Privatize part of the leak detector mechanism, which turned out to be heavily contended

when trying to run opt in parallel.  This lets parallel opt crunch 403.gcc in about a third
of the time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79387 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/LeakDetector.h

@@ -56,9 +56,9 @@ struct LeakDetector {
   /// The specified message will be printed indicating when the check was
   /// performed.
   ///
-  static void checkForGarbage(const std::string &Message) {
+  static void checkForGarbage(LLVMContext &C, const std::string &Message) {
 #ifndef NDEBUG
-    checkForGarbageImpl(Message);
+    checkForGarbageImpl(C, Message);
 #endif
   }
 
@@ -83,7 +83,7 @@ private:
   static void removeGarbageObjectImpl(const Value *Object);
   static void addGarbageObjectImpl(void *Object);
   static void removeGarbageObjectImpl(void *Object);
-  static void checkForGarbageImpl(const std::string &Message);
+  static void checkForGarbageImpl(LLVMContext &C, const std::string &Message);
 };
 
 } // End llvm namespace

lib/VMCore/LLVMContextImpl.h

@@ -16,6 +16,7 @@
 #define LLVM_LLVMCONTEXT_IMPL_H
 
 #include "ConstantsContext.h"
+#include "LeaksContext.h"
 #include "TypesContext.h"
 #include "llvm/LLVMContext.h"
 #include "llvm/Constants.h"
@@ -134,6 +135,10 @@ public:
   ConstantInt *TheTrueVal;
   ConstantInt *TheFalseVal;
   
+  // Lock used for guarding access to the leak detector
+  sys::SmartMutex<true> LLVMObjectsLock;
+  LeakDetectorImpl<Value> LLVMObjects;
+  
   // Lock used for guarding access to the type maps.
   sys::SmartMutex<true> TypeMapLock;
   

lib/VMCore/LeakDetector.cpp

@@ -11,129 +11,63 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "LLVMContextImpl.h"
 #include "llvm/Support/LeakDetector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Streams.h"
-#include "llvm/System/RWMutex.h"
+#include "llvm/System/Mutex.h"
 #include "llvm/System/Threading.h"
 #include "llvm/Value.h"
 using namespace llvm;
 
-namespace {
+static ManagedStatic<sys::SmartMutex<true> > ObjectsLock;
-  template <class T>
+static ManagedStatic<LeakDetectorImpl<void> > Objects;
-  struct VISIBILITY_HIDDEN PrinterTrait {
-    static void print(const T* P) { cerr << P; }
-  };
 
-  template<>
+static void clearGarbage(LLVMContext &Context) {
-  struct VISIBILITY_HIDDEN PrinterTrait<Value> {
+  Objects->clear();
-    static void print(const Value* P) { cerr << *P; }
+  Context.pImpl->LLVMObjects.clear();
-  };
-
-  ManagedStatic<sys::SmartRWMutex<true> > LeakDetectorLock;
-
-  template <typename T>
-  struct VISIBILITY_HIDDEN LeakDetectorImpl {
-    explicit LeakDetectorImpl(const char* const name = "") : 
-      Cache(0), Name(name) { }
-
-    void clear() {
-      Cache = 0;
-      Ts.clear();
-    }
-    
-    void setName(const char* n) { 
-      Name = n;
-    }
-    
-    // Because the most common usage pattern, by far, is to add a
-    // garbage object, then remove it immediately, we optimize this
-    // case.  When an object is added, it is not added to the set
-    // immediately, it is added to the CachedValue Value.  If it is
-    // immediately removed, no set search need be performed.
-    void addGarbage(const T* o) {
-      sys::SmartScopedWriter<true> Writer(*LeakDetectorLock);
-      if (Cache) {
-        assert(Ts.count(Cache) == 0 && "Object already in set!");
-        Ts.insert(Cache);
-      }
-      Cache = o;
-    }
-
-    void removeGarbage(const T* o) {
-      sys::SmartScopedWriter<true> Writer(*LeakDetectorLock);
-      if (o == Cache)
-        Cache = 0; // Cache hit
-      else
-        Ts.erase(o);
-    }
-
-    bool hasGarbage(const std::string& Message) {
-      addGarbage(0); // Flush the Cache
-
-      sys::SmartScopedReader<true> Reader(*LeakDetectorLock);
-      assert(Cache == 0 && "No value should be cached anymore!");
-
-      if (!Ts.empty()) {
-        cerr << "Leaked " << Name << " objects found: " << Message << ":\n";
-        for (typename SmallPtrSet<const T*, 8>::iterator I = Ts.begin(),
-               E = Ts.end(); I != E; ++I) {
-          cerr << "\t";
-          PrinterTrait<T>::print(*I);
-          cerr << "\n";
-        }
-        cerr << '\n';
-
-        return true;
-      }
-      
-      return false;
-    }
-
-  private:
-    SmallPtrSet<const T*, 8> Ts;
-    const T* Cache;
-    const char* Name;
-  };
-
-  static ManagedStatic<LeakDetectorImpl<void> > Objects;
-  static ManagedStatic<LeakDetectorImpl<Value> > LLVMObjects;
-
-  static void clearGarbage() {
-    Objects->clear();
-    LLVMObjects->clear();
-  }
 }
 
 void LeakDetector::addGarbageObjectImpl(void *Object) {
+  sys::SmartScopedLock<true> Lock(*ObjectsLock);
   Objects->addGarbage(Object);
 }
 
 void LeakDetector::addGarbageObjectImpl(const Value *Object) {
-  LLVMObjects->addGarbage(Object);
+  LLVMContextImpl *pImpl = Object->getContext().pImpl;
+  sys::SmartScopedLock<true> Lock(pImpl->LLVMObjectsLock);
+  pImpl->LLVMObjects.addGarbage(Object);
 }
 
 void LeakDetector::removeGarbageObjectImpl(void *Object) {
+  sys::SmartScopedLock<true> Lock(*ObjectsLock);
   Objects->removeGarbage(Object);
 }
 
 void LeakDetector::removeGarbageObjectImpl(const Value *Object) {
-  LLVMObjects->removeGarbage(Object);
+  LLVMContextImpl *pImpl = Object->getContext().pImpl;
+  sys::SmartScopedLock<true> Lock(pImpl->LLVMObjectsLock);
+  pImpl->LLVMObjects.removeGarbage(Object);
 }
 
-void LeakDetector::checkForGarbageImpl(const std::string &Message) {
+void LeakDetector::checkForGarbageImpl(LLVMContext &Context, 
+                                       const std::string &Message) {
+  LLVMContextImpl *pImpl = Context.pImpl;
+  sys::SmartScopedLock<true> Lock(*ObjectsLock);
+  sys::SmartScopedLock<true> CLock(pImpl->LLVMObjectsLock);
+  
   Objects->setName("GENERIC");
-  LLVMObjects->setName("LLVM");
+  pImpl->LLVMObjects.setName("LLVM");
   
   // use non-short-circuit version so that both checks are performed
   if (Objects->hasGarbage(Message) |
-      LLVMObjects->hasGarbage(Message))
+      pImpl->LLVMObjects.hasGarbage(Message))
     cerr << "\nThis is probably because you removed an object, but didn't "
          << "delete it.  Please check your code for memory leaks.\n";
 
   // Clear out results so we don't get duplicate warnings on
   // next call...
-  clearGarbage();
+  clearGarbage(Context);
 }