Backed out changeset 4887ddabba31 (bug 939231) for mochitest hangs.

CLOSED TREE

xpcom/glue/BlockingResourceBase.cpp

@@ -39,7 +39,7 @@ BlockingResourceBase::DeadlockDetectorEntry::Print(
     bool aPrintFirstSeenCx) const
 {
     CallStack lastAcquisition = mAcquisitionContext; // RACY, but benign
-    bool maybeCurrentlyAcquired = !lastAcquisition.IsEmpty();
+    bool maybeCurrentlyAcquired = (CallStack::kNone != lastAcquisition);
     CallStack printAcquisition =
         (aPrintFirstSeenCx || !maybeCurrentlyAcquired) ?
             aFirstSeen.mCallContext : lastAcquisition;
@@ -134,7 +134,7 @@ BlockingResourceBase::Acquire(const CallStack& aCallContext)
             "FIXME bug 456272: annots. to allow Acquire()ing condvars");
         return;
     }
-    NS_ASSERTION(mDDEntry->mAcquisitionContext.IsEmpty(),
+    NS_ASSERTION(mDDEntry->mAcquisitionContext == CallStack::kNone,
                  "reacquiring already acquired resource");
 
     ResourceChainAppend(ResourceChainFront());
@@ -152,7 +152,8 @@ BlockingResourceBase::Release()
     }
       
     BlockingResourceBase* chainFront = ResourceChainFront();
-    NS_ASSERTION(chainFront && !mDDEntry->mAcquisitionContext.IsEmpty(),
+    NS_ASSERTION(chainFront
+                 && CallStack::kNone != mDDEntry->mAcquisitionContext,
                  "Release()ing something that hasn't been Acquire()ed");
 
     if (chainFront == this) {
@@ -177,7 +178,7 @@ BlockingResourceBase::Release()
             curr->mChainPrev = prev->mChainPrev;
     }
 
-    mDDEntry->mAcquisitionContext = CallStack::NullCallStack();
+    mDDEntry->mAcquisitionContext = CallStack::kNone;
 }
 
 
@@ -300,7 +301,7 @@ ReentrantMonitor::Wait(PRIntervalTime interval)
     CallStack savedAcquisitionContext = GetAcquisitionContext();
     BlockingResourceBase* savedChainPrev = mChainPrev;
     mEntryCount = 0;
-    SetAcquisitionContext(CallStack::NullCallStack());
+    SetAcquisitionContext(CallStack::kNone);
     mChainPrev = 0;
 
     // give up the monitor until we're back from Wait()
@@ -327,7 +328,7 @@ CondVar::Wait(PRIntervalTime interval)
     // save mutex state and reset to empty
     CallStack savedAcquisitionContext = mLock->GetAcquisitionContext();
     BlockingResourceBase* savedChainPrev = mLock->mChainPrev;
-    mLock->SetAcquisitionContext(CallStack::NullCallStack());
+    mLock->SetAcquisitionContext(CallStack::kNone);
     mLock->mChainPrev = 0;
 
     // give up mutex until we're back from Wait()

xpcom/glue/BlockingResourceBase.h

@@ -74,7 +74,7 @@ private:
                               BlockingResourceType aType) :
             mName(aName),
             mType(aType),
-            mAcquisitionContext(CallStack::NullCallStack())
+            mAcquisitionContext(CallStack::kNone)
         {
             NS_ABORT_IF_FALSE(mName, "Name must be nonnull");
         }
@@ -117,7 +117,7 @@ private:
         /**
          * mAcquisitionContext
          * The calling context from which this resource was acquired, or
-         * |CallStack::NullCallStack()| if it is currently free (or freed).
+         * |CallStack::kNone| if it is currently free (or freed).
          */
         CallStack mAcquisitionContext;
     };
@@ -239,7 +239,7 @@ protected:
     /**
      * GetAcquisitionContext
      * Return the calling context from which this resource was acquired,
-     * or CallStack::NullCallStack() if it's currently free.
+     * or CallStack::kNone if it's currently free.
      *
      * *NOT* thread safe.  Requires ownership of underlying resource.
      */

xpcom/glue/DeadlockDetector.cpp

@@ -5,46 +5,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "DeadlockDetector.h"
-#include "nsStackWalk.h"
-#include "mozilla/Util.h"
 
 namespace mozilla {
-
-static void
-StackCallback(void* pc, void* sp, void* closure)
-{
-  nsTArray<void*>* stack = static_cast<nsTArray<void*>*>(closure);
-  stack->AppendElement(pc);
-}
-
-nsTArray<void*>
-CallStack::GetBacktrace()
-{
-  nsTArray<void*> callstack;
-  callstack.SetCapacity(32); // Hopefully 32 frames is a good average
-  NS_StackWalk(StackCallback, 2, 0, &callstack, 0, nullptr);
-  return mozilla::Move(callstack);
-}
-
-void
-CallStack::Print(FILE* f) const
-{
-  if (mCallStack.IsEmpty()) {
-    fputs("  [stack trace unavailable]\n", f);
-  } else {
-    nsCodeAddressDetails addr;
-    for (uint32_t i = 0; i < mCallStack.Length(); ++i) {
-      nsresult rv = NS_DescribeCodeAddress(mCallStack[i], &addr);
-      if (NS_SUCCEEDED(rv)) {
-        char buf[1024];
-        NS_FormatCodeAddressDetails(mCallStack[i], &addr, buf, ArrayLength(buf));
-        fputs(buf, f);
-      } else {
-        fprintf(f, "Frame information for %p unavailable", mCallStack[i]);
-      }
-    }
-  }
-  fflush(f);
-}
-
+const CallStack CallStack::kNone((CallStack::callstack_id) -1);
 }

xpcom/glue/DeadlockDetector.h

@@ -7,7 +7,6 @@
 #define mozilla_DeadlockDetector_h
 
 #include "mozilla/Attributes.h"
-#include "mozilla/Move.h"
 
