@startuml scale 5 as 100 pixels robust "PD 1" as pd1 robust "PD 2" as pd2 robust "seL4" as kernel concise "Buffer" as buf kernel has running,stopped pd1 has running,ready,stopped pd2 has running,ready,stopped @0 pd1 is running #palegreen pd2 is stopped kernel is stopped buf is {-} @5 buf is A @10 pd1 is ready kernel is running @11 pd2 is running #palegreen kernel is stopped @15 pd2 is stopped kernel is running @16 pd1 is running #palegreen kernel is stopped @17 buf is B pd1@10 -> pd2@11 : Notification pd1@5 -> buf@5.5 : Write 'A' pd1@17 -> buf@17.5 : Write 'B' buf@11.5 -> pd2@12 : Read 'A' caption When PD 1 sends a notification to the higher priority PD 2, it gets immediately preempted, until when PD 2 finishes. The data written to the buffer can be consumed by PD 2, provided that it takes less time than the remaining budget in the current period of PD 2. end caption @enduml Submit amiga aws-orange black-knight bluegray blueprint cerulean-outline cerulean crt-amber crt-green cyborg-outline cyborg hacker lightgray mars materia-outline materia metal mimeograph minty plain reddress-darkblue reddress-darkgreen reddress-darkorange reddress-darkred reddress-lightblue reddress-lightgreen reddress-lightorange reddress-lightred sandstone silver sketchy-outline sketchy spacelab spacelab-white superhero-outline superhero toy united vibrant       🎉 Discover the future PlantUML Web Editor! 🚀  PNG  SVG  ASCII Art