X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=signal.c;h=9168e918205a5f6733761db31ea7fc6573b2bbae;hp=33449c632f5214e5acd464faeeae079b0701f0d5;hb=dded41e5bed40cca8876e1056351cc1dbab309d0;hpb=7a3352c3c6969a3019fd4adb3a957c711441160e diff --git a/signal.c b/signal.c index 33449c63..9168e918 100644 --- a/signal.c +++ b/signal.c @@ -1,9 +1,9 @@ /* - * Copyright (C) 2004-2006 Andre Noll + * Copyright (C) 2004-2008 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file signal.c signal handling functions */ +/** \file signal.c Signal handling functions. */ #include #include @@ -40,15 +40,15 @@ int para_signal_init(void) ret = -ERRNO_TO_PARA_ERROR(errno); goto err_out; } - ret = mark_fd_nonblock(signal_pipe[0]); + ret = mark_fd_nonblocking(signal_pipe[0]); if (ret < 0) goto err_out; - ret = mark_fd_nonblock(signal_pipe[1]); + ret = mark_fd_nonblocking(signal_pipe[1]); if (ret < 0) goto err_out; return signal_pipe[0]; err_out: - PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret)); + PARA_EMERG_LOG("%s\n", para_strerror(-ret)); exit(EXIT_FAILURE); } @@ -57,8 +57,15 @@ err_out: */ static void generic_signal_handler(int s) { - write(signal_pipe[1], &s, sizeof(int)); - //fprintf(stderr, "got sig %i, write returned %d\n", s, ret); + ssize_t ret = write(signal_pipe[1], &s, sizeof(int)); + + if (ret == sizeof(int)) + return; + if (ret < 0) + PARA_EMERG_LOG("%s\n", strerror(errno)); + else + PARA_EMERG_LOG("short write to signal pipe\n"); + exit(EXIT_FAILURE); } /** @@ -73,7 +80,7 @@ static void generic_signal_handler(int s) * one otherwise. If and only if the function returns one, the content of \a * pid is meaningful. * - * \sa waitpid(2) + * \sa waitpid(2). */ int para_reap_child(pid_t *pid) { @@ -85,13 +92,13 @@ int para_reap_child(pid_t *pid) if (*pid < 0) return -ERRNO_TO_PARA_ERROR(errno); if (WIFEXITED(status)) - PARA_DEBUG_LOG("child %i exited. Exit status: %i\n", *pid, + PARA_DEBUG_LOG("child %i exited. Exit status: %i\n", (int)*pid, WEXITSTATUS(status)); else if (WIFSIGNALED(status)) - PARA_DEBUG_LOG("child %i was killed by signal %i\n", *pid, + PARA_DEBUG_LOG("child %i was killed by signal %i\n", (int)*pid, WTERMSIG(status)); else - PARA_WARNING_LOG("child %i terminated abormally\n", *pid); + PARA_WARNING_LOG("child %i terminated abormally\n", (int)*pid); return 1; } @@ -110,12 +117,15 @@ void para_reap_children(void) } /** - * wrapper around signal(2) - * \param sig the number of the signal to catch + * Wrapper around signal(2). + * + * \param sig The number of the signal to catch. * * This installs the generic signal handler for the given signal. + * * \return This function returns 1 on success and \p -E_SIGNAL_SIG_ERR on errors. - * \sa signal(2) + * + * \sa signal(2). */ int para_install_sighandler(int sig) { @@ -124,26 +134,36 @@ int para_install_sighandler(int sig) } /** - * return number of next pending signal + * Return the number of next pending signal. * * This should be called if the fd for the signal pipe is ready for reading. * - * \return On success, the number of the received signal is returned. \p - * -E_SIGNAL_READ is returned if a read error occurred while reading the signal - * pipe. If the read was interrupted by another signal the function returns 0. + * \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. */ int para_next_signal(void) { int s; - ssize_t r; + ssize_t r = read(signal_pipe[0], &s, sizeof(s)); - if ((r = read(signal_pipe[0], &s, sizeof(s)) == sizeof(s)) > 0) { - PARA_DEBUG_LOG("next signal: %d\n", s); - return s; + 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); } - return r < 0 && (errno != EAGAIN)? 0 : -E_SIGNAL_READ; + assert(r == sizeof(s)); + PARA_DEBUG_LOG("next signal: %d\n", s); + return s; } +/** + * Close the write end of the signal pipe. + */ void para_signal_shutdown(void) { close(signal_pipe[1]);