[llvm] r374421 - win: Move Parallel.h off concrt to cross-platform code

[Nico Weber via llvm-commits]

Author: nico
Date: Thu Oct 10 11:57:23 2019
New Revision: 374421

URL: http://llvm.org/viewvc/llvm-project?rev=374421&view=rev
Log:
win: Move Parallel.h off concrt to cross-platform code

r179397 added Parallel.h and implemented it terms of concrt in 2013.

In 2015, a cross-platform implementation of the functions has appeared
and is in use everywhere but on Windows (r232419).  r246219 hints that
<thread> had issues in MSVC2013, but r296906 suggests they've been fixed
now that we require 2015+.

So remove the concrt code. It's less code, and it sounds like concrt has
conceptual and performance issues, see PR41198.

I built blink_core.dll in a debug component build with full symbols and
in a release component build without any symbols.  I couldn't measure a
performance difference for linking blink_core.dll before and after this
patch.

Differential Revision: https://reviews.llvm.org/D68820

Modified:
    llvm/trunk/include/llvm/Support/Parallel.h
    llvm/trunk/lib/Support/Parallel.cpp

Modified: llvm/trunk/include/llvm/Support/Parallel.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Parallel.h?rev=374421&r1=374420&r2=374421&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Parallel.h (original)
+++ llvm/trunk/include/llvm/Support/Parallel.h Thu Oct 10 11:57:23 2019
@@ -18,14 +18,6 @@
 #include <functional>
 #include <mutex>
 
-#if defined(_MSC_VER) && LLVM_ENABLE_THREADS
-#pragma warning(push)
-#pragma warning(disable : 4530)
-#include <concrt.h>
-#include <ppl.h>
-#pragma warning(pop)
-#endif
-
 namespace llvm {
 
 namespace parallel {
@@ -84,23 +76,6 @@ public:
   void sync() const { L.sync(); }
 };
 
-#if defined(_MSC_VER)
-template <class RandomAccessIterator, class Comparator>
-void parallel_sort(RandomAccessIterator Start, RandomAccessIterator End,
-                   const Comparator &Comp) {
-  concurrency::parallel_sort(Start, End, Comp);
-}
-template <class IterTy, class FuncTy>
-void parallel_for_each(IterTy Begin, IterTy End, FuncTy Fn) {
-  concurrency::parallel_for_each(Begin, End, Fn);
-}
-
-template <class IndexTy, class FuncTy>
-void parallel_for_each_n(IndexTy Begin, IndexTy End, FuncTy Fn) {
-  concurrency::parallel_for(Begin, End, Fn);
-}
-
-#else
 const ptrdiff_t MinParallelSize = 1024;
 
 /// Inclusive median.
@@ -188,8 +163,6 @@ void parallel_for_each_n(IndexTy Begin,
 
 #endif
 
-#endif
-
 template <typename Iter>
 using DefComparator =
     std::less<typename std::iterator_traits<Iter>::value_type>;

Modified: llvm/trunk/lib/Support/Parallel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Parallel.cpp?rev=374421&r1=374420&r2=374421&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Parallel.cpp (original)
+++ llvm/trunk/lib/Support/Parallel.cpp Thu Oct 10 11:57:23 2019
@@ -32,34 +32,6 @@ public:
   static Executor *getDefaultExecutor();
 };
 
-#if defined(_MSC_VER)
-/// An Executor that runs tasks via ConcRT.
-class ConcRTExecutor : public Executor {
-  struct Taskish {
-    Taskish(std::function<void()> Task) : Task(Task) {}
-
-    std::function<void()> Task;
-
-    static void run(void *P) {
-      Taskish *Self = static_cast<Taskish *>(P);
-      Self->Task();
-      concurrency::Free(Self);
-    }
-  };
-
-public:
-  virtual void add(std::function<void()> F) {
-    Concurrency::CurrentScheduler::ScheduleTask(
-        Taskish::run, new (concurrency::Alloc(sizeof(Taskish))) Taskish(F));
-  }
-};
-
-Executor *Executor::getDefaultExecutor() {
-  static ConcRTExecutor exec;
-  return &exec;
-}
-
-#else
 /// An implementation of an Executor that runs closures on a thread pool
 ///   in filo order.
 class ThreadPoolExecutor : public Executor {
@@ -117,8 +89,7 @@ Executor *Executor::getDefaultExecutor()
   static ThreadPoolExecutor exec;
   return &exec;
 }
-#endif
-}
+} // namespace
 
 static std::atomic<int> TaskGroupInstances;