X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FSTM.c;h=01155b1107acf49191f15cd6df3926271bee127f;hb=73566e25d75588185b0581722406da5c48965c51;hp=424796265aafbd4b585db031ae944c2f709e9944;hpb=a9e6c4411ab70eb2d16aba32c96ee963d86ebdae;p=ghc-hetmet.git

diff --git a/rts/STM.c b/rts/STM.c
index 4247962..01155b1 100644
--- a/rts/STM.c
+++ b/rts/STM.c
@@ -90,6 +90,7 @@
 #include "SMP.h"
 #include "STM.h"
 #include "Storage.h"
+#include "Trace.h"
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -113,16 +114,7 @@
 // If SHAKE is defined then validation will sometime spuriously fail.  They helps test
 // unusualy code paths if genuine contention is rare
 
-#if defined(DEBUG)
-#define SHAKE
-#if defined(THREADED_RTS)
-#define TRACE(_x...) IF_DEBUG(stm, debugBelch("STM  (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()); debugBelch ( _x ))
-#else
-#define TRACE(_x...) IF_DEBUG(stm, debugBelch ( _x ))
-#endif
-#else
-#define TRACE(_x...) /*Nothing*/
-#endif
+#define TRACE(_x...) debugTrace(DEBUG_stm, "STM: " _x)
 
 #ifdef SHAKE
 static const int do_shake = TRUE;
@@ -336,15 +328,21 @@ static void park_tso(StgTSO *tso) {
 }
 
 static void unpark_tso(Capability *cap, StgTSO *tso) {
-  // We will continue unparking threads while they remain on one of the wait
-  // queues: it's up to the thread itself to remove it from the wait queues
-  // if it decides to do so when it is scheduled.
-  if (tso -> why_blocked == BlockedOnSTM) {
-    TRACE("unpark_tso on tso=%p\n", tso);
-    unblockOne(cap,tso);
-  } else {
-    TRACE("spurious unpark_tso on tso=%p\n", tso);
-  }
+    // We will continue unparking threads while they remain on one of the wait
+    // queues: it's up to the thread itself to remove it from the wait queues
+    // if it decides to do so when it is scheduled.
+
+    // Unblocking a TSO from BlockedOnSTM is done under the TSO lock,
+    // to avoid multiple CPUs unblocking the same TSO, and also to
+    // synchronise with throwTo().
+    lockTSO(tso);
+    if (tso -> why_blocked == BlockedOnSTM) {
+	TRACE("unpark_tso on tso=%p\n", tso);
+	unblockOne(cap,tso);
+    } else {
+	TRACE("spurious unpark_tso on tso=%p\n", tso);
+    }
+    unlockTSO(tso);
 }
 
 static void unpark_waiters_on(Capability *cap, StgTVar *s) {