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Draft double-ended stack allocator for temp malloc

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Doyle Thai 2018-02-03 20:58:15 +11:00
parent 7228a8b344
commit b8157a3c9f
2 changed files with 313 additions and 144 deletions
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387
dqn.h
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@ -242,19 +242,19 @@ public:
struct Alloc_ struct Alloc_
{ {
bool zeroClear; bool zeroClear;
usize requestSize; isize requestSize;
} alloc; } alloc;
struct Free_ struct Free_
{ {
void *ptrToFree; void *ptrToFree;
usize sizeToFree; isize sizeToFree;
} free; } free;
struct Realloc_ struct Realloc_
{ {
usize newRequestSize; isize newSize;
usize oldSize; isize oldSize;
void *oldMemPtr; void *oldMemPtr;
} realloc; } realloc;
}; };
@ -265,18 +265,18 @@ public:
Allocator *allocator; Allocator *allocator;
void *userContext; void *userContext;
usize bytesAllocated; isize bytesAllocated;
usize lifetimeBytesAllocated; isize lifetimeBytesAllocated;
usize lifetimeBytesFreed; isize lifetimeBytesFreed;
static DqnMemAPI HeapAllocator (); static DqnMemAPI HeapAllocator ();
// TODO(doyle): No longer necessary now that stack creates its own on init? // TODO(doyle): No longer necessary now that stack creates its own on init?
static DqnMemAPI StackAllocator(struct DqnMemStack *const stack); static DqnMemAPI StackAllocator(struct DqnMemStack *const stack);
void *Realloc(void *const oldPtr, usize const oldSize, usize const newSize); void *Realloc(void *const oldPtr, isize const oldSize, isize const newSize);
void *Alloc (usize const size, bool const zeroClear = true); void *Alloc (isize const size, bool const zeroClear = true);
void Free (void *const ptrToFree, usize const sizeToFree); void Free (void *const ptrToFree, isize const sizeToFree);
bool IsValid() const { return (this->allocator != nullptr); } bool IsValid() const { return (this->allocator != nullptr); }
}; };
@ -376,13 +376,13 @@ struct DqnAllocatorMetadata
auto GetAllocHeadSize () const { return allocHeadSize; } auto GetAllocHeadSize () const { return allocHeadSize; }
auto GetAllocTailSize () const { return allocTailSize; } auto GetAllocTailSize () const { return allocTailSize; }
usize GetAllocationSize (usize size, u8 alignment) const { return GetAllocHeadSize() + size + GetAllocTailSize() + (alignment - 1); } isize GetAllocationSize (isize size, u8 alignment) const { return GetAllocHeadSize() + size + GetAllocTailSize() + (alignment - 1); }
u32 *PtrToHeadBoundsGuard(u8 const *ptr) const; // ptr: The ptr given to the client when allocating. u32 *PtrToHeadBoundsGuard(u8 const *ptr) const; // ptr: The ptr given to the client when allocating.
u32 *PtrToTailBoundsGuard(u8 const *ptr) const; // IMPORTANT: Uses "Alloc Amount" metadata to find the tail! u32 *PtrToTailBoundsGuard(u8 const *ptr) const; // IMPORTANT: Uses "Alloc Amount" metadata to find the tail!
u8 *PtrToAlignment (u8 const *ptr) const; u8 *PtrToAlignment (u8 const *ptr) const;
u8 *PtrToOffsetToSrc (u8 const *ptr) const; u8 *PtrToOffsetToSrc (u8 const *ptr) const;
usize *PtrToAllocAmount (u8 const *ptr) const; isize *PtrToAllocAmount (u8 const *ptr) const;
private: private:
u32 boundsGuardSize; // sizeof(GUARD_VALUE) OR 0 if BoundsGuard is disabled. u32 boundsGuardSize; // sizeof(GUARD_VALUE) OR 0 if BoundsGuard is disabled.
