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runtime_loader: Resync heap impl with the one of the bootloader.

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The heap implementation of the runtime_loader was switched to the one
of the bootloader in 6f0994d but was since updated independently.

To keep the diff between the two implementations as small as possible,
the bootloader implementation was first copied to the runtime_loader
and then some features not relevant in the runtime_loader (like the
special large allocation handling) have been removed and the
runtime_loader specific features (grow_heap, add_area) have been
reintegrated. But basically this applies 96689a5..HEAD of
src/system/boot/loader/heap.cpp to the runtime_loader heap.

This brings in the switch from a linked list to a splay tree based
free chunk management. Since the allocation counts in the runtime_loader
are rather small, this does not perceptibly affect performance in either
direction though.
This commit is contained in:
Michael Lotz 2015-12-27 12:39:43 +01:00
parent 8bbfae7b05
commit 28d3c8ca50
1 changed files with 284 additions and 216 deletions
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500
src/system/runtime_loader/heap.cpp
View File

@ -1,5 +1,5 @@
/*
* Copyright 2003-2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
* Copyright 2003-2013, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*/
@ -7,192 +7,267 @@
#include "runtime_loader_private.h"
#include <syscalls.h>
#include <util/kernel_cpp.h>
#include <stdio.h>
#ifdef HEAP_TEST
# include <stdio.h>
#endif
#include <stdlib.h>
#include <string.h>
#include <algorithm>
static const size_t kInitialHeapSize = 65536;
#include <util/SplayTree.h>
/* This is a very simple malloc()/free() implementation - it only
* manages a free list.
* After heap_init() is called, all free memory is contained in one
* big chunk, the only entry in the free link list (which is a single
* linked list).
* When memory is allocated, the smallest free chunk that contains
* the requested size is split (or taken as a whole if it can't be
* splitted anymore), and it's lower half will be removed from the
* free list.
* The free list is ordered by size, starting with the smallest
* free chunk available. When a chunk is freed, it will be joint
* with its predecessor or successor, if possible.
* To ease list handling, the list anchor itself is a free chunk with
* size 0 that can't be allocated.
*/
/*! This is a very simple malloc()/free() implementation - it only
manages a free list.
After heap_init() is called, all free memory is contained in one
big chunk, the only entry in the free link list (which is a single
linked list).
When memory is allocated, the smallest free chunk that contains
the requested size is split (or taken as a whole if it can't be
splitted anymore), and it's lower half will be removed from the
free list.
The free list is ordered by size, starting with the smallest
free chunk available. When a chunk is freed, it will be joint
with its predecessor or successor, if possible.
To ease list handling, the list anchor itself is a free chunk with
size 0 that can't be allocated.
*/
const static size_t kAlignment = 8;
// all memory chunks will be a multiple of this
const static size_t kInitialHeapSize = 64 * 1024;
const static size_t kHeapGrowthAlignment = 32 * 1024;
struct free_chunk {
size_t size;
free_chunk *next;
class Chunk {
public:
size_t CompleteSize() const
{
return fSize;
}
size_t Size() const;
free_chunk *Split(size_t splitSize);
bool IsTouching(free_chunk *link);
free_chunk *Join(free_chunk *link);
void Remove(free_chunk *previous = NULL);
void Enqueue();
void *AllocatedAddress() const;
static free_chunk *SetToAllocated(void *allocated);
protected:
union {
size_t fSize;
char fAlignment[kAlignment];
};
};
class FreeChunk;
struct FreeChunkData : SplayTreeLink<FreeChunk> {
FreeChunk* Next() const
{
return fNext;
}
FreeChunk** NextLink()
{
return &fNext;
}
protected:
FreeChunk* fNext;
};
class FreeChunk : public Chunk, public FreeChunkData {
public:
void SetTo(size_t size);
size_t Size() const;
FreeChunk* Split(size_t splitSize);
bool IsTouching(FreeChunk* link);
FreeChunk* Join(FreeChunk* link);
void* AllocatedAddress() const;
static FreeChunk* SetToAllocated(void* allocated);
};
struct FreeChunkKey {
FreeChunkKey(size_t size)
:
fSize(size),
fChunk(NULL)
{
}
FreeChunkKey(const FreeChunk* chunk)
:
fSize(chunk->Size()),
fChunk(chunk)
{
}
int Compare(const FreeChunk* chunk) const
{
size_t chunkSize = chunk->Size();
if (chunkSize != fSize)
return fSize < chunkSize ? -1 : 1;
if (fChunk == chunk)
return 0;
return fChunk < chunk ? -1 : 1;
}
private:
size_t fSize;
const FreeChunk* fChunk;
};
struct FreeChunkTreeDefinition {
typedef FreeChunkKey KeyType;
typedef FreeChunk NodeType;
static FreeChunkKey GetKey(const FreeChunk* node)
{
return FreeChunkKey(node);
}
static SplayTreeLink<FreeChunk>* GetLink(FreeChunk* node)
{
return node;
}
static int Compare(const FreeChunkKey& key, const FreeChunk* node)
{
return key.Compare(node);
}
static FreeChunk** GetListLink(FreeChunk* node)
{
return node->NextLink();
}
};
typedef IteratableSplayTree<FreeChunkTreeDefinition> FreeChunkTree;
static size_t sAvailable;
static free_chunk sFreeAnchor;
static FreeChunkTree sFreeChunkTree;
/** Returns the amount of bytes that can be allocated
* in this chunk.
