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To: "'cygwin'" <cygwin AT cygwin DOT com>
Subject: open descriptor to named pipes sometimes fail
Date: Tue, 7 Apr 2020 17:10:26 +0200
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From: Kristian Ivarsson via Cygwin <cygwin AT cygwin DOT com>
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Opening a (second) descriptor for (blocking) write sometimes fail

The provided test case sometimes succeed, but quite often fail with ENOENT
(in various indexes)

I haven't dug deeper to find the underlaying cause yet

Have anyone experienced this before ?

Kristian

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	name="fifo.cpp"
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#include <string.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>

int print_error(const int line, const int index, const int error)
{
   printf("%d\t%d\t%s\n", line, index, strerror(error));
   return error;
}

#define HANDLE_ERROR(result) do{if(result < 0){return =
print_error(__LINE__, idx, errno);}}while(0);

int main()
{
   const char *name =3D "/tmp/my_pipe";

   /* just in case it exists */
   remove(name);

   for (long idx =3D 0; idx < 1000; ++idx)
   {
      const int fifo =3D mkfifo(name, 0666) ? -1 : 0;
      HANDLE_ERROR(fifo);

      const int rfd =3D open(name, O_RDONLY | O_NONBLOCK);
      HANDLE_ERROR(rfd);

      const int wfd =3D open(name, O_WRONLY);
      HANDLE_ERROR(wfd);

      HANDLE_ERROR(close(wfd));
      HANDLE_ERROR(close(rfd));

      HANDLE_ERROR(unlink(name));
   }

   return 0;
}
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