Reduce Host emulator CPU load #2472
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Simplify build by using cmake for lwip only, sming glue built as regular sming library Pull out common linux/Windows code Service using event timer rather than polled timer Remove LWIP_SERVICE_INTERVAL and adjust interval dynamically
Code required by both CMake and sming library builds
Time is absolute so must base on system clock. Because this wasn't done will always succeed. Change parameter to microseconds.
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| extern CSemaphore host_main_loop_semaphore; |
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@mikee47 Can you move this line to the beginning of the file?
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I'll need to rewrite this using functions anyway.
As you know from CI the Windows run keeps stalling. It happens because the Windows pthreads library uses a mutex to guard semaphores. If that mutex is locked when the main thread is suspended, the next call to sem_post() results in a deadlock. Oh, the joys of multithreading.
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| extern void host_init_bootloader(); | |||
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@mikee47 Can you move this line to the beginning of the file or a separate header file?
| lwip_initialised = host_lwip_init(&config.lwip); | ||
| if(lwip_initialised) { | ||
| if(host_lwip_init(config.lwip)) { | ||
| extern void host_wifi_lwip_init_complete(); |
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@mikee47 Can you move this line to the beginning of the file or a separate header file?
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Time structure same as sem_timedwait Consistent with example code
Investigating cause of Windows deadlock. May have other uses.
Replace global semaphore with `host_thread_wait` and `host_thread_kick`
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@mikee47 this PR looks much better now. Shall I merge it or you would like to add something? |
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@slaff All done thanks |
This PR improves Host performance by using efficient waiting for tasks & timers rather than just looping.
Running the
HttpServer_ConfigNetworkexample sees a drop from 100% CPU usage to < 2% running in linux. Difference in Windows is less pronounced as the lwip layer incorporates a 1ms wait.LWIP is now serviced using an event timer. The interval is adjusted dynamically which allows good file transfer performance and reduced CPU usage when idle.