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Merge gbichot@bk-internal.mysql.com:/home/bk/mysql-4.0

Browse source 
into mysql.com:/home/mysql_src/mysql-4.0
This commit is contained in:
guilhem@mysql.com 2003-12-04 15:31:14 +01:00
commit ae67b97c4b
1 changed files with 26 additions and 5 deletions
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29
sql/slave.cc
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@ -3498,7 +3498,19 @@ rli->relay_log_pos=%s rli->pending=%lu",
flush_relay_log_info(rli);
}
// next log is hot
/*
Now we want to open this next log. To know if it's a hot log (the one
being written by the I/O thread now) or a cold log, we can use
is_active(); if it is hot, we use the I/O cache; if it's cold we open
the file normally. But if is_active() reports that the log is hot, this
may change between the test and the consequence of the test. So we may
open the I/O cache whereas the log is now cold, which is nonsense.
To guard against this, we need to have LOCK_log.
*/
DBUG_PRINT("info",("hot_log: %d",hot_log));
if (!hot_log) /* if hot_log, we already have this mutex */
pthread_mutex_lock(log_lock);
if (rli->relay_log.is_active(rli->linfo.log_file_name))
{
#ifdef EXTRA_DEBUG
@ -3511,15 +3523,24 @@ rli->relay_log_pos=%s rli->pending=%lu",
/*
Read pointer has to be at the start since we are the only
reader
reader.
We must keep the LOCK_log to read the 4 first bytes, as this is a hot
log (same as when we call read_log_event() above: for a hot log we
take the mutex).
*/
if (check_binlog_magic(cur_log,&errmsg))
{
if (!hot_log) pthread_mutex_unlock(log_lock);
goto err;
}
if (!hot_log) pthread_mutex_unlock(log_lock);
continue;
}
if (!hot_log) pthread_mutex_unlock(log_lock);
/*
if we get here, the log was not hot, so we will have to
open it ourselves
if we get here, the log was not hot, so we will have to open it
ourselves. We are sure that the log is still not hot now (a log can get
from hot to cold, but not from cold to hot). No need for LOCK_log.
*/
#ifdef EXTRA_DEBUG
sql_print_error("next log '%s' is not active",