@ -419,9 +419,9 @@ struct DqnMemStack
struct Info // Statistics of the memory stack. struct Info // Statistics of the memory stack.
{ {
usize totalUsed; isize totalUsed;
usize totalSize; isize totalSize;
usize wastedSize; isize wastedSize;
i32 numBlocks; i32 numBlocks;
}; };
@ -430,9 +430,12 @@ struct DqnMemStack
struct Block struct Block
{ {
u8 *memory; u8 *memory;
usize size; // Read-Only isize size; // Read-Only
usize used; // Read/Write at your peril. isize used_; // Read/Write at your peril.
Block *prevBlock; // Uses a linked list approach for additional blocks Block *prevBlock; // Uses a linked list approach for additional blocks
u8 *head;
u8 *tail;
}; };
DqnAllocatorMetadata metadata; DqnAllocatorMetadata metadata;
@ -447,17 +450,19 @@ struct DqnMemStack
// Uses fixed buffer, allocations will be sourced from the buffer and fail after buffer is full. // Uses fixed buffer, allocations will be sourced from the buffer and fail after buffer is full.
// mem: Memory to use for the memory stack // mem: Memory to use for the memory stack
// return: FALSE if args are invalid, or insufficient memSize. // return: FALSE if args are invalid, or insufficient memSize.
bool Init(void *const mem, usize size, bool zeroClear, u32 flags_ = 0); bool Init(void *const mem, isize size, bool zeroClear, u32 flags_ = 0);
// Memory Stack capable of expanding when full, but only if NonExpandable flag is not set. // Memory Stack capable of expanding when full, but only if NonExpandable flag is not set.
bool Init(usize size, bool zeroClear, u32 flags_ = 0, DqnMemAPI *const api = &DQN_DEFAULT_HEAP_ALLOCATOR); bool Init(isize size, bool zeroClear, u32 flags_ = 0, DqnMemAPI *const api = &DQN_DEFAULT_HEAP_ALLOCATOR);
// Allocation API // Allocation API
// ============================================================================================= // =============================================================================================
void *PushOnTail (isize size, u8 alignment = 4);
// Allocate memory from the MemStack. // Allocate memory from the MemStack.
// alignment: Ptr returned from allocator is aligned to this value and MUST be power of 2. // alignment: Ptr returned from allocator is aligned to this value and MUST be power of 2.
// return: nullptr if out of space OR stack is using fixed memory/size OR stack full and platform malloc fails. // return: nullptr if out of space OR stack is using fixed memory/size OR stack full and platform malloc fails.
void *Push (usize size, u8 alignment = 4); void *Push (isize size, u8 alignment = 4);
// Frees the given ptr. It MUST be the last allocated item in the stack, asserts otherwise. // Frees the given ptr. It MUST be the last allocated item in the stack, asserts otherwise.
void Pop (void *const ptr, bool zeroClear = false); void Pop (void *const ptr, bool zeroClear = false);
@ -484,7 +489,8 @@ struct DqnMemStack
{ {
DqnMemStack *stack; // Stack associated with this TempRegion DqnMemStack *stack; // Stack associated with this TempRegion
Block *startingBlock; // Remember the block to revert to and its memory usage. Block *startingBlock; // Remember the block to revert to and its memory usage.
usize used; u8 *startingBlockHead;
u8 *startingBlockTail;
isize allocationCount; // Debug only: For ensuring BoundsGuard allocation tracker reverts as well. isize allocationCount; // Debug only: For ensuring BoundsGuard allocation tracker reverts as well.
