Modify the implementation of the plugin manager take over

    A plugin that is taken over, if the plugin was called before being taken over
    and has a registered SESSION_EVENT_CLOSING event,
    it will be called again when the SESSION_EVENT_CLOSING event comes.
    Otherwise, the plugin will not be called.

6 files changed, 55 insertions, 31 deletions

diff --git a/readme.md b/readme.md
index b6d1023..e889e1d 100644
--- a/readme.md
+++ b/readme.md
@@ -48,12 +48,18 @@ Plugin Management APIs
 pm_session_dettach_me(session);
 
 /*
- * The current plugin takes over the current session, the pm_session_take_over setting flag disables other plugins,
+ * The current plugin(cb2) takes over the current session, the pm_session_take_over setting flag disables other plugins,
  * and the current session does not call other plugins except for the SESSION_EVENT_CLOSING event.
  *
- * The current plugin may be taken over while the session is open (SESSION_EVENT_OPENING),
- * other plugins event_cb is not called, the session pme on other plugins is NULL,
- * When the session is closed (SESSION_EVENT_CLOSING), call other plugin even_cb to destroy pme must check if pme is NULL.
+ *                               +-----+   +-----+   +-----+   +-----+
+ * Plugin runtime callback list: | cb1 |-->| cb2 |-->| cb3 |-->| cb4 |
+ *                               +-----+   +-----+   +-----+   +-----+
+ *                                           /|\
+ *                                            |
+ *                         plugin cb2 run pm_session_take_over
+ * 
+ * A plugin(cb1/cb3/cb4) that is taken over, if the plugin was called before being taken over and has a registered SESSION_EVENT_CLOSING event,
+ * it will be called again when the SESSION_EVENT_CLOSING event comes. Otherwise, the plugin will not be called.
  */
 pm_session_take_over(session);
 ```
diff --git a/sdk/include/plugin.h b/sdk/include/plugin.h
index 301363a..7042bbe 100644
--- a/sdk/include/plugin.h
+++ b/sdk/include/plugin.h
@@ -22,12 +22,18 @@ typedef void plugin_exit_callback(void);
 void pm_session_dettach_me(const struct stellar_session *session);
 
 /*
- * The current plugin takes over the current session, the pm_session_take_over setting flag disables other plugins,
+ * The current plugin(cb2) takes over the current session, the pm_session_take_over setting flag disables other plugins,
  * and the current session does not call other plugins except for the SESSION_EVENT_CLOSING event.
  *
- * The current plugin may be taken over while the session is open (SESSION_EVENT_OPENING),
- * other plugins event_cb is not called, the session pme on other plugins is NULL,
- * When the session is closed (SESSION_EVENT_CLOSING), call other plugin even_cb to destroy pme must check if pme is NULL.
+ *                               +-----+   +-----+   +-----+   +-----+
+ * Plugin runtime callback list: | cb1 |-->| cb2 |-->| cb3 |-->| cb4 |
+ *                               +-----+   +-----+   +-----+   +-----+
+ *                                           /|\
+ *                                            |
+ *                         plugin cb2 run pm_session_take_over
+ * 
+ * A plugin(cb1/cb3/cb4) that is taken over, if the plugin was called before being taken over and has a registered SESSION_EVENT_CLOSING event,
+ * it will be called again when the SESSION_EVENT_CLOSING event comes. Otherwise, the plugin will not be called.
