To content | To menu | To search

Tag - multithread

Entries feed

2011, Friday May 20

How to write fast multi-thread Delphi applications

How to make your software run fast, especially in a multi-threaded architecture?

We tried to remove the Memory Manager scaling problems in our SynScaleMM. It worked as expected in a multi-threaded server environment. Scaling is much better than FastMM4, for some critical tests. But it's not ready for production yet...

To be honest, the Memory Manager is perhaps not the bigger bottleneck in Multi-Threaded applications.

Here are some (not dogmatic, just from experiment and knowledge of low-level Delphi RTL) advice if you want to write FAST multi-threaded application in Delphi.

Continue reading...

2010, Saturday December 4

SynScaleMM - a multi-thread scaling Memory Manager

We just released a new unit to the source code repository.

It's a simple, small and compact MM, built on top of the main Memory Manager(FastMM4 is a good candidate, standard since Delphi 2007), architectured in order to scale on multi core CPU's (which is what FastMM4 is lacking).

Original code is ScaleMM - Fast scaling memory manager for Delphi by André Mussche.

Continue reading...

When inlining works

It was told on this Blog that the Delphi memory manager (FastMM4 since Borland 2006 - but it was even worse with the previous "Borland's" MM), doesn't scale well on multi-code CPU. That is, if you have a multi-threaded application with a lot of memory handling (e.g. aString := aString+someString), the Delphi MM won't scale with multi cores. When I mean "don't scale", I mean that the optimistic though of "my CPU has 4 cores, therefore the same work run in 4 threads will be 4 times faster than with 1 thread" is false. It performs even worse with multiple threads than with 1 thread...

So we went into forking a nice project, named ScaleMM, and created our scalable optimized MM, named SynScaleMM. Our forked modifications were even included in the main ScaleMM branch.

During my profiling of our SynScaleMM, I discovered some very nice results with Delphi compiler inlining features.

Continue reading...

2010, Tuesday August 24

Synopse SQLite3 Framework 1.9.1

The Synopse SQLite3 Database Framework was just released under version 1.9.1:
- internal SQLite3 database engine is updated to version 3.7.2;
- new TSQLRecordFTS3 record, for using FTS3 virtual tables, i.e. implementing full-text search;
- new SQLite3UIEdit unit, to edit table content with a dialog created from RTTI;
- new dedicated BLOB methods and JSON array serialization;
- a lot of fixes and speed enhancements (including our HTTP/1.1 RESTful server now using Thread Pool).

The new 3.7.2 version of the SQLite3 engine, which is mandatory according to SQLite3's authors, is included.

Continue reading...

2010, Friday July 30

Compiler enhancement proposal: threadlocalvar

As I wrote in a previous post, Delphi string, dynamic array and memory manager don't like multi-core CPU.

My proposal is to add a threadlocalvar keyword, to be used instead of var in your code, to mark some variables to be used in only the current thread. Then the compiler and RTL won't have to use the LOCK instruction, and the application will be MUCH faster in multi-thread environment.

Continue reading...

2010, Thursday July 15

Delphi doesn't like multi-core CPUs (or the contrary)

If you're like me, you are proud of the new CPU your computer runs on - in my case a i7-720Q with 8 embedded cores...

But Delphi is not very multi-thread or multi-core friendly... guess why....

Continue reading...

page 2 of 2 -