Regression: Cygwin 3.5.1 freezes when launching several mingw processes in parallel

[Dimitry Andric]

I think I've been experiencing something similar with 3.5.1, where date.exe randomly hangs with a full core pegged. Loading it in gdb shows:

Thread 1 received signal SIGTRAP, Trace/breakpoint trap.
0x00007ffe23b0b503 in KERNELBASE!DebugBreak () from /cygdrive/c/Windows/System32/KERNELBASE.dll
(gdb) bt
#0  0x00007ffe23b0b503 in KERNELBASE!DebugBreak () from /cygdrive/c/Windows/System32/KERNELBASE.dll
#1  0x00007ffe19cf6367 in break_here () at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/dcrt0.cc:472
#2  0x00007ffe19d10339 in try_to_debug () at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/exceptions.cc:597
#3  exception::handle (e=0x7ffffc7b0, frame=<optimized out>, in=0x7ffffc2c0, dispatch=<optimized out>)
    at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/exceptions.cc:810
#4  0x00007ffe261123af in ntdll!.chkstk () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
#5  0x00007ffe260c14b4 in ntdll!RtlRaiseException () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
#6  0x00007ffe26110ebe in ntdll!KiUserExceptionDispatcher () from /cygdrive/c/Windows/SYSTEM32/ntdll.dll
#7  0x00007ffe19da92d7 in fhandler_console::set_output_mode (m=(unknown: 0x2610d444), t=0x1, p=0x7ffffb9e8)
    at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/fhandler/console.cc:843
#8  0x00007ffe19d095ca in dtable::init_std_file_from_handle (this=<optimized out>, fd=<optimized out>, handle=0xffffffffffffffff)
    at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/dtable.cc:425
#9  0x00007ffe19d099c2 in dtable::stdio_init (this=0x800004870) at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/dtable.cc:186
#10 0x00007ffe19cf7187 in dll_crt0_1 () at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/dcrt0.cc:925
#11 0x00007ffe19cf5e08 in _cygtls::call2 (this=0x7ffffce00, func=0x7ffe19cf6fb8 <dll_crt0_1(void*)>, arg=0x0, buf=buf@entry=0x7ffffcdf0)
    at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/cygtls.cc:41
#12 0x00007ffe19cf5e86 in _cygtls::call (func=<optimized out>, arg=<optimized out>) at /usr/src/debug/cygwin-3.5.1-1/winsup/cygwin/cygtls.cc:28
#13 0x0000000000000000 in ?? ()
Backtrace stopped: previous frame inner to this frame (corrupt stack?)

I will check out 3.6.0-0.71.gb160b690b6ac to see if it fixes this hang.

-Dimitry

> On 4 Mar 2024, at 13:06, Takashi Yano via Cygwin <cygwin@cygwin.com> wrote:
> 
> On Mon, 4 Mar 2024 20:00:13 +0900
> Takashi Yano via Cygwin wrote:
>> On Sun, 3 Mar 2024 13:07:11 +0900
>> Takashi Yano wrote:
>>> On Sat, 2 Mar 2024 11:49:36 +0000
>>> Kate Deplaix wrote:
>>>> I'm running cygwin on baremetal on an Intel i5-750 (4 cores), with 7GB of RAM and with an up-to-date Windows 10.
>>> 
>>> Thanks for the information. I could reproduce the problem with
>>> Core i5 M 540 + 8GB RAM machine.
>>> 
>>> Let consider how to debug.
>> 
>> I found the cause. I'll push the patch shortly.
>> Thanks!
> 
> Please try:
> cygwin 3.6.0-0.71.gb160b690b6ac (TEST)
> 
> -- 
> Takashi Yano <takashi.yano@nifty.ne.jp>
> 
> -- 
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