On 2016-02-16 17:31, Jacob Carlborg wrote:
I'm trying to use the Postgres client ddb [1] in a vibe.d application. I'm using it according to the documentation [2] with a connection pool from vibe.d. I store in the PostgresDB instance as a TLS variable.
As soon as I do concurrent requests to the application I get the error below. Any ideas?
Task terminated with unhandled exception: Acquiring reader of already owned connection. core.exception.AssertError@../../../d/vibe.d/source/vibe/core/drivers/libevent2_tcp.d(412): Acquiring reader of already owned connection. ---------------- 4 admin 0x000000010bff7032 _d_assert_msg + 142 5 admin 0x000000010bf721ef void vibe.core.drivers.libevent2_tcp.Libevent2TCPConnection.checkReader() + 115 6 admin 0x000000010bf72209 void vibe.core.drivers.libevent2_tcp.Libevent2TCPConnection.acquireReader() + 21 7 admin 0x000000010bf71774 void vibe.core.drivers.libevent2_tcp.Libevent2TCPConnection.read(ubyte[]) + 216 8 admin 0x000000010be55279 ddb.postgres.Message ddb.postgres.PGConnection.getMessage() + 181 9 admin 0x000000010be5659b void ddb.postgres.PGConnection.prepare(immutable(char)[], immutable(char)[], ddb.postgres.PGParameters) + 127 10 admin 0x000000010be58d16 void ddb.postgres.PGCommand.checkPrepared(bool) + 70[1] https://github.com/pszturmaj/ddb
[2] https://github.com/pszturmaj/ddb/blob/master/source/ddb/postgres.d#L71-L92
I found a fix for this problem. I'm still not sure what the original
problem was though. I did something like this:
auto pdb = new PostgresDB( ... );
auto executeQuery(string query)
{
scope cmd = new PGCommand(pdb.lockConnection(), query);
return cmd.executeQuery();
}
The fix was to store the connection in a local variable:
auto executeQuery(string query)
{
auto conn = pdb.lockConnection();
scope cmd = new PGCommand(conn, query);
return cmd.executeQuery();
}
Could it be an issue related to how the reference counting in the
connection pool works?
/Jacob Carlborg