*/
size_t
free_chunk::Size() const
static inline size_t
align(size_t size, size_t alignment = kAlignment)
{
return size - sizeof(size_t);
return (size + alignment - 1) & ~(alignment - 1);
}
/** Splits the upper half at the requested location
* and returns it.
*/
free_chunk *
free_chunk::Split(size_t splitSize)
void
FreeChunk::SetTo(size_t size)
{
free_chunk *chunk = (free_chunk *)((uint8 *)this + sizeof(size_t) + splitSize);
chunk->size = size - splitSize - sizeof(size_t);
chunk->next = next;
fSize = size;
fNext = NULL;
}
size = splitSize + sizeof(size_t);
/*! Returns the amount of bytes that can be allocated
in this chunk.
*/
size_t
FreeChunk::Size() const
{
return (addr_t)this + fSize - (addr_t)AllocatedAddress();
}
/*! Splits the upper half at the requested location and returns it. This chunk
will no longer be a valid FreeChunk object; only its fSize will be valid.
*/
FreeChunk*
FreeChunk::Split(size_t splitSize)
{
splitSize = align(splitSize);
FreeChunk* chunk = (FreeChunk*)((addr_t)AllocatedAddress() + splitSize);
size_t newSize = (addr_t)chunk - (addr_t)this;
chunk->fSize = fSize - newSize;
chunk->fNext = NULL;
fSize = newSize;
return chunk;
}
/** Checks if the specified chunk touches this chunk, so
* that they could be joined.
*/
/*! Checks if the specified chunk touches this chunk, so
that they could be joined.
*/
bool
free_chunk::IsTouching(free_chunk *chunk)
FreeChunk::IsTouching(FreeChunk* chunk)
{
return chunk
&& (((uint8 *)this + size == (uint8 *)chunk)
|| (uint8 *)chunk + chunk->size == (uint8 *)this);
&& (((uint8*)this + fSize == (uint8*)chunk)
|| (uint8*)chunk + chunk->fSize == (uint8*)this);
}
/** Joins the chunk to this chunk and returns the pointer
* to the new chunk - which will either be one of the
* two chunks.
* Note, the chunks must be joinable, or else this method
* doesn't work correctly. Use free_chunk::IsTouching()
* to check if this method can be applied.
*/
free_chunk *
free_chunk::Join(free_chunk *chunk)
/*! Joins the chunk to this chunk and returns the pointer
to the new chunk - which will either be one of the
two chunks.
Note, the chunks must be joinable, or else this method
doesn't work correctly. Use FreeChunk::IsTouching()
to check if this method can be applied.