}; };
@ -3010,7 +3016,8 @@ FILE_SCOPE void DqnMemAPIInternal_ValidateRequest(DqnMemAPI::Request request_)
{ {
auto *request = &request_.realloc; auto *request = &request_.realloc;
DQN_ASSERT(request->oldSize > 0); DQN_ASSERT(request->oldSize > 0);
DQN_ASSERT(request->newRequestSize > 0); DQN_ASSERT(request->newSize > 0);
DQN_ASSERT((request->newSize - request->oldSize) != 0);
DQN_ASSERT(request->oldMemPtr); DQN_ASSERT(request->oldMemPtr);
return; return;
} }
@ -3029,10 +3036,10 @@ FILE_SCOPE void DqnMemAPIInternal_UpdateAPIStatistics(DqnMemAPI *api, DqnMemAPI:
if (request_->type == DqnMemAPI::Type::Realloc) if (request_->type == DqnMemAPI::Type::Realloc)
{ {
auto *request = &request_->realloc; auto *request = &request_->realloc;
api->lifetimeBytesAllocated += request->newRequestSize; api->lifetimeBytesAllocated += request->newSize;
api->lifetimeBytesFreed += request->oldSize; api->lifetimeBytesFreed += request->oldSize;
api->bytesAllocated += request->newRequestSize; api->bytesAllocated += request->newSize;
api->bytesAllocated -= request->oldSize; api->bytesAllocated -= request->oldSize;
return; return;
} }
@ -3066,13 +3073,13 @@ FILE_SCOPE u8 *DqnMemAPIInternal_HeapAllocatorCallback(DqnMemAPI *api, DqnMemAPI
else if (request_.type == DqnMemAPI::Type::Realloc) else if (request_.type == DqnMemAPI::Type::Realloc)
{ {
auto const *request = &request_.realloc; auto const *request = &request_.realloc;
if (request->newRequestSize == request->oldSize) if (request->newSize == request->oldSize)
{ {
result = (u8 *)request->oldMemPtr; result = (u8 *)request->oldMemPtr;
} }
else else
{ {
result = (u8 *)DqnMem_Realloc(request->oldMemPtr, request->newRequestSize); result = (u8 *)DqnMem_Realloc(request->oldMemPtr, request->newSize);
success = (result != nullptr); success = (result != nullptr);
} }
} }
@ -3104,6 +3111,50 @@ FILE_SCOPE u8 *DqnMemAPIInternal_StackAllocatorCallback(DqnMemAPI *api, DqnMemAP
u8 *result = nullptr; u8 *result = nullptr;
bool success = false; bool success = false;
enum class PtrType
{
NotInCurrentBlock,
Head,
Tail,
};
auto ClassifyPtr = [](DqnMemStack::Block const *block, u8 const *ptr) -> PtrType {
PtrType result = PtrType::NotInCurrentBlock;
u8 const *const blockEnd = block->memory + block->size;
if (ptr >= block->memory && ptr < block->head)
{
result = PtrType::Head;
}
else if (ptr >= block->tail && ptr < blockEnd)
{
result = PtrType::Tail;
}
return result;
};
auto PtrIsLastAllocationInBlock = [&ClassifyPtr](DqnAllocatorMetadata const *metadata,
DqnMemStack::Block const *block,
u8 const *ptr) -> bool {
PtrType type = ClassifyPtr(block, ptr);
bool result = false;
if (type == PtrType::Head)
{
isize const oldMemSize = *(metadata->PtrToAllocAmount(ptr));
u8 const *ptrEnd = ptr + oldMemSize + metadata->GetAllocTailSize();
result = (ptrEnd == block->head);
}
else if (type == PtrType::Tail)
{
u8 offsetToSrc = *(metadata->PtrToOffsetToSrc(ptr));
auto *actualPtr = ptr - offsetToSrc;
result = (actualPtr == block->tail);
}
return result;
};
if (request_.type == DqnMemAPI::Type::Alloc) if (request_.type == DqnMemAPI::Type::Alloc)
{ {
auto *request = &request_.alloc; auto *request = &request_.alloc;
@ -3119,61 +3170,115 @@ FILE_SCOPE u8 *DqnMemAPIInternal_StackAllocatorCallback(DqnMemAPI *api, DqnMemAP
{ {
// IMPORTANT: This is a _naive_ realloc scheme for stack allocation. // IMPORTANT: This is a _naive_ realloc scheme for stack allocation.
