8.12.5.3. Delayed-Insert Thread States

These thread states are associated with processing for DELAYED inserts (see Section 13.2.5.2, "INSERT DELAYED Syntax"). Some states are associated with connection threads that process INSERT DELAYED statements from clients. Other states are associated with delayed-insert handler threads that insert the rows. There is a delayed-insert handler thread for each table for which INSERT DELAYED statements are issued.

States associated with a connection thread that processes an INSERT DELAYED statement from the client:

allocating local table

The thread is preparing to feed rows to the delayed-insert handler thread.
Creating delayed handler

The thread is creating a handler for DELAYED inserts.
got handler lock

This occurs before the allocating local table state and after the waiting for handler lock state, when the connection thread gets access to the delayed-insert handler thread.
got old table

This occurs after the waiting for handler open state. The delayed-insert handler thread has signaled that it has ended its initialization phase, which includes opening the table for delayed inserts.
storing row into queue

The thread is adding a new row to the list of rows that the delayed-insert handler thread must insert.
waiting for delay_list

This occurs during the initialization phase when the thread is trying to find the delayed-insert handler thread for the table, and before attempting to gain access to the list of delayed-insert threads.
waiting for handler insert

An INSERT DELAYED handler has processed all pending inserts and is waiting for new ones.
waiting for handler lock

This occurs before the allocating local table state when the connection thread waits for access to the delayed-insert handler thread.
waiting for handler open

This occurs after the Creating delayed handler state and before the got old table state. The delayed-insert handler thread has just been started, and the connection thread is waiting for it to initialize.

States associated with a delayed-insert handler thread that inserts the rows:

insert

The state that occurs just before inserting rows into the table.
reschedule

After inserting a number of rows, the delayed-insert thread sleeps to let other threads do work.
upgrading lock

A delayed-insert handler is trying to get a lock for the table to insert rows.
Waiting for INSERT

A delayed-insert handler is waiting for a connection thread to add rows to the queue (see storing row into queue).