Bug #68382 for TermReadKey: [perl #90788] Term::ReadKey broken by signal(s)

> > This is a bug report for perl from perl-diddler@tlinx.org, > generated with the help of perlbug 1.36 running under perl 5.10.0. > > > ----------------------------------------------------------------- > [Please enter your report here] > > I was using sleep in a program that displays output periodically. > I setup a SIGWINCH handler to get new term size parameters if the > window was resized. > > Then I wanted to add the ability to press keys during the wait > to alter program behavior, and was directed to 'Term::ReadKey' by > 'perlfaq8'. Reading its documentation, showed that it could take > a single parameter to use as a timeout -- allowing it to return > after a keypress OR the timeout. This, however, only works > apart from the SIGWINCH handler. > > Most system calls will return immediately if interupted by a signal, > though some are restartable. Sleep and read calls usually return > immediately. > > However, Term::ReadKey does neither. If interrupted by a SIGWINCH, > it loses it's 'timeout' and waits forever for a key to be pressed. > > Ideally, it would behave like other read calls and return immediately. > > However, if that's not possible, I believe it would be > technically correct behavior if it returned at the end > of the the timeout period (in which case the call wouldn't be useful > to me -- and I'd have to find another solution: likely writing my own > using 'select'. > > The following program demonstrates the problem (or shows a non- > interactive, > working version using sleep, based on a var setting). > --------------- > > #!/usr/bin/perl -w > use strict; > > #select STDERR; $|=1; > select STDOUT; $|=1; # pipin' hot output... > > use Readonly; sub RO(\[$@%]@) {goto &Readonly}; > use POSIX qw{sigaction}; > > RO my $SIGWINCH => 28; > > my $need_winsize_update = 0; > > sub update_winsize { # update winsize info...and reset flag > $need_winsize_update=0; > } > > my $handler = sub { print "SIGWINCH\n";$need_winsize_update = 1 }; > > sigaction($SIGWINCH, POSIX::SigAction->new( $handler )); > > > # set to 0 uses sleep & SIGWINCH handler works > # set to 1 uses readkey & prog "hangs", (forever), waiting for a key > > # would expect an interrupt to either > # 1) cause an immediate return, (consistent with system read call) > # or (less desirable behavior) > # 2) return when the original wait_time expires > # > > my $use_readkey = 1; > > sub timed_wait ($) { > my $wait_time = $_[0]; > if ($use_readkey) { > use Term::ReadKey; > print "Enter Readkey ($wait_time)..."; > ReadMode 3; > my $char = ReadKey $wait_time; > ReadMode 0; > print "Exit Readkey.\n"; > } else { > print "Enter sleep ($wait_time)..."; > sleep $wait_time; > print "Exit sleep.\n"; > } > } > > > while (1) { > timed_wait 3; > if ($need_winsize_update) { > print "Need Winsize_update!"; > update_winsize(); > } > } > > # vim: ts=2 sw=2 > > --------------- > > > [Please do not change anything below this line] > ----------------------------------------------------------------- > --- > Flags: > category=library > severity=medium > --- > This perlbug was built using Perl 5.10.0 - Fri Jul 30 00:12:10 UTC > 2010 > It is being executed now by Perl 5.10.0 - Thu Sep 16 16:14:28 UTC > 2010. > > Site configuration information for perl 5.10.0: > > Configured by abuild at Thu Sep 16 16:14:28 UTC 2010. > > Summary of my perl5 (revision 5 version 10 subversion 0) > configuration: > Platform: > osname=linux, osvers=2.6.31, archname=x86_64-linux-thread-multi > uname='linux build35 2.6.31 #1 smp 2010-01-06 16:07:25 +0100 > x86_64 x86_64 x86_64 gnulinux ' > config_args='-ds -e -Dprefix=/usr -Dvendorprefix=/usr > -Dinstallusrbinperl -Dusethreads -Di_db -Di_dbm -Di_ndbm -Di_gdbm > -Duseshrplib=true -DEBUGGING=both -Doptimize=-fmessage-length=0 -O2 > -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables > -fasynchronous-unwind-tables -Wall -pipe > -Accflags=-DPERL_USE_SAFE_PUTENV' > hint=recommended, useposix=true, d_sigaction=define > useithreads=define, usemultiplicity=define > useperlio=define, d_sfio=undef, uselargefiles=define, > usesocks=undef > use64bitint=define, use64bitall=define, uselongdouble=undef > usemymalloc=n, bincompat5005=undef > Compiler: > cc='cc', ccflags ='-D_REENTRANT -D_GNU_SOURCE > -DPERL_USE_SAFE_PUTENV -DDEBUGGING -fno-strict-aliasing -pipe > -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64', > optimize='-fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 > -fstack-protector -funwind-tables -fasynchronous-unwind-tables > -Wall -pipe -g', > cppflags='-D_REENTRANT -D_GNU_SOURCE -DPERL_USE_SAFE_PUTENV > -DDEBUGGING -fno-strict-aliasing -pipe' > ccversion='', gccversion='4.4.1 [gcc-4_4-branch revision 150839]', > gccosandvers='' > intsize=4, longsize=8, ptrsize=8, doublesize=8, byteorder=12345678 > d_longlong=define, longlongsize=8, d_longdbl=define, > longdblsize=16 > ivtype='long', ivsize=8, nvtype='double', nvsize=8, Off_t='off_t', > lseeksize=8 > alignbytes=8, prototype=define > Linker and Libraries: > ld='cc', ldflags =' -L/usr/local/lib64' > libpth=/lib64 /usr/lib64 /usr/local/lib64 > libs=-lm -ldl -lcrypt -lpthread > perllibs=-lm -ldl -lcrypt -lpthread > libc=/lib64/libc-2.10.1.so, so=so, useshrplib=true, > libperl=libperl.so > gnulibc_version='2.10.1' > Dynamic Linking: > dlsrc=dl_dlopen.xs, dlext=so, d_dlsymun=undef, ccdlflags='-Wl,-E > -Wl,-rpath,/usr/lib/perl5/5.10.0/x86_64-linux-thread-multi/CORE' > cccdlflags='-fPIC', lddlflags='-shared -L/usr/local/lib64' > > Locally applied patches: > > > --- > @INC for perl 5.10.0: > /usr/lib/perl5/5.10.0/x86_64-linux-thread-multi > /usr/lib/perl5/5.10.0 > /usr/lib/perl5/site_perl/5.10.0/x86_64-linux-thread-multi > /usr/lib/perl5/site_perl/5.10.0 > /usr/lib/perl5/vendor_perl/5.10.0/x86_64-linux-thread-multi > /usr/lib/perl5/vendor_perl/5.10.0 > /usr/lib/perl5/vendor_perl > . > > --- > Environment for perl 5.10.0: > HOME=/home/law > LANG=en_US.UTF-8 > LANGUAGE (unset) > LC_CTYPE=en_US.UTF-8 > LD_LIBRARY_PATH=/usr/lib64/mpi/gcc/openmpi/lib64 > LOGDIR (unset) >

> PERL_BADLANG (unset) > SHELL=/bin/bash