auto *request = &request_.realloc; auto *request = &request_.realloc;
u8 *const ptr = (u8 *)request->oldMemPtr;
DqnMemStack::Block *block = stack->block; for (DqnMemStack::Block *block = stack->block; block; block = block->prevBlock)
u8 const *blockEnd = block->memory + block->size;
u8 const *blockUsedUpTo = block->memory + block->used;
usize oldMemSize = *stack->metadata.PtrToAllocAmount((u8 *)request->oldMemPtr);
u8 alignment = *stack->metadata.PtrToAlignment((u8 *)request->oldMemPtr);
u8 *checkPtr = (u8 *)request->oldMemPtr + oldMemSize + stack->metadata.GetAllocTailSize();
// Last allocation, can safely allocate the remainder space.
if (checkPtr == blockUsedUpTo)
{ {
usize extraBytesRequired = request->newRequestSize - oldMemSize; DQN_ASSERT(ptr >= block->memory && ptr <= (block->memory + block->size));
DQN_ASSERT(extraBytesRequired > 0); }
bool enoughSpace = (blockUsedUpTo + extraBytesRequired) < blockEnd; DqnMemStack::Block *const block = stack->block;
isize const oldMemSize = *stack->metadata.PtrToAllocAmount(ptr);
isize const extraBytesReq = request->newSize - oldMemSize;
u8 const alignment = *stack->metadata.PtrToAlignment(ptr);
DQN_ASSERT(extraBytesReq > 0);
PtrType type = ClassifyPtr(block, ptr);
if (PtrIsLastAllocationInBlock(&stack->metadata, block, ptr))
{
bool enoughSpace = false;
if (type == PtrType::Head)
{
DQN_ASSERT((block->head + extraBytesReq) >= block->memory);
enoughSpace = (block->head + extraBytesReq) < block->tail;
if (enoughSpace) if (enoughSpace)
{ {
stack->Pop(request->oldMemPtr, false); stack->Pop(ptr, false);
result = (u8 *)stack->Push(request->newRequestSize, alignment); result = (u8 *)stack->Push(request->newSize, alignment);
DQN_ASSERT(stack->block == block && result == request->oldMemPtr); DQN_ASSERT(stack->block == block && result == request->oldMemPtr);
success = true; success = true;
} }
}
else else
{
DQN_ASSERT(type == PtrType::Tail);
DQN_ASSERT((block->tail - extraBytesReq) < (block->memory + block->size));
enoughSpace = (block->tail - extraBytesReq) > block->head;
if (enoughSpace)
{
stack->Pop(ptr, false);
result = (u8 *)stack->Push(request->newSize, alignment);
DqnMem_Copy(result, ptr, oldMemSize);
result[oldMemSize] = 0;
success = true;
DQN_ASSERT(stack->block == block);
}
}
if (!enoughSpace)
{ {
// TODO(doyle): Does realloc need clear to zero flag as well? // TODO(doyle): Does realloc need clear to zero flag as well?
// Else, last allocation but not enough space in block. Create a new block and copy // Else, last allocation but not enough space in block. Create a new block and
// copy
DqnMemStack::Block *oldBlock = block; DqnMemStack::Block *oldBlock = block;
result = (u8 *)stack->Push(request->newRequestSize, alignment); if (type == PtrType::Head)
{
result = (u8 *)stack->Push(request->newSize, alignment);
}
else
{
DQN_ASSERT(type == PtrType::Tail);
result = (u8 *)stack->PushOnTail(request->newSize, alignment);
}
if (result) if (result)
{ {
DQN_ASSERT(stack->block->prevBlock == oldBlock); DQN_ASSERT(stack->block->prevBlock == oldBlock);
DQN_ASSERT(stack->block != oldBlock); DQN_ASSERT(stack->block != oldBlock);
DqnMem_Copy(result, ptr, oldMemSize);
DqnMem_Copy(result, (u8 *)request->oldMemPtr, request->oldSize);
// Switch to old block, pop the ptr and return the new block on top. // Switch to old block, pop the ptr and return the new block on top.
