Much of a Qtopia application's startup time is spent in the slow but necessary tasks of C++ symbol relocation and QtopiaApplication/QApplication construction. Doing this predictable, repetitive work at the last moment gives poor application launch performance.
To avoid this, at startup the Qtopia Server launches the quicklauncher stub application. While the user is still idling, this process is busy starting up, and performing all the common application initialization work. By the time the user gets around to launching an application, the quicklauncher process is idling in the background. Rather than running a new process from scratch the quicklauncher loads the requested application, as a shared library, into its address space and starts executing application specific code with no delay.
The quicklauncher process is restarted once used, with a small delay to avoid poor performance of the foreground application. On typical devices, if the user starts two applications within 5-7 seconds, no quicklauncher process will exist for the second, and so the second application starts up slower.
