From 4e28c00e7bb5f2e7c49f48ddf3cdb897828ea9a7 Mon Sep 17 00:00:00 2001
From: Dmitry Kurtaev <dmitry.kurtaev+github@gmail.com>
Date: Thu, 17 Aug 2017 12:48:02 +0300
Subject: [PATCH] Fix Halide buffer behavior in case of OpenCL device memory
 allocation

---
 modules/dnn/src/op_halide.cpp | 12 ++++++++++++
 modules/dnn/src/op_halide.hpp |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/modules/dnn/src/op_halide.cpp b/modules/dnn/src/op_halide.cpp
index dc46ace..51c7a57 100644
--- a/modules/dnn/src/op_halide.cpp
+++ b/modules/dnn/src/op_halide.cpp
@@ -76,6 +76,7 @@ HalideBackendNode::HalideBackendNode(const Ptr<HalideBackendNode>& base,
 HalideBackendWrapper::HalideBackendWrapper(int targetId, const cv::Mat& m)
     : BackendWrapper(DNN_BACKEND_HALIDE, targetId)
 {
+    managesDevMemory = true;
     buffer = wrapToHalideBuffer(m);
     if (targetId == DNN_TARGET_CPU)
     {
@@ -95,6 +96,7 @@ HalideBackendWrapper::HalideBackendWrapper(const Ptr<BackendWrapper>& base,
                                            const MatShape& shape)
     : BackendWrapper(DNN_BACKEND_HALIDE, base->targetId)
 {
+    managesDevMemory = false;
     int w, h, c, n;
     getCanonicalSize(shape, &w, &h, &c, &n);
     Halide::Buffer<float> baseBuffer = halideBuffer(base);
@@ -113,6 +115,16 @@ HalideBackendWrapper::HalideBackendWrapper(const Ptr<BackendWrapper>& base,
     }
 }
 
+HalideBackendWrapper::~HalideBackendWrapper()
+{
+    if (buffer.has_device_allocation() && !managesDevMemory)
+    {
+        buffer.raw_buffer()->device = 0;
+        buffer.raw_buffer()->device_interface = 0;
+        buffer.set_device_dirty(false);
+    }
+}
+
 void HalideBackendWrapper::copyToHost()
 {
     CV_Assert(targetId == DNN_TARGET_CPU || buffer.device_dirty());
diff --git a/modules/dnn/src/op_halide.hpp b/modules/dnn/src/op_halide.hpp
index f91e3fb..1e0358e 100644
--- a/modules/dnn/src/op_halide.hpp
+++ b/modules/dnn/src/op_halide.hpp
@@ -57,9 +57,14 @@ namespace dnn
 
         HalideBackendWrapper(const Ptr<BackendWrapper>& base, const MatShape& shape);
 
+        ~HalideBackendWrapper();
+
         virtual void copyToHost();
 
         Halide::Buffer<float> buffer;
+
+    private:
+        bool managesDevMemory;
     };
 #endif  // HAVE_HALIDE
 
-- 
2.7.4