auto *newBlock = stack->block; auto *newBlock = stack->block;
stack->block = oldBlock; stack->block = oldBlock;
stack->Pop(request->oldMemPtr, false); stack->Pop(ptr, false);
stack->block = newBlock; stack->block = newBlock;
success = true; success = true;
} }
} }
} }
else else
{
if (request->newSize < request->oldSize)
{
// NOTE: This is questionable behaviour. We don't reclaim data since it's not
// well-defined in a stack allocator. This would cause gaps in memory.
success = false; // Deny updating statistics.
result = ptr;
}
else
{ {
DQN_LOGE( DQN_LOGE(
"Lost %$_d, the ptr to realloc is sandwiched between other allocations (LIFO)", oldMemSize); "Lost %$_d, the ptr to realloc is sandwiched between other allocations (LIFO)",
result = (u8 *)stack->Push(request->newRequestSize, alignment); oldMemSize);
if (type == PtrType::Head)
{
result = (u8 *)stack->Push(request->newSize, alignment);
}
else
{
DQN_ASSERT(type == PtrType::Tail);
result = (u8 *)stack->PushOnTail(request->newSize, alignment);
}
if (result) if (result)
{ {
success = true; success = true;
DqnMem_Copy(result, (u8 *)request->oldMemPtr, request->oldSize); DqnMem_Copy(result, ptr, oldMemSize);
}
} }
} }
} }
@ -3182,22 +3287,17 @@ FILE_SCOPE u8 *DqnMemAPIInternal_StackAllocatorCallback(DqnMemAPI *api, DqnMemAP
auto *request = &request_.free; auto *request = &request_.free;
DQN_ASSERT(request_.type == DqnMemAPI::Type::Free); DQN_ASSERT(request_.type == DqnMemAPI::Type::Free);
DqnMemStack::Block *block = stack->block; DqnMemStack::Block *const block = stack->block;
u8 const *blockUsedUpTo = block->memory + block->used; u8 *const ptr = (u8 *)request->ptrToFree;
usize oldMemSize = *stack->metadata.PtrToAllocAmount((u8 *)request->ptrToFree); if (PtrIsLastAllocationInBlock(&stack->metadata, block, ptr))
u8 *checkPtr = (u8 *)request->ptrToFree + oldMemSize + stack->metadata.GetAllocTailSize();
// Last allocation, can safely pop the allocation
if (checkPtr == blockUsedUpTo)
{ {
success = true; stack->Pop(ptr, false);
stack->Pop(request->ptrToFree);
} }
else else
{ {
DQN_LOGE("Lost %$_d, the ptr to free is sandwiched between other allocations (LIFO)", isize const oldMemSize = *(stack->metadata.PtrToAllocAmount(ptr));
oldMemSize); DQN_LOGE("Lost %$_d, the ptr to free is sandwiched between other allocations (LIFO)", oldMemSize);
} }
} }
@ -3209,12 +3309,12 @@ FILE_SCOPE u8 *DqnMemAPIInternal_StackAllocatorCallback(DqnMemAPI *api, DqnMemAP
return result; return result;
} }
void *DqnMemAPI::Realloc(void *const oldPtr, usize const oldSize, usize const newSize) void *DqnMemAPI::Realloc(void *const oldPtr, isize const oldSize, isize const newSize)
{ {
Request request = {}; Request request = {};
request.type = Type::Realloc; request.type = Type::Realloc;
request.userContext = this->userContext; request.userContext = this->userContext;
request.realloc.newRequestSize = newSize; request.realloc.newSize = newSize;
request.realloc.oldMemPtr = oldPtr; request.realloc.oldMemPtr = oldPtr;
request.realloc.oldSize = oldSize; request.realloc.oldSize = oldSize;
@ -3222,7 +3322,7 @@ void *DqnMemAPI::Realloc(void *const oldPtr, usize const oldSize, usize const ne
return result; return result;
