From 1c48b5a62f73234ed26bb20f0ab345ab61cda0ab Mon Sep 17 00:00:00 2001 From: Stephen Gallagher Date: Thu, 18 Feb 2010 07:49:04 -0500 Subject: Rename server/ directory to src/ Also update BUILD.txt --- src/util/signal.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 src/util/signal.c (limited to 'src/util/signal.c') diff --git a/src/util/signal.c b/src/util/signal.c new file mode 100644 index 0000000..e4a782d --- /dev/null +++ b/src/util/signal.c @@ -0,0 +1,146 @@ +/* + Unix SMB/CIFS implementation. + signal handling functions + + Copyright (C) Andrew Tridgell 1998 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . +*/ + +#include "util/util.h" +#include +#include + + +/** + * @file + * @brief Signal handling + */ + +/**************************************************************************** + Catch child exits and reap the child zombie status. +****************************************************************************/ + +static void sig_cld(int signum) +{ + while (waitpid((pid_t)-1,(int *)NULL, WNOHANG) > 0) + ; + + /* + * Turns out it's *really* important not to + * restore the signal handler here if we have real POSIX + * signal handling. If we do, then we get the signal re-delivered + * immediately - hey presto - instant loop ! JRA. + */ + +#if !defined(HAVE_SIGACTION) + CatchSignal(SIGCLD, sig_cld); +#endif +} + +/**************************************************************************** +catch child exits - leave status; +****************************************************************************/ + +static void sig_cld_leave_status(int signum) +{ + /* + * Turns out it's *really* important not to + * restore the signal handler here if we have real POSIX + * signal handling. If we do, then we get the signal re-delivered + * immediately - hey presto - instant loop ! JRA. + */ + +#if !defined(HAVE_SIGACTION) + CatchSignal(SIGCLD, sig_cld_leave_status); +#endif +} + +/** + Block sigs. +**/ + +void BlockSignals(bool block, int signum) +{ +#ifdef HAVE_SIGPROCMASK + sigset_t set; + sigemptyset(&set); + sigaddset(&set,signum); + sigprocmask(block?SIG_BLOCK:SIG_UNBLOCK,&set,NULL); +#elif defined(HAVE_SIGBLOCK) + if (block) { + sigblock(sigmask(signum)); + } else { + sigsetmask(siggetmask() & ~sigmask(signum)); + } +#else + /* yikes! This platform can't block signals? */ + static int done; + if (!done) { + DEBUG(0,("WARNING: No signal blocking available\n")); + done=1; + } +#endif +} + +/** + Catch a signal. This should implement the following semantics: + + 1) The handler remains installed after being called. + 2) The signal should be blocked during handler execution. +**/ + +void (*CatchSignal(int signum,void (*handler)(int )))(int) +{ +#ifdef HAVE_SIGACTION + struct sigaction act; + struct sigaction oldact; + + ZERO_STRUCT(act); + + act.sa_handler = handler; +#ifdef SA_RESTART + /* + * We *want* SIGALRM to interrupt a system call. + */ + if(signum != SIGALRM) + act.sa_flags = SA_RESTART; +#endif + sigemptyset(&act.sa_mask); + sigaddset(&act.sa_mask,signum); + sigaction(signum,&act,&oldact); + return oldact.sa_handler; +#else /* !HAVE_SIGACTION */ + /* FIXME: need to handle sigvec and systems with broken signal() */ + return signal(signum, handler); +#endif +} + +/** + Ignore SIGCLD via whatever means is necessary for this OS. +**/ + +void CatchChild(void) +{ + CatchSignal(SIGCLD, sig_cld); +} + +/** + Catch SIGCLD but leave the child around so it's status can be reaped. +**/ + +void CatchChildLeaveStatus(void) +{ + CatchSignal(SIGCLD, sig_cld_leave_status); +} -- cgit