*/
FreeChunk*
FreeChunk::Join(FreeChunk* chunk)
{
if (chunk < this) {
chunk->size += size;
chunk->next = next;
chunk->fSize += fSize;
chunk->fNext = fNext;
return chunk;
}
size += chunk->size;
next = chunk->next;
fSize += chunk->fSize;
fNext = chunk->fNext;
return this;
}
void
free_chunk::Remove(free_chunk *previous)
void*
FreeChunk::AllocatedAddress() const
{
if (previous == NULL) {
// find the previous chunk in the list
free_chunk *chunk = sFreeAnchor.next;
while (chunk != NULL && chunk != this) {
previous = chunk;
chunk = chunk->next;
}
if (chunk == NULL) {
printf("runtime_loader: try to remove chunk that's not in list");
return;
}
}
previous->next = this->next;
this->next = NULL;
return (void*)static_cast<const FreeChunkData*>(this);
}
void
free_chunk::Enqueue()
FreeChunk*
FreeChunk::SetToAllocated(void* allocated)
{
free_chunk *chunk = sFreeAnchor.next, *last = &sFreeAnchor;
while (chunk && chunk->Size() < size) {
last = chunk;
chunk = chunk->next;
}
this->next = chunk;
last->next = this;
return static_cast<FreeChunk*>((FreeChunkData*)allocated);
}
void *
free_chunk::AllocatedAddress() const
{
return (void *)&next;
}
free_chunk *
free_chunk::SetToAllocated(void *allocated)
{
return (free_chunk *)((uint8 *)allocated - sizeof(size_t));
}
// #pragma mark - private functions
// #pragma mark -
static status_t
add_area(size_t size)
{
void *base;
void* base;
area_id area = _kern_create_area("rld heap", &base,
B_RANDOMIZED_ANY_ADDRESS, size, B_NO_LOCK, B_READ_AREA | B_WRITE_AREA);
if (area < B_OK)
if (area < 0)
return area;
sAvailable += size - sizeof(size_t);
// declare the whole area as one chunk, and add it to the free tree
FreeChunk* chunk = (FreeChunk*)base;
chunk->SetTo(size);
sFreeChunkTree.Insert(chunk);
// declare the whole heap as one chunk, and add it
// to the free list
free_chunk *chunk = (free_chunk *)base;
chunk->size = size;
chunk->next = sFreeAnchor.next;
sFreeAnchor.next = chunk;
sAvailable += chunk->Size();
return B_OK;
}
@ -200,24 +275,17 @@ add_area(size_t size)
static status_t
grow_heap(size_t bytes)
{
// align the area size to an 32768 bytes boundary
bytes = (bytes + 32767) & ~32767;
return add_area(bytes + sizeof(size_t));
return add_area(align(align(sizeof(Chunk)) + bytes, kHeapGrowthAlignment));
}
// #pragma mark - public API
// #pragma mark -
status_t
heap_init(void)
{
status_t status = add_area(kInitialHeapSize);
if (status < B_OK)
return status;
sFreeAnchor.size = 0;
return B_OK;
return add_area(kInitialHeapSize);
}
@ -225,136 +293,136 @@ heap_init(void)
void
dump_chunks(void)
{
free_chunk *chunk = sFreeAnchor.next, *last = &sFreeAnchor;
FreeChunk* chunk = sFreeChunkTree.FindMin();
while (chunk != NULL) {
last = chunk;
printf("\t%p: chunk size = %ld, end = %p, next = %p\n", chunk, chunk->size, (uint8 *)chunk + chunk->size, chunk->next);
chunk = chunk->next;
printf("\t%p: chunk size = %ld, end = %p, next = %p\n", chunk,
chunk->Size(), (uint8*)chunk + chunk->CompleteSize(),
chunk->Next());
chunk = chunk->Next();
}
}
#endif
void *
realloc(void *allocation, size_t newSize)
{
// free, if new size is 0
if (newSize == 0) {
free(allocation);
return NULL;
}
// just malloc(), if no previous allocation
if (allocation == NULL)
return malloc(newSize);
// we're lazy and don't shrink allocations
free_chunk* chunk = free_chunk::SetToAllocated(allocation);
if (chunk->Size() >= newSize)
return allocation;
// the allocation needs to grow -- allocate a new one and memcpy()
void* newAllocation = malloc(newSize);
if (newAllocation != NULL) {
memcpy(newAllocation, allocation, chunk->Size());
free(allocation);
}
return newAllocation;
}
void *
void*
malloc(size_t size)
{
if (size == 0)
return NULL;
// align the size requirement to an 8 bytes boundary
size = (size + 7) & ~7;
// align the size requirement to a kAlignment bytes boundary
if (size < sizeof(FreeChunkData))
size = sizeof(FreeChunkData);
size = align(size);
restart:
if (size > sAvailable) {
// try to enlarge heap
if (grow_heap(size) < B_OK)
if (grow_heap(size) != B_OK)
return NULL;
}
free_chunk *chunk = sFreeAnchor.next, *last = &sFreeAnchor;
while (chunk && chunk->Size() < size) {
last = chunk;
chunk = chunk->next;
}
FreeChunkKey key(size);
FreeChunk* chunk = sFreeChunkTree.FindClosest(key, true, true);
if (chunk == NULL) {
// could not find a free chunk as large as needed
if (grow_heap(size) < B_OK)
if (grow_heap(size) != B_OK)
return NULL;
goto restart;
chunk = sFreeChunkTree.FindClosest(key, true, true);
if (chunk == NULL) {
TRACE(("no allocation chunk found after growing the heap\n"));
return NULL;
}
}
if (chunk->Size() > size + sizeof(free_chunk) + sizeof(size_t)) {
// if this chunk is bigger than the requested size,
// we split it to form two chunks (with a minimal
// size of sizeof(size_t) allocatable bytes).
