[Orc] Roll back ThreadPool to std::function

MSVC doesn't allow move-only types in std::packaged_task. Boo.

llvm-svn: 371844

Author: d0k

llvm/examples/SpeculativeJIT/SpeculativeJIT.cpp

@@ -114,7 +114,9 @@ class SpeculativeJIT {
     this->ES->setDispatchMaterialization(
 
         [this](JITDylib &JD, std::unique_ptr<MaterializationUnit> MU) {
-          auto Work = [MU = std::move(MU), &JD] { MU->doMaterialize(JD); };
+          // FIXME: Switch to move capture once we have C++14.
+          auto SharedMU = std::shared_ptr<MaterializationUnit>(std::move(MU));
+          auto Work = [SharedMU, &JD]() { SharedMU->doMaterialize(JD); };
           CompileThreads.async(std::move(Work));
         });
     ExitOnErr(S.addSpeculationRuntime(this->ES->getMainJITDylib(), Mangle));

llvm/include/llvm/Support/ThreadPool.h

@@ -13,7 +13,6 @@
 #ifndef LLVM_SUPPORT_THREAD_POOL_H
 #define LLVM_SUPPORT_THREAD_POOL_H
 
-#include "llvm/ADT/FunctionExtras.h"
 #include "llvm/Config/llvm-config.h"
 #include "llvm/Support/thread.h"
 
@@ -36,7 +35,7 @@ namespace llvm {
 /// for some work to become available.
 class ThreadPool {
 public:
-  using TaskTy = unique_function<void()>;
+  using TaskTy = std::function<void()>;
   using PackagedTaskTy = std::packaged_task<void()>;
 
   /// Construct a pool with the number of threads found by

llvm/lib/ExecutionEngine/Orc/LLJIT.cpp

@@ -132,7 +132,9 @@ LLJIT::LLJIT(LLJITBuilderState &S, Error &Err)
     CompileThreads = std::make_unique<ThreadPool>(S.NumCompileThreads);
     ES->setDispatchMaterialization(
         [this](JITDylib &JD, std::unique_ptr<MaterializationUnit> MU) {
-          auto Work = [MU = std::move(MU), &JD] { MU->doMaterialize(JD); };
+          // FIXME: Switch to move capture once we have c++14.
+          auto SharedMU = std::shared_ptr<MaterializationUnit>(std::move(MU));
+          auto Work = [SharedMU, &JD]() { SharedMU->doMaterialize(JD); };
           CompileThreads->async(std::move(Work));
         });
   }