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7.4.2 LabRAD Manager
The LabRAD Manager acts as the central routing agent for all LabRAD traffic.
This makes it a potential bottleneck for the entire system and thus extra care had
to be employed when designing it to ensure maximal performance. The LabRAD
Manager was written in Delphi, a version of Object Pascal that provides RAD
(Rapid Application Development) capabilities through visual designers that assist
in the design of the user interface. Delphi has not received much attention in
the US market, but in Europe it is highly valued as a very efficient language
with a compiler that produces code that rivals any modern C++ compiler’s in
execution performance. It provides the usual high-performance features like code
optimization, data alignment, inlined Assembly, etc.
Apart from optimized memory management, one major point of concern was
a well-designed thread layout for the application. A first approach that dedicated
one thread to each network connection had to be abandoned due to the high cost of
Windows context switching (switching between threads). Making the application
dual-threaded instead yielded an order of magnitude performance improvement.
The first thread, the network thread, is dedicated to routing all traffic and handling
Requests to the Manager and the Registry Server Module. It uses direct access
to the event-based, non-blocking methods provided by the Windows Sockets 2
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