diff options
Diffstat (limited to 'sql/slave.h')
| -rw-r--r-- | sql/slave.h | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/sql/slave.h b/sql/slave.h index 0cd291a50f8..3afa1723cf1 100644 --- a/sql/slave.h +++ b/sql/slave.h @@ -32,6 +32,30 @@ *****************************************************************************/ +/* + MUTEXES in replication: + + LOCK_active_mi: this is meant for multimaster, when we can switch from a + master to another. It protects active_mi. We don't care of it for the moment, + as active_mi never moves (it's created at startup and deleted at shutdown, + and not changed: it always points to the same MASTER_INFO struct), because we + don't have multimaster. So for the moment, mi does not move, and mi->rli does + not either. + + In MASTER_INFO: run_lock, data_lock + run_lock protects all information about the run state: slave_running, and the + existence of the I/O thread (to stop/start it, you need this mutex). + data_lock protects some moving members of the struct: counters (log name, + position) and relay log (MYSQL_LOG object). + + In RELAY_LOG_INFO: run_lock, data_lock + see MASTER_INFO + + In MYSQL_LOG: LOCK_log, LOCK_index of the binlog and the relay log + LOCK_log: when you write to it. LOCK_index: when you create/delete a binlog + (so that you have to update the .index file). +*/ + extern ulong master_retry_count; extern MY_BITMAP slave_error_mask; extern bool use_slave_mask; @@ -43,10 +67,6 @@ extern my_bool opt_log_slave_updates; extern ulonglong relay_log_space_limit; struct st_master_info; -extern "C" { - extern ulong slave_net_timeout; -}; - enum enum_binlog_formats { BINLOG_FORMAT_CURRENT=0, /* 0 is important for easy 'if (mi->old_format)' */ BINLOG_FORMAT_323_LESS_57, |