7 files changed, 153 insertions, 23 deletions
diff --git a/src/backends/cl/CMakeLists.txt b/src/backends/cl/CMakeLists.txt
index 7182332956..a0f1e4d9cc 100644
--- a/src/backends/cl/CMakeLists.txt
+++ b/src/backends/cl/CMakeLists.txt
@@ -3,18 +3,23 @@
 # SPDX-License-Identifier: MIT
 #
 
+list(APPEND armnnClBackend_sources
+    ClBackendId.hpp
+    ClLayerSupport.cpp
+    ClLayerSupport.hpp
+    ClWorkloadFactory.cpp
+    ClWorkloadFactory.hpp
+)
+
 if(ARMCOMPUTECL)
     list(APPEND armnnClBackend_sources
+        ClBackendContext.cpp
+        ClBackendContext.hpp
         ClBackend.cpp
         ClBackend.hpp
-        ClBackendId.hpp
         ClContextControl.cpp
         ClContextControl.hpp
-        ClLayerSupport.cpp
-        ClLayerSupport.hpp
         ClTensorHandle.hpp
-        ClWorkloadFactory.cpp
-        ClWorkloadFactory.hpp
         OpenClTimer.cpp
         OpenClTimer.hpp
     )
@@ -24,20 +29,10 @@ if(ARMCOMPUTECL)
     if(BUILD_UNIT_TESTS)
         add_subdirectory(test)
     endif()
-
-else()
-    list(APPEND armnnClBackend_sources
-        ClBackendId.hpp
-        ClContextControl.cpp
-        ClContextControl.hpp
-        ClLayerSupport.cpp
-        ClLayerSupport.hpp
-        ClWorkloadFactory.cpp
-        ClWorkloadFactory.hpp
-    )
 endif()
 
 add_library(armnnClBackend OBJECT ${armnnClBackend_sources})
 target_include_directories(armnnClBackend PRIVATE ${PROJECT_SOURCE_DIR}/src)
 target_include_directories(armnnClBackend PRIVATE ${PROJECT_SOURCE_DIR}/src/armnn)
 target_include_directories(armnnClBackend PRIVATE ${PROJECT_SOURCE_DIR}/src/armnnUtils)
+
diff --git a/src/backends/cl/ClBackend.cpp b/src/backends/cl/ClBackend.cpp
index d6a3a89391..da91de8e48 100644
--- a/src/backends/cl/ClBackend.cpp
+++ b/src/backends/cl/ClBackend.cpp
@@ -8,8 +8,7 @@
 #include "ClWorkloadFactory.hpp"
 
 #include <backends/BackendRegistry.hpp>
-
-#include <boost/cast.hpp>
+#include <boost/log/trivial.hpp>
 
 namespace armnn
 {
@@ -21,13 +20,13 @@ static StaticRegistryInitializer<BackendRegistry> g_RegisterHelper
 {
     BackendRegistryInstance(),
     ClBackend::GetIdStatic(),
-    []()
+    [](const EmptyInitializer&)
     {
         return IBackendInternalUniquePtr(new ClBackend);
     }
 };
 
-}
+} // anonymous namespace
 
 const BackendId& ClBackend::GetIdStatic()
 {
diff --git a/src/backends/cl/ClBackend.hpp b/src/backends/cl/ClBackend.hpp
index 4eae6c92ec..201702eee3 100644
--- a/src/backends/cl/ClBackend.hpp
+++ b/src/backends/cl/ClBackend.hpp
@@ -12,8 +12,8 @@ namespace armnn
 class ClBackend : public IBackendInternal
 {
 public:
-    ClBackend()  = default;
-    ~ClBackend() = default;
+    ClBackend() = default;
+    ~ClBackend() override = default;
 
