From 7b2ff4cc95ce49081d84c25184aec796377fbc35 Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Thu, 9 Feb 2006 12:30:56 +0000 Subject: [PATCH] improvement to the deadlock detection When the RTS is idle, as detected by the timer signal, instead of prodding capabilities from the signal handler (which is not guaranteed to work - pthread_cond_signal() can't be called from signal handlers), create a new thread to do it. --- ghc/rts/Timer.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/ghc/rts/Timer.c b/ghc/rts/Timer.c index b6414f8..425ada5 100644 --- a/ghc/rts/Timer.c +++ b/ghc/rts/Timer.c @@ -21,6 +21,7 @@ #include "Timer.h" #include "Ticker.h" #include "Capability.h" +#include "OSThreads.h" /* ticks left before next pre-emptive context switch */ static int ticks_to_ctxt_switch = 0; @@ -30,6 +31,10 @@ static int ticks_to_ctxt_switch = 0; static int ticks_to_gc = 0; #endif +#if defined(THREADED_RTS) +static void OSThreadProcAttr proddingThread(void *p); +#endif + /* * Function: handle_tick() * @@ -60,7 +65,8 @@ handle_tick(int unused STG_UNUSED) recent_activity = ACTIVITY_MAYBE_NO; ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTicks; break; - case ACTIVITY_MAYBE_NO: + case ACTIVITY_MAYBE_NO: { + OSThreadId id; if (ticks_to_gc == 0) break; /* 0 ==> no idle GC */ ticks_to_gc--; if (ticks_to_gc == 0) { @@ -69,14 +75,15 @@ handle_tick(int unused STG_UNUSED) blackholes_need_checking = rtsTrue; /* hack: re-use the blackholes_need_checking flag */ - /* ToDo: this doesn't work. Can't invoke - * pthread_cond_signal from a signal handler. - * Furthermore, we can't prod a capability that we - * might be holding. What can we do? + /* We can't prod the Capability from inside the + * signal handler, because pthread_cond_signal() + * doesn't work from signal handlers. Let's hope + * that pthread_create() works: */ - prodOneCapability(); + createOSThread(&id, proddingThread, NULL); } break; + } default: break; } @@ -85,6 +92,15 @@ handle_tick(int unused STG_UNUSED) } } +#if defined(THREADED_RTS) +static void OSThreadProcAttr +proddingThread(void *p STG_UNUSED) +{ + prodOneCapability(); + // and exit again. +} +#endif + int startTimer(nat ms) { -- 1.7.10.4