Memory allocation failed

[bubnenkoff]

I am trying to build simple app Windows 10 that produce select query to PG 9.6.
But on example I am getting error: core.exception.OutOfMemoryError@src\core\exception.d(696): Memory allocation failed
I am using latest DMD 2.077

What can be wrong?

[jacob-carlborg]

Do you have the source for the application available?

[bubnenkoff]

PGConnection sourceConnection;
PGConnection targetConnection;

class Database
{
	Config config;

	this(Config config)
	{
		this.config = config;

		sourceConnection = new PGConnection(["host" : config.source_dbhost, "user": config.source_dbuser, "password" : config.source_dbpassword, "database" : config.source_dbname, "port" : config.source_port.to!string]);
		
	}
	
	int get_last_status_changes_counter_value()
	{
		writeln("aaa");
		string sql = `SELECT 	"last_status_changes_counter_value" FROM "tcopy_settings" WHERE "id" = 1;`;
		auto cmd = new PGCommand(sourceConnection, sql);
		writeln("bbb");
		auto result = cmd.executeQuery;

		foreach(i; result)
		{
			writeln(i);
		}

		return 1;
	}


}

[bubnenkoff]

[jacob-carlborg]

Can you run it inside a debugger to get any more information? It's not much information to go on.

[bubnenkoff]

For my regret now I can't do it. I have no free time :(
I understand that you support this lib in you free time, but I really have a lot of other job...

[jacob-carlborg]

Do you have the data set available that you run this query against?

[bubnenkoff]

There is only two columns:
"id", "last_status_changes_counter_value"
rows value:
1;576

[bubnenkoff]

I am connecting to DB with VPN. But I do not thing it does matter. With Python all worked fine.

[jacob-carlborg]

• Ok. Is it a 32bit or a 64bit build. If it's a 32bit build, do you use the Visual Studio tool chain?
• To you have a possibility to test it without VPN or even on localhost?

[bubnenkoff]

32, I have not VS
ok I will try to test on local PC

[jacob-carlborg]

OK, that would be great, trying to reduce things that can go wrong.

[bubnenkoff]

Yes, it's work fine with PG 10.1 on Windows 10 without VPN.
I have no ideas how VPN can cause problem.

[jacob-carlborg]

Perhaps it's something in the socket implementation that the client is using to connect to the server. It would be quite difficult for me to debug since I don't have a VPN connection.

If you can compile druntime and Phobos you could try a debug build of the garbage collector. Basically enabling these three debug identifiers [1] and recompile druntime and Phobos. Then recompiling and run your application. After running the application it should have created a file gcx.log in the current directory with some debug info.

[1] https://github.com/dlang/druntime/blob/master/src/gc/impl/conservative/gc.d#L20-L22

[bubnenkoff]

If it's issue with GC than mysql-native have same problem on x32 builds. Because I remember that developer of mysql-native said that GC on 32 is very buggy. But now I do not want to install any VS-related stuff, because now I am writing on D no more that 1 hour per week.

In any case thanks!

[jacob-carlborg]

The GC might not be the issue but a debug build can provide some additional information to figure out what's wrong, perhaps a stacktrace.