  */
 void pm_session_take_over(const struct stellar_session *session);
 
diff --git a/src/plugin_manager/plugin_manager.cpp b/src/plugin_manager/plugin_manager.cpp
index d90122c..88aae1e 100644
--- a/src/plugin_manager/plugin_manager.cpp
+++ b/src/plugin_manager/plugin_manager.cpp
@@ -19,11 +19,12 @@ enum plugin_status
 
 struct callback_runtime
 {
-	enum plugin_status status;
 	void *cb_args;
+	fn_session_event_callback *event_cb;
 
 	enum session_event_type event;
-	fn_session_event_callback *event_cb;
+	enum plugin_status status;
+	int is_be_called;
 };
 
 struct session_plugin_ctx
@@ -95,6 +96,7 @@ static struct session_plugin_ctx *plugin_manager_create_plugin_ctx(struct plugin
 
 		for (int i = 0; i < plug_ctx->callback_num; i++)
 		{
+			plug_ctx->callbacks[i].is_be_called = 0;
 			plug_ctx->callbacks[i].status = PLUGIN_STATUS_NORMAL;
 			plug_ctx->callbacks[i].event = elem->callbacks[i].event;
 			plug_ctx->callbacks[i].event_cb = elem->callbacks[i].event_cb;
@@ -435,12 +437,7 @@ void plugin_manager_dispatch(struct plugin_manager *plug_mgr, struct stellar_eve
 			}
 			else if (runtime->status == PLUGIN_STATUS_TAKEN_OVER)
 			{
-				/*
-				 * This plugin may be taken over when the session is open (SESSION_EVENT_OPENING),
-				 * and the pme may be NULL when event_cb() is run to free memory with the session is closed (SESSION_EVENT_CLOSING).
-				 * So, The plugin must check whether the pme is NULL before freeing memory.
-				 */
-				if (event_type & SESSION_EVENT_CLOSING)
+				if ((event_type & SESSION_EVENT_CLOSING) && (runtime->event & SESSION_EVENT_CLOSING) && runtime->is_be_called)
 				{
 					plug_ctx->callback_index = i;
 					plugin_manager_log(DEBUG, "dispatch, run event_cb: %p, plugin status: 'taken over', session: %s, event: (%d, %s)", runtime->event_cb, session_name, event_type, event_str_buffer);
@@ -459,6 +456,7 @@ void plugin_manager_dispatch(struct plugin_manager *plug_mgr, struct stellar_eve
 					plug_ctx->callback_index = i;
 					plugin_manager_log(DEBUG, "dispatch, run event_cb: %p, plugin status: 'normal', session: %s, event: (%d, %s)", runtime->event_cb, session_name, event_type, event_str_buffer);
 					runtime->event_cb(seesion, event_type, packet, payload, payload_len, &runtime->cb_args);
+					runtime->is_be_called = 1;
 				}
 				else
 				{
@@ -499,12 +497,18 @@ void pm_session_dettach_me(const struct stellar_session *session)
 }
 
 /*
- * The current plugin takes over the current session, the pm_session_take_over setting flag disables other plugins,
+ * The current plugin(cb2) takes over the current session, the pm_session_take_over setting flag disables other plugins,
  * and the current session does not call other plugins except for the SESSION_EVENT_CLOSING event.
  *
- * The current plugin may be taken over while the session is open (SESSION_EVENT_OPENING),
- * other plugins event_cb is not called, the session pme on other plugins is NULL,
- * When the session is closed (SESSION_EVENT_CLOSING), call other plugin even_cb to destroy pme must check if pme is NULL
+ *                               +-----+   +-----+   +-----+   +-----+
+ * Plugin runtime callback list: | cb1 |-->| cb2 |-->| cb3 |-->| cb4 |
+ *                               +-----+   +-----+   +-----+   +-----+
+ *                                           /|\
+ *                                            |
+ *                         plugin cb2 run pm_session_take_over
+ * 
+ * A plugin(cb1/cb3/cb4) that is taken over, if the plugin was called before being taken over and has a registered SESSION_EVENT_CLOSING event,
+ * it will be called again when the SESSION_EVENT_CLOSING event comes. Otherwise, the plugin will not be called.
