Edit report at https://bugs.php.net/bug.php?id=55614&edit=1
ID: 55614
User updated by: i3367890 at gmail dot com
Reported by: i3367890 at gmail dot com
Summary: pcntl_signal() + fgetc() is not allowing me to break
with CTRL+C
Status: Open
Type: Bug
Package: PCNTL related
Operating System: (Arch) Linux
PHP Version: 5.3.8
Block user comment: N
Private report: N
New Comment:
I forgot to mention something!
In the first script pressing a key (any key) causes PHP to shut down properly.
Here's what it looks like:
My console | strace console
| (....)
| rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
| read(0, 0x8b825f8, 8192) = ? ERESTARTSYS (To be restarted)
^C ---------------^
| --- SIGINT (Interrupt) @ 0 (0) ---
I | sigreturn() = ? (mask now [])
pressed | read(0, "d", 8192) = 1
"d" -------------^
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
! --> | write(1, "X\n", 2) = 2
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], ~[KILL STOP RTMIN RT_1],
8) = 0
| rt_sigprocmask(SIG_SETMASK, ~[KILL STOP RTMIN RT_1], NULL, 8) = 0
| close(2) = 0
My console | strace console
| (....)
=======
NOTE:
=======
If fgetc(STDIN) does not return immediately after a single character - it
doesn't on my system, it waits for a newline - you might need to run "stty
cbreak". When you're done run "stty -cbreak" if you want to switch whatever
cbreak does back off, or just close the terminal.
i336
Previous Comments:
------------------------------------------------------------------------
[2011-09-06 03:15:08] i3367890 at gmail dot com
Description:
------------
Running the following code at the commandline as demonstrated simply does not
work for me. It gobbles up all presses of ^C and will not quit (^\ ie CTRL+\
produces SIGQUIT and is useful in this situation):
php -r "declare(ticks = 1); function quit() { print \"X\\n\"; die; }
pcntl_signal(SIGINT, \"quit\"); fgetc(STDIN);"
Running the following, on the other hand, works for me just fine.
php -r "declare(ticks = 1); function quit() { print \"X\\n\"; die; }
pcntl_signal(SIGINT, \"quit\"); while(1) { sleep(1); };"
Pressing ^C shuts the script down nicely.
I see no problems with the first code example. It should work, right? Here's
what
strace is saying:
My console | strace console
| (....)
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
| rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
| read(0, 0x943e5f4, 8192) = ? ERESTARTSYS (To be restarted)
| --- SIGINT (Interrupt) @ 0 (0) ---
| sigreturn() = ? (mask now [])
| read(0, 0x943e5f4, 8192) = ? ERESTARTSYS (To be restarted)
^C ---------------^
| --- SIGINT (Interrupt) @ 0 (0) ---
| sigreturn() = ? (mask now [])
| read(0, 0x943e5f4, 8192) = ? ERESTARTSYS (To be restarted)
^C ---------------^
| --- SIGINT (Interrupt) @ 0 (0) ---
| sigreturn() = ? (mask now [])
| read(0,
(waiting) ---------^
It gets even more interesting. Setting parameter 3 to pcntl_signal,
restart_signals, to false makes PHP gobble up one ^C *then* quit:
php -r "declare(ticks = 1); function quit() { print \"X\\n\"; die; }
pcntl_signal(SIGINT, \"quit\", 0); fgetc(STDIN);"
Like so:
My console | strace console
| (...)
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
| rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
| rt_sigaction(SIGINT, {0x82d8690, ~[RTMIN RT_1], SA_INTERRUPT},
{SIG_DFL, [], 0}, 8) = 0
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
| rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
| read(0, 0x9e985f8, 8192) = ? ERESTARTSYS (To be restarted)
^C --------------^
| --- SIGINT (Interrupt) @ 0 (0) ---
| sigreturn() = ? (mask now [])
| read(0, 0x9e985f8, 8192) = ? ERESTARTSYS (To be restarted)
^C --------------^
| --- SIGINT (Interrupt) @ 0 (0) ---
| sigreturn() = ? (mask now [])
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], [], 8) = 0
! --> | write(1, "X\n", 2) = 2
| rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1], ~[KILL STOP RTMIN RT_1],
8)
= 0
| rt_sigprocmask(SIG_SETMASK, ~[KILL STOP RTMIN RT_1], NULL, 8) = 0
| close(2) = 0
| close(1) = 0
| (...)
As you can see from my exclamation, *the custom quit function is WORKING* in
the
second example, just not straight away. PHP seems to be having indigestion with
the restart_syscalls bit...?
I wasn't sure what to put in what boxes since there were multiple scripts and
backtraces (if you could call them such) so I put them all here. Hope that's
okay.
i336
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=55614&edit=1
