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Diffstat (limited to 'man/10/kproc')
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diff --git a/man/10/kproc b/man/10/kproc new file mode 100644 index 00000000..eff495c2 --- /dev/null +++ b/man/10/kproc @@ -0,0 +1,142 @@ +.TH KPROC 10.2 +.SH NAME +kproc, setpri, swiproc, pexit \- kernel process creation, priority change, interrupt and termination +.SH SYNOPSIS +.ta \w'\fLchar* 'u +.B +void kproc(char *name, void (*func)(void*), void *arg, int flags); +.PP +.B +int setpri(int pri); +.PP +.B +void swiproc(Proc *p, int interp); +.PP +.B +void pexit(char*, int); +.SH DESCRIPTION +.I Kproc +creates a new Inferno kernel process +to run the function +.IR func , +which is invoked as +.BR "(*func)(arg)" . +The string +.I name +is copied into the +.B text +field of the +.B Proc +structure of the new process; although the value is not visible to Limbo +applications, it can appear in system messages written to the console. +The process is made runnable; it +will run when selected by the scheduler. +.PP +The new process always acquires the following attributes from the creating process: +.IP +owner (Inferno user name) +.br +host user and group IDs (in +.I emu +only) +.br +floating-point attributes +.PP +Several resources can be shared with the creating process on request, as determined by +.IR flags , +which is the logical OR +of a subset of the following: +.TF KPDUPENVG +.TP +.B KPDUPPG +If set, the new process shares the caller's process group, +which includes its process group ID +(for +.IR killgrp ), +name space (mounts, root and current directory), +and PIN for +.B /dev/pin +(see +.IR cons (3)). +.TP +.B KPDUPFDG +If set, the new process shares the caller's file descriptor group; +otherwise, it has no file descriptor group, and (if it intends to open files) must call +.IR newfgrp (10.2) +to obtain an empty file descriptor group. +.TP +.B KPDUPENVG +If set, the new process shares the caller's environment group +(currently applies in +.I emu +only). +.TP +.B KPDUP +Equivalent to all of the above. +.PD +.PP +If a particular option is not set, the new process will have a +.B nil +reference for the corresponding resource. +.PP +.I Setpri +sets the priority of the calling process to +.I pri +and returns its previous priority level. +If a (now) higher priority process is ready to run, the system will reschedule. +The available priority levels are shown below, +arranged from highest to lowest priority, +with examples of the type of processes intended to use them: +.TF PriBackground +.TP +.B PriLock +The highest priority, used by +.IR lock (10.2) +for a process entering a critical section +.TP +.B PriRealtime +Intended for processes supporting applications with real-time constraints, such as video telephony. +.TP +.B PriHicodec +MPEG codec +.TP +.B PriLocodec +Audio codec +.TP +.B PriHi +Any task with keen time constraints. +.TP +.B PriNormal +The priority of most processes in the system. +.TP +.B PriLo +.TP +.B PriBackground +.PD +.PP +.I Swiproc +sends a software interrupt to process +.IR p , +causing it to wake from +.IR sleep (10.2) +with an +.IR error (10.2) +`interrupted'. +Unless +.I interp +is non-zero (ie, the Dis interpreter is the caller), the process is also marked `killed'. +.PP +An Inferno process terminates only when it calls +.IR pexit , +thereby terminating itself. +There is no mechanism for one process to force the termination of another, +although it can send a software interrupt using +.IR swiproc . +The arguments to +.I pexit +are ignored in Inferno, but are included for compatibility +with kernel components of Plan 9; use +.IP +.EX +pexit("", 0); +.EE |