  */
 void pm_session_take_over(const struct stellar_session *session)
 {
diff --git a/src/plugin_manager/plugin_manager_config.cpp b/src/plugin_manager/plugin_manager_config.cpp
index 1772900..b73fb8d 100644
--- a/src/plugin_manager/plugin_manager_config.cpp
+++ b/src/plugin_manager/plugin_manager_config.cpp
@@ -149,6 +149,10 @@ static int toml_parse_session_section(toml_table_t *root, struct plugin_manager_
             (config->session_section[config->session_section_num].event) = (enum session_event_type)((config->session_section[config->session_section_num].event) | type_int);
             safe_free(type_str.u.s);
         }
+        if ((config->session_section[config->session_section_num].event & SESSION_EVENT_CLOSING) == 0)
+        {
+            plugin_manager_log(WARN, "can't find 'SESSION_EVENT_CLOSING' value for 'SESSION_EVENT_TYPE' configuration item in '[SESSION_NAME.%s]' section of %s", session_name, file);
+        }
 
         config->session_section_num++;
     }
diff --git a/src/plugin_manager/plugin_manager_util.cpp b/src/plugin_manager/plugin_manager_util.cpp
index 08f903f..43de099 100644
--- a/src/plugin_manager/plugin_manager_util.cpp
+++ b/src/plugin_manager/plugin_manager_util.cpp
@@ -29,15 +29,14 @@ struct event_type_map
 	enum session_event_type type_int;
 };
 
-static struct event_type_map evtype_map[] =
-	{
-		{"SESSION_EVENT_UNKNOWN", SESSION_EVENT_UNKNOWN},
-		{"SESSION_EVENT_OPENING", SESSION_EVENT_OPENING},
-		{"SESSION_EVENT_RAWPKT", SESSION_EVENT_RAWPKT},
-		{"SESSION_EVENT_ORDPKT", SESSION_EVENT_ORDPKT},
-		{"SESSION_EVENT_META", SESSION_EVENT_META},
-		{"SESSION_EVENT_CLOSING", SESSION_EVENT_CLOSING},
-		{"SESSION_EVENT_ALL", SESSION_EVENT_ALL},
+static struct event_type_map evtype_map[] = {
+	{"SESSION_EVENT_UNKNOWN", SESSION_EVENT_UNKNOWN},
+	{"SESSION_EVENT_OPENING", SESSION_EVENT_OPENING},
+	{"SESSION_EVENT_RAWPKT", SESSION_EVENT_RAWPKT},
+	{"SESSION_EVENT_ORDPKT", SESSION_EVENT_ORDPKT},
+	{"SESSION_EVENT_META", SESSION_EVENT_META},
+	{"SESSION_EVENT_CLOSING", SESSION_EVENT_CLOSING},
+	{"SESSION_EVENT_ALL", SESSION_EVENT_ALL},
 };
 
 enum session_event_type session_event_type_str2int(const char *evtype_str)
diff --git a/src/plugin_manager/plugin_manager_util.h b/src/plugin_manager/plugin_manager_util.h
index 13b85db..890e61d 100644
--- a/src/plugin_manager/plugin_manager_util.h
+++ b/src/plugin_manager/plugin_manager_util.h
@@ -38,8 +38,9 @@ char *safe_dup(const char *str);
 enum plugin_manager_log_level
 {
     DEBUG = 0x11,
-    INFO = 0x12,
-    ERROR = 0x13,
+    WARN = 0x12,
+    INFO = 0x13,
+    ERROR = 0x14,
 };
 
 #ifndef plugin_manager_log
@@ -51,6 +52,10 @@ enum plugin_manager_log_level
             fprintf(stdout, "PLUGIN_MANAGER [DEBUG] " format "\n", ##__VA_ARGS__); \
             fflush(stdout);                                                        \
             break;                                                                 \
+        case WARN:                                                                 \
+            fprintf(stdout, "PLUGIN_MANAGER [WARN] " format "\n", ##__VA_ARGS__);  \
+            fflush(stdout);                                                        \
+            break;                                                                 \
         case INFO:                                                                 \
             fprintf(stdout, "PLUGIN_MANAGER [INFO] " format "\n", ##__VA_ARGS__);  \
             fflush(stdout);                                                        \