     static const BackendId& GetIdStatic();
     const BackendId& GetId() const override { return GetIdStatic(); }
diff --git a/src/backends/cl/ClBackendContext.cpp b/src/backends/cl/ClBackendContext.cpp
new file mode 100644
index 0000000000..4d1be33fc6
--- /dev/null
+++ b/src/backends/cl/ClBackendContext.cpp
@@ -0,0 +1,111 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "ClBackendContext.hpp"
+#include "ClBackendId.hpp"
+#include "ClContextControl.hpp"
+
+#include <backends/BackendContextRegistry.hpp>
+#include <boost/log/trivial.hpp>
+
+#include <mutex>
+
+#ifdef ARMCOMPUTECL_ENABLED
+// Needed for the CL scheduler calls
+#include <arm_compute/core/CL/OpenCL.h>
+#include <arm_compute/core/CL/CLKernelLibrary.h>
+#include <arm_compute/runtime/CL/CLScheduler.h>
+#endif
+
+namespace armnn
+{
+
+namespace
+{
+
+static StaticRegistryInitializer<BackendContextRegistry> g_RegisterHelper
+{
+    BackendContextRegistryInstance(),
+    ClBackendId(),
+    [](const IRuntime::CreationOptions& options)
+    {
+        return IBackendContextUniquePtr(new ClBackendContext{options});
+    }
+};
+
+static std::mutex g_ContextControlMutex;
+
+std::shared_ptr<ClBackendContext::ContextControlWrapper>
+GetContextControlWrapper(const IRuntime::CreationOptions& options)
+{
+    static std::weak_ptr<ClBackendContext::ContextControlWrapper> contextControlWrapper;
+
+    std::lock_guard<std::mutex> lockGuard(g_ContextControlMutex);
+    std::shared_ptr<ClBackendContext::ContextControlWrapper> result;
+
+    if (contextControlWrapper.expired())
+    {
+        result = std::make_shared<ClBackendContext::ContextControlWrapper>(options);
+        contextControlWrapper = result;
+    }
+    else
+    {
+        result = contextControlWrapper.lock();
+    }
+
+    return result;
+}
+
+} // anonymous namespace
+
+
+#ifdef ARMCOMPUTECL_ENABLED
+struct ClBackendContext::ContextControlWrapper
+{
+    ContextControlWrapper(const IRuntime::CreationOptions& options)
+    : m_ClContextControl{options.m_GpuAccTunedParameters.get(),
+                         options.m_EnableGpuProfiling}
+    {
+    }
+
+    ~ContextControlWrapper()
+    {
+        if (arm_compute::CLScheduler::get().context()() != NULL)
+        {
+            // Waits for all queued CL requests to finish before unloading the network they may be using.
+            try
+            {
+                // Coverity fix: arm_compute::CLScheduler::sync() may throw an exception of type cl::Error.
+                arm_compute::CLScheduler::get().sync();
+                m_ClContextControl.ClearClCache();
+            }
+            catch (const cl::Error&)
+            {
+                BOOST_LOG_TRIVIAL(warning) << "WARNING: Runtime::UnloadNetwork(): an error occurred while waiting for "
+                                            "the queued CL requests to finish";
+            }
+        }
+    }
+
+    ClContextControl m_ClContextControl;
+};
+#else //ARMCOMPUTECL_ENABLED
+struct ClBackendContext::ContextControlWrapper
+{
+    ContextControlWrapper(const IRuntime::CreationOptions&){}
+};
+#endif //ARMCOMPUTECL_ENABLED
+
+ClBackendContext::ClBackendContext(const IRuntime::CreationOptions& options)
+: IBackendContext{options}
+, m_ContextControl{GetContextControlWrapper(options)}
+{
+}
+
+ClBackendContext::~ClBackendContext()
+{
+}
+
+} // namespace armnn
+\ No newline at end of file
diff --git a/src/backends/cl/ClBackendContext.hpp b/src/backends/cl/ClBackendContext.hpp
new file mode 100644
index 0000000000..3df403efc5
--- /dev/null
+++ b/src/backends/cl/ClBackendContext.hpp
@@ -0,0 +1,23 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+#pragma once
+
+#include <backends/IBackendContext.hpp>
+
+namespace armnn
+{
+
+class ClBackendContext : public IBackendContext
+{
+public:
+    ClBackendContext(const IRuntime::CreationOptions& options);
+    ~ClBackendContext() override;
+
+    struct ContextControlWrapper;
+private:
+    std::shared_ptr<ContextControlWrapper> m_ContextControl;
+};
+
+} // namespace armnn
+\ No newline at end of file
diff --git a/src/backends/cl/ClLayerSupport.cpp b/src/backends/cl/ClLayerSupport.cpp
index 6c5704d7ab..ebb90a5abf 100644
--- a/src/backends/cl/ClLayerSupport.cpp
+++ b/src/backends/cl/ClLayerSupport.cpp
@@ -53,7 +53,7 @@ ILayerSupportSharedPtr GetLayerSupportPointer()
 static StaticRegistryInitializer<LayerSupportRegistry> g_RegisterHelper{
     LayerSupportRegistryInstance(),
     ClBackendId(),
-    []()
+    [](const EmptyInitializer&)
     {
         return GetLayerSupportPointer();
     }
diff --git a/src/backends/cl/backend.mk b/src/backends/cl/backend.mk
index 97df8e4903..8433240ae9 100644
--- a/src/backends/cl/backend.mk
+++ b/src/backends/cl/backend.mk
@@ -8,6 +8,7 @@
 # file in the root of ArmNN
 
 BACKEND_SOURCES := \
+        ClBackendContext.cpp \
         ClBackend.cpp \
         ClContextControl.cpp \
         ClLayerSupport.cpp \
@@ -54,3 +55,4 @@ BACKEND_TEST_SOURCES := \
         test/ClRuntimeTests.cpp \
         test/Fp16SupportTest.cpp \
         test/OpenClTimerTest.cpp
+