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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Quick arena hack for xpt. */
/* XXX This exists because we don't want to drag in NSPR. It *seemed*
* to make more sense to write a quick and dirty arena than to clone
* plarena (like js/src did). This is not optimal, but it works.
*/
#include "xpt_arena.h"
#include "mozilla/MemoryReporting.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
/****************************************************/
/* Block header for each block in the arena */
struct BLK_HDR
{
BLK_HDR *next;
};
#define XPT_MIN_BLOCK_SIZE 32
/* XXX this is lame. Should clone the code to do this bitwise */
#define ALIGN_RND(s,a) ((a)==1?(s):((((s)+(a)-1)/(a))*(a)))
struct XPTSubArena
{
BLK_HDR *first;
uint8_t *next;
size_t space;
size_t block_size;
};
struct XPTArena
{
// We have one sub-arena with 8-byte alignment for most allocations, and
// one with 1-byte alignment for C string allocations. The latter sub-arena
// avoids significant amounts of unnecessary padding between C strings.
XPTSubArena subarena8;
XPTSubArena subarena1;
};
XPT_PUBLIC_API(XPTArena *)
XPT_NewArena(size_t block_size8, size_t block_size1)
{
XPTArena *arena = static_cast<XPTArena*>(calloc(1, sizeof(XPTArena)));
if (arena) {
if (block_size8 < XPT_MIN_BLOCK_SIZE)
block_size8 = XPT_MIN_BLOCK_SIZE;
arena->subarena8.block_size = ALIGN_RND(block_size8, 8);
if (block_size1 < XPT_MIN_BLOCK_SIZE)
block_size1 = XPT_MIN_BLOCK_SIZE;
arena->subarena1.block_size = block_size1;
}
return arena;
}
static void
DestroySubArena(XPTSubArena *subarena)
{
BLK_HDR* cur = subarena->first;
while (cur) {
BLK_HDR* next = cur->next;
free(cur);
cur = next;
}
}
XPT_PUBLIC_API(void)
XPT_DestroyArena(XPTArena *arena)
{
DestroySubArena(&arena->subarena8);
DestroySubArena(&arena->subarena1);
free(arena);
}
/*
* Our alignment rule is that we always round up the size of each allocation
* so that the 'arena->next' pointer one will point to properly aligned space.
*/
XPT_PUBLIC_API(void *)
XPT_ArenaCalloc(XPTArena *arena, size_t size, size_t alignment)
{
if (!size)
return NULL;
if (!arena) {
XPT_ASSERT(0);
return NULL;
}
XPTSubArena *subarena;
if (alignment == 8) {
subarena = &arena->subarena8;
} else if (alignment == 1) {
subarena = &arena->subarena1;
} else {
XPT_ASSERT(0);
return NULL;
}
size_t bytes = ALIGN_RND(size, alignment);
if (bytes > subarena->space) {
BLK_HDR* new_block;
size_t block_header_size = ALIGN_RND(sizeof(BLK_HDR), alignment);
size_t new_space = subarena->block_size;
while (bytes > new_space - block_header_size)
new_space += subarena->block_size;
new_block =
static_cast<BLK_HDR*>(calloc(new_space / alignment, alignment));
if (!new_block) {
subarena->next = NULL;
subarena->space = 0;
return NULL;
}
/* link block into the list of blocks for use when we destroy */
new_block->next = subarena->first;
subarena->first = new_block;
/* set info for current block */
subarena->next =
reinterpret_cast<uint8_t*>(new_block) + block_header_size;
subarena->space = new_space - block_header_size;
#ifdef DEBUG
/* mark block for corruption check */
memset(subarena->next, 0xcd, subarena->space);
#endif
}
#ifdef DEBUG
{
/* do corruption check */
size_t i;
for (i = 0; i < bytes; ++i) {
XPT_ASSERT(subarena->next[i] == 0xcd);
}
/* we guarantee that the block will be filled with zeros */
memset(subarena->next, 0, bytes);
}
#endif
uint8_t* p = subarena->next;
subarena->next += bytes;
subarena->space -= bytes;
return p;
}
/***************************************************************************/
#ifdef DEBUG
XPT_PUBLIC_API(void)
XPT_AssertFailed(const char *s, const char *file, uint32_t lineno)
{
fprintf(stderr, "Assertion failed: %s, file %s, line %d\n",
s, file, lineno);
abort();
}
#endif
static size_t
SizeOfSubArenaExcludingThis(XPTSubArena *subarena, MozMallocSizeOf mallocSizeOf)
{
size_t n = 0;
BLK_HDR* cur = subarena->first;
while (cur) {
BLK_HDR* next = cur->next;
n += mallocSizeOf(cur);
cur = next;
}
return n;
}
XPT_PUBLIC_API(size_t)
XPT_SizeOfArenaIncludingThis(XPTArena *arena, MozMallocSizeOf mallocSizeOf)
{
size_t n = mallocSizeOf(arena);
n += SizeOfSubArenaExcludingThis(&arena->subarena8, mallocSizeOf);
n += SizeOfSubArenaExcludingThis(&arena->subarena1, mallocSizeOf);
return n;
}
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