sys/sys/pipe.h

   1 /*
   2  * Copyright (c) 1996 John S. Dyson
   3  * All rights reserved.
   4  * Copyright (c) 2003-2017 The DragonFly Project.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to The DragonFly Project
   7  * by Matthew Dillon <dillon@backplane.com>
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice immediately at the beginning of the file, without modification,
  14  *    this list of conditions, and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Absolutely no warranty of function or purpose is made by the author
  19  *    John S. Dyson.
  20  * 4. This work was done expressly for inclusion into FreeBSD.  Other use
  21  *    is allowed if this notation is included.
  22  * 5. Modifications may be freely made to this file if the above conditions
  23  *    are met.
  24  */
  25
  26 #ifndef _SYS_PIPE_H_
  27 #define _SYS_PIPE_H_
  28
  29 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
  30
  31 #ifndef _SYS_TYPES_H_
  32 #include <sys/types.h>
  33 #endif
  34 #ifndef _SYS_TIME_H_
  35 #include <sys/time.h>                   /* for struct timespec */
  36 #endif
  37 #ifndef _SYS_EVENT_H_
  38 #include <sys/event.h>                  /* for struct kqinfo */
  39 #endif
  40 #ifndef _SYS_XIO_H_
  41 #include <sys/xio.h>                    /* for struct xio */
  42 #endif
  43 #ifndef _SYS_THREAD_H_
  44 #include <sys/thread.h>                 /* for struct lwkt_token */
  45 #endif
  46 #ifndef _MACHINE_PARAM_H_
  47 #include <machine/param.h>              /* for PAGE_SIZE */
  48 #endif
  49
  50 /*
  51  * Pipe buffer information.
  52  */
  53 struct pipebuf {
  54         struct {
  55                 struct lwkt_token rlock;
  56                 size_t          rindex; /* current read index (FIFO)    */
  57                 int32_t         rip;    /* blocking read requested (FIFO) */
  58                 int32_t         unu01;  /* blocking read requested (FIFO) */
  59                 struct timespec atime;  /* time of last access */
  60         } __cachealign;
  61         struct {
  62                 struct lwkt_token wlock;
  63                 size_t          windex; /* current write index (FIFO)   */
  64                 int32_t         wip;
  65                 int32_t         unu02;
  66                 struct timespec mtime;  /* time of last modify */
  67         } __cachealign;
  68         size_t          size;           /* size of buffer */
  69         caddr_t         buffer;         /* kva of buffer */
  70         struct vm_object *object;       /* VM object containing buffer */
  71         struct kqinfo   kq;             /* for compat with select/poll/kq */
  72         struct sigio    *sigio;         /* information for async I/O */
  73         uint32_t        state;          /* pipe status info */
  74 } __cachealign;
  75
  76 /*
  77  * Bits in pipebuf.state.
  78  */
  79 #define PIPE_ASYNC      0x0004  /* Async? I/O */
  80 #define PIPE_WANTR      0x0008  /* Reader wants some characters */
  81 #define PIPE_WANTW      0x0010  /* Writer wants space to put characters */
  82 #define PIPE_REOF       0x0040  /* Pipe is in EOF condition (read EOF) */
  83 #define PIPE_WEOF       0x0080  /* Pipe is in EOF condition (write shutdown) */
  84 #define PIPE_CLOSED     0x1000  /* Pipe has been closed */
  85
  86 /*
  87  * The pipe() data structure encompasses two pipes.  Bit 0 in fp->f_data
  88  * denotes which.
  89  */
  90 struct pipe {
  91         struct pipebuf  bufferA;        /* data storage */
  92         struct pipebuf  bufferB;        /* data storage */
  93         struct timespec ctime;          /* time of status change */
  94         struct pipe     *next;
  95         uint32_t        open_count;
  96         uint32_t        unused01;
  97         uint64_t        inum;
  98 } __cachealign;
  99
 100 #endif  /* _KERNEL || _KERNEL_STRUCTURES */
 101 #endif /* !_SYS_PIPE_H_ */