id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,field_blocks,field_dependson,field_seealso 414,Graceful system shutdown,Jakub Jermář,,"Design and implement graceful shutdown of HelenOS. Details:: The current support for shutdown in HelenOS is rather minimal. It is possible to halt the CPUs or reboot the machine. What is missing is a ''graceful'' way to tell running tasks that the system is about to be shut down. For example, the reboot sequence now consists of forceful kill of all existing tasks.[[br]] The goal is to design and implement way to notify tasks of imminent shutdown (reboot) to allow them terminate in a clean and consistent way. The design decisions must reflect microkernel-specific issues, such as order of shutdown of vital services (e. g. VFS, naming service or drivers). What Gains and Benefits will this bring?:: The benefits of this task come at rather low level but are nevertheless very important. Graceful shutdown means that drivers could terminate communication with hardware in a predictable manner or that filesystem servers would be able to unmount file systems cleanly. Difficulty:: Medium to difficult. The solution will require work both in kernel and in userspace. Required skills:: A successful applicant will have good skills of programming in the C languages and the ability to survive in a non-standard non-POSIX application environment. Possible mentors:: HelenOS Core Team ",enhancement,new,major,,helenos/unspecified,mainline,,"gsoc12, needswork",,,,