From cffb4836e9887964dc595b6e63a271e0ce216c0d Mon Sep 17 00:00:00 2001
From: Chanwoo Choi <cw00.choi@samsung.com>
Date: Thu, 22 Apr 2021 19:12:04 +0900
Subject: [PATCH] halapi: Split the internal functions finely to get
 flexibility

New functions will use only __open_backend() without __close_backend()
in order to get the data of hal_backend structure. But this code have
been tightly coupled implemented in __get_backend and __put_backend.
In order to make the code more flexibility, split __get_backend/__put_backend
finley to two steps such as open/close and init/exit.

[Simple description for functions]
- __open_backend() : Open backend library and get backend symbol
- __close_backend() : Close backend library
- __init_backend() : After getting backend, initialize HAL backend driver
- __exit_backend() : After getting backend, exit HAL backend driver
- __get_backend()
	__open_backend()
	__init_backend()
	Increase usage_count
- __put_backend()
	__exit_backen()
	__close_backend()
	Decrease usage_count

[Change variable name in struct __hal_module_info]
- library_backend -> backend
- library_handle -> handle

Change-Id: I358e3f4db1991d26c8cf0498b3f37ec543da3e38
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 src/common.h         |   4 +-
 src/hal-api-common.c | 279 ++++++++++++++++++++++++++++++---------------------
 2 files changed, 169 insertions(+), 114 deletions(-)

diff --git a/src/common.h b/src/common.h
index c641610..69d7c13 100644
--- a/src/common.h
+++ b/src/common.h
@@ -93,8 +93,8 @@ struct __hal_module_info {
 
 	char *library_name;
 	char *library_name_64bit;
-	void *library_handle;
-	hal_backend *library_backend;
+	void *handle;
+	hal_backend *backend;
 	char *symbol_name;
 
 	unsigned int num_abi_versions;
diff --git a/src/hal-api-common.c b/src/hal-api-common.c
index 530d18c..18eab76 100644
--- a/src/hal-api-common.c
+++ b/src/hal-api-common.c
@@ -132,23 +132,157 @@ out:
 	return ret;
 }
 
-static int __get_backend(enum hal_module module, void **data, const char *library_name)
+static int __open_backend(struct __hal_module_info *info)
 {
-	struct __hal_module_info *info = NULL;
-	void *handle = NULL;
-	hal_backend *backend;
-	const char *symbol_name = NULL;
 	const char *backend_library_name = NULL;
-	int ret = 0;
+	int ret;
+
+	if (info->backend && info->handle)
+		return 0;
+
+	backend_library_name = get_backend_library_name(info);
+	if (!backend_library_name) {
+		_E("%s: Failed to get backend library name\n",
+				info->module_name);
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto err;
+	}
+
+	if (!info->symbol_name) {
+		_E("%s: Failed to get backend symbol name\n",
+				info->module_name);
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto err;
+	}
+
+	ret = access(backend_library_name, F_OK);
+	if (ret < 0) {
+		_E("%s: Failed to find backend library (%s)\n",
+				info->module_name, backend_library_name);
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto err;
+	}
+
+	info->handle = dlopen(backend_library_name, RTLD_LAZY);
+	if (!info->handle) {
+		_E("%s: Failed to load backend library (%s)\n",
+				info->module_name, dlerror());
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto err;
+	}
+
+	info->backend = dlsym(info->handle, info->symbol_name);
+	if (!info->backend) {
+		_E("%s: Failed to find backend data (%s)\n",
+				info->module_name, dlerror());
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto err_dlclose;
+	}
+
+	_I("%s: Open HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
+		info->module_name, info->backend->name, info->backend->vendor,
+		backend_library_name, info->usage_count,
+		program_invocation_name);
+
+	return 0;
+
+err_dlclose:
+	dlclose(info->handle);
+err:
+	info->backend = NULL;
+	info->handle = NULL;
+
+	return ret;
+}
+
+static void __close_backend(struct __hal_module_info *info)
+{
+	if (!info->backend || !info->handle)
+		return;
+
+	_I("%s: Close HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
+		info->module_name, info->backend->name, info->backend->vendor,
+		get_backend_library_name(info), info->usage_count,
+		program_invocation_name);
+
+	if (info->handle)
+		dlclose(info->handle);
+
+	info->backend = NULL;
+	info->handle = NULL;
+}
+
+static int __init_backend(struct __hal_module_info *info, void **data,
+				const char *library_name)
+{
+	int ret;
+
+	if (!info->handle || !info->backend) {
+		_I("%s: Has not yet dlopend backend\n", info->module_name);
+		return TIZEN_ERROR_NONE;
+	}
+
+	if (!info->backend->init) {
+		_E("%s: hal_backend->init() is NULL\n", info->module_name);
+		return TIZEN_ERROR_INVALID_PARAMETER;
+	}
+
+	/* Check HAL ABI Version */
+	ret = hal_common_check_backend_abi_version(info->module,
+						info->backend->abi_version);
+	if (ret < 0) {
+		_E("%s: Failed to check ABI version\n", info->module_name);
+		return TIZEN_ERROR_INVALID_PARAMETER;
+	}
+
+	/* Initialize backend */
+	ret = info->backend->init(data);
+	if (ret < 0) {
+		_E("%s: Failed to initialize backend: name(%s)/vendor(%s)\n",
+			info->module_name, info->backend->name,
+			info->backend->vendor);
+		return TIZEN_ERROR_INVALID_PARAMETER;
+	}
+
+	return TIZEN_ERROR_NONE;
+}
+
+static int __exit_backend(struct __hal_module_info *info, void *data,
+				const char *library_name)
+{
+	int ret;
+
+	if (!info->handle || !info->backend) {
+		_I("%s: Has not yet dlopend backend\n", info->module_name);
+		return TIZEN_ERROR_NONE;
+	}
+
+	/* Exit backend */
+	if (info->backend->exit) {
+		ret = info->backend->exit(data);
+		if (ret < 0) {
+			_E("%s: Failed to exit backend: name(%s)/vendor(%s)\n",
+				info->module_name, info->backend->name,
+				info->backend->vendor);
+			return TIZEN_ERROR_INVALID_PARAMETER;
+		}
+	}
+
+	return 0;
+}
+
+static int __get_backend(enum hal_module module, void **data,
+				const char *library_name)
+{
+	struct __hal_module_info *info = NULL;
+	int ret;
 
