mdw@git.distorted.org.uk Git - ssr/blob - StraySrc/Dynamite/dynamite/sh/dynHeap

   1 ;
   2 ; dynHeap.sh
   3 ;
   4 ; New heap management for Dynamite
   5 ;
   6 ; © 1994 Straylight
   7 ;
   8
   9 ;----- Overview -------------------------------------------------------------
  10 ;
  11 ; Functions provided:
  12 ;
  13 ;  dh_alloc
  14 ;  dh_free
  15 ;  dh_freeWithID
  16 ;  dh_blockInfo
  17 ;  dh_changeID
  18 ;  dh_reduce
  19 ;  dh_compact
  20 ;  dh_lock
  21 ;  dh_unlock
  22 ;  dh_save
  23 ;  dh_load
  24 ;  dh_extend
  25 ;  dh_midExtend
  26 ;  dh_checkHeap
  27 ;  dh_changeAnchor
  28 ;  dh_dump
  29
  30                 [       :LNOT::DEF:dynHeap__dfn
  31                 GBLL    dynHeap__dfn
  32
  33 ; --- dh_alloc ---
  34 ;
  35 ; On entry:     R0 == pointer to anchor
  36 ;               R1 == size to allocate in bytes
  37 ;               R2 == ID value to store
  38 ;
  39 ; On exit:      R0 and R1 preserved
  40 ;               R2 == address of block allocated
  41 ;
  42 ; Use:          Allocates a block from the Dynamite heap.
  43
  44                 IMPORT  dh_alloc
  45
  46 ; --- dh_free ---
  47 ;
  48 ; On entry:     R0 == pointer to anchor of block to free
  49 ;
  50 ; On exit:      --
  51 ;
  52 ; Use:          Frees a Dynamite block.
  53
  54                 IMPORT  dh_free
  55
  56 ; --- dh_freeWithID ---
  57 ;
  58 ; On entry:     R0 == ID of all blocks to free
  59 ;
  60 ; On exit:      --
  61 ;
  62 ; Use:          Frees all allocated blocks with a given ID number.
  63
  64                 IMPORT  dh_freeWithID
  65
  66 ; --- dh_blockInfo ---
  67 ;
  68 ; On entry:     R0 == address of block anchor
  69 ;
  70 ; On exit:      R0 preserved
  71 ;               R1 == address of block
  72 ;               R2 == size of block
  73 ;               R3 == block ID
  74 ;
  75 ; Use:          Returns information about a Dynamite block
  76
  77                 IMPORT  dh_blockInfo
  78
  79 ; --- dh_changeID ---
  80 ;
  81 ; On entry:     R0 == address of anchor block, or 0 for all
  82 ;               R1 == new ID
  83 ;               R2 == old ID (if R0 == 0)
  84 ;
  85 ; On exit:      --
  86 ;
  87 ; Use:          This call is use to change the ID of either an individual
  88 ;               block (R0 == address of anchor), or the ID of all the
  89 ;               blocks with the ID passed in R2 (if R0 == 0).
  90
  91                 IMPORT  dh_changeID
  92
  93 ; --- dh_reduce ---
  94 ;
  95 ; On entry:     --
  96 ;
  97 ; On exit:      CS if there was nothing we could do
  98 ;
  99 ; Use:          Tries to shunt the free space in the heap off the end and
 100 ;               back into the operating system's free pool.  It does it a
 101 ;               little bit and then stops, rather like those workmen on the
 102 ;               M40.
 103
 104                 IMPORT  dh_reduce
 105
 106 ; --- dh_compact ---
 107 ;
 108 ; On entry:     --
 109 ;
 110 ; On exit:      --
 111 ;
 112 ; Use:          Does a full compaction of the heap.
 113
 114                 IMPORT  dh_compact
 115
 116 ; --- dh_lock ---
 117 ;
 118 ; On entry:     --
 119 ;
 120 ; On exit:      R10 corrupted (SWIs don't care about this)
 121 ;
 122 ; Use:          Locks the heap, so that compaction entirely fails to happen.
 123
 124                 IMPORT  dh_lock
 125
 126 ; --- dh_unlock ---
 127 ;
 128 ; On entry:     --
 129 ;
 130 ; On exit:      R10 corrupted (SWIs don't care about this)
 131 ;
 132 ; Use:          Unlocks the heap, so that compaction can happen again, maybe.
 133
 134                 IMPORT  dh_unlock
 135
 136 ; --- dh_save ---
 137 ;
 138 ; On entry:     R0 == mask of registers to save
 139 ;
 140 ; On exit:      R10, R11 corrupted
 141 ;
 142 ; Use:          Saves a load of registers on the Dynamite relocation stack.
 143 ;               The mask in R0 contains a bit set for each register to save:
 144 ;               bit 3 set means save R3 etc.  Since this is a SWI, only
 145 ;               R1-R9 can be saved on the stack.
 146
 147                 IMPORT  dh_save
 148
 149 ; --- dh_load ---
 150 ;
 151 ; On entry:     R0 == mask of registers to load
 152 ;
 153 ; On exit:      R10, R11 corrupted
 154 ;
 155 ; Use:          Loads a load of registers on the Dynamite relocation stack.
 156 ;               The mask in R0 contains a bit set for each register to load:
 157 ;               bit 3 set means load R3 etc.  Since this is a SWI, only
 158 ;               R1-R9 can be read from the stack.
 159
 160                 IMPORT  dh_load
 161
 162 ; --- dh_extend ---
 163 ;
 164 ; On entry:     R0 == address of block anchor
 165 ;               R1 == new size for block
 166 ;
 167 ; On exit:      R0 preserved
 168 ;               R1 == address of block, may have moved
 169 ;
 170 ; Use:          Changes the size of a block.
 171
 172                 IMPORT  dh_extend
 173
 174 ; --- dh_midExtend ---
 175 ;
 176 ; On entry:     R0 == address of block anchor
 177 ;               R1 == byte offset from block start
 178 ;               R2 == number of bytes to insert
 179 ;
 180 ; On exit:      R0 preserved
 181 ;               R1 == address of block, may have moved
 182 ;
 183 ; Use:          Inserts or removes bytes at a given offset into a Dynamite
 184 ;               heap block.
 185
 186                 IMPORT  dh_midExtend
 187
 188 ; --- dh_checkHeap ---
 189 ;
 190 ; On entry:     --
 191 ;
 192 ; On exit:      May return an error
 193 ;
 194 ; Use:          Checks the current internal format of the heap to make
 195 ;               sure that it hasn't been corrupted in any way.
 196 ;               If the integrity check fails then an error is returned.
 197
 198                 IMPORT  dh_checkHeap
 199
 200 ; --- dh_changeAnchor ---
 201 ;
 202 ; On entry:     R0 == pointer to anchor for block
 203 ;               R1 == address of new anchor
 204 ;
 205 ; On exit:      --
 206 ;
 207 ; Use:          Adjusts a block's anchor, in case it moves.
 208
 209                 IMPORT  dh_changeAnchor
 210
 211 ; --- dh_dump ---
 212 ;
 213 ; On entry:     --
 214 ;
 215 ; On exit:      --
 216 ;
 217 ; Use:          Outputs a textual description of the dynamite heap, giving
 218 ;               details of each block within it.
 219
 220                 IMPORT  dh_dump
 221
 222                 ]
 223
 224 ;----- That's all, folks ----------------------------------------------------
 225
 226                 END