0002-session_end_hook-v4.patch

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 24346fb..0dbbd7b 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -169,9 +169,9 @@ static ProcSignalReason RecoveryConflictReason;
 static MemoryContext row_description_context = NULL;
 static StringInfoData row_description_buf;
 
-/* Hook for plugins to get control at start of session */
+/* Hook for plugins to get control at start or end of session */
 session_start_hook_type session_start_hook = NULL;
-
+session_end_hook_type session_end_hook = NULL;
 /* ----------------------------------------------------------------
  *		decls for routines only used in this file
  * ----------------------------------------------------------------
@@ -196,6 +196,7 @@ static void drop_unnamed_stmt(void);
 static void log_disconnections(int code, Datum arg);
 static void enable_statement_timeout(void);
 static void disable_statement_timeout(void);
+static void do_session_end_hook(int code, Datum arg);
 
 
 /* ----------------------------------------------------------------
@@ -3864,6 +3865,12 @@ PostgresMain(int argc, char *argv[],
 		(*session_start_hook) (dbname, username);
 
 	/*
+	 * Setup handler to session end hook
+	 */
+	if (IsUnderPostmaster)
+		on_proc_exit(do_session_end_hook, 0);
+
+	/*
 	 * POSTGRES main processing loop begins here
 	 *
 	 * If an exception is encountered, processing resumes here so we abort the
@@ -4615,3 +4622,15 @@ disable_statement_timeout(void)
 		stmt_timeout_active = false;
 	}
 }
+
+/*
+ * on_proc_exit handler to call session end hook
+ */
+static void
+do_session_end_hook(int code, Datum arg)
+{
+	Port	   *port = MyProcPort;
+
+	if (session_end_hook)
+		(*session_end_hook) (port->database_name, port->user_name);
+}
\ No newline at end of file
diff --git a/src/include/tcop/tcopprot.h b/src/include/tcop/tcopprot.h
index d349592..b7fb8c3 100644
--- a/src/include/tcop/tcopprot.h
+++ b/src/include/tcop/tcopprot.h
@@ -35,10 +35,14 @@ extern PGDLLIMPORT const char *debug_query_string;
 extern int	max_stack_depth;
 extern int	PostAuthDelay;
 
-/* Hook for plugins to get control at start of session */
+/* Hook for plugins to get control at start and end of session */
 typedef void (*session_start_hook_type) (const char *dbname,
 										 const char *username);
+typedef void (*session_end_hook_type) (const char *dbname,
+									   const char *username);
+
 extern PGDLLIMPORT session_start_hook_type session_start_hook;
+extern PGDLLIMPORT session_end_hook_type session_end_hook;
 
 /* GUC-configurable parameters */