-	/* Check parameter whether is valid or not */
 	if (module <= HAL_MODULE_UNKNOWN || module >= HAL_MODULE_END) {
 		_E("Invalid parameter of HAL module (%d)\n", module);
 		return TIZEN_ERROR_INVALID_PARAMETER;
 	}
 
 	G_LOCK(hal_common_lock);
-
 	if (_hal_api_conf_init()) {
 		ret = TIZEN_ERROR_UNKNOWN;
 		goto err;
@@ -165,96 +299,27 @@ static int __get_backend(enum hal_module module, void **data, const char *librar
 		goto err;
 	}
 
-	backend_library_name = get_backend_library_name(info);
-	if (!backend_library_name) {
-		_E("%s: Failed to get backend library name\n",
+	ret = __open_backend(info);
+	if (ret < 0) {
+		_E("%s: Failed to get the backend library by dlopen\n",
 				info->module_name);
 		ret = TIZEN_ERROR_INVALID_PARAMETER;
 		goto err;
 	}
 
-	if (info->usage_count == 0) {
-		/*
-		 * Load HAL backend library at first loading time
-		 * when usage_count is 0.
-		 */
-		ret = access(backend_library_name, F_OK);
-		if (ret < 0) {
-			_E("%s: Failed to find backend library (%s)\n",
-					info->module_name, backend_library_name);
-			ret = TIZEN_ERROR_INVALID_PARAMETER;
-			goto err;
-		}
-
-		handle = dlopen(backend_library_name, RTLD_LAZY);
-		if (!handle) {
-			_E("%s: Failed to load backend library (%s)\n",
-					info->module_name, dlerror());
-			ret = TIZEN_ERROR_INVALID_PARAMETER;
-			goto err;
-		}
-
-		symbol_name = info->symbol_name;
-		if (!symbol_name) {
-			_E("%s: Failed to get backend symbol name\n",
-					info->module_name);
-			ret = TIZEN_ERROR_INVALID_PARAMETER;
-			goto err_dlclose;
-		}
-
-		backend = dlsym(handle, symbol_name);
-		if (!backend) {
-			_E("%s: Failed to find backend data (%s)\n",
-					info->module_name, dlerror());
-			ret = TIZEN_ERROR_INVALID_PARAMETER;
-			goto err_dlclose;
-		}
-
-		_I("%s: Open HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
-			info->module_name, backend->name, backend->vendor,
-			get_backend_library_name(info), info->usage_count,
-			program_invocation_name);
-
-		info->library_backend = backend;
-		info->library_handle = handle;
-	} else {
-		/*
-		 * Re-use the already loaded HAL backend instance
-		 * when usage_count is larger than 0.
-		 */
-		backend = info->library_backend;
-	}
-
-	/* Check HAL ABI Version */
-	ret = hal_common_check_backend_abi_version(module, backend->abi_version);
+	ret = __init_backend(info, data, NULL);
 	if (ret < 0) {
-		_E("%s: Failed to check ABI version\n",
+		_E("%s: Failed to initialize the backend library\n",
 				info->module_name);
 		ret = TIZEN_ERROR_INVALID_PARAMETER;
 		goto err_dlclose;
 	}
 
