[ORC] Make LocalIndirectStubsManager's operations thread-safe.

Locks stub management operations and switches to atomic update for stub
pointers.

llvm-svn: 343262

llvm/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h

@@ -295,6 +295,7 @@ class LocalIndirectStubsManager : public IndirectStubsManager {
 public:
   Error createStub(StringRef StubName, JITTargetAddress StubAddr,
                    JITSymbolFlags StubFlags) override {
+    std::lock_guard<std::mutex> Lock(StubsMutex);
     if (auto Err = reserveStubs(1))
       return Err;
 
@@ -304,6 +305,7 @@ public:
   }
 
   Error createStubs(const StubInitsMap &StubInits) override {
+    std::lock_guard<std::mutex> Lock(StubsMutex);
     if (auto Err = reserveStubs(StubInits.size()))
       return Err;
 
@@ -315,6 +317,7 @@ public:
   }
 
   JITEvaluatedSymbol findStub(StringRef Name, bool ExportedStubsOnly) override {
+    std::lock_guard<std::mutex> Lock(StubsMutex);
     auto I = StubIndexes.find(Name);
     if (I == StubIndexes.end())
       return nullptr;
@@ -330,6 +333,7 @@ public:
   }
 
   JITEvaluatedSymbol findPointer(StringRef Name) override {
+    std::lock_guard<std::mutex> Lock(StubsMutex);
     auto I = StubIndexes.find(Name);
     if (I == StubIndexes.end())
       return nullptr;
@@ -342,11 +346,15 @@ public:
   }
 
   Error updatePointer(StringRef Name, JITTargetAddress NewAddr) override {
+    using AtomicIntPtr = std::atomic<uintptr_t>;
+
+    std::lock_guard<std::mutex> Lock(StubsMutex);
     auto I = StubIndexes.find(Name);
     assert(I != StubIndexes.end() && "No stub pointer for symbol");
     auto Key = I->second.first;
-    *IndirectStubsInfos[Key.first].getPtr(Key.second) =
-        reinterpret_cast<void *>(static_cast<uintptr_t>(NewAddr));
+    AtomicIntPtr *AtomicStubPtr = reinterpret_cast<AtomicIntPtr *>(
+        IndirectStubsInfos[Key.first].getPtr(Key.second));
+    *AtomicStubPtr = static_cast<uintptr_t>(NewAddr);
     return Error::success();
   }
 
@@ -376,6 +384,7 @@ private:
     StubIndexes[StubName] = std::make_pair(Key, StubFlags);
   }
 
+  std::mutex StubsMutex;
   std::vector<typename TargetT::IndirectStubsInfo> IndirectStubsInfos;
   using StubKey = std::pair<uint16_t, uint16_t>;
   std::vector<StubKey> FreeStubs;