Simplify pthreadpool implementation on top of Caffe2 thread pool (#7666)

Remove one layer of pointer dereference when calling the thread pool.

caffe2/share/contrib/nnpack/conv_op.cc

@@ -11,7 +11,6 @@
 #include "caffe2/operators/conv_pool_op_base.h"
 
 #include "caffe2/utils/math.h"
-#include "caffe2/utils/threadpool/pthreadpool_impl.h"
 #include "nnpack.h"
 
 CAFFE2_DEFINE_bool(caffe2_profile_nnpack, false, "");
@@ -196,7 +195,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
   const nnp_size output_subsample = {.width = static_cast<size_t>(stride_w()),
                                      .height = static_cast<size_t>(stride_h())};
   initNNPACK();
-  pthreadpool pool(ws_->GetThreadPool());
+  pthreadpool_t pool = reinterpret_cast<pthreadpool_t>(ws_->GetThreadPool());
 
   runWithSharedBuffer<CPUContext>(ws_, [&](Tensor<CPUContext>* buffer) {
     if (transformStrategy_ == nnp_convolution_transform_strategy_precompute) {
@@ -220,7 +219,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
           &transformedFilterSize,
           nnp_activation_identity,
           nullptr /* activation parameter */,
-          &pool,
+          pool,
           nullptr /* profile */);
       if (status == nnp_status_success) {
         /* For these convolution parameters filter transforms can be
@@ -257,7 +256,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
               &transformedFilterSize,
               nnp_activation_identity,
               nullptr /* activation parameter */,
-              &pool,
+              pool,
               nullptr /* profile */);
           CAFFE_ENFORCE(
               nnp_status_success == status,
@@ -320,7 +319,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
             &workspaceSize,
             activation_,
             nullptr /* activation parameter */,
-            &pool,
+            pool,
             FLAGS_caffe2_profile_nnpack ? &profile : nullptr);
         if (status == nnp_status_insufficient_buffer) {
           /* Query required workspace size, increase buffer, and try again */
@@ -341,7 +340,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
               &workspaceSize,
               activation_,
               nullptr /* activation parameter */,
-              &pool,
+              pool,
               nullptr /* profile */);
           if (status == nnp_status_success) {
             /* Division with rounding up, in case size is not multiple of
@@ -374,7 +373,7 @@ bool NNPACKConvOp::RunOnDeviceWithOrderNCHW() {
                 &workspaceSize,
                 activation_,
                 nullptr /* activation parameter */,
-                &pool,
+                pool,
                 FLAGS_caffe2_profile_nnpack ? &profile : nullptr);
           }
         }

caffe2/utils/threadpool/pthreadpool_impl.cc

@@ -1,5 +1,4 @@
 #include "caffe2/utils/threadpool/pthreadpool.h"
-#include "caffe2/utils/threadpool/pthreadpool_impl.h"
 #include "caffe2/utils/threadpool/ThreadPool.h"
 
 
@@ -7,17 +6,19 @@
 // External API
 //
 
-void pthreadpool_compute_1d(struct pthreadpool* threadpool,
-                            pthreadpool_function_1d_t function,
-                            void* argument,
-                            size_t range) {
-    threadpool->pool_->run(
-      [function, argument](int threadId, size_t workId) {
-        function(argument, workId);
-      },
-      range);
+void pthreadpool_compute_1d(
+    pthreadpool_t threadpool,
+    pthreadpool_function_1d_t function,
+    void* argument,
+    size_t range) {
+  reinterpret_cast<caffe2::ThreadPool*>(threadpool)
+      ->run(
+          [function, argument](int threadId, size_t workId) {
+            function(argument, workId);
+          },
+          range);
 }
 
-size_t pthreadpool_get_threads_count(struct pthreadpool* threadpool) {
-  return threadpool->pool_->getNumThreads();
+size_t pthreadpool_get_threads_count(pthreadpool_t threadpool) {
+  return reinterpret_cast<caffe2::ThreadPool*>(threadpool)->getNumThreads();
 }

caffe2/utils/threadpool/pthreadpool_impl.h

@@ -1,23 +0,0 @@
-#ifndef CAFFE2_UTILS_PTHREADPOOL_IMPL_H_
-#define CAFFE2_UTILS_PTHREADPOOL_IMPL_H_
-
-#include "ThreadPoolCommon.h"
-
-
-namespace caffe2 {
-
-class ThreadPool;
-
-} // namespace caffe2
-
-extern "C" {
-
-// Wrapper for the caffe2 threadpool for the usage of NNPACK
-struct pthreadpool {
-  pthreadpool(caffe2::ThreadPool* pool) : pool_(pool) {}
-  caffe2::ThreadPool* pool_;
-};
-
-} // extern "C"
-
-#endif  // CAFFE2_UTILS_PTHREADPOOL_IMPL_H_