X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=signal.c;h=0b7b47fa3d1401d57ae11ed107f487e9036a2870;hp=59a0d45aba7ad975fc287862308891435c4e9095;hb=d4b040af5e31260dbf71f4547484179f32be4746;hpb=3781a3df94ce9bb28c98369df7a140fb4c086c23;ds=sidebyside diff --git a/signal.c b/signal.c index 59a0d45a..0b7b47fa 100644 --- a/signal.c +++ b/signal.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2004-2009 Andre Noll + * Copyright (C) 2004-2012 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -7,7 +7,6 @@ #include #include -#include #include "para.h" #include "error.h" @@ -102,20 +101,6 @@ int para_reap_child(pid_t *pid) return 1; } -/** - * Paraslash's zombie killer. - * - * It just calls \p para_reap_child() until there are no more children left to - * reap. - */ -void para_reap_children(void) -{ - pid_t pid; - - while (para_reap_child(&pid) > 0) - ; /* nothing */ -} - /** * Install the given handler for the given signal. * @@ -163,29 +148,66 @@ void para_install_sighandler(int sig) } /** - * Return the number of next pending signal. + * Block a signal for the caller. + * + * \param sig The signal to block. * - * This should be called if the fd for the signal pipe is ready for reading. + * This sets the given signal in the current signal mask of the calling process + * to prevent this signal from delivery. * - * \return On success, the number of the received signal is returned. If the - * read returned zero or was interrupted by another signal the function returns - * 0. Otherwise, a negative error value is returned. + * \sa \ref para_unblock_signal(), sigprocmask(2), sigaddset(3). */ -int para_next_signal(void) +void para_block_signal(int sig) { - int s; - ssize_t r = read(signal_pipe[0], &s, sizeof(s)); + sigset_t set; - if (!r) { - PARA_CRIT_LOG("read from signal pipe returned zero\n"); - return 0; - } - if (r < 0) { - if (errno == EAGAIN || errno == EINTR) - return 0; - return -ERRNO_TO_PARA_ERROR(errno); + PARA_DEBUG_LOG("blocking signal %d\n", sig); + sigemptyset(&set); + sigaddset(&set, sig); + sigprocmask(SIG_BLOCK, &set, NULL); +} + +/** + * Unblock a signal. + * + * \param sig The signal to unblock. + * + * This function removes the given signal from the current set of blocked + * signals. + * + * \sa \ref para_block_signal(), sigprocmask(2), sigaddset(3). + */ +void para_unblock_signal(int sig) +{ + sigset_t set; + + PARA_DEBUG_LOG("unblocking signal %d\n", sig); + sigemptyset(&set); + sigaddset(&set, sig); + sigprocmask(SIG_UNBLOCK, &set, NULL); +} + +/** + * Return the number of the next pending signal. + * + * \param rfds The fd_set containing the signal pipe. + * + * \return On success, the number of the received signal is returned. If there + * is no signal currently pending, the function returns zero. On read errors + * from the signal pipe, the process is terminated. + */ +int para_next_signal(fd_set *rfds) +{ + size_t n; + int s, ret = read_nonblock(signal_pipe[0], &s, sizeof(s), rfds, &n); + + if (ret < 0) { + PARA_EMERG_LOG("%s\n", para_strerror(-ret)); + exit(EXIT_FAILURE); } - assert(r == sizeof(s)); + if (n == 0) + return 0; + assert(n == sizeof(s)); PARA_DEBUG_LOG("next signal: %d\n", s); return s; }