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| -rw-r--r-- | research/heap.sh | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/research/heap.sh b/research/heap.sh new file mode 100644 index 0000000..54ce1e3 --- /dev/null +++ b/research/heap.sh @@ -0,0 +1,42 @@ +__malloc() +{ + __heap=${1} + + if eval "\${${__heap}_size:+true}"; then + # Empty heap + __mr="${__heap}0" + eval "${__heap}_size=1" + elif eval "\${${__heap}_free_head:+false}"; then + # No free blocks, grow heap + eval "__mr=\${__heap}\${${__heap}_size}" + eval "${__heap}_size=\$((\${${__heap}_size} + 1))" + else + # Free block(s) available, allocate + eval "__mr=\${${__heap}_free_head}" + if eval "\${${__mr}_next_free:+false}"; then + # Last free block, clear heap's free list + eval "${__heap}_free_head=" + eval "${__heap}_free_tail=" + else + # Multiple free blocks, move heap's free list head + eval "${__heap}_free_head=\${${__mr}_next_free}" + fi + fi +} + +__free() +{ + __heap=${1} + __ptr=${2} + + if eval "\${${__heap}_free_tail:+false}"; then + # Empty free list + eval "${__heap}_free_head=\${__ptr}" + eval "${__heap}_free_tail=\${__ptr}" + else + # Non-empty free list, push to tail + eval "__free_tail=\${${__heap}_free_tail}" + eval "${__free_tail}_next_free=\${__ptr}" + eval "${__heap}_free_tail=\${__ptr}" + fi +} |