ****
  			*((void **)0x44eL) = curproc->logbase;
  #endif
  		do_wakeup_things();
! 		return;
  	}
  /*
   * save per-process variables here
--- 550,556 ----
  			*((void **)0x44eL) = curproc->logbase;
  #endif
  		do_wakeup_things();
! 		return (onsigs != curproc->nsigs);
  	}
  /*
   * save per-process variables here
***************
*** 567,572 ****
--- 569,576 ----
  	}
  	assert(p->magic == CTXT_MAGIC);
  	change_context(&(p->ctxt[CURRENT]));
+ 	/* not reached */
+ 	return 0;
  }
  
  /*
*** proc.h.orig	Fri Oct 22 18:38:30 1993
--- proc.h	Fri Oct 22 18:39:56 1993
***************
*** 170,175 ****
--- 170,177 ----
  	ushort	sigflags[NSIG];		/* signal flags			*/
  	ulong	sigextra[NSIG];		/* additional signals to be masked
  					   on delivery 	*/
+ 	ulong	nsigs;			/* # of delivered signals	*/
+ 	
  	char	*mb_ptr;		/* p_msg buffer ptr		*/
  	long	mb_long1, mb_long2;	/* p_msg storage		*/
  	long	mb_mbid;		/* p_msg id being waited for	*/
*** proto.h.orig	Fri Oct 22 18:50:02 1993
--- proto.h	Fri Oct 22 18:50:36 1993
***************
*** 246,252 ****
  void add_q P_((int que, PROC *proc));
  void rm_q P_((int que, PROC *proc));
  void ARGS_ON_STACK preempt P_((void));
! void ARGS_ON_STACK sleep P_((int que, long cond));
  void ARGS_ON_STACK wake P_((int que, long cond));
  void ARGS_ON_STACK wakeselect P_((long param));
  void DUMPPROC P_((void));
--- 246,252 ----
  void add_q P_((int que, PROC *proc));
  void rm_q P_((int que, PROC *proc));
  void ARGS_ON_STACK preempt P_((void));
! short ARGS_ON_STACK sleep P_((int que, long cond));
  void ARGS_ON_STACK wake P_((int que, long cond));
  void ARGS_ON_STACK wakeselect P_((long param));
  void DUMPPROC P_((void));
*** signal.c.orig	Fri Sep 17 15:32:58 1993
--- signal.c	Fri Oct 22 20:50:50 1993
***************
*** 265,270 ****
--- 263,269 ----
  
  	extern void sig_return();
  
+ 	++curproc->nsigs;
  	if (curproc->sighandle[sig] == SIG_IGN)
  		return;
  	else if (curproc->sighandle[sig] == SIG_DFL) {