} }
void *DqnMemAPI::Alloc(usize const size, bool const zeroClear) void *DqnMemAPI::Alloc(isize const size, bool const zeroClear)
{ {
Request request = {}; Request request = {};
request.type = Type::Alloc; request.type = Type::Alloc;
@ -3234,7 +3334,7 @@ void *DqnMemAPI::Alloc(usize const size, bool const zeroClear)
return result; return result;
} }
void DqnMemAPI::Free(void *const ptrToFree, usize const sizeToFree) void DqnMemAPI::Free(void *const ptrToFree, isize const sizeToFree)
{ {
Request request = {}; Request request = {};
request.type = Type::Free; request.type = Type::Free;
@ -3355,20 +3455,20 @@ u8 *DqnAllocatorMetadata::PtrToOffsetToSrc(u8 const *ptr) const
return (u8 *)u8Ptr; return (u8 *)u8Ptr;
} }
usize *DqnAllocatorMetadata::PtrToAllocAmount(u8 const *ptr) const isize *DqnAllocatorMetadata::PtrToAllocAmount(u8 const *ptr) const
{ {
union { union {
u8 const *u8Ptr; u8 const *u8Ptr;
u32 const *u32Ptr; u32 const *u32Ptr;
usize const *usizePtr; isize const *isizePtr;
}; };
u8Ptr = ptr - this->allocHeadSize + OFFSET_TO_SRC_SIZE + ALIGNMENT_SIZE; u8Ptr = ptr - this->allocHeadSize + OFFSET_TO_SRC_SIZE + ALIGNMENT_SIZE;
return (usize *)usizePtr; return (isize *)isizePtr;
} }
u32 *DqnAllocatorMetadata::PtrToTailBoundsGuard(u8 const *ptr) const u32 *DqnAllocatorMetadata::PtrToTailBoundsGuard(u8 const *ptr) const
{ {
usize size = *PtrToAllocAmount(ptr); isize size = *PtrToAllocAmount(ptr);
union { union {
u8 const *u8Ptr; u8 const *u8Ptr;
u32 const *u32Ptr; u32 const *u32Ptr;
@ -3379,30 +3479,32 @@ u32 *DqnAllocatorMetadata::PtrToTailBoundsGuard(u8 const *ptr) const
// #DqnMemStack // #DqnMemStack
// ================================================================================================= // =================================================================================================
DQN_FILE_SCOPE DqnMemStack::Block *DqnMemStackInternal_AllocateBlock(usize size, bool zeroClear, DQN_FILE_SCOPE DqnMemStack::Block *DqnMemStackInternal_AllocateBlock(isize size, bool zeroClear,
DqnMemAPI *const api) DqnMemAPI *const api)
{ {
DQN_ASSERT(size > 0);
if (!api || !api->IsValid()) if (!api || !api->IsValid())
{ {
DQN_LOGE("Could not allocate block with api, api is null or is valid check failed."); DQN_LOGE("Could not allocate block with api, api is null or is valid check failed.");
return nullptr; return nullptr;
} }
usize totalSize = sizeof(DqnMemStack::Block) + size; isize totalSize = sizeof(DqnMemStack::Block) + size;
auto *result = (DqnMemStack::Block *)api->Alloc(totalSize, zeroClear); auto *result = (DqnMemStack::Block *)api->Alloc(totalSize, zeroClear);
if (!result) if (!result)
{ {
return nullptr; return nullptr;
} }
result->memory = (u8 *)(result + sizeof(*result)); result->memory = ((u8 *)result) + sizeof(*result);
result->size = size; result->size = size;
result->used = 0; result->head = result->memory;
result->tail = result->memory + size;
result->prevBlock = nullptr; result->prevBlock = nullptr;
return result; return result;
} }
bool DqnMemStack::Init(void *const mem, usize size, bool zeroClear, u32 flags_) bool DqnMemStack::Init(void *const mem, isize size, bool zeroClear, u32 flags_)
{ {
if (!mem) if (!mem)
