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/* enable mremap on GNU/Linux */ |
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#ifdef __linux__ |
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# define _GNU_SOURCE |
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#endif |
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|
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/* enable the POSIX prototypes of mmap/munmap on Solaris */ |
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#ifdef __sun |
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# if __STDC_VERSION__ >= 199901L |
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# define _XOPEN_SOURCE 600 |
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# else |
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# define _XOPEN_SOURCE 500 |
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# endif |
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#endif |
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|
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#include "emman.h" |
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|
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#include <ecb.h> |
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|
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#include <string.h> |
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|
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#ifndef _WIN32 |
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# include <unistd.h> |
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#endif |
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|
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#if _POSIX_MAPPED_FILES |
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# define USE_MMAP 1 |
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# include <sys/mman.h> |
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# ifndef MAP_FAILED |
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# define MAP_FAILED ((void *)-1) |
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# endif |
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# ifndef MAP_ANONYMOUS |
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# ifdef MAP_ANON |
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# define MAP_ANONYMOUS MAP_ANON |
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# else |
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# undef USE_MMAP |
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# endif |
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# endif |
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# include <limits.h> |
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# ifndef PAGESIZE |
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static uint32_t pagesize; |
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# define BOOT_PAGESIZE if (!pagesize) pagesize = sysconf (_SC_PAGESIZE) |
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# define PAGESIZE pagesize |
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# else |
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# define BOOT_PAGESIZE |
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# endif |
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#else |
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# define PAGESIZE 1 |
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#endif |
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|
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size_t |
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chunk_round (size_t size) |
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{ |
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BOOT_PAGESIZE; |
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|
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return (size + (PAGESIZE - 1)) & ~(size_t)(PAGESIZE - 1); |
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} |
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|
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size_t |
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chunk_fit (size_t header, size_t element_size, size_t max_increase) |
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{ |
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uint32_t fill, maximum_fill = 0; |
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size_t minimum_size; |
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|
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max_increase += header + element_size; |
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|
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BOOT_PAGESIZE; |
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|
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do |
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{ |
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header += element_size; |
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|
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fill = (uint32_t)header & (PAGESIZE - 1); |
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|
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if (fill >= maximum_fill) |
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{ |
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maximum_fill = fill + 16; /* size increase results in at least 16 bytes improvement */ |
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minimum_size = header; |
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} |
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} |
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while (header < max_increase); |
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|
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return minimum_size; |
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} |
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|
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void * |
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chunk_alloc (size_t size, int populate) |
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{ |
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#if USE_MMAP |
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void *ptr = MAP_FAILED; |
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|
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#ifdef MAP_POPULATE |
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if (populate & 1) |
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ptr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE, -1, 0); |
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#endif |
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|
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if (ptr == MAP_FAILED) |
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ptr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); |
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|
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if (ptr == MAP_FAILED) |
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return 0; |
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|
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return ptr; |
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#else |
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return malloc (size); |
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#endif |
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} |
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|
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void * |
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chunk_realloc (void *ptr, size_t old_size, size_t new_size) |
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{ |
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#if USE_MMAP |
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#ifdef MREMAP_MAYMOVE /* requires _GNU_SOURCE */ |
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void *ptr2 = mremap (ptr, old_size, new_size, MREMAP_MAYMOVE); |
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|
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if (ptr2 == MAP_FAILED) |
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return 0; |
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|
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return ptr2; |
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#else |
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void *ptr2 = chunk_alloc (new_size, 0); |
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|
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if (!ptr2) |
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return ptr2; |
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|
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/* TODO: prepopulate old_size pages instead of faulting them in */ |
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|
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memcpy (ptr2, ptr, old_size); |
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munmap (ptr, old_size); |
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return ptr2; |
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#endif |
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#else |
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return realloc (ptr, new_size); |
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#endif |
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} |
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|
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void |
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chunk_free (void *ptr, size_t size) |
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{ |
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#if USE_MMAP |
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/* we assume the OS never mmaps at address 0 */ |
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if (ptr) |
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munmap (ptr, size); |
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#else |
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return free (ptr); |
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#endif |
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} |
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