Fix concurrency related issue

Author: SahilPatidar

interpreter/llvm-project/llvm/include/llvm/ExecutionEngine/Orc/Shared/LibraryResolver.h

@@ -212,6 +212,22 @@ class LibraryManager {
     return FilteredView(Libraries.begin(), Libraries.end(), S, K);
   }
 
+  using LibraryFilterFn = std::function<bool(const LibraryInfo &)>;
+  void getLibraries(
+      LibState S, PathType K,
+      std::vector<std::shared_ptr<LibraryInfo>> &Outs,
+      LibraryFilterFn Filter = nullptr) const {
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
+    for (const auto &[_, Entry] : Libraries) {
+      const auto &Info = *Entry;
+      if (Info.getKind() != K || Info.getState() != S)
+        continue;
+      if (Filter && !Filter(Info))
+        continue;
+      Outs.push_back(Entry);
+    }
+  }
+
   void forEachLibrary(const LibraryVisitor &visitor) const {
     std::unique_lock<std::shared_mutex> Lock(Mtx);
     for (const auto &[_, entry] : Libraries) {
@@ -221,14 +237,14 @@ class LibraryManager {
   }
 
   bool isLoaded(StringRef Path) const {
-    std::unique_lock<std::shared_mutex> Lock(Mtx);
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
     if (auto It = Libraries.find(Path.str()); It != Libraries.end())
       return It->second->getState() == LibState::Loaded;
     return false;
   }
 
   bool isQueried(StringRef Path) const {
-    std::unique_lock<std::shared_mutex> Lock(Mtx);
+    std::shared_lock<std::shared_mutex> Lock(Mtx);
     if (auto It = Libraries.find(Path.str()); It != Libraries.end())
       return It->second->getState() == LibState::Queried;
     return false;

interpreter/llvm-project/llvm/lib/ExecutionEngine/Orc/Shared/LibraryResolver.cpp

@@ -185,17 +185,17 @@ class SymbolSearchContext {
 public:
   SymbolSearchContext(SymbolQuery &Q) : Q(Q) {}
 
-  bool hasSearched(LibraryInfo *Lib) const { return Searched.count(Lib); }
+  bool hasSearched(const LibraryInfo *Lib) const { return Searched.count(Lib); }
 
-  void markSearched(LibraryInfo *Lib) { Searched.insert(Lib); }
+  void markSearched(const LibraryInfo *Lib) { Searched.insert(Lib); }
 
   inline bool allResolved() const { return Q.allResolved(); }
 
   SymbolQuery &query() { return Q; }
 
 private:
   SymbolQuery &Q;
-  DenseSet<LibraryInfo *> Searched;
+  DenseSet<const LibraryInfo *> Searched;
 };
 
 void LibraryResolver::resolveSymbolsInLibrary(
@@ -288,24 +288,22 @@ void LibraryResolver::searchSymbolsInLibraries(
 
     SymbolSearchContext Ctx(Q);
     while (!Ctx.allResolved()) {
+      std::vector<std::shared_ptr<LibraryInfo>> Libs;
+      LibMgr.getLibraries(S, K, Libs, [&](const LibraryInfo &Lib) {
+        return !Ctx.hasSearched(&Lib);
+      });
 
-      for (auto &Lib : LibMgr.getView(S, K)) {
-        if (Ctx.hasSearched(Lib.get()))
-          continue;
+      if (Libs.empty() && !scanLibrariesIfNeeded(K, scanBatchSize))
+        break; // no more new libs to scan
 
+      for (auto &Lib : Libs) {
         // can use Async here?
         resolveSymbolsInLibrary(*Lib, Ctx.query(), Config.Options);
         Ctx.markSearched(Lib.get());
 
         if (Ctx.allResolved())
           return;
       }
-
-      if (Ctx.allResolved())
-        return;
-
-      if (!scanLibrariesIfNeeded(K, scanBatchSize))
-        break; // no more new libs to scan
     }
   };