{ {
@ -3424,8 +3526,9 @@ bool DqnMemStack::Init(void *const mem, usize size, bool zeroClear, u32 flags_)
this->block = (DqnMemStack::Block *)mem; this->block = (DqnMemStack::Block *)mem;
this->block->memory = (u8 *)mem + sizeof(DqnMemStack::Block); this->block->memory = (u8 *)mem + sizeof(DqnMemStack::Block);
this->block->used = 0;
this->block->size = size - sizeof(DqnMemStack::Block); this->block->size = size - sizeof(DqnMemStack::Block);
this->block->head = this->block->memory;
this->block->tail = this->block->memory + this->block->size;
this->block->prevBlock = nullptr; this->block->prevBlock = nullptr;
this->memAPI = nullptr; this->memAPI = nullptr;
@ -3439,7 +3542,7 @@ bool DqnMemStack::Init(void *const mem, usize size, bool zeroClear, u32 flags_)
return true; return true;
} }
bool DqnMemStack::Init(usize size, bool zeroClear, u32 flags_, DqnMemAPI *const api) bool DqnMemStack::Init(isize size, bool zeroClear, u32 flags_, DqnMemAPI *const api)
{ {
if (!this || size < 0) return false; if (!this || size < 0) return false;
@ -3474,7 +3577,7 @@ bool DqnMemStack::Init(usize size, bool zeroClear, u32 flags_, DqnMemAPI *const
return true; return true;
} }
void *DqnMemStack::Push(usize size, u8 alignment) FILE_SCOPE void *DqnMemStackInternal_Push(DqnMemStack *stack, isize size, u8 alignment, bool pushToHead)
{ {
DQN_ASSERT(size >= 0 && (alignment % 2 == 0)); DQN_ASSERT(size >= 0 && (alignment % 2 == 0));
DQN_ASSERTM(alignment <= 128, DQN_ASSERTM(alignment <= 128,
@ -3486,33 +3589,28 @@ void *DqnMemStack::Push(usize size, u8 alignment)
// Allocate New Block If Full // Allocate New Block If Full
// ============================================================================================= // =============================================================================================
DqnAllocatorMetadata *myMetadata = &this->metadata; DqnAllocatorMetadata *myMetadata = &stack->metadata;
usize actualSize = myMetadata->GetAllocationSize(size, alignment); isize actualSize = myMetadata->GetAllocationSize(size, alignment);
bool needNewBlock = false; bool needNewBlock = false;
if (!block) if (stack->block)
{ {
needNewBlock = true; if (pushToHead) needNewBlock = ((stack->block->head + actualSize) > stack->block->tail);
} else needNewBlock = ((stack->block->tail - actualSize) < stack->block->head);
else
{
u8 const *blockUsedUpTo = this->block->memory + this->block->used;
u8 const *blockEnd = this->block->memory + this->block->size;
needNewBlock = ((blockUsedUpTo + actualSize) > blockEnd);
} }
if (needNewBlock) if (needNewBlock)
{ {
if (Dqn_BitIsSet(this->flags, Flag::NonExpandable)) if (Dqn_BitIsSet(stack->flags, DqnMemStack::Flag::NonExpandable))
{ {
DQN_LOGE("Allocator is non-expandable and has run out of memory."); DQN_LOGE("Allocator is non-expandable and has run out of memory.");
if (Dqn_BitIsSet(this->flags, Flag::NonExpandableAssert)) if (Dqn_BitIsSet(stack->flags, DqnMemStack::Flag::NonExpandableAssert))
DQN_ASSERT(DQN_INVALID_CODE_PATH); DQN_ASSERT(DQN_INVALID_CODE_PATH);
return nullptr; return nullptr;
} }
usize newBlockSize = DQN_MAX(actualSize, DqnMemStack::MINIMUM_BLOCK_SIZE); isize newBlockSize = DQN_MAX(actualSize, DqnMemStack::MINIMUM_BLOCK_SIZE);
