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Date: Fri, 14 Jan 2022 08:52:27 +0900
From: Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>
To: cygwin AT cygwin DOT com
Subject: Re: proc_waiter: error on read of child wait pipe 0x0, Win32 error 6
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On Wed, 12 Jan 2022 07:41:41 +0100
Marco Atzeri wrote:
> On 12.01.2022 07:27, Jay K wrote:
> > Ok, here is a small demonstration of the problem.
> > 
> > #include <stdlib.h>
> > #include <stdio.h>
> > #include <windows.h>
> > 
> > unsigned __stdcall thread(void* p)
> > {
> >    unsigned i;
> >    for (i = 0; i < 100; ++i)
> >     system("./a.exe");
> >    return 0;
> > }
> > 
> > int main()
> > {
> > unsigned i;
> > HANDLE threads[100] = {0};
> > FILE* f = fopen("a.c", "w");
> > fprintf(f, "int main() { return 0; }\n");
> > fclose(f);
> 
> 
> so you are mixing Cygwin and Windows calls ?
> That is looking for trouble.
> 
> Or it is a tentative to produce a test case ?

I found that the same happens even with pthread rather than
win32 thread functions.

#include <stdlib.h>
#include <pthread.h>

void *thread(void *p)
{
	system("true");
	return NULL;
}

int main()
{
	int i;
	pthread_t threads[2];

	for (i = 0; i < 2; i++)
		pthread_create(&threads[i], NULL, thread, NULL);

	for (i = 0; i < 2; i++)
		pthread_join(threads[i], NULL);

	return 0;
}

Executing above code results in hang with message:
      0 [waitproc] a 786 proc_waiter: error on read of child wait pipe 0x0, Win32 error 6

-- 
Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>

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