Bug 1335854 - Tone down non-zero refcount message for dynamic atoms. r=froydnj

--HG--
extra : rebase_source : 31bef82b308fc5f7bd4eebbf898820e0b10640c0

xpcom/ds/nsAtomTable.cpp

@@ -376,6 +376,8 @@ DynamicAtom::GCAtomTableLocked(const MutexAutoLock& aProofOfLock,
                                GCKind aKind)
 {
   uint32_t removedCount = 0; // Use a non-atomic temporary for cheaper increments.
+  nsAutoCString nonZeroRefcountAtoms;
+  uint32_t nonZeroRefcountAtomsCount = 0;
   for (auto i = gAtomTable->Iter(); !i.Done(); i.Next()) {
     auto entry = static_cast<AtomTableEntry*>(i.Get());
     if (entry->mAtom->IsStaticAtom()) {
@@ -393,10 +395,21 @@ DynamicAtom::GCAtomTableLocked(const MutexAutoLock& aProofOfLock,
       // later on in this function.
       nsAutoCString name;
       atom->ToUTF8String(name);
-      nsPrintfCString msg("dynamic atom with non-zero refcount %s!", name.get());
-      NS_ASSERTION(false, msg.get());
+      if (nonZeroRefcountAtomsCount == 0) {
+        nonZeroRefcountAtoms = name;
+      } else if (nonZeroRefcountAtomsCount < 20) {
+        nonZeroRefcountAtoms += NS_LITERAL_CSTRING(",") + name;
+      } else if (nonZeroRefcountAtomsCount == 20) {
+        nonZeroRefcountAtoms += NS_LITERAL_CSTRING(",...");
+      }
+      nonZeroRefcountAtomsCount++;
     }
   }
+  if (nonZeroRefcountAtomsCount) {
+    nsPrintfCString msg("%d dynamic atom(s) with non-zero refcount: %s",
+                        nonZeroRefcountAtomsCount, nonZeroRefcountAtoms.get());
+    NS_ASSERTION(nonZeroRefcountAtomsCount == 0, msg.get());
+  }
 
   // During the course of this function, the atom table is locked. This means
   // that, barring refcounting bugs in consumers, an atom can never go from