From 724a5105cba31fe48bd0a2754d074d8942b21153 Mon Sep 17 00:00:00 2001 From: Alexander Barkov Date: Thu, 28 Jun 2018 16:55:42 +0400 Subject: MDEV-16584 SP with a cursor inside a loop wastes THD memory aggressively Problem: push_handler() created sp_handler_entry instances on THD::main_mem_root, which is freed only after the SP instructions execution. So in case of a CONTINUE HANDLER inside a loop (e.g. WHILE) this approach leaked thread memory on every loop iteration. Changes: - Removing sp_handler_entry declaration, it's not really needed. - Fixing the data type of sp_rcontext::m_handlers from Dynamic_array to Dynamic_array - Fixing sp_rcontext::push_handler() to push the pointer to an sp_instr_hpush_jump instance to the handler stack. This instance contains everything we need. There is no a need to allocate anything else. --- sql/sp_rcontext.cc | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-) (limited to 'sql/sp_rcontext.cc') diff --git a/sql/sp_rcontext.cc b/sql/sp_rcontext.cc index d77309b9bc0..24777abe1c3 100644 --- a/sql/sp_rcontext.cc +++ b/sql/sp_rcontext.cc @@ -448,19 +448,9 @@ void sp_rcontext::pop_cursors(THD *thd, size_t count) } -bool sp_rcontext::push_handler(sp_handler *handler, uint first_ip) +bool sp_rcontext::push_handler(sp_instr_hpush_jump *entry) { - /* - We should create handler entries in the callers arena, as - they could be (and usually are) used in several instructions. - */ - sp_handler_entry *he= - new (callers_arena->mem_root) sp_handler_entry(handler, first_ip); - - if (he == NULL) - return true; - - return m_handlers.append(he); + return m_handlers.append(entry); } @@ -548,12 +538,12 @@ bool sp_rcontext::handle_sql_condition(THD *thd, DBUG_ASSERT(found_condition); - sp_handler_entry *handler_entry= NULL; + sp_instr_hpush_jump *handler_entry= NULL; for (size_t i= 0; i < m_handlers.elements(); ++i) { - sp_handler_entry *h= m_handlers.at(i); + sp_instr_hpush_jump *h= m_handlers.at(i); - if (h->handler == found_handler) + if (h->get_handler() == found_handler) { handler_entry= h; break; @@ -582,7 +572,7 @@ bool sp_rcontext::handle_sql_condition(THD *thd, // Mark active conditions so that they can be deleted when the handler exits. da->mark_sql_conditions_for_removal(); - uint continue_ip= handler_entry->handler->type == sp_handler::CONTINUE ? + uint continue_ip= handler_entry->get_handler()->type == sp_handler::CONTINUE ? cur_spi->get_cont_dest() : 0; /* End aborted result set. */ @@ -601,7 +591,7 @@ bool sp_rcontext::handle_sql_condition(THD *thd, new (callers_arena->mem_root) Handler_call_frame(cond_info, continue_ip); m_handler_call_stack.append(frame); - *ip= handler_entry->first_ip; + *ip= handler_entry->m_ip + 1; DBUG_RETURN(true); } -- cgit v1.2.1