Reorganisation of the source tree

Most of the other users of the fptools build system have migrated to
Cabal, and with the move to darcs we can now flatten the source tree
without losing history, so here goes.

The main change is that the ghc/ subdir is gone, and most of what it
contained is now at the top level.  The build system now makes no
pretense at being multi-project, it is just the GHC build system.

No doubt this will break many things, and there will be a period of
instability while we fix the dependencies.  A straightforward build
should work, but I haven't yet fixed binary/source distributions.
Changes to the Building Guide will follow, too.

1 files changed, 102 insertions, 0 deletions

diff --git a/rts/Timer.c b/rts/Timer.c
new file mode 100644
index 0000000000..0bfea2d6fd
--- /dev/null
+++ b/rts/Timer.c
@@ -0,0 +1,102 @@
+/* -----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1995-2005
+ *
+ * Interval timer service for profiling and pre-emptive scheduling.
+ *
+ * ---------------------------------------------------------------------------*/
+
+/*
+ * The interval timer is used for profiling and for context switching in the
+ * threaded build. 
+ *
+ * This file defines the platform-independent view of interval timing, relying
+ * on platform-specific services to install and run the timers.
+ *
+ */
+#include "Rts.h"
+#include "RtsFlags.h"
+#include "Proftimer.h"
+#include "Schedule.h"
+#include "Timer.h"
+#include "Ticker.h"
+#include "Capability.h"
+
+/* ticks left before next pre-emptive context switch */
+static int ticks_to_ctxt_switch = 0;
+
+#if defined(THREADED_RTS)
+/* idle ticks left before we perform a GC */
+static int ticks_to_gc = 0;
+#endif
+
+/*
+ * Function: handle_tick()
+ *
+ * At each occurrence of a tick, the OS timer will invoke
+ * handle_tick().
+ */
+static
+void
+handle_tick(int unused STG_UNUSED)
+{
+#ifdef PROFILING
+  handleProfTick();
+#endif
+  if (RtsFlags.ConcFlags.ctxtSwitchTicks > 0) {
+      ticks_to_ctxt_switch--;
+      if (ticks_to_ctxt_switch <= 0) {
+	  ticks_to_ctxt_switch = RtsFlags.ConcFlags.ctxtSwitchTicks;
+	  context_switch = 1;	/* schedule a context switch */
+      }
+  }
+
+#if defined(THREADED_RTS)
+  /* 
+   * If we've been inactive for idleGCDelayTicks (set by +RTS
+   * -I), tell the scheduler to wake up and do a GC, to check
+   * for threads that are deadlocked.
+   */
+  switch (recent_activity) {
+  case ACTIVITY_YES:
+      recent_activity = ACTIVITY_MAYBE_NO;
+      ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTicks;
+      break;
+  case ACTIVITY_MAYBE_NO:
+      if (ticks_to_gc == 0) break; /* 0 ==> no idle GC */
+      ticks_to_gc--;
+      if (ticks_to_gc == 0) {
+	  ticks_to_gc = RtsFlags.GcFlags.idleGCDelayTicks;
+	  recent_activity = ACTIVITY_INACTIVE;
+	  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?
+	   */
+	  prodOneCapability();
+      }
+      break;
+  default:
+      break;
+  }
+#endif
+}
+
+int
+startTimer(nat ms)
+{
+#ifdef PROFILING
+  initProfTimer();
+#endif
+
+  return startTicker(ms, handle_tick);
+}
+
+int
+stopTimer()
+{
+  return stopTicker();
+}