src/include/gpxe/process.h

   1 #ifndef _GPXE_PROCESS_H
   2 #define _GPXE_PROCESS_H
   3
   4 /** @file
   5  *
   6  * Processes
   7  *
   8  */
   9
  10 #include <gpxe/list.h>
  11 #include <gpxe/refcnt.h>
  12 #include <gpxe/tables.h>
  13
  14 /** A process */
  15 struct process {
  16         /** List of processes */
  17         struct list_head list;
  18         /**
  19          * Single-step the process
  20          *
  21          * This method should execute a single step of the process.
  22          * Returning from this method is isomorphic to yielding the
  23          * CPU to another process.
  24          */
  25         void ( * step ) ( struct process *process );
  26         /** Reference counter
  27          *
  28          * If this interface is not part of a reference-counted
  29          * object, this field may be NULL.
  30          */
  31         struct refcnt *refcnt;
  32 };
  33
  34 extern void process_add ( struct process *process );
  35 extern void process_del ( struct process *process );
  36 extern void step ( void );
  37
  38 /**
  39  * Initialise process without adding to process list
  40  *
  41  * @v process           Process
  42  * @v step              Process' step() method
  43  */
  44 static inline __attribute__ (( always_inline )) void
  45 process_init_stopped ( struct process *process,
  46                        void ( * step ) ( struct process *process ),
  47                        struct refcnt *refcnt ) {
  48         process->step = step;
  49         process->refcnt = refcnt;
  50 }
  51
  52 /**
  53  * Initialise process and add to process list
  54  *
  55  * @v process           Process
  56  * @v step              Process' step() method
  57  */
  58 static inline __attribute__ (( always_inline )) void
  59 process_init ( struct process *process,
  60                void ( * step ) ( struct process *process ),
  61                struct refcnt *refcnt ) {
  62         process_init_stopped ( process, step, refcnt );
  63         process_add ( process );
  64 }
  65
  66 /**
  67  * Declare a permanent process
  68  *
  69  * Permanent processes will be automatically added to the process list
  70  * at initialisation time.
  71  */
  72 #define __permanent_process \
  73         __table ( struct process, processes, 01 )
  74
  75 #endif /* _GPXE_PROCESS_H */