X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=signal.c;h=0b7b47fa3d1401d57ae11ed107f487e9036a2870;hp=da395157c29ae8aff0459a2731e10ae7a13e90e6;hb=e5fbc490c2c16ecfa7bce58a18e11a0f7d382b91;hpb=a284d2903ef9a14f944eae3c14088a42701ca2cf

diff --git a/signal.c b/signal.c
index da395157..0b7b47fa 100644
--- a/signal.c
+++ b/signal.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2004-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2004-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -7,7 +7,6 @@
 
 #include <signal.h>
 #include <sys/types.h>
-#include <dirent.h>
 
 #include "para.h"
 #include "error.h"
@@ -149,29 +148,66 @@ void para_install_sighandler(int sig)
 }
 
 /**
- * Return the number of next pending signal.
+ * Block a signal for the caller.
  *
- * This should be called if the fd for the signal pipe is ready for reading.
+ * \param sig The signal to block.
  *
- * \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.
+ * This sets the given signal in the current signal mask of the calling process
+ * to prevent this signal from delivery.
+ *
+ * \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;
 }