mysql5/mysql-5.7.27/plugin/semisync/semisync_master_ack_receiver.cc

289 lines
7.8 KiB
C++

/* Copyright (c) 2014, 2018, 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 as published by
the Free Software Foundation; version 2 of the License.
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 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 */
#include "semisync_master.h"
#include "semisync_master_ack_receiver.h"
#include "semisync_master_socket_listener.h"
extern ReplSemiSyncMaster repl_semisync;
#ifdef HAVE_PSI_INTERFACE
extern PSI_stage_info stage_waiting_for_semi_sync_ack_from_slave;
extern PSI_stage_info stage_waiting_for_semi_sync_slave;
extern PSI_stage_info stage_reading_semi_sync_ack;
extern PSI_mutex_key key_ss_mutex_Ack_receiver_mutex;
extern PSI_cond_key key_ss_cond_Ack_receiver_cond;
extern PSI_thread_key key_ss_thread_Ack_receiver_thread;
#endif
/* Callback function of ack receive thread */
extern "C" void *ack_receive_handler(void *arg)
{
my_thread_init();
reinterpret_cast<Ack_receiver *>(arg)->run();
my_thread_end();
my_thread_exit(0);
return NULL;
}
Ack_receiver::Ack_receiver()
{
const char *kWho = "Ack_receiver::Ack_receiver";
function_enter(kWho);
m_status= ST_DOWN;
mysql_mutex_init(key_ss_mutex_Ack_receiver_mutex, &m_mutex,
MY_MUTEX_INIT_FAST);
mysql_cond_init(key_ss_cond_Ack_receiver_cond, &m_cond);
function_exit(kWho);
}
Ack_receiver::~Ack_receiver()
{
const char *kWho = "Ack_receiver::~Ack_receiver";
function_enter(kWho);
stop();
mysql_mutex_destroy(&m_mutex);
mysql_cond_destroy(&m_cond);
function_exit(kWho);
}
bool Ack_receiver::start()
{
const char *kWho = "Ack_receiver::start";
function_enter(kWho);
if(m_status == ST_DOWN)
{
my_thread_attr_t attr;
m_status= ST_UP;
if (DBUG_EVALUATE_IF("rpl_semisync_simulate_create_thread_failure", 1, 0) ||
my_thread_attr_init(&attr) != 0 ||
my_thread_attr_setdetachstate(&attr, MY_THREAD_CREATE_JOINABLE) != 0 ||
#ifndef _WIN32
pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM) != 0 ||
#endif
mysql_thread_create(key_ss_thread_Ack_receiver_thread, &m_pid,
&attr, ack_receive_handler, this))
{
sql_print_error("Failed to start semi-sync ACK receiver thread, "
" could not create thread(errno:%d)", errno);
m_status= ST_DOWN;
return function_exit(kWho, true);
}
(void) my_thread_attr_destroy(&attr);
}
return function_exit(kWho, false);
}
void Ack_receiver::stop()
{
const char *kWho = "Ack_receiver::stop";
function_enter(kWho);
int ret;
if (m_status == ST_UP)
{
mysql_mutex_lock(&m_mutex);
m_status= ST_STOPPING;
mysql_cond_broadcast(&m_cond);
while (m_status == ST_STOPPING)
mysql_cond_wait(&m_cond, &m_mutex);
mysql_mutex_unlock(&m_mutex);
/*
When arriving here, the ack thread already exists. Join failure has no
side effect aganst semisync. So we don't return an error.
*/
ret= my_thread_join(&m_pid, NULL);
if (DBUG_EVALUATE_IF("rpl_semisync_simulate_thread_join_failure", -1, ret))
sql_print_error("Failed to stop ack receiver thread on my_thread_join, "
"errno(%d)", errno);
}
function_exit(kWho);
}
bool Ack_receiver::add_slave(THD *thd)
{
Slave slave;
const char *kWho = "Ack_receiver::add_slave";
function_enter(kWho);
slave.thread_id= thd->thread_id();
slave.server_id= thd->server_id;
slave.net_compress= thd->get_protocol_classic()->get_compression();
slave.vio= *thd->get_protocol_classic()->get_vio();
slave.vio.mysql_socket.m_psi= NULL;
slave.vio.read_timeout= 1;
/* push_back() may throw an exception */
try
{
mysql_mutex_lock(&m_mutex);
DBUG_EXECUTE_IF("rpl_semisync_simulate_add_slave_failure", throw 1;);
m_slaves.push_back(slave);
m_slaves_changed= true;
mysql_cond_broadcast(&m_cond);
mysql_mutex_unlock(&m_mutex);
}
catch (...)
