Reid Spencer | b13cf98 | 2005-12-22 03:23:46 +0000 | [diff] [blame^] | 1 | //===-- Alarm.inc - Implement Unix Alarm Support --------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file was developed by the Reid Spencer and is distributed under the |
| 6 | // University of Illinois Open Source License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements the UNIX Alarm support. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include <signal.h> |
| 15 | #include <unistd.h> |
| 16 | #include <cassert> |
| 17 | using namespace llvm; |
| 18 | |
| 19 | /// AlarmCancelled - This flag is set by the SIGINT signal handler if the |
| 20 | /// user presses CTRL-C. |
| 21 | static volatile bool AlarmCancelled = false; |
| 22 | |
| 23 | /// AlarmTriggered - This flag is set by the SIGALRM signal handler if the |
| 24 | /// alarm was triggered. |
| 25 | static volatile bool AlarmTriggered = false; |
| 26 | |
| 27 | /// NestedSOI - Sanity check. Alarms cannot be nested or run in parallel. |
| 28 | /// This ensures that they never do. |
| 29 | static bool NestedSOI = false; |
| 30 | |
| 31 | static RETSIGTYPE SigIntHandler(int Sig) { |
| 32 | AlarmCancelled = true; |
| 33 | signal(SIGINT, SigIntHandler); |
| 34 | } |
| 35 | |
| 36 | static RETSIGTYPE SigAlarmHandler(int Sig) { |
| 37 | AlarmTriggered = true; |
| 38 | } |
| 39 | |
| 40 | static void (*OldSigIntHandler) (int); |
| 41 | |
| 42 | void sys::SetupAlarm(unsigned seconds) { |
| 43 | assert(!NestedSOI && "sys::SetupAlarm calls cannot be nested!"); |
| 44 | NestedSOI = true; |
| 45 | AlarmCancelled = false; |
| 46 | AlarmTriggered = false; |
| 47 | ::signal(SIGALRM, SigAlarmHandler); |
| 48 | OldSigIntHandler = ::signal(SIGINT, SigIntHandler); |
| 49 | ::alarm(seconds); |
| 50 | } |
| 51 | |
| 52 | void sys::TerminateAlarm() { |
| 53 | assert(NestedSOI && "sys::TerminateAlarm called without sys::SetupAlarm!"); |
| 54 | ::alarm(0); |
| 55 | ::signal(SIGALRM, SIG_DFL); |
| 56 | ::signal(SIGINT, OldSigIntHandler); |
| 57 | AlarmCancelled = false; |
| 58 | AlarmTriggered = false; |
| 59 | NestedSOI = false; |
| 60 | } |
| 61 | |
| 62 | int sys::AlarmStatus() { |
| 63 | if (AlarmCancelled) |
| 64 | return -1; |
| 65 | if (AlarmTriggered) |
| 66 | return 1; |
| 67 | return 0; |
| 68 | } |