WIP: add an OpenCL ICD loader extension to shut down and free memory

CMakeLists.txt

@@ -219,6 +219,31 @@ if((CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME OR OPENCL_ICD_LOADER_BUILD_TESTING)
     add_subdirectory (test)
 endif()
 
+if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME)
+    find_package(Python3 COMPONENTS Interpreter)
+    set(OPENCL_ICD_LOADER_XML_PATH CACHE FILEPATH "Path to cl.xml for OpenCL ICD Loader code generation")
+    set(OPENCL_ICD_LOADER_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/generated)
+    add_custom_target(icd_loader_generate
+        COMMAND ${CMAKE_COMMAND} -E make_directory ${OPENCL_ICD_LOADER_OUTPUT_DIRECTORY}
+        COMMAND ${CMAKE_COMMAND} -E chdir ${CMAKE_CURRENT_SOURCE_DIR}/scripts
+            ${Python3_EXECUTABLE} gen_loader.py
+            -registry ${OPENCL_ICD_LOADER_XML_PATH}
+            -o ${OPENCL_ICD_LOADER_OUTPUT_DIRECTORY}
+        COMMAND ${CMAKE_COMMAND} -E chdir ${CMAKE_CURRENT_SOURCE_DIR}/scripts
+            ${Python3_EXECUTABLE} gen_print_layer.py
+            -registry ${OPENCL_ICD_LOADER_XML_PATH}
+            -o ${OPENCL_ICD_LOADER_OUTPUT_DIRECTORY}
+    )
+    add_custom_target(icd_loader_copy
+        COMMAND ${CMAKE_COMMAND} -E copy
+            ${OPENCL_ICD_LOADER_OUTPUT_DIRECTORY}/icd_dispatch_generated.c
+            ${CMAKE_CURRENT_SOURCE_DIR}/loader
+        COMMAND ${CMAKE_COMMAND} -E copy
+            ${OPENCL_ICD_LOADER_OUTPUT_DIRECTORY}/icd_print_layer_generated.c
+            ${CMAKE_CURRENT_SOURCE_DIR}/test/layer
+    )
+endif()
+
 include (GNUInstallDirs)
 
 install(

loader/icd.c

@@ -303,10 +303,10 @@ void khrIcdLayerAdd(const char *libraryName)
     if (khrFirstLayer) {
         targetDispatch = &(khrFirstLayer->dispatch);
     } else {
-        targetDispatch = &khrMasterDispatch;
+        targetDispatch = &khrActualDispatch;
     }
 
-    loaderDispatchNumEntries = sizeof(khrMasterDispatch)/sizeof(void*);
+    loaderDispatchNumEntries = sizeof(khrActualDispatch)/sizeof(void*);
     result = p_clInitLayer(
         loaderDispatchNumEntries,
         targetDispatch,
@@ -430,3 +430,65 @@ void khrIcdContextPropertiesGetPlatform(const cl_context_properties *properties,
     }
 }
 
+#if defined(CL_ENABLE_LAYERS)
+extern struct _cl_icd_dispatch khrShutdownDispatch;
+static struct KHRLayer shutdown_layer = {0};
+#endif
+
+void khrIcdShutdown(void)
+{
+    KHRicdVendor* prevVendor = NULL;
+    KHRicdVendor* vendor = NULL;
+
+#if defined(CL_ENABLE_LAYERS)
+    struct KHRLayer* layer = khrFirstLayer;
+    struct KHRLayer* nextLayer = NULL;
+#endif
+
+    KHR_ICD_TRACE("Shutdown starting\n");
+
+#if defined(CL_ENABLE_LAYERS)
+    KHR_ICD_TRACE("Installing shutdown layer\n");
+    shutdown_layer.dispatch = khrShutdownDispatch;
+    khrFirstLayer = &shutdown_layer;
+#endif
+
+#if defined(CL_ENABLE_LAYERS)
+    // Layers are freed in the reverse order they were added,
+    // so front-to-back.
+    KHR_ICD_TRACE("Cleaning up Layers\n");
+    // Handle the case where shutdown is called twice:
+    if (layer != &shutdown_layer) {
+        while (layer) {
+            nextLayer = layer->next;
+#if defined(CL_LAYER_INFO)
+            free(layer->libraryName);
+#endif
+            free(layer);
+            layer = nextLayer;
+        }
+    }
+#endif
+
+    // Vendors are freed in the reverse order they were added,
+    // so back-to-front.
+    KHR_ICD_TRACE("Cleaning up Vendors\n");
+    while (khrIcdVendors) {
+        if (khrIcdVendors->next == NULL) {
+            vendor = khrIcdVendors;
+            khrIcdVendors = NULL;
+        } else {
+            prevVendor = khrIcdVendors;
+            vendor = khrIcdVendors->next;
+            while (vendor->next) {
+                prevVendor = vendor;
+                vendor = vendor->next;
+            }
+            prevVendor->next = NULL;
+        }
+        free(vendor->suffix);
+        free(vendor);
+    }
+
+    KHR_ICD_TRACE("Shutdown complete\n");
+}

loader/icd.h

@@ -117,14 +117,14 @@ struct KHRLayer
 #ifdef CL_LAYER_INFO
     // The layer library name
     char *libraryName;
-    // the pointer to the clGetLayerInfo funciton
+    // the pointer to the clGetLayerInfo function
     void *p_clGetLayerInfo;
 #endif
 };
 
 // the global layer state
 extern struct KHRLayer * khrFirstLayer;
-extern struct _cl_icd_dispatch khrMasterDispatch;
+extern struct _cl_icd_dispatch khrActualDispatch;
 #endif // defined(CL_ENABLE_LAYERS)
 
 /* 
@@ -175,6 +175,8 @@ void khrIcdContextPropertiesGetPlatform(
     const cl_context_properties *properties, 
     cl_platform_id *outPlatform);
 
+void khrIcdShutdown(void);
+
 // internal tracing macros
 #define KHR_ICD_TRACE(...) \
 do \

loader/icd_dispatch.c

@@ -65,6 +65,13 @@ clGetICDLoaderInfoOCLICD(
     return CL_SUCCESS;
 }
 
+// !!! TODO: Switch this to use the function typedef when it's in the headers!
+static cl_int CL_API_CALL clShutdownOCLICD(void)
+{
+    khrIcdShutdown();
+    return CL_SUCCESS;
+}
+
 static void* khrIcdGetExtensionFunctionAddress(const char* function_name)
 {
 // Most extensions, including multi-vendor KHR and EXT extensions,
@@ -139,6 +146,9 @@ static void* khrIcdGetExtensionFunctionAddress(const char* function_name)
     // cl_icdl
     KHR_ICD_CHECK_EXTENSION_FUNCTION(clGetICDLoaderInfoOCLICD);
 
+    // cl_icd_shutdown
+    KHR_ICD_CHECK_EXTENSION_FUNCTION(clShutdownOCLICD);
+
 #undef KHR_ICD_CHECK_EXTENSION_FUNCTION
 
     return NULL;