Adds a "currentThreadIndex" method to Eigen's ThreadPoolDevice. Use it to handle per-thread buffer allocation for the tileable executor without resorting to thread_local that is not fully supported on Android.

Change: 126009029

eigen.BUILD

@@ -1,7 +1,6 @@
 package(default_visibility = ["//visibility:public"])
 
-archive_dir = "eigen-eigen-802d984ade26"
-
+archive_dir = "eigen-eigen-334b1d428283"
 cc_library(
     name = "eigen",
     hdrs = glob([archive_dir+"/**/*.h", archive_dir+"/unsupported/Eigen/CXX11/*", archive_dir+"/Eigen/*"]),

tensorflow/core/common_runtime/eigen_thread_pool.h

@@ -27,6 +27,8 @@ class EigenThreadPoolWrapper : public Eigen::ThreadPoolInterface {
   ~EigenThreadPoolWrapper() override {}
 
   void Schedule(std::function<void()> fn) override { pool_->Schedule(fn); }
+  int NumThreads() const override { return pool_->NumThreads(); }
+  int CurrentThreadId() const override { return pool_->CurrentThreadId(); }
 
  private:
   thread::ThreadPool* pool_ = nullptr;

tensorflow/core/kernels/cwise_ops.h

@@ -35,7 +35,6 @@ struct scalar_fmod2_op {
     return std::fmod(a, b);
   }
 };
-
 template <typename T>
 struct functor_traits<scalar_fmod2_op<T>> {
   enum {
@@ -44,6 +43,24 @@ struct functor_traits<scalar_fmod2_op<T>> {
   };
 };
 
+// TODO(rmlarsen): This is a workaround for upstream change
+// https://bitbucket.org/eigen/eigen/commits/f339468d04d0f87caeb6cab9aef568627e9f6ea9
+// that renamed scalar_binary_pow_op to scalar_pow_op and deleted the unary
+// version of the latter. Remove once we upgrade to Eigen 3.3.
+template <typename Scalar, typename Exponent>
+struct scalar_binary_pow_op_google {
+  EIGEN_EMPTY_STRUCT_CTOR(scalar_binary_pow_op_google)
+  EIGEN_DEVICE_FUNC inline Scalar operator()(const Scalar& a,
+                                             const Exponent& b) const {
+    return numext::pow(a, b);
+  }
+};
+
+template <typename Scalar, typename Exponent>
+struct functor_traits<scalar_binary_pow_op_google<Scalar, Exponent>> {
+  enum { Cost = 5 * NumTraits<Scalar>::MulCost, PacketAccess = false };
+};
+
 template <typename T, typename DivOrMod>
 struct safe_div_or_mod_op {
   static_assert(std::is_integral<T>::value, "Integer type expected");
@@ -477,7 +494,7 @@ struct safe_mod : base<T, Eigen::internal::safe_div_or_mod_op<
 };
 
 template <typename T>
-struct pow : base<T, Eigen::internal::scalar_binary_pow_op<T, T> > {};
+struct pow : base<T, Eigen::internal::scalar_binary_pow_op_google<T, T>> {};
 
 template <typename T>
 struct maximum : base<T, Eigen::internal::scalar_max_op<T> > {};

tensorflow/core/lib/core/threadpool.cc

@@ -74,15 +74,14 @@ struct ThreadPool::Impl : Eigen::ThreadPoolTempl<EigenEnvironment> {
   Impl(Env* env, const ThreadOptions& thread_options, const string& name,
        int num_threads)
       : Eigen::ThreadPoolTempl<EigenEnvironment>(
-            num_threads, EigenEnvironment(env, thread_options, name)),
-        num_threads_(num_threads) {}
+            num_threads, EigenEnvironment(env, thread_options, name)) {}
 
