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Fix log manager race condition

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The log manager could send two messages if a log message was posted soon
before the log manager was stopped. This caused a debug assertion which
then manifested as a deadlock inside the log manager.
This commit is contained in:
Markus Mäkelä 2018-01-03 16:07:21 +02:00
parent e0a584a626
commit e9fceff8ce
3 changed files with 16 additions and 5 deletions
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17
server/core/log_manager.cc
View File

@ -2321,7 +2321,9 @@ static void* thr_filewriter_fun(void* data)
/** Inform log manager about the state. */
skygw_message_send(fwr->fwr_clientmes);
while (!skygw_thread_must_exit(thr))
bool running = true;
do
{
/**
* Wait until new log arrival message appears.
@ -2347,14 +2349,23 @@ static void* thr_filewriter_fun(void* data)
}
}
bool send_message = false;
if (flushall_done_flag)
{
flushall_done_flag = false;
flushall_logfiles(false);
skygw_message_send(fwr->fwr_clientmes);
send_message = true;
}
} /* while (!skygw_thread_must_exit) */
running = !skygw_thread_must_exit(thr);
if (running && send_message)
{
skygw_message_send(fwr->fwr_clientmes);
}
}
while (running);
ss_debug(skygw_thread_set_state(thr, THR_STOPPED));
/** Inform log manager that file writer thread has stopped. */

2
server/core/skygw_utils.cc
View File

@ -436,7 +436,9 @@ bool skygw_thread_set_exitflag(skygw_thread_t* thr, skygw_message_t* sendmes,
skygw_message_wait(recmes);
}
ss_dassert(simple_mutex_lock(thr->sth_mutex, true) == 0);
ss_dassert(thr->sth_state == THR_STOPPED);
ss_dassert(simple_mutex_unlock(thr->sth_mutex) == 0);
return_succp:
return succp;

2
server/core/test/testlog.c
View File

@ -221,8 +221,6 @@ int main(int argc, char* argv[])
err = MXS_NOTICE("%s", logstr);
ss_dassert(err == 0);
succp = mxs_log_init(NULL, "/tmp", MXS_LOG_TARGET_FS);
ss_dassert(succp);
skygw_log_enable(LOG_INFO);
logstr = ("6.\tWrite to ERROR and thus also to MESSAGE and TRACE logs.");
err = MXS_ERROR("%s", logstr);