On 5/31/2016 5:41 AM, Corinna Vinschen wrote:
Any chance you could bisect Cygwin to help finding the culprit?
The culprit is
commit 252a07b0ad3353abcd0fcd9b1b65ff977acd679e
Author: Takashi Yano <takashi.y...@nifty.ne.jp>
Date: Fri Apr 3 13:07:35 2015 +0900
Cygwin hangs up if several keys are typed during outputting a lot of texts.
* fhandler_tty.cc (fhandler_pty_slave::read): Change calculation of
"readlen" not to use "bytes_in_pipe" value directly.
Reverting that commit fixes the problem. To test, compile and run the attached
file.
$ gcc gdbstc.cc
$ ./a
1-inferior-tty-set /dev/pty3
2-gdb-set height 0
3-gdb-set non-stop 1
4-file-list-exec-source-files
5-file-list-exec-source-file
6-gdb-show prompt
7-stack-info-frame
8-thread-info
9-break-list
q
*** using gdb
=thread-group-added,id="i1"
~"GNU gdb (GDB) (Cygwin 7.10.1-1) 7.10.1\n"
~"Copyright (C) 2015 Free Software Foundation, Inc.\n"
~"License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>\nThis is free software:
you are free to change and redistribute it.\nThere is NO WARRANTY, to the extent permitted by law. Type
\"show copying\"\nand \"show warranty\" for details.\n"
~"This GDB was configured as \"i686-pc-cygwin\".\nType \"show configuration\" for
configuration details."
~"\nFor bug reporting instructions, please see:\n"
~"<http://www.gnu.org/software/gdb/bugs/>.\n"
~"Find the GDB manual and other documentation resources online
at:\n<http://www.gnu.org/software/gdb/documentation/>.\n"
~"For help, type \"help\".\n"
~"Type \"apropos word\" to search for commands related to \"word\".\n"
=cmd-param-changed,param="auto-load safe-path",value="/"
(gdb)
...
In bad cases (bug present), the program hangs and doesn't complete until the
gdb process is killed from a different terminal. In good cases it runs to
completion.
Ken
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pty.h>
#include <string.h>
#include <sys/wait.h>
void get_output (int fd);
int
main (int argc, const char **argv)
{
int master;
pid_t pid;
if ((pid = forkpty (&master, NULL, NULL, NULL)) < 0)
{
perror ("forkpty");
exit (1);
}
/* child */
if (pid == 0)
{
const char *av[100];
// putenv ("HOME=/tmp");
int i = 0;
#ifdef STRACE_GDB
av[i++] = "strace";
av[i++] = "-o";
av[i++] = "/tmp/strace.out";
#ifdef __CYGWIN__
av[i++] = "--mask=all+paranoid";
#endif
#endif
av[i++] = argv[1] ?: "gdb";
fprintf (stderr, "*** using %s\n", av[0]);
av[i++] = "-i=mi";
av[i] = NULL;
execvp (av[0], (char * const *) av);
/* shouldn't get here */
exit (1);
}
/* parent */
const char *input[20];
int i = 0;
input[i++] = "1-inferior-tty-set /dev/pty3\n";
input[i++] = "2-gdb-set height 0\n";
input[i++] = "3-gdb-set non-stop 1\n";
input[i++] = "4-file-list-exec-source-files\n";
input[i++] = "5-file-list-exec-source-file\n";
input[i++] = "6-gdb-show prompt\n";
input[i++] = "7-stack-info-frame\n";
input[i++] = "8-thread-info\n";
input[i++] = "9-break-list\n";
input[i++] = "q\n";
input[i] = NULL;
for (int i = 0; input[i]; ++i)
{
write (master, input[i], strlen (input[i]));
// sleep (1);
}
get_output (master);
wait (NULL);
}
void
get_output (int fd)
{
char buf[4096];
while (1)
{
int nread = read (fd, buf, sizeof (buf));
if (nread > 0)
write (STDOUT_FILENO, buf, nread);
else
{
printf ("No more output. nread %d\n", nread);
break;
}
}
}
--
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