   void ParallelFor(int64 total, int64 cost_per_unit,
                    std::function<void(int64, int64)> fn) {
 #ifdef EIGEN_USE_NONBLOCKING_THREAD_POOL
     CHECK_GE(total, 0);
     CHECK_EQ(total, (int64)(Eigen::Index)total);
-    Eigen::ThreadPoolDevice device(this, num_threads_);
+    Eigen::ThreadPoolDevice device(this, this->NumThreads());
     device.parallelFor(
         total, Eigen::TensorOpCost(0, 0, cost_per_unit),
         [&fn](Eigen::Index first, Eigen::Index last) { fn(first, last); });
@@ -90,10 +89,6 @@ struct ThreadPool::Impl : Eigen::ThreadPoolTempl<EigenEnvironment> {
     CHECK(0);  // should not be used with the old thread pool
 #endif
   }
-
-  int NumThreads() const { return num_threads_; };
-
-  const int num_threads_;
 };
 
 ThreadPool::ThreadPool(Env* env, const string& name, int num_threads)
@@ -120,5 +115,7 @@ void ThreadPool::ParallelFor(int64 total, int64 cost_per_unit,
 
 int ThreadPool::NumThreads() const { return impl_->NumThreads(); }
 
+int ThreadPool::CurrentThreadId() const { return impl_->CurrentThreadId(); }
+
 }  // namespace thread
 }  // namespace tensorflow

tensorflow/core/lib/core/threadpool.h

@@ -57,6 +57,10 @@ class ThreadPool {
   // Returns the number of threads in the pool.
   int NumThreads() const;
 
+  // Returns current thread id between 0 and NumThreads() - 1, if called from a
+  // thread in the pool. Returns -1 otherwise.
+  int CurrentThreadId() const;
+
   struct Impl;
 
  private:

tensorflow/workspace.bzl

@@ -6,8 +6,8 @@
 def tf_workspace(path_prefix = "", tf_repo_name = ""):
   native.new_http_archive(
     name = "eigen_archive",
-    url = "https://bitbucket.org/eigen/eigen/get/802d984ade26.tar.gz",
-    sha256 = "1499997676bd9006082950a761b88d5c48554fd550747763b2b34951da29a2e8",
+    url = "https://bitbucket.org/eigen/eigen/get/334b1d428283.tar.gz",
+    sha256 = "6d5efd02c7c11fbb9d02df4f0b64f22ecbd348e7549f8a83c13fb4d8d9e19d4b",
     build_file = path_prefix + "eigen.BUILD",
   )
 
@@ -146,7 +146,7 @@ def tf_workspace(path_prefix = "", tf_repo_name = ""):
     remote = "https://boringssl.googlesource.com/boringssl",
     build_file = path_prefix + "boringssl.BUILD",
   )
-  
+
   native.bind(
     name = "boringssl_err_data_c",
     actual = "@//" + path_prefix + "third_party/boringssl:err_data_c",

third_party/eigen3/Eigen/Cholesky

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/Eigen/Cholesky"
+#include "eigen-eigen-334b1d428283/Eigen/Cholesky"

third_party/eigen3/Eigen/Core

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/Eigen/Core"
+#include "eigen-eigen-334b1d428283/Eigen/Core"

third_party/eigen3/Eigen/Eigenvalues

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/Eigen/Eigenvalues"
+#include "eigen-eigen-334b1d428283/Eigen/Eigenvalues"

third_party/eigen3/Eigen/LU

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/Eigen/LU"
+#include "eigen-eigen-334b1d428283/Eigen/LU"

third_party/eigen3/Eigen/QR

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/Eigen/QR"
+#include "eigen-eigen-334b1d428283/Eigen/QR"

third_party/eigen3/unsupported/Eigen/CXX11/Tensor

@@ -1 +1 @@
-#include "eigen-eigen-802d984ade26/unsupported/Eigen/CXX11/Tensor"
+#include "eigen-eigen-334b1d428283/unsupported/Eigen/CXX11/Tensor"