#ifndef _ZEND_ARENA_H_
#define _ZEND_ARENA_H_
#include "zend.h"
typedef struct _zend_arena zend_arena;
struct _zend_arena {
char *ptr;
char *end;
zend_arena *prev;
};
static zend_always_inline zend_arena* zend_arena_create(size_t size)
{
zend_arena *arena = (zend_arena*)emalloc(size);
arena->ptr = (char*) arena + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena));
arena->end = (char*) arena + size;
arena->prev = NULL;
return arena;
}
static zend_always_inline void zend_arena_destroy(zend_arena *arena)
{
do {
zend_arena *prev = arena->prev;
efree(arena);
arena = prev;
} while (arena);
}
#define ZEND_ARENA_ALIGNMENT 8U
static zend_always_inline void* zend_arena_alloc(zend_arena **arena_ptr, size_t size)
{
zend_arena *arena = *arena_ptr;
char *ptr = arena->ptr;
size = ZEND_MM_ALIGNED_SIZE(size);
if (EXPECTED(size <= (size_t)(arena->end - ptr))) {
arena->ptr = ptr + size;
} else {
size_t arena_size =
UNEXPECTED((size + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))) > (size_t)(arena->end - (char*) arena)) ?
(size + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena))) :
(size_t)(arena->end - (char*) arena);
zend_arena *new_arena = (zend_arena*)emalloc(arena_size);
ptr = (char*) new_arena + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena));
new_arena->ptr = (char*) new_arena + ZEND_MM_ALIGNED_SIZE(sizeof(zend_arena)) + size;
new_arena->end = (char*) new_arena + arena_size;
new_arena->prev = arena;
*arena_ptr = new_arena;
}
return (void*) ptr;
}
static zend_always_inline void* zend_arena_calloc(zend_arena **arena_ptr, size_t count, size_t unit_size)
{
int overflow;
size_t size;
void *ret;
size = zend_safe_address(unit_size, count, 0, &overflow);
if (UNEXPECTED(overflow)) {
zend_error(E_ERROR, "Possible integer overflow in zend_arena_calloc() (%zu * %zu)", unit_size, count);
}
ret = zend_arena_alloc(arena_ptr, size);
memset(ret, 0, size);
return ret;
}
static zend_always_inline void* zend_arena_checkpoint(zend_arena *arena)
{
return arena->ptr;
}
static zend_always_inline void zend_arena_release(zend_arena **arena_ptr, void *checkpoint)
{
zend_arena *arena = *arena_ptr;
while (UNEXPECTED((char*)checkpoint > arena->end) ||
UNEXPECTED((char*)checkpoint <= (char*)arena)) {
zend_arena *prev = arena->prev;
efree(arena);
*arena_ptr = arena = prev;
}
ZEND_ASSERT((char*)checkpoint > (char*)arena && (char*)checkpoint <= arena->end);
arena->ptr = (char*)checkpoint;
}
#endif