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Diffstat (limited to 'kern/shuttle.h')
-rw-r--r-- | kern/shuttle.h | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/kern/shuttle.h b/kern/shuttle.h new file mode 100644 index 0000000..e8e574b --- /dev/null +++ b/kern/shuttle.h @@ -0,0 +1,71 @@ +/* + * Copyright (c) 1993,1994 The University of Utah and + * the Computer Systems Laboratory (CSL). All rights reserved. + * + * Permission to use, copy, modify and distribute this software and its + * documentation is hereby granted, provided that both the copyright + * notice and this permission notice appear in all copies of the + * software, derivative works or modified versions, and any portions + * thereof, and that both notices appear in supporting documentation. + * + * THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS + * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSL DISCLAIM ANY LIABILITY OF + * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. + * + * CSL requests users of this software to return to csl-dist@cs.utah.edu any + * improvements that they make and grant CSL redistribution rights. + * + * Author: Bryan Ford, University of Utah CSL + */ +/* + * File: shuttle.h + * Author: Bryan Ford + * + * This file contains definitions for shuttles, + * which handle microscheduling for individual threads. + * + */ + +#ifndef _KERN_SHUTTLE_H_ +#define _KERN_SHUTTLE_H_ + +#include <kern/lock.h> + + + +struct Shuttle { + /* XXX must be first in thread */ +/* + * NOTE: The runq field in the thread structure has an unusual + * locking protocol. If its value is RUN_QUEUE_NULL, then it is + * locked by the thread_lock, but if its value is something else + * (i.e. a run_queue) then it is locked by that run_queue's lock. + */ + queue_chain_t links; /* current run queue links */ + run_queue_t runq; /* run queue p is on SEE BELOW */ + + /* Next pointer when on a queue */ + struct Shuttle *next; + + /* Micropriority level */ + int priority; + + /* General-purpose pointer field whose use depends on what the + thread happens to be doing */ + void *message; + + int foobar[1]; +}; +typedef struct Shuttle Shuttle; + + + +/* Exported functions */ + + + +/* Machine-dependent code must define the following functions */ + + + +#endif _KERN_SHUTTLE_H_ |