!452 fix bugs when cancel autonomous transaction

Merge pull request !452 from scarbor_fair/bug_in_AT

src/common/backend/utils/error/elog.cpp

@@ -590,7 +590,7 @@ void errfinish(int dummy, ...)
             if (t_thrd.msqueue_cxt.is_changed) {
                 pq_stop_redirect_to_shm_mq();
             }
-            if (t_thrd.autonomous_cxt.handle) {
+            if (t_thrd.autonomous_cxt.handle.slot >= 0) {
                 StopBackgroundWorker();
             }
         }

src/gausskernel/process/postmaster/bgworker.cpp

@@ -94,11 +94,6 @@ typedef struct BackgroundWorkerArray {
     BackgroundWorkerSlot slot[FLEXIBLE_ARRAY_MEMBER];
 } BackgroundWorkerArray;
 
-struct BackgroundWorkerHandle {
-    int slot;
-    uint64 generation;
-};
-
 /*
  * List of internal background worker entry points.  We need this for
  * reasons explained in LookupBackgroundWorkerFunction(), below.
@@ -1172,7 +1167,7 @@ void TerminateBackgroundWorker(const BackgroundWorkerHandle *handle)
 {
     bool signal_postmaster = false;
 
-    Assert(handle->slot < g_instance.attr.attr_storage.max_background_workers);
+    Assert( handle->slot >= 0 && handle->slot < g_instance.attr.attr_storage.max_background_workers);
     BackgroundWorkerSlot* slot = &t_thrd.bgworker_cxt.background_worker_data->slot[handle->slot];
 
     /* Set terminate flag in shared memory, unless slot has been reused. */
@@ -1191,9 +1186,11 @@ void TerminateBackgroundWorker(const BackgroundWorkerHandle *handle)
 
 void StopBackgroundWorker() 
 {
-    TerminateBackgroundWorker(t_thrd.autonomous_cxt.handle);
-    (void)WaitForBackgroundWorkerShutdown(t_thrd.autonomous_cxt.handle);
-    t_thrd.autonomous_cxt.handle = NULL;
+    TerminateBackgroundWorker(&(t_thrd.autonomous_cxt.handle));
+    (void)WaitForBackgroundWorkerShutdown(&(t_thrd.autonomous_cxt.handle));
+    // reset handle of autonomous_cxt
+    t_thrd.autonomous_cxt.handle.slot = -1;
+    t_thrd.autonomous_cxt.handle.generation = 0;
 }
 
 /*

src/gausskernel/process/tcop/autonomous.cpp

@@ -137,7 +137,7 @@ AutonomousSession *AutonomousSessionStart(void)
     shm_toc_estimate_chunk(&e, guc_len);
     shm_toc_estimate_keys(&e, AUTONOMOUS_NKEYS);
     segsize = shm_toc_estimate(&e);
-    seg = (char *)palloc(sizeof(char) * segsize);
+    seg = (char *)MemoryContextAlloc(t_thrd.top_mem_cxt, sizeof(char) * segsize);
 
     session->seg = seg;
 
@@ -191,7 +191,8 @@ AutonomousSession *AutonomousSessionStart(void)
     shm_mq_set_handle(session->command_qh, session->worker_handle);
     shm_mq_set_handle(session->response_qh, session->worker_handle);
 
-    t_thrd.autonomous_cxt.handle = session->worker_handle;
+    t_thrd.autonomous_cxt.handle.slot = session->worker_handle->slot;
+    t_thrd.autonomous_cxt.handle.generation = session->worker_handle->generation;
 
     bgwstatus = WaitForBackgroundWorkerStartup(session->worker_handle, &pid);
     if (bgwstatus != BGWH_STARTED)
@@ -246,7 +247,8 @@ void AutonomousSessionEnd(AutonomousSession *session)
     pfree(session->worker_handle);
     pfree(session->seg);
     pfree(session);
-    t_thrd.autonomous_cxt.handle = NULL;
+    t_thrd.autonomous_cxt.handle.slot = -1;
+    t_thrd.autonomous_cxt.handle.generation = 0;
 }
 
 AutonomousResult *AutonomousSessionExecute(AutonomousSession *session, const char *sql)

src/gausskernel/process/tcop/postgres.cpp

@@ -7436,7 +7436,7 @@ int PostgresMain(int argc, char* argv[], const char* dbname, const char* usernam
         if (t_thrd.msqueue_cxt.is_changed) {
             pq_stop_redirect_to_shm_mq();
         }
-        if (t_thrd.autonomous_cxt.handle) {
+        if (t_thrd.autonomous_cxt.handle.slot >= 0) {
             StopBackgroundWorker();
         }
         gstrace_tryblock_exit(true, oldTryCounter);

src/gausskernel/process/threadpool/knl_thread.cpp

@@ -1390,7 +1390,8 @@ static void knl_t_heartbeat_init(knl_t_heartbeat_context* heartbeat_cxt)
 static void knl_t_autonomous_init(knl_t_autonomous_context* autonomous_cxt)
 {
     autonomous_cxt->isnested = false;
-    autonomous_cxt->handle = NULL;
+    autonomous_cxt->handle.slot = -1;
+    autonomous_cxt->handle.generation = 0;
     autonomous_cxt->sqlstmt = NULL;
     autonomous_cxt->check_client_encoding_hook = NULL;
 }

src/include/knl/knl_thread.h

@@ -2690,7 +2690,7 @@ typedef void (*check_client_encoding_hook_type)(void);
 typedef struct knl_t_autonomous_context {
     PLpgSQL_expr* sqlstmt;
     bool isnested;
-    BackgroundWorkerHandle* handle;
+    BackgroundWorkerHandle handle;
     check_client_encoding_hook_type check_client_encoding_hook;
 } knl_t_autonomous_context;
 

src/include/postmaster/bgworker.h

@@ -106,7 +106,10 @@ typedef enum BgwHandleStatus {
     BGWH_POSTMASTER_DIED        /* postmaster died; worker status unclear */
 } BgwHandleStatus;
 
-struct BackgroundWorkerHandle;
+struct BackgroundWorkerHandle {
+    int slot;
+    uint64 generation;
+};
 typedef struct BackgroundWorkerHandle BackgroundWorkerHandle;
 struct BackgroundWorkerArray;