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