Use of signal() should be avoided because the behavior of signal() varies
across Unix versions, and has also varied historically across different
versions of Linux.
This patch rewrites para_install_sighandler so that it calls sigaction()
instead of signal(). The implementation is taken from good old APUE.
There are a couple of other users of signal() in the paraslash code. Most
of which are OK because they use signal() only to ignore/reset a signal which
happens to be the only portable use of signal(). All other users of signal()
have to be converted in subsequent patches.
- * Wrapper around signal(2).
+ * Install the generic signal handler for the given signal number.
*
* \param sig The number of the signal to catch.
*
*
* \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.
*
* \return This function returns 1 on success and \p -E_SIGNAL_SIG_ERR on errors.
*
+ * \sa signal(2), sigaction(2).
*/
int para_install_sighandler(int sig)
{
*/
int para_install_sighandler(int sig)
{
+ struct sigaction act;
+
PARA_DEBUG_LOG("catching signal %d\n", sig);
PARA_DEBUG_LOG("catching signal %d\n", sig);
- return signal(sig, &generic_signal_handler) == SIG_ERR? -E_SIGNAL_SIG_ERR : 1;
+ act.sa_handler = &generic_signal_handler;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = 0;
+ if (sig == SIGALRM) {
+ #ifdef SA_INTERRUPT /* SunOS */
+ act.sa_flags |= SA_INTERRUPT;
+ #endif
+ } else {
+ #ifdef SA_RESTART /* BSD */
+ act.sa_flags |= SA_RESTART;
+ #endif
+ }
+ if (sigaction(sig, &act, NULL) < 0)
+ return -E_SIGNAL_SIG_ERR;
+ return 1;