From: Leandro Lucarella Date: Mon, 20 Sep 2010 00:04:50 +0000 (-0300) Subject: Make realloc() a little more readable X-Git-Url: https://git.llucax.com/software/dgc/cdgc.git/commitdiff_plain/c13d9fa4737aed2c0849b1c73c0c11e2eddbcb28 Make realloc() a little more readable This is only an aesthetic change, some unneeded indentation is remove by removing some "else" blocks when return statements ensures that path wouldn't be followed anyway. --- diff --git a/rt/gc/cdgc/gc.d b/rt/gc/cdgc/gc.d index 52f798d..2ec72c4 100644 --- a/rt/gc/cdgc/gc.d +++ b/rt/gc/cdgc/gc.d @@ -1464,141 +1464,125 @@ private void *calloc(size_t size, uint attrs, size_t* pm_bitmask) private void *realloc(void *p, size_t size, uint attrs, size_t* pm_bitmask) { - if (!size) - { + if (!size) { if (p) - { free(p); - p = null; - } + return null; } - else if (!p) - { - p = malloc(size, attrs, pm_bitmask); + + if (p is null) + return malloc(size, attrs, pm_bitmask); + + Pool* pool = findPool(p); + if (pool is null) + return null; + + // Set or retrieve attributes as appropriate + auto bit_i = cast(size_t)(p - pool.baseAddr) / 16; + if (attrs) { + clrAttr(pool, bit_i, BlkAttr.ALL_BITS); + setAttr(pool, bit_i, attrs); } else - { - Pool* pool = findPool(p); - if (pool is null) - return null; + attrs = getAttr(pool, bit_i); - // Set or retrieve attributes as appropriate - auto bit_i = cast(size_t)(p - pool.baseAddr) / 16; - if (attrs) { - clrAttr(pool, bit_i, BlkAttr.ALL_BITS); - setAttr(pool, bit_i, attrs); + void* blk_base_addr = pool.findBase(p); + size_t blk_size = pool.findSize(p); + bool has_pm = has_pointermap(attrs); + size_t pm_bitmask_size = 0; + if (has_pm) { + pm_bitmask_size = size_t.sizeof; + // Retrieve pointer map bit mask if appropriate + if (pm_bitmask is null) { + auto end_of_blk = cast(size_t**)( + blk_base_addr + blk_size - size_t.sizeof); + pm_bitmask = *end_of_blk; } - else - attrs = getAttr(pool, bit_i); - - void* blk_base_addr = pool.findBase(p); - size_t blk_size = pool.findSize(p); - bool has_pm = has_pointermap(attrs); - size_t pm_bitmask_size = 0; - if (has_pm) { - pm_bitmask_size = size_t.sizeof; - // Retrieve pointer map bit mask if appropriate - if (pm_bitmask is null) { - auto end_of_blk = cast(size_t**)(blk_base_addr + - blk_size - size_t.sizeof); - pm_bitmask = *end_of_blk; - } + } + + if (opts.options.sentinel) { + sentinel_Invariant(p); + size_t sentinel_stored_size = *sentinel_size(p); + if (sentinel_stored_size != size) { + void* p2 = malloc(size, attrs, pm_bitmask); + if (sentinel_stored_size < size) + size = sentinel_stored_size; + cstring.memcpy(p2, p, size); + p = p2; } + return p; + } - if (opts.options.sentinel) - { - sentinel_Invariant(p); - size_t sentinel_stored_size = *sentinel_size(p); - if (sentinel_stored_size != size) - { - void* p2 = malloc(size, attrs, pm_bitmask); - if (sentinel_stored_size < size) - size = sentinel_stored_size; - cstring.memcpy(p2, p, size); - p = p2; + size += pm_bitmask_size; + if (blk_size >= PAGESIZE && size >= PAGESIZE) { + auto psz = blk_size / PAGESIZE; + auto newsz = round_up(size, PAGESIZE); + if (newsz == psz) + return p; + + auto pagenum = (p - pool.baseAddr) / PAGESIZE; + + if (newsz < psz) { + // Shrink in place + if (opts.options.mem_stomp) + memset(p + size - pm_bitmask_size, 0xF2, + blk_size - size - pm_bitmask_size); + pool.freePages(pagenum + newsz, psz - newsz); + auto new_blk_size = (PAGESIZE * newsz); + gc.free_mem += blk_size - new_blk_size; + // update the size cache, assuming that is very likely the + // size of this block will be queried in the near future + pool.update_cache(p, new_blk_size); + if (has_pm) { + auto end_of_blk = cast(size_t**)(blk_base_addr + + new_blk_size - pm_bitmask_size); + *end_of_blk = pm_bitmask; } + return p; } - else - { - size += pm_bitmask_size; - if (blk_size >= PAGESIZE && size >= PAGESIZE) - { - auto psz = blk_size / PAGESIZE; - auto newsz = round_up(size, PAGESIZE); - if (newsz == psz) - return p; - auto pagenum = (p - pool.baseAddr) / PAGESIZE; - - if (newsz < psz) - { - // Shrink in place + if (pagenum + newsz <= pool.npages) { + // Attempt to expand in place + for (size_t i = pagenum + psz; 1;) { + if (i == pagenum + newsz) { if (opts.options.mem_stomp) - memset(p + size - pm_bitmask_size, 0xF2, - blk_size - size - pm_bitmask_size); - pool.freePages(pagenum + newsz, psz - newsz); + memset(p + blk_size - pm_bitmask_size, 0xF0, + size - blk_size - pm_bitmask_size); + memset(pool.pagetable + pagenum + psz, B_PAGEPLUS, + newsz - psz); auto new_blk_size = (PAGESIZE * newsz); - gc.free_mem += blk_size - new_blk_size; - // update the size cache, assuming that is very likely the - // size of this block will be queried in the near future + gc.free_mem -= new_blk_size - blk_size; + // update the size cache, assuming that is very + // likely the size of this block will be queried in + // the near future pool.update_cache(p, new_blk_size); if (has_pm) { - auto end_of_blk = cast(size_t**)(blk_base_addr + - new_blk_size - pm_bitmask_size); + auto end_of_blk = cast(size_t**)( + blk_base_addr + new_blk_size - pm_bitmask_size); *end_of_blk = pm_bitmask; } return p; } - else if (pagenum + newsz <= pool.npages) - { - // Attempt to expand in place - for (size_t i = pagenum + psz; 1;) - { - if (i == pagenum + newsz) - { - if (opts.options.mem_stomp) - memset(p + blk_size - pm_bitmask_size, - 0xF0, size - blk_size - - pm_bitmask_size); - memset(pool.pagetable + pagenum + - psz, B_PAGEPLUS, newsz - psz); - auto new_blk_size = (PAGESIZE * newsz); - gc.free_mem -= new_blk_size - blk_size; - // update the size cache, assuming that is very - // likely the size of this block will be queried in - // the near future - pool.update_cache(p, new_blk_size); - if (has_pm) { - auto end_of_blk = cast(size_t**)( - blk_base_addr + new_blk_size - - pm_bitmask_size); - *end_of_blk = pm_bitmask; - } - return p; - } - if (i == pool.npages) - { - break; - } - if (pool.pagetable[i] != B_FREE) - break; - i++; - } - } - } - // if new size is bigger or less than half - if (blk_size < size || blk_size > size * 2) - { - size -= pm_bitmask_size; - blk_size -= pm_bitmask_size; - void* p2 = malloc(size, attrs, pm_bitmask); - if (blk_size < size) - size = blk_size; - cstring.memcpy(p2, p, size); - p = p2; + if (i == pool.npages) + break; + if (pool.pagetable[i] != B_FREE) + break; + i++; } } } + + // if new size is bigger or less than half + if (blk_size < size || blk_size > size * 2) { + size -= pm_bitmask_size; + blk_size -= pm_bitmask_size; + void* p2 = malloc(size, attrs, pm_bitmask); + if (blk_size < size) + size = blk_size; + cstring.memcpy(p2, p, size); + p = p2; + } + return p; }