Defined private interface to THD variables, first step to plugin API

include/mysql/thread_pool_priv.h

@@ -39,8 +39,26 @@
 #include <table.h>
 
 /* Needed to get access to scheduler variables */
-void* thd_get_scheduler(THD *thd);
+void* thd_get_scheduler_data(THD *thd);
+void thd_set_scheduler_data(THD *thd, void *data);
 PSI_thread* thd_get_psi(THD *thd);
+void thd_set_psi(THD *thd, PSI_thread *psi);
+
+/* Interface to THD variables and functions */
+void thd_set_killed(THD *thd);
+void thd_clear_errors(THD *thd);
+void thd_set_thread_stack(THD *thd, char *stack_start);
+void thd_lock_connection_data(THD *thd);
+void thd_unlock_connection_data(THD *thd);
+void thd_close_connection(THD *thd);
+THD *thd_get_current_thd();
+void thd_new_connection_setup(THD *thd, char *stack_start);
+void thd_lock_data(THD *thd);
+void thd_unlock_data(THD *thd);
+bool thd_is_transaction_active(THD *thd);
+int thd_connection_has_data(THD *thd);
+void thd_set_net_read_write(THD *thd, uint val);
+void thd_set_mysys_var(THD *thd, st_my_thread_var *mysys_var);
 
 /*
   The thread pool must be able to execute commands using the connection

sql/sql_class.cc

@@ -217,26 +217,222 @@ bool foreign_key_prefix(Key *a, Key *b)
 ** Thread specific functions
 ****************************************************************************/
 
+/**
+  Get reference to scheduler data object
+
+  @param thd            THD object
+
+  @retval               Scheduler data object on THD
+*/
 void *thd_get_scheduler_data(THD *thd)
 {
   return thd->scheduler.data;
 }
 
+/**
+  Set reference to Scheduler data object for THD object
+
+  @param thd            THD object
+  @param psi            Scheduler data object to set on THD
+*/
 void thd_set_scheduler_data(THD *thd, void *data)
 {
   thd->scheduler.data= data;
 }
 
+/**
+  Get reference to Performance Schema object for THD object
+
+  @param thd            THD object
+
+  @retval               Performance schema object for thread on THD
+*/
 PSI_thread *thd_get_psi(THD *thd)
 {
   return thd->scheduler.m_psi;
 }
 
+/**
+  Set reference to Performance Schema object for THD object
+
+  @param thd            THD object
+  @param psi            Performance schema object for thread
+*/
 void thd_set_psi(THD *thd, PSI_thread *psi)
 {
   thd->scheduler.m_psi= psi;
 }
 
+/**
+  Set the state on connection to killed
+
+  @param thd               THD object
+*/
+void thd_set_killed(THD *thd)
+{
+  thd->killed= THD::KILL_CONNECTION;
+}
+
+/**
+  Clear errors from the previous THD
+
+  @param thd              THD object
+*/
+void thd_clear_errors(THD *thd)
+{
+  my_errno= 0;
+  thd->mysys_var->abort= 0;
+}
+
+/**
+  Set thread stack in THD object
+
+  @param thd              Thread object
+  @param stack_start      Start of stack to set in THD object
+*/
+void thd_set_thread_stack(THD *thd, char *stack_start)
+{
+  thd->thread_stack= stack_start;
+}
+
+/**
+  Lock connection data for the set of connections this connection
+  belongs to
+
+  @param thd                       THD object
+*/
+void thd_lock_connection_data(THD *thd)
+{
+  (void)thd;
+  mysql_mutex_lock(&LOCK_thread_count);
+}
+
+/**
+  Lock connection data for the set of connections this connection
+  belongs to
+
+  @param thd                       THD object
+*/
+void thd_unlock_connection_data(THD *thd)
+{
+  (void)thd;
+  mysql_cond_broadcast(&COND_thread_count);
+  mysql_mutex_unlock(&LOCK_thread_count);
+}
+
+/**
+  Close the socket used by this connection
+
+  @param thd                THD object
+*/
+void thd_close_connection(THD *thd)
+{
+  if (thd->net.vio)
+    vio_close(thd->net.vio);
+}
+
+/**
+  Get current THD object from thread local data
+
+  @retval     The THD object for the thread, NULL if not connection thread
+*/
+THD *thd_get_current_thd()
+{
+  return current_thd;
+}
+
+/**
+  Set up various THD data for a new connection
+
+  thd_new_connection_setup
+
+  @param              thd            THD object
+  @param              stack_start    Start of stack for connection
+*/
+void thd_new_connection_setup(THD *thd, char *stack_start)
+{
+#ifdef HAVE_PSI_INTERFACE
+  if (PSI_server)
+    thd_set_psi(thd,
+                PSI_server->new_thread(key_thread_one_connection,
+                                       thd,
+                                       thd_get_thread_id((MYSQL_THD)thd)));
+#endif
+  thd->set_time();
+  thd->prior_thr_create_utime= thd->thr_create_utime= thd->start_utime=
+    my_micro_time();
+  threads.append(thd);
+  thd_unlock_connection_data(thd);
+  DBUG_PRINT("info", ("init new connection. thd: 0x%lx fd: %d",
+          (ulong)thd, thd->net.vio->sd));
+  thd_set_thread_stack(thd, stack_start);
+}
+
+/**
+  Lock data that needs protection in THD object
+
+  @param thd                   THD object
+*/
+void thd_lock_data(THD *thd)
+{
+  mysql_mutex_lock(&thd->LOCK_thd_data);
+}
+
+/**
+  Unlock data that needs protection in THD object
+
+  @param thd                   THD object
+*/
+void thd_unlock_data(THD *thd)
+{
+  mysql_mutex_unlock(&thd->LOCK_thd_data);
+}
+
+/**
+  Support method to check if connection has already started transcaction
+
+  @param client_cntx    Low level client context
+
+  @retval               TRUE if connection already started transaction
+*/
+bool thd_is_transaction_active(THD *thd)
+{
+  return thd->transaction.is_active();
+}
+
+/**
+  Check if there is buffered data on the socket representing the connection
+
+  @param thd                  THD object
+*/
+int thd_connection_has_data(THD *thd)
+{
+  Vio *vio= thd->net.vio;
+  return vio->has_data(vio);
+}
+
+/**
+  Set reading/writing on socket, used by SHOW PROCESSLIST
+
+  @param thd                       THD object
+  @param val                       Value to set it to (0 or 1)
+*/
+void thd_set_net_read_write(THD *thd, uint val)
+{
+  thd->net.reading_or_writing= val;
+}
+
+/**
+  Set reference to mysys variable in THD object
+
+  @param thd             THD object
+  @param mysys_var       Reference to set
+*/
+void thd_set_mysys_var(THD *thd, st_my_thread_var *mysys_var)
+{
+  thd->set_mysys_var(mysys_var);
+}
+
 /*
   The following functions form part of the C plugin API
 */