Commit Graph

24 Commits

Author SHA1 Message Date
Jilles Tjoelker
b823fb59f1 sh: Fix race condition with signals and wait or set -T.
The change in r238888 was incomplete. It was still possible for a trapped
signal to arrive before the shell went to sleep (sigsuspend()) because a
check was missing or because the signal arrived before in_waitcmd was set.

On SMP, this bug sometimes caused the builtins/wait4.0 test to take 1 second
to execute; it then might or might not fail. On UP, the test almost always
failed.
2013-09-02 21:57:46 +00:00
Jilles Tjoelker
184dcee217 sh: Remove unused variable in_dowait. 2012-07-15 10:49:16 +00:00
Jilles Tjoelker
caf29fab8c sh: Use vfork in a few common cases.
This uses vfork() for simple commands and command substitutions containing a
single simple command, invoking an external program under certain conditions
(no redirections or variable assignments, non-interactive shell, no job
control). These restrictions limit the amount of code executed in a vforked
child.

There is a large speedup (for example 35%) in microbenchmarks. The
difference in buildkernel is smaller (for example 0.5%) but still
statistically significant. See
http://lists.freebsd.org/pipermail/freebsd-hackers/2012-January/037581.html
for some numbers.

The use of vfork() can be disabled by setting a variable named
SH_DISABLE_VFORK.
2012-02-04 23:12:14 +00:00
Jilles Tjoelker
454a02b372 sh: Fix duplicate prototypes for builtins.
Have mkbuiltins write the prototypes for the *cmd functions to builtins.h
instead of builtins.c and include builtins.h in more .c files instead of
duplicating prototypes for *cmd functions in other headers.
2011-06-13 21:03:27 +00:00
Jilles Tjoelker
ed4c3b5f86 sh: Forget about terminated background processes sooner.
Unless $! has been referenced for a particular job or $! still contains that
job's pid, forget about it after it has terminated. If $! has been
referenced, remember the job until the wait builtin has reported its
completion (either with the pid as parameter or without parameters).

In interactive mode, jobs are forgotten after termination has been reported,
which happens before primary prompts and through the jobs builtin. Even
then, though, remember a job if $! has been referenced.

This is similar to what is suggested by POSIX and should fix most memory
leaks (which also tend to cause sh to use more CPU time) with long running
scripts that start background jobs.

Caveats:
* Repeatedly referencing $! without ever doing 'wait', like
    while :; do foo & echo started foo: $!; sleep 60; done
  will still use a lot of memory and CPU time in the long run.
* The jobs and jobid builtins do not cause a job to be remembered for longer
  like expanding $! does.

PR:		bin/55346
2010-06-29 22:37:45 +00:00
Stefan Farfeleder
de37e41c23 Add the POSIX option -p to the jobs builtin command. It prints the PID of the
process leader for each job.  Now the last specified option for the output
format (-l, -p or -s) wins, previously -s trumped -l.

PR:		99926
Submitted by:	Ed Schouten and novel (patches modified by me)
2006-10-07 16:51:16 +00:00
Mark Murray
6195fb4102 Remove clause 3 from the UCB licenses.
OK'ed by:	imp, core
2004-04-06 20:06:54 +00:00
Tim J. Robbins
b80be28218 Avoid using ints or shorts to store process id's, use pid_t instead.
The pgrp member of struct job was declared as a short and could not store
every possible process group ID value, the rest of them were benign because
pid_t happens to be an int.
2002-07-18 10:22:42 +00:00
Tim J. Robbins
f1ae2c66c8 Make the message that is printed when the foreground process is terminated
by a signal the same as pdksh/bash/sh before rev. 1.34.
2002-07-18 09:37:51 +00:00
Tim J. Robbins
ad8a075902 Add -s (output PID's only) and -l (show PID's) options to the jobs(1)
builtin. Modify the output format to match what SUSv3 requires.
2002-05-31 14:04:23 +00:00
Tim J. Robbins
d86825beb8 Instead of keeping just the jobid of the most recently bg'd or fg'd job,
keep a linked list of the jobs, most recently used first. This is required
to support the idea of `previous job', and to allow the jobs fg and bg
default to be correct according to POSIX.
2002-05-31 12:31:23 +00:00
Warner Losh
5134c3f799 o __P has been reoved
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
  they already are.
o Change
	int
	foo() {
	...
  to
	int
	foo(void)
	{
	...
2002-02-02 06:50:57 +00:00
Peter Wemm
2a4562393f $Id$ -> $FreeBSD$ 1999-08-27 23:15:48 +00:00
Martin Cracauer
57b2932a14 Next approach to make loops in interactive interruptable.
PR:		bin/9173
1999-04-21 11:52:39 +00:00
Martin Cracauer
9bbfa41541 Narrow down conditions to break wait() to process traps.
Improve comments.
1998-09-10 22:09:11 +00:00
Martin Cracauer
135421ddbf If traps are set, they are now executed even when a signal-blocking
foreground child is running. Formerly, traps were exceuted after the
next child exit.

The enables the user to put a breaking wrapper around a blocking
application:
  (trap 'echo trap ; exit 1' 2; ./pestyblocker; echo -n)

The "echo -n" after the child call is needed to prevent sh from
optimizing the trap-executing shell away. I'm working on this.
1998-09-08 13:16:52 +00:00
Martin Cracauer
1f40b47b46 Improve bookkeeping of in_waitcmd and style fixes.
Submitted by:	Bruce Evans
1998-08-25 09:33:34 +00:00
Martin Cracauer
7a8e920bb9 Do not exit on SIGINT in non-interactive shells, fixes PR 1206,
i.e. this makes emacs usable from system(3). Programs called from
shellscripts are now required to exit with proper signal status. That
means, they have to kill themself. Exiting with faked numerical exit
code is not sufficient.

Exit with proper signal status if script exits on signal.

Make the wait builtin interruptable, both with and without traps set.

Use volatile sig_atomic_t where (and only where) appropriate.

(Almost) fix printing of newlines on SIGINT.

Make traps setable from trap handlers. This is needed for shellscripts
that catch SIGINT for cleanup work but intend to exit on it, hance
have to kill themself from a trap handler. I.e. mkdep.

While I'm at it, make it -Wall clean. -Wall is not enabled in
Makefile, since vararg warnx() macro calls in usr.bin/printf/printf.c
are not -Wall-able.
PR:		1206
Obtained from:	Basic SIGINT fix from Bruce Evans
1998-08-24 10:20:37 +00:00
Steve Price
ead152eb86 Make all status values an integral type and use
pid_t when referring to process IDs.
1997-08-18 02:53:20 +00:00
Peter Wemm
b97fa2ef50 Revert $FreeBSD$ to $Id$ 1997-02-22 14:13:04 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Peter Wemm
aa9caaf657 Merge of 4.4-Lite2 sh source, plus some gcc -Wall cleaning. This is a
merge of parallel duplicate work by Steve Price and myself. :-]

There are some changes to the build that are my fault...  mkinit.c was
trying (poorly) to duplicate some of the work that make(1) is designed to
do.  The Makefile hackery is my fault too, the depend list was incomplete
because of some explicit OBJS+= entries, so mkdep wasn't picking up their
source file #includes.

This closes a pile of /bin/sh PR's, but not all of them..

Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter
1996-09-01 10:22:36 +00:00
David Greenman
89730b290a Added $Id$ 1994-09-24 02:59:15 +00:00
Rodney W. Grimes
4b88c807ea BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00