Lines 1-114
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/***************************************************************** |
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This file should be kept compatible with Python 2.3, see PEP 291. |
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*****************************************************************/ |
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#include <Python.h> |
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#include <ffi.h> |
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#ifdef MS_WIN32 |
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#include <windows.h> |
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#else |
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#include <sys/mman.h> |
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#include <unistd.h> |
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# if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) |
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# define MAP_ANONYMOUS MAP_ANON |
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# endif |
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#endif |
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#include "ctypes.h" |
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/* BLOCKSIZE can be adjusted. Larger blocksize will take a larger memory |
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overhead, but allocate less blocks from the system. It may be that some |
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systems have a limit of how many mmap'd blocks can be open. |
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*/ |
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#define BLOCKSIZE _pagesize |
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/* #define MALLOC_CLOSURE_DEBUG */ /* enable for some debugging output */ |
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/******************************************************************/ |
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typedef union _tagITEM { |
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ffi_closure closure; |
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union _tagITEM *next; |
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} ITEM; |
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static ITEM *free_list; |
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static int _pagesize; |
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static void more_core(void) |
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{ |
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ITEM *item; |
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int count, i; |
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/* determine the pagesize */ |
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#ifdef MS_WIN32 |
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if (!_pagesize) { |
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SYSTEM_INFO systeminfo; |
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GetSystemInfo(&systeminfo); |
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_pagesize = systeminfo.dwPageSize; |
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} |
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#else |
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if (!_pagesize) { |
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#ifdef _SC_PAGESIZE |
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_pagesize = sysconf(_SC_PAGESIZE); |
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#else |
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_pagesize = getpagesize(); |
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#endif |
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} |
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#endif |
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|
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/* calculate the number of nodes to allocate */ |
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count = BLOCKSIZE / sizeof(ITEM); |
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|
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/* allocate a memory block */ |
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#ifdef MS_WIN32 |
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item = (ITEM *)VirtualAlloc(NULL, |
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count * sizeof(ITEM), |
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MEM_COMMIT, |
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PAGE_EXECUTE_READWRITE); |
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if (item == NULL) |
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return; |
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#else |
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item = (ITEM *)mmap(NULL, |
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count * sizeof(ITEM), |
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PROT_READ | PROT_WRITE | PROT_EXEC, |
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MAP_PRIVATE | MAP_ANONYMOUS, |
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-1, |
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0); |
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if (item == (void *)MAP_FAILED) |
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return; |
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#endif |
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|
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#ifdef MALLOC_CLOSURE_DEBUG |
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printf("block at %p allocated (%d bytes), %d ITEMs\n", |
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item, count * sizeof(ITEM), count); |
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#endif |
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/* put them into the free list */ |
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for (i = 0; i < count; ++i) { |
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item->next = free_list; |
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free_list = item; |
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++item; |
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} |
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} |
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/******************************************************************/ |
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|
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/* put the item back into the free list */ |
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void FreeClosure(void *p) |
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{ |
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ITEM *item = (ITEM *)p; |
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item->next = free_list; |
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free_list = item; |
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} |
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/* return one item from the free list, allocating more if needed */ |
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void *MallocClosure(void) |
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{ |
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ITEM *item; |
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if (!free_list) |
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more_core(); |
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if (!free_list) |
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return NULL; |
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item = free_list; |
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free_list = item->next; |
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return item; |
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} |