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+/* Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License, version 2.0,
+ as published by the Free Software Foundation.
+
+ This program is also distributed with certain software (including
+ but not limited to OpenSSL) that is licensed under separate terms,
+ as designated in a particular file or component or in included license
+ documentation. The authors of MySQL hereby grant you an additional
+ permission to link the program and your derivative works with the
+ separately licensed software that they have included with MySQL.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License, version 2.0, for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+
+/**
+ @file storage/perfschema/table_status_by_thread.cc
+ Table STATUS_BY_THREAD (implementation).
+*/
+
+#include "my_global.h"
+#include "table_status_by_thread.h"
+#include "my_thread.h"
+#include "pfs_instr_class.h"
+#include "pfs_column_types.h"
+#include "pfs_column_values.h"
+#include "pfs_global.h"
+
+THR_LOCK table_status_by_thread::m_table_lock;
+
+PFS_engine_table_share
+table_status_by_thread::m_share=
+{
+ { C_STRING_WITH_LEN("status_by_thread") },
+ &pfs_truncatable_acl,
+ table_status_by_thread::create,
+ NULL, /* write_row */
+ table_status_by_thread::delete_all_rows,
+ table_status_by_thread::get_row_count,
+ sizeof(pos_t),
+ &m_table_lock,
+ { C_STRING_WITH_LEN("CREATE TABLE status_by_thread("
+ "THREAD_ID BIGINT unsigned not null,"
+ "VARIABLE_NAME VARCHAR(64) not null,"
+ "VARIABLE_VALUE VARCHAR(1024))") },
+ false /* perpetual */
+};
+
+PFS_engine_table*
+table_status_by_thread::create(void)
+{
+ return new table_status_by_thread();
+}
+
+int table_status_by_thread::delete_all_rows(void)
+{
+ /* Lock required to aggregate to global_status_vars. */
+ mysql_mutex_lock(&LOCK_status);
+
+ reset_status_by_thread();
+
+ mysql_mutex_unlock(&LOCK_status);
+ return 0;
+}
+
+ha_rows table_status_by_thread::get_row_count(void)
+{
+ mysql_mutex_lock(&LOCK_status);
+ size_t status_var_count= all_status_vars.elements;
+ mysql_mutex_unlock(&LOCK_status);
+ return (global_thread_container.get_row_count() * status_var_count);
+}
+
+table_status_by_thread::table_status_by_thread()
+ : PFS_engine_table(&m_share, &m_pos),
+ m_status_cache(true), m_row_exists(false), m_pos(), m_next_pos()
+{}
+
+void table_status_by_thread::reset_position(void)
+{
+ m_pos.reset();
+ m_next_pos.reset();
+}
+
+int table_status_by_thread::rnd_init(bool scan)
+{
+ if (show_compatibility_56)
+ return 0;
+
+ /*
+ Build array of SHOW_VARs from the global status array prior to materializing
+ threads in rnd_next() or rnd_pos().
+ */
+ m_status_cache.initialize_session();
+
+ /* Record the current number of status variables to detect subsequent changes. */
+ ulonglong status_version= m_status_cache.get_status_array_version();
+
+ /*
+ The table context holds the current version of the global status array
+ and a record of which threads were materialized. If scan == true, then
+ allocate a new context from mem_root and store in TLS. If scan == false,
+ then restore from TLS.
+ */
+ m_context= (table_status_by_thread_context *)current_thd->alloc(sizeof(table_status_by_thread_context));
+ new(m_context) table_status_by_thread_context(status_version, !scan);
+ return 0;
+}
+
+int table_status_by_thread::rnd_next(void)
+{
+ if (show_compatibility_56)
+ return HA_ERR_END_OF_FILE;
+
+ /* If global status array changes, exit with warning. */ // TODO: Issue warning
+ if (!m_context->versions_match())
+ return HA_ERR_END_OF_FILE;
+
+ bool has_more_thread= true;
+
+ for (m_pos.set_at(&m_next_pos);
+ has_more_thread;
+ m_pos.next_thread())
+ {
+ PFS_thread *pfs_thread= global_thread_container.get(m_pos.m_index_1, &has_more_thread);
+ if (m_status_cache.materialize_session(pfs_thread) == 0)
+ {
+ /* Mark this thread as materialized. */
+ m_context->set_item(m_pos.m_index_1);
+ const Status_variable *stat_var= m_status_cache.get(m_pos.m_index_2);
+ if (stat_var != NULL)
+ {
+ make_row(pfs_thread, stat_var);
+ m_next_pos.set_after(&m_pos);
+ return 0;
+ }
+ }
+ }
+ return HA_ERR_END_OF_FILE;
+}
+
+int
+table_status_by_thread::rnd_pos(const void *pos)
+{
+ if (show_compatibility_56)
+ return HA_ERR_RECORD_DELETED;
+
+ /* If global status array has changed, do nothing. */
+ if (!m_context->versions_match())
+ return HA_ERR_RECORD_DELETED;
+
+ set_position(pos);
+ DBUG_ASSERT(m_pos.m_index_1 < global_thread_container.get_row_count());
+
+ PFS_thread *pfs_thread= global_thread_container.get(m_pos.m_index_1);
+ /*
+ Only materialize threads that were previously materialized by rnd_next().
+ If a thread cannot be rematerialized, then do nothing.
+ */
+ if (m_context->is_item_set(m_pos.m_index_1) &&
+ m_status_cache.materialize_session(pfs_thread) == 0)
+ {
+ const Status_variable *stat_var= m_status_cache.get(m_pos.m_index_2);
+ if (stat_var != NULL)
+ {
+ make_row(pfs_thread, stat_var);
+ return 0;
+ }
+ }
+ return HA_ERR_RECORD_DELETED;
+}
+
+void table_status_by_thread
+::make_row(PFS_thread *thread, const Status_variable *status_var)
+{
+ pfs_optimistic_state lock;
+ m_row_exists= false;
+ if (status_var->is_null())
+ return;
+
+ /* Protect this reader against a thread termination */
+ thread->m_lock.begin_optimistic_lock(&lock);
+
+ m_row.m_thread_internal_id= thread->m_thread_internal_id;
+ m_row.m_variable_name.make_row(status_var->m_name, status_var->m_name_length);
+ m_row.m_variable_value.make_row(status_var);
+
+ if (!thread->m_lock.end_optimistic_lock(&lock))
+ return;
+
+ m_row_exists= true;
+}
+
+int table_status_by_thread
+::read_row_values(TABLE *table,
+ unsigned char *buf,
+ Field **fields,
+ bool read_all)
+{
+ Field *f;
+
+ if (unlikely(! m_row_exists))
+ return HA_ERR_RECORD_DELETED;
+
+ /* Set the null bits */
+ DBUG_ASSERT(table->s->null_bytes == 1);
+ buf[0]= 0;
+
+ for (; (f= *fields) ; fields++)
+ {
+ if (read_all || bitmap_is_set(table->read_set, f->field_index))
+ {
+ switch(f->field_index)
+ {
+ case 0: /* THREAD_ID */
+ set_field_ulonglong(f, m_row.m_thread_internal_id);
+ break;
+ case 1: /* VARIABLE_NAME */
+ set_field_varchar_utf8(f, m_row.m_variable_name.m_str, m_row.m_variable_name.m_length);
+ break;
+ case 2: /* VARIABLE_VALUE */
+ m_row.m_variable_value.set_field(f);
+ break;
+ default:
+ DBUG_ASSERT(false);
+ }
+ }
+ }
+
+ return 0;
+}
+