-	/* Get the backend module data */
-	if (!backend->init) {
-		_E("%s: hal_backend->init() is NULL\n",
-				info->module_name);
-		ret = TIZEN_ERROR_INVALID_PARAMETER;
-		goto err_dlclose;
-	}
-
-	ret = backend->init(data);
-	if (ret < 0) {
-		_E("%s: Failed to initialize backend: name(%s)/vendor(%s)\n",
-				info->module_name, backend->name, backend->vendor);
-		ret = TIZEN_ERROR_INVALID_PARAMETER;
-		goto err_dlclose;
-	}
-
 	info->usage_count++;
 
 	_I("%s: Get HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
-		info->module_name, backend->name, backend->vendor,
-		backend_library_name, info->usage_count,
+		info->module_name, info->backend->name, info->backend->vendor,
+		get_backend_library_name(info), info->usage_count,
 		program_invocation_name);
 
 	G_UNLOCK(hal_common_lock);
@@ -262,17 +327,16 @@ static int __get_backend(enum hal_module module, void **data, const char *librar
 
 err_dlclose:
 	_hal_api_conf_exit();
-	dlclose(handle);
+	__close_backend(info);
 err:
 	G_UNLOCK(hal_common_lock);
 	return ret;
 }
 
-static int __put_backend(enum hal_module module, void *data, const char *library_name)
+static int __put_backend(enum hal_module module, void *data,
+				const char *library_name)
 {
 	struct __hal_module_info *info = NULL;
-	hal_backend *backend = NULL;
-	void *handle = NULL;
 	int ret;
 
 	/* Check parameter whether is valid or not */
@@ -290,29 +354,30 @@ static int __put_backend(enum hal_module module, void *data, const char *library
 		goto out;
 	}
 
-	backend = info->library_backend;
-	handle = info->library_handle;
+	if (!info->handle || !info->backend) {
+		_I("%s: Has not yet dlopend backend\n", info->module_name);
+		ret = TIZEN_ERROR_NONE;
+		goto out;
+	}
 
-	if (!backend || info->usage_count == 0) {
+	if (!info->usage_count) {
 		_I("%s: Already fully put for HAL module\n", info->module_name);
-		ret = TIZEN_ERROR_NONE;
+		ret =  TIZEN_ERROR_NONE;
 		goto out;
 	}
 
-	if (backend->exit) {
-		ret = backend->exit(data);
-		if (ret < 0) {
-			_E("%s: Failed to exit backend: name(%s)/vendor(%s)\n",
-				info->module_name, backend->name, backend->vendor);
-			ret = TIZEN_ERROR_INVALID_PARAMETER;
-			goto out;
-		}
+	ret = __exit_backend(info, data, NULL);
+	if (ret < 0) {
+		_E("%s: Failed to exit the backend library\n",
+				info->module_name);
+		ret = TIZEN_ERROR_INVALID_PARAMETER;
+		goto out;
 	}
 
 	info->usage_count--;
 
 	_I("%s: Put HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
-		info->module_name, backend->name, backend->vendor,
+		info->module_name, info->backend->name, info->backend->vendor,
 		get_backend_library_name(info), info->usage_count,
 		program_invocation_name);
 
@@ -321,17 +386,7 @@ static int __put_backend(enum hal_module module, void *data, const char *library
 		goto out;
 	}
 
-	_I("%s: Close HAL backend: name(%s)/vendor(%s)/library(%s)/count(%d) by %s\n",
-		info->module_name, backend->name, backend->vendor,
-		get_backend_library_name(info), info->usage_count,
-		program_invocation_name);
-
-	if (handle)
-		dlclose(handle);
-
-	info->library_backend = NULL;
-	info->library_handle = NULL;
-
+	__close_backend(info);
 	_hal_api_conf_exit();
 
 	ret = TIZEN_ERROR_NONE;
-- 
2.7.4