User:Ccw

This user is an MTA developer

2011 October 22

How do you solve a problem like my server stalling?

Answer: coroutines and threaded database access

dbQuery

handle dbQuery( sting query )

• dbQuery starts a database query and returns a handle

dbPoll

table dbPoll( handle[, int timeout = 0, bool autoFree = true ] )

• dbPoll returns the result of the query started with the supplied handle, or nil if the query has not completed yet. Setting timeout above 0 will make the function wait a bit longer if the query is not ready. A timeout of -1 will make it wait for ever. If autoFree is true, the query handle gets automatically freed when dbPoll is able to return a result

dbFree

dbFree( handle )

• dbFree makes a handle go away and never come back

Example usage of the above three functions:

Perform a query such as UPDATE, without waiting for the result (super fast)

function dbQueryExec(...)
    local handle = dbQuery(...)
    dbFree(handle)
end

Perform a query such as SELECT, and wait for the result (super slow)

function dbQueryResult(...)
    local handle = dbQuery(...)
    return dbPoll(handle,-1)
end

Perform a query such as SELECT, and yield until the result is ready (avoids server stalling, but must be called in a coroutine)

function dbQueryLatent(...)
    local handle = dbQuery(...)
    local result
    do
        coroutine.yield()
        result = dbPoll(handle)
    until result ~= nil
    return result
end

2011 October 2

Master Plan 8012

Outline

To enhance MTA, keeps devs motivated and ensure stuff actually gets tested and used, I propose that features developed in the trunk be backported to the current version where possible.

Problem

However, when scripters start to use the new features, there will be compatibility problems with some servers & clients.

Solution

Therefore I present to you 'Master Plan 8012', which is:

• When a script is loaded into a server, its minimum version requirement is evaluated.
  • If the script requires an updated server, it should not run and instead inform the server owner to update
  • When the script is running, connecting clients below the script required minimum version are auto-updated

Benefits of this plan are:

• Scripters can use latest functions and not worry about checking version numbers and such
• Server owners can use any scripts without have to worry about setting <minclientversion> etc
• And more players will update because they will have a compelling reason to do so. (i.e. To join fav server)

Release dates

History

Version	Date	Highlights	User comments
1.0	22 August 2009	First release	DP2 was better
1.0.1	02 October 2009	Crash fixes and less lag	1.0 was better
1.0.2	24 October 2009	Crash fixes	1.0.1 was better
1.0.3	17 December 2009	Sync improved	1.0.2 was better
1.0.4 (r1752)	7 June 2010	Security improved	1.0.3 was better
1.0.4 (r1854)	10 July 2010	Crash fixes	It crashes more
1.0.4 (r2033)	14 October 2010	Crash fixes	It crashes more
1.0.4 (r2106)	14 December 2010	Browser improved	+
1.0.5 (r2488)	27 March 2011	AC improved	It crashes more & 1.0.4 was better
1.0.5 (r2519/2520)	4 April 2011	Performance fixed	'It's almost as good as 1.0.2 now'
1.0.5 (r2560)	16 April 2011	Performance improvements
1.1.0	25 August 2011	Many new features	Possibly the worst thing that has happened in the history of the world
1.1.1	20 September 2011	Accumulation of post release fixes	Lags more than 1.1