sal: fix watch/breakpoint perf implementation

This commit changes the entities in a ResultSet from listener indexes
(into ListenerManagers m_BufferList) to BaseListener pointers, as
ListenerManager::makeActive(BaseListener*) (called from
FastBreakpoints/Watchpoints.ah) may invalidate indexes temporarily
stored in a ResultSet.  The issue occurs when multiple breakpoints
(watchpoints) fire at the same time, and one added more recently than
the others occupies the largest index position in m_BufferList.

Although this issue is extremely rare and was only observed in a few
corner cases up to now, it may have falsified results in the past.

Change-Id: I7b788a06d412f15700ca75f56f2be5d3b78465fa

src/core/sal/perf/BreakpointBuffer.cc

@@ -16,7 +16,7 @@ ResultSet& PerfVectorBreakpoints::gather(BPEvent* pData)
 			// Update trigger IPtr:
 			pLi->setTriggerInstructionPointer(pData->getTriggerInstructionPointer());
 			pLi->setTriggerCPU(pData->getTriggerCPU());
-			res.add(*it);
+			res.add(pLi);
 		}
 	}
 	return res;

src/core/sal/perf/BufferInterface.hpp

@@ -44,14 +44,15 @@ public:
  * Results (= indices of matching listeners) returned by the "gather"-method,
  * see below. (This class can be seen as a "temporary fire-list".)
  */
+class BaseListener;
 class ResultSet {
 private:
-	std::vector<index_t> m_Res; //!< vector of matching listener indices
+	std::vector<BaseListener *> m_Res; //!< vector of pointers to matching listeners
 public:
 	ResultSet() { }
 	bool hasMore() const { return !m_Res.empty(); }
-	index_t getNext() { index_t idx = m_Res.back(); m_Res.pop_back(); return idx; }
-	void add(index_t idx) { m_Res.push_back(idx); }
+	BaseListener *getNext() { BaseListener *l = m_Res.back(); m_Res.pop_back(); return l; }
+	void add(BaseListener *l) { m_Res.push_back(l); }
 	size_t size() const { return m_Res.size(); }
 	void clear() { m_Res.clear(); }
 };

src/core/sal/perf/FastBreakpoints.ah

@@ -65,12 +65,12 @@ aspect FastBreakpoints {
 		// Check for matching BPSingleListeners:
 		fail::ResultSet& res1 = ref.getSingleListeners().gather(&tmp);
 		while (res1.hasMore())
-			ref.makeActive(ref.dereference(res1.getNext()));
+			ref.makeActive(res1.getNext());
 
 		// Check for matching BPRangeListeners:
 		fail::ResultSet& res2 = ref.getRangeListeners().gather(&tmp);
 		while (res2.hasMore())
-			ref.makeActive(ref.dereference(res2.getNext()));
+			ref.makeActive(res2.getNext());
 
 		ref.triggerActiveListeners();
 	}

src/core/sal/perf/FastWatchpoints.ah

@@ -64,7 +64,7 @@ aspect FastWatchpoints {
 		// Check for matching MemAccessListener:
 		fail::ResultSet& res = ref.getMemoryListeners().gather(&tmp);
 		while (res.hasMore())
-			ref.makeActive(ref.dereference(res.getNext()));
+			ref.makeActive(res.getNext());
 
 		ref.triggerActiveListeners();
 	}

src/core/sal/perf/WatchpointBuffer.cc

@@ -20,7 +20,7 @@ ResultSet& PerfVectorWatchpoints::gather(MemAccessEvent* pData)
 			pmal->setTriggerWidth(pData->getTriggerWidth());
 			pmal->setTriggerAccessType(pData->getTriggerAccessType());
 			pmal->setTriggerCPU(pData->getTriggerCPU());
-			res.add(*it);
+			res.add(pmal);
 		}
 	}
 	return res;