thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-10-04 15:40:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

Try fix race in RemoteQueryExecutor.

Browse Source
This commit is contained in:
Nikolai Kochetov 2020-12-17 13:07:28 +03:00
parent 53d5012a20
commit a860f128f5
2 changed files with 13 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
src/DataStreams/RemoteQueryExecutor.cpp
View File

@ -210,10 +210,13 @@ std::variant<Block, int> RemoteQueryExecutor::read(std::unique_ptr<ReadContext>
return Block();
}
if (!read_context)
{
std::lock_guard lock(was_cancelled_mutex);
if (!read_context)
read_context = std::make_unique<ReadContext>(*multiplexed_connections);
if (was_cancelled)
return Block();
read_context = std::make_unique<ReadContext>(*multiplexed_connections);
}
do
@ -312,15 +315,12 @@ void RemoteQueryExecutor::finish(std::unique_ptr<ReadContext> * read_context)
if (!isQueryPending() || hasThrownException())
return;
if (read_context && *read_context)
(*read_context)->cancel();
/** If you have not read all the data yet, but they are no longer needed.
* This may be due to the fact that the data is sufficient (for example, when using LIMIT).
*/
/// Send the request to abort the execution of the request, if not already sent.
tryCancel("Cancelling query because enough data has been read");
tryCancel("Cancelling query because enough data has been read", read_context);
/// Get the remaining packets so that there is no out of sync in the connections to the replicas.
Packet packet = multiplexed_connections->drain();
@ -363,13 +363,7 @@ void RemoteQueryExecutor::cancel(std::unique_ptr<ReadContext> * read_context)
if (!isQueryPending() || hasThrownException())
return;
{
std::lock_guard lock(was_cancelled_mutex);
if (read_context && *read_context)
(*read_context)->cancel();
}
tryCancel("Cancelling query");
tryCancel("Cancelling query", read_context);
}
void RemoteQueryExecutor::sendScalars()
@ -421,7 +415,7 @@ void RemoteQueryExecutor::sendExternalTables()
multiplexed_connections->sendExternalTablesData(external_tables_data);
}
void RemoteQueryExecutor::tryCancel(const char * reason)
void RemoteQueryExecutor::tryCancel(const char * reason, std::unique_ptr<ReadContext> * read_context)
{
{
/// Flag was_cancelled is atomic because it is checked in read().
@ -431,6 +425,10 @@ void RemoteQueryExecutor::tryCancel(const char * reason)
return;
was_cancelled = true;
if (read_context && *read_context)
(*read_context)->cancel();
multiplexed_connections->sendCancel();
}

2
src/DataStreams/RemoteQueryExecutor.h
View File

@ -164,7 +164,7 @@ private:
void sendExternalTables();
/// If wasn't sent yet, send request to cancel all connections to replicas
void tryCancel(const char * reason);
void tryCancel(const char * reason, std::unique_ptr<ReadContext> * read_context);
/// Returns true if query was sent
bool isQueryPending() const;