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[PATCH v2 1/2] remote: Use `catch' in killing pending force-kills
From: |
Maciej W. Rozycki |
Subject: |
[PATCH v2 1/2] remote: Use `catch' in killing pending force-kills |
Date: |
Thu, 11 Jun 2020 02:30:44 +0100 (BST) |
User-agent: |
Alpine 2.21 (LFD 202 2017-01-01) |
Address an execution race in `close_wait_program' and use `catch' in
killing pending force-kills issued there in the recovery of a stuck test
case, in case the force-kill sequence has completed before the command
to kill the sequence had a chance to run, so that no error is thrown and
a testsuite run does not get interrupted early like:
PASS: gcc.c-torture/execute/postmod-1.c -O0 (test for excess errors)
Executing on remote-localhost: .../gcc/testsuite/gcc/postmod-1.exe (timeout
= 15)
spawn [open ...]
WARNING: program timed out
ERROR: tcl error sourcing .../gcc/testsuite/gcc.c-torture/execute/execute.exp.
ERROR: child process exited abnormally
while executing
"exec sh -c "exec > /dev/null 2>&1 && kill -9 $exec_pid""
(procedure "close_wait_program" line 57)
invoked from within
"close_wait_program $spawn_id $pid wres"
(procedure "local_exec" line 104)
[...]
"uplevel #0 source .../gcc/testsuite/gcc.c-torture/execute/execute.exp"
invoked from within
"catch "uplevel #0 source $test_file_name""
testcase .../gcc/testsuite/gcc.c-torture/execute/execute.exp completed in 196
seconds
=== gcc Summary ===
# of expected passes 1
-- therefore not letting `execute.exp' continue (here with the GCC `c'
testsuite invoked with `execute.exp=postmod-1.c' for 8 compilation and 8
execution tests).
The completion of the force-kill sequence would have to happen in the
window between the `wait' command has returned, which would at worst
happen as a result of the final `kill -9' command in the sequence, and
the `kill -9 $exec_pid' command issued here, and the `sleep 5' command
issued at the end of the force-kill sequence makes the likelihood of
such a scenario low, but this might still happen with a loaded host
system and there is no drawback from using `catch' here, so let's do it.
* lib/remote.exp (close_wait_program): Use `catch' in killing
pending force-kills.
Signed-off-by: Maciej W. Rozycki <macro@wdc.com>
---
Hi,
Please apply. FAOD this has been formatted for `git am' use.
Maciej
Changes from v1:
- Simplify `catch' invocation, no functional change.
---
lib/remote.exp | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
dejagnu-remote-close-wait-kill-catch.diff
Index: dejagnu/lib/remote.exp
===================================================================
--- dejagnu.orig/lib/remote.exp
+++ dejagnu/lib/remote.exp
@@ -113,7 +113,10 @@ proc close_wait_program { program_id pid
# We reaped the process, so cancel the pending force-kills, as
# otherwise if the PID is reused for some other unrelated
# process, we'd kill the wrong process.
- exec sh -c "exec > /dev/null 2>&1 && kill -9 $exec_pid"
+ #
+ # Use `catch' in case the force-kills have completed, so as not
+ # to cause TCL to choke if `kill' returns a failure.
+ catch {exec sh -c "kill -9 $exec_pid" >& /dev/null}
}
return $res