[llvm] 9eb591f - [ORC] Only use JITDylib::GeneratorsMutex while running generators.

[Lang Hames via llvm-commits]

Author: Lang Hames
Date: 2021-12-02T17:36:32+11:00
New Revision: 9eb591f0ace7275ce8c3be190975e10aaa142171

URL: https://github.com/llvm/llvm-project/commit/9eb591f0ace7275ce8c3be190975e10aaa142171
DIFF: https://github.com/llvm/llvm-project/commit/9eb591f0ace7275ce8c3be190975e10aaa142171.diff

LOG: [ORC] Only use JITDylib::GeneratorsMutex while running generators.

GeneratorsMutex should prevent lookups from proceeding through the
generators of a single JITDylib concurrently (since this could
result in redundant attempts to generate definitions). Mutation of
the generators list itself should be done under the session lock.

Added: 
    

Modified: 
    llvm/include/llvm/ExecutionEngine/Orc/Core.h
    llvm/lib/ExecutionEngine/Orc/Core.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/ExecutionEngine/Orc/Core.h b/llvm/include/llvm/ExecutionEngine/Orc/Core.h
index d11a0c9df74d..8ca2725566c5 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/Core.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/Core.h
@@ -1680,8 +1680,9 @@ Error MaterializationResponsibility::withResourceKeyDo(Func &&F) const {
 template <typename GeneratorT>
 GeneratorT &JITDylib::addGenerator(std::unique_ptr<GeneratorT> DefGenerator) {
   auto &G = *DefGenerator;
-  std::lock_guard<std::mutex> Lock(GeneratorsMutex);
-  DefGenerators.push_back(std::move(DefGenerator));
+  ES.runSessionLocked([&] {
+    DefGenerators.push_back(std::move(DefGenerator));
+  });
   return G;
 }
 

diff  --git a/llvm/lib/ExecutionEngine/Orc/Core.cpp b/llvm/lib/ExecutionEngine/Orc/Core.cpp
index afd116b646ad..15648a8541cc 100644
--- a/llvm/lib/ExecutionEngine/Orc/Core.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/Core.cpp
@@ -642,13 +642,14 @@ ResourceTrackerSP JITDylib::createResourceTracker() {
 }
 
 void JITDylib::removeGenerator(DefinitionGenerator &G) {
-  std::lock_guard<std::mutex> Lock(GeneratorsMutex);
-  auto I = llvm::find_if(DefGenerators,
-                         [&](const std::shared_ptr<DefinitionGenerator> &H) {
-                           return H.get() == &G;
-                         });
-  assert(I != DefGenerators.end() && "Generator not found");
-  DefGenerators.erase(I);
+  ES.runSessionLocked([&] {
+    auto I = llvm::find_if(DefGenerators,
+                           [&](const std::shared_ptr<DefinitionGenerator> &H) {
+                             return H.get() == &G;
+                           });
+    assert(I != DefGenerators.end() && "Generator not found");
+    DefGenerators.erase(I);
+  });
 }
 
 Expected<SymbolFlagsMap>
@@ -2311,8 +2312,11 @@ void ExecutionSession::OL_applyQueryPhase1(
       });
 
       // Build the definition generator stack for this JITDylib.
-      for (auto &DG : reverse(JD.DefGenerators))
-        IPLS->CurDefGeneratorStack.push_back(DG);
+      runSessionLocked([&] {
+        IPLS->CurDefGeneratorStack.reserve(JD.DefGenerators.size());
+        for (auto &DG : reverse(JD.DefGenerators))
+          IPLS->CurDefGeneratorStack.push_back(DG);
+      });
 
       // Flag that we've done our initialization.
       IPLS->NewJITDylib = false;