 #include <stdlib.h>
 
@@ -16,13 +15,30 @@
 
 #include "nsTArray.h"
 
+#ifdef NS_TRACE_MALLOC
+#  include "nsTraceMalloc.h"
+#endif  // ifdef NS_TRACE_MALLOC
+
 namespace mozilla {
 
 
+// FIXME bug 456272: split this off into a convenience API on top of
+// nsStackWalk?
 class NS_COM_GLUE CallStack
 {
 private:
-    nsTArray<void*> mCallStack;
+#ifdef NS_TRACE_MALLOC
+    typedef nsTMStackTraceID callstack_id;
+    // needs to be a macro to avoid disturbing the backtrace
+#   define NS_GET_BACKTRACE() NS_TraceMallocGetStackTrace()
+#   define NS_DEADLOCK_DETECTOR_CONSTEXPR
+#else
+    typedef void* callstack_id;
+#   define NS_GET_BACKTRACE() 0
+#   define NS_DEADLOCK_DETECTOR_CONSTEXPR MOZ_CONSTEXPR
+#endif  // ifdef NS_TRACE_MALLOC
+
+    callstack_id mCallStack;
 
 public:
     /**
@@ -37,10 +53,12 @@ public:
      * constructor: it *will* construct a backtrace.  This can cause
      * unexpected performance issues.
      */
-    CallStack(const nsTArray<void*>& aCallStack = GetBacktrace()) :
-        mCallStack(mozilla::Move(aCallStack))
+    NS_DEADLOCK_DETECTOR_CONSTEXPR
+    CallStack(const callstack_id aCallStack = NS_GET_BACKTRACE()) :
+        mCallStack(aCallStack)
     {
     }
+    NS_DEADLOCK_DETECTOR_CONSTEXPR
     CallStack(const CallStack& aFrom) :
         mCallStack(aFrom.mCallStack)
     {
@@ -59,19 +77,22 @@ public:
         return mCallStack != aOther.mCallStack;
     }
 
-    bool IsEmpty() const
+    // FIXME bug 456272: if this is split off,
+    // NS_TraceMallocPrintStackTrace should be modified to print into
+    // an nsACString
+    void Print(FILE* f) const
     {
-      return mCallStack.IsEmpty();
+#ifdef NS_TRACE_MALLOC
+        if (this != &kNone && mCallStack) {
+            NS_TraceMallocPrintStackTrace(f, mCallStack);
+            return;
+        }
+#endif
+        fputs("  [stack trace unavailable]\n", f);
     }
 
-    void Print(FILE* f) const;
-
-    static nsTArray<void*> GetBacktrace();
-
-    static const CallStack NullCallStack()
-    {
-      return CallStack(nsTArray<void*>());
-    }
+    /** The "null" callstack. */
+    static const CallStack kNone;
 };
 
 
@@ -137,7 +158,7 @@ public:
 
         ResourceAcquisition(
             const T* aResource,
-            const CallStack aCallContext=CallStack::NullCallStack()) :
+            const CallStack aCallContext=CallStack::kNone) :
             mResource(aResource),
             mCallContext(aCallContext)
         {
@@ -174,7 +195,7 @@ private:
     struct OrderingEntry
     {
         OrderingEntry() :
-            mFirstSeen(CallStack::NullCallStack()),
+            mFirstSeen(CallStack::kNone),
             mOrderedLT()        // FIXME bug 456272: set to empirical
         {                       // dep size?
         }
@@ -386,7 +407,7 @@ public:
 
         PLHashEntry* second = *GetEntry(aProposed);
         OrderingEntry* e = static_cast<OrderingEntry*>(second->value);
-        if (e->mFirstSeen.IsEmpty())
+        if (CallStack::kNone == e->mFirstSeen)
             e->mFirstSeen = aCallContext;
 
         if (!aLast)

xpcom/glue/nsTArray.h

@@ -1653,18 +1653,6 @@ public:
   nsTArray() {}
   explicit nsTArray(size_type capacity) : base_type(capacity) {}
   explicit nsTArray(const nsTArray& other) : base_type(other) {}
-  nsTArray(nsTArray&& other) {
-    this->SwapElements(other);
-  }
-
-  nsTArray& operator=(const nsTArray& other) {
-    base_type::operator=(other);
-    return *this;
-  }
-  nsTArray& operator=(nsTArray&& other) {
-    this->SwapElements(other);
-    return *this;
-  }
 
   template<class Allocator>
   explicit nsTArray(const nsTArray_Impl<E, Allocator>& other) : base_type(other) {}