On 01/15/2013 09:04 PM, Christopher Faylor wrote:
On Tue, Jan 15, 2013 at 05:16:57PM -0500, Tom Honermann wrote:
I noticed that some changes were checked in related to signal handling
and process termination recently, so I downloaded the most recent
snapshot (20130114) and tested again. I was still able to produce
hanging processes (including hangs of strace.exe) by hitting ctrl-c in a
mintty window while Cygwin processes ran in an infinite loop inside of a
.bat file. I was able to produce a hang ~1 out of 20 times.
How does one run a .bat file inside mintty which handles CTRL-C? AFAIK,
a CTRL-C will just cause the .bat file to exit when run under bash.
Here is the test case:
1) Install the latest snapshot
2) Copy bash.exe, false.exe, and their dependent DLLs from a Cygwin
install into the usr/bin directory of the snapshot. For me this
consisted of:
bash.exe
cygintl-8.dll
cygiconv-2.dll
cygreadline7.dll
cygncurses-10.dll
cygncursesw-10.dll
cyggcc_s-1.dll
false.exe
3) Create 'test.bat' in the usr/bin directory of the snapshot with the
following contents:
@echo off
setlocal
set PATH=%CD%;%PATH%
:loop
echo test...
bash -c false
if not errorlevel 1 (
echo exiting...
exit /B 1
)
goto loop
4) Launch mintty using an existing Cygwin installation. Naturally, this
will run a shell from the existing Cygwin install.
5) Change directories to the usr/bin directory of the snapshot.
6) Start task manager or some other process monitoring tool and keep it
running. Run ./test.bat from the Cygwin shell running within mintty and
interrupt it with ctrl-c. Repeat until you see a new bash.exe or
false.exe process persisting following the interrupt. You'll likely
have multiple bash processes running. If you are able to reproduce, you
should see one with a command line of 'bash -c false'. Alternatively,
if your process monitoring tool shows the path to the executable, you'll
be able to identify it as the one from the usr/bin directory of the
snapshot.
I rather doubt that the use of a .bat file is necessary to reproduce
this hang, but I haven't tried producing a test case that doesn't use a
.bat file. This is a test case I was using when debugging the
intermittent incorrect exit code issue.
Tom.
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