{
mysql_mutex_unlock(&m_mutex);
return function_exit(kWho, true);
}
return function_exit(kWho, false);
}
void Ack_receiver::remove_slave(THD *thd)
{
const char *kWho = "Ack_receiver::remove_slave";
function_enter(kWho);
mysql_mutex_lock(&m_mutex);
Slave_vector_it it;
for (it= m_slaves.begin(); it != m_slaves.end(); it++)
{
if (it->thread_id == thd->thread_id())
{
m_slaves.erase(it);
m_slaves_changed= true;
break;
}
}
mysql_mutex_unlock(&m_mutex);
function_exit(kWho);
}
inline void Ack_receiver::set_stage_info(const PSI_stage_info &stage)
{
#ifdef HAVE_PSI_STAGE_INTERFACE
MYSQL_SET_STAGE(stage.m_key, __FILE__, __LINE__);
#endif /* HAVE_PSI_STAGE_INTERFACE */
}
inline void Ack_receiver::wait_for_slave_connection()
{
set_stage_info(stage_waiting_for_semi_sync_slave);
mysql_cond_wait(&m_cond, &m_mutex);
}
/* Auxilary function to initialize a NET object with given net buffer. */
static void init_net(NET *net, unsigned char *buff, unsigned int buff_len)
{
memset(net, 0, sizeof(NET));
net->max_packet= buff_len;
net->buff= buff;
net->buff_end= buff + buff_len;
net->read_pos= net->buff;
}
void Ack_receiver::run()
{
NET net;
unsigned char net_buff[REPLY_MESSAGE_MAX_LENGTH];
uint i;
Socket_listener listener;
sql_print_information("Starting ack receiver thread");
init_net(&net, net_buff, REPLY_MESSAGE_MAX_LENGTH);
mysql_mutex_lock(&m_mutex);
m_slaves_changed= true;
mysql_mutex_unlock(&m_mutex);
while (1)
{
Slave_vector_it it;
int ret;
mysql_mutex_lock(&m_mutex);
if (unlikely(m_status == ST_STOPPING))
goto end;
set_stage_info(stage_waiting_for_semi_sync_ack_from_slave);
if (unlikely(m_slaves_changed))
{
if (unlikely(m_slaves.empty()))
{
wait_for_slave_connection();
mysql_mutex_unlock(&m_mutex);
continue;
}
if (!listener.init_slave_sockets(m_slaves))
goto end;
m_slaves_changed= false;
}
mysql_mutex_unlock(&m_mutex);
ret= listener.listen_on_sockets();
if (ret <= 0)
{
ret= DBUG_EVALUATE_IF("rpl_semisync_simulate_select_error", -1, ret);
if (ret == -1 && errno != EINTR)
sql_print_information("Failed to wait on semi-sync dump sockets, "
"error: errno=%d", socket_errno);
/* Sleep 1us, so other threads can catch the m_mutex easily. */
my_sleep(1);
continue;
}
set_stage_info(stage_reading_semi_sync_ack);
i= 0;
while (i < listener.number_of_slave_sockets() && m_status == ST_UP)
{
if (listener.is_socket_active(i))
{
Slave slave_obj= listener.get_slave_obj(i);
ulong len;
net.vio= &slave_obj.vio;
/*
Set compress flag. This is needed to support
Slave_compress_protocol flag enabled Slaves
*/
net.compress= slave_obj.net_compress;
do {
net_clear(&net, 0);
len= my_net_read(&net);
if (likely(len != packet_error))
repl_semisync.reportReplyPacket(slave_obj.server_id,
net.read_pos, len);
else if (net.last_errno == ER_NET_READ_ERROR)
listener.clear_socket_info(i);
} while (net.vio->has_data(net.vio) && m_status == ST_UP);
}
i++;
}
}
end:
sql_print_information("Stopping ack receiver thread");
m_status= ST_DOWN;
mysql_cond_broadcast(&m_cond);
mysql_mutex_unlock(&m_mutex);
}