sFreeChunkTree.Remove(chunk);
sAvailable -= chunk->Size();
free_chunk *freeChunk = chunk->Split(size);
last->next = freeChunk;
void* allocatedAddress = chunk->AllocatedAddress();
// re-enqueue the free chunk at the correct position
freeChunk->Remove(last);
freeChunk->Enqueue();
} else {
// remove the chunk from the free list
last->next = chunk->next;
// If this chunk is bigger than the requested size and there's enough space
// left over for a new chunk, we split it.
if (chunk->Size() >= size + align(sizeof(FreeChunk))) {
FreeChunk* freeChunk = chunk->Split(size);
sFreeChunkTree.Insert(freeChunk);
sAvailable += freeChunk->Size();
}
sAvailable -= size + sizeof(size_t);
TRACE(("malloc(%lu) -> %p\n", size, allocatedAddress));
return allocatedAddress;
}
return chunk->AllocatedAddress();
void*
realloc(void* oldBuffer, size_t newSize)
{
if (newSize == 0) {
TRACE(("realloc(%p, %lu) -> NULL\n", oldBuffer, newSize));
free(oldBuffer);
return NULL;
}
size_t oldSize = 0;
if (oldBuffer != NULL) {
FreeChunk* oldChunk = FreeChunk::SetToAllocated(oldBuffer);
oldSize = oldChunk->Size();
// Check if the old buffer still fits, and if it makes sense to keep it.
if (oldSize >= newSize
&& (oldSize < 128 || newSize > oldSize / 3)) {
TRACE(("realloc(%p, %lu) old buffer is large enough\n",
oldBuffer, newSize));
return oldBuffer;
}
}
void* newBuffer = malloc(newSize);
if (newBuffer == NULL)
return NULL;
if (oldBuffer != NULL) {
memcpy(newBuffer, oldBuffer, std::min(oldSize, newSize));
free(oldBuffer);
}
TRACE(("realloc(%p, %lu) -> %p\n", oldBuffer, newSize, newBuffer));
return newBuffer;
}
void
free(void *allocated)
free(void* allocated)
{
if (allocated == NULL)
return;
free_chunk *freedChunk = free_chunk::SetToAllocated(allocated);
sAvailable += freedChunk->size;
TRACE(("free(%p)\n", allocated));
FreeChunk* freedChunk = FreeChunk::SetToAllocated(allocated);
// try to join the new free chunk with an existing one
// it may be joined with up to two chunks
free_chunk *chunk = sFreeAnchor.next, *last = &sFreeAnchor;
FreeChunk* chunk = sFreeChunkTree.FindMin();
int32 joinCount = 0;
while (chunk) {
if (chunk->IsTouching(freedChunk)) {
// almost "insert" it into the list before joining
// because the next pointer is inherited by the chunk
freedChunk->next = chunk->next;
freedChunk = chunk->Join(freedChunk);
FreeChunk* nextChunk = chunk->Next();
// remove the joined chunk from the list
last->next = freedChunk->next;
chunk = last;
if (chunk->IsTouching(freedChunk)) {
sFreeChunkTree.Remove(chunk);
sAvailable -= chunk->Size();
freedChunk = chunk->Join(freedChunk);
if (++joinCount == 2)
break;
}
last = chunk;
chunk = chunk->next;
chunk = nextChunk;
}
// enqueue the link at the right position; the
// free link queue is ordered by size
freedChunk->Enqueue();
sFreeChunkTree.Insert(freedChunk);
sAvailable += freedChunk->Size();
}