+//===-- Alarm.inc - Implement Unix Alarm Support --------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the Reid Spencer and is distributed under the
+// University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the UNIX Alarm support.
+//
+//===----------------------------------------------------------------------===//
+
+#include <signal.h>
+#include <unistd.h>
+#include <cassert>
+using namespace llvm;
+
+/// AlarmCancelled - This flag is set by the SIGINT signal handler if the
+/// user presses CTRL-C.
+static volatile bool AlarmCancelled = false;
+
+/// AlarmTriggered - This flag is set by the SIGALRM signal handler if the
+/// alarm was triggered.
+static volatile bool AlarmTriggered = false;
+
+/// NestedSOI - Sanity check. Alarms cannot be nested or run in parallel.
+/// This ensures that they never do.
+static bool NestedSOI = false;
+
+static RETSIGTYPE SigIntHandler(int Sig) {
+ AlarmCancelled = true;
+ signal(SIGINT, SigIntHandler);
+}
+
+static RETSIGTYPE SigAlarmHandler(int Sig) {
+ AlarmTriggered = true;
+}
+
+static void (*OldSigIntHandler) (int);
+
+void sys::SetupAlarm(unsigned seconds) {
+ assert(!NestedSOI && "sys::SetupAlarm calls cannot be nested!");
+ NestedSOI = true;
+ AlarmCancelled = false;
+ AlarmTriggered = false;
+ ::signal(SIGALRM, SigAlarmHandler);
+ OldSigIntHandler = ::signal(SIGINT, SigIntHandler);
+ ::alarm(seconds);
+}
+
+void sys::TerminateAlarm() {
+ assert(NestedSOI && "sys::TerminateAlarm called without sys::SetupAlarm!");
+ ::alarm(0);
+ ::signal(SIGALRM, SIG_DFL);
+ ::signal(SIGINT, OldSigIntHandler);
+ AlarmCancelled = false;
+ AlarmTriggered = false;
+ NestedSOI = false;
+}
+
+int sys::AlarmStatus() {
+ if (AlarmCancelled)
+ return -1;
+ if (AlarmTriggered)
+ return 1;
+ return 0;
+}