Fixes #331 and other module.hpp-related issues.

* Comment tweaks
* Added missing function variants
* Fixed inconsistency in C++17-conditional-compiled code

examples/modified_cuda_samples/simpleDrvRuntimePTX/simpleDrvRuntimePTX.cpp

@@ -124,7 +124,7 @@ int main(int argc, char** argv)
 // first search for the module path before we load the results
     auto ptx_filename = create_ptx_file();
 
-    auto module = cuda::module::load_from_file(ptx_filename);
+    auto module = cuda::module::load_from_file(context, ptx_filename);
     auto vecAdd_kernel = module.get_kernel("VecAdd_kernel");
     auto dummy_kernel = module.get_kernel("dummy");
 

src/cuda/api/module.hpp

@@ -31,6 +31,8 @@ class kernel_t;
 
 namespace module {
 
+using handle_t = CUmodule;
+
 namespace detail_ {
 
 inline module_t construct(
@@ -59,23 +61,6 @@ ::std::string identify(const module_t &module);
 
 } // namespace detail_
 
-/**
- * Load a module from an appropriate compiled or semi-compiled file, allocating all
- * relevant resources for it.
- *
- * @param path of a cubin, PTX, or fatbin file constituting the module to be loaded.
- * @return the loaded module
- *
- * @note this covers cuModuleLoadFatBinary() even though that's not directly used
- */
-module_t load_from_file(const char *path, link::options_t link_options = {});
-
-module_t load_from_file(const ::std::string &path, link::options_t link_options = {});
-
-#if __cplusplus >= 201703L
-module_t load_from_file(const ::std::filesystem::path& path, link::options_t options = {});
-#endif
-
 /**
  * Create a CUDA driver module from raw module image data.
  *
@@ -195,37 +180,113 @@ namespace module {
 
 using handle_t = CUmodule;
 
-/**
-* Loads a populated module from a file on disk
-*
-* @param path Filesystem path of a fatbin, cubin or PTX file
-*
-* @todo: Do we really need link options here?
- * @todo: Make this take a context_t; and consider adding load_module methods to context_t
-*/
-inline module_t load_from_file(const char* path, link::options_t link_options)
+namespace detail_ {
+
+inline module_t load_from_file_in_current_context(
+	device::id_t current_context_device_id,
+	context::handle_t current_context_handle,
+	const char *path,
+	link::options_t link_options)
 {
 	handle_t new_module_handle;
 	auto status = cuModuleLoad(&new_module_handle, path);
 	throw_if_error(status, ::std::string("Failed loading a module from file ") + path);
-	bool do_take_ownership { true };
-	auto current_context_handle = context::current::detail_::get_handle();
-	auto current_device_id = context::detail_::get_device_id(current_context_handle);
-	return detail_::construct(current_device_id, current_context_handle, new_module_handle, link_options,
+	bool do_take_ownership{true};
+	return construct(
+		current_context_device_id,
+		current_context_handle,
+		new_module_handle,
+		link_options,
 		do_take_ownership);
 }
 
-inline module_t load_from_file(const ::std::string& path, link::options_t link_options)
+} // namespace detail_
+
+
+/**
+ * Load a module from an appropriate compiled or semi-compiled file, allocating all
+ * relevant resources for it.
+ *
+ * @param path of a cubin, PTX, or fatbin file constituting the module to be loaded.
+ * @return the loaded module
+ *
+ * @note this covers cuModuleLoadFatBinary() even though that's not directly used
+ *
+ * @todo: consider adding load_module methods to context_t
+ * @todo: When switching to the C++17 standard, use string_view's instead of the const char*
+ * and std::string reference
+ */
+///@{
+inline module_t load_from_file(
+	const context_t&  context,
+	const char*       path,
+	link::options_t   link_options = {})
+{
+	context::current::detail_::scoped_override_t set_context_for_this_scope(context.handle());
+	return detail_::load_from_file_in_current_context(
+		context.device_id(), context.handle(), path, link_options);
+}
+
+inline module_t load_from_file(
+	const context_t&      context,
+	const ::std::string&  path,
+	link::options_t       link_options = {})
+{
+	return load_from_file(context, path.c_str(), link_options);
+}
+
+inline module_t load_from_file(
+	const device_t&  device,
+	const char*      path,
+	link::options_t  link_options = {})
+{
+	auto pc = device.primary_context();
+	device::primary_context::detail_::increase_refcount(device.id());
+	return load_from_file(pc, path, link_options);
+}
+
+inline module_t load_from_file(
+	const device_t&       device,
+	const ::std::string*  path,
+	link::options_t       link_options = {})
 {
-	return load_from_file(path.c_str(), link_options);
+	return load_from_file(device, path->c_str(), link_options);
 }
 
+inline module_t load_from_file(
+	const char*      path,
+	link::options_t  link_options = {})
+{
+	return load_from_file(device::current::get(), path, link_options);
+}
+
+inline module_t load_from_file(
+	const ::std::string&  path,
+	link::options_t       link_options)
+{
+	return load_from_file(device::current::get(), path.c_str(), link_options);
+}
+
+
 #if __cplusplus >= 201703L
-inline module_t load_from_file(const ::std::filesystem::path& path)
+
+inline module_t load_from_file(
+	const device_t&                 device,
+	const ::std::filesystem::path&  path,
+	link::options_t                 link_options = {})
+{
+	return load_from_file(device, path.c_str(), link_options);
+}
+
+inline module_t load_from_file(
+	const ::std::filesystem::path&  path,
+	link::options_t                 link_options = {})
 {
-	return load_from_file(path.c_str());
+	return load_from_file(device::current::get(), path, link_options);
 }
+
 #endif
+///@}
 
 namespace detail_ {