DqnMemStack::Block *newBlock = DqnMemStackInternal_AllocateBlock(newBlockSize, true, this->memAPI); DqnMemStack::Block *newBlock = DqnMemStackInternal_AllocateBlock(newBlockSize, true, stack->memAPI);
if (!newBlock) if (!newBlock)
{ {
DQN_LOGE( DQN_LOGE(
@ -3521,20 +3619,28 @@ void *DqnMemStack::Push(usize size, u8 alignment)
return nullptr; return nullptr;
} }
newBlock->prevBlock = this->block; newBlock->prevBlock = stack->block;
this->block = newBlock; stack->block = newBlock;
} }
// Calculate Ptr To Give Client // Calculate Ptr To Give Client
// ============================================================================================= // =============================================================================================
u8 *currPtr = this->block->memory + this->block->used; u8 *currPtr = (pushToHead) ? (stack->block->head) : (stack->block->tail - actualSize);
u8 *result = (u8 *)DQN_ALIGN_POW_N((currPtr + myMetadata->GetAllocHeadSize()), alignment); u8 *result = (u8 *)DQN_ALIGN_POW_N((currPtr + myMetadata->GetAllocHeadSize()), alignment);
usize const offsetToSrc = result - currPtr; isize const offsetToSrc = result - currPtr;
DQN_ASSERT(offsetToSrc > 0 && offsetToSrc < (u8)-1); DQN_ASSERT(offsetToSrc > 0 && offsetToSrc < (u8)-1);
this->block->used += actualSize; if (pushToHead)
DQN_ASSERT(this->block->used <= this->block->size); {
stack->block->head += actualSize;
DQN_ASSERT(stack->block->head <= stack->block->tail);
}
else
{
stack->block->tail -= actualSize;
DQN_ASSERT(stack->block->tail >= stack->block->head);
}
// Instrument allocation with guards and metadata // Instrument allocation with guards and metadata
// ============================================================================================= // =============================================================================================
@ -3548,7 +3654,7 @@ void *DqnMemStack::Push(usize size, u8 alignment)
auto *allocAmount = myMetadata->PtrToAllocAmount(result); auto *allocAmount = myMetadata->PtrToAllocAmount(result);
*allocAmount = size; *allocAmount = size;
if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard)) if (Dqn_BitIsSet(stack->flags, DqnMemStack::Flag::BoundsGuard))
{ {
auto *headGuard = myMetadata->PtrToHeadBoundsGuard(result); auto *headGuard = myMetadata->PtrToHeadBoundsGuard(result);
auto *tailGuard = myMetadata->PtrToTailBoundsGuard(result); auto *tailGuard = myMetadata->PtrToTailBoundsGuard(result);
@ -3565,7 +3671,7 @@ void *DqnMemStack::Push(usize size, u8 alignment)
"Adding bounds guard should not destroy alignment! %p != %p", result, "Adding bounds guard should not destroy alignment! %p != %p", result,
checkAlignment); checkAlignment);
if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard)) if (Dqn_BitIsSet(stack->flags, DqnMemStack::Flag::BoundsGuard))
{ {
myMetadata->AddAllocation(result); myMetadata->AddAllocation(result);
myMetadata->CheckAllocations(); myMetadata->CheckAllocations();
@ -3575,6 +3681,18 @@ void *DqnMemStack::Push(usize size, u8 alignment)
return result; return result;
} }
void *DqnMemStack::PushOnTail(isize size, u8 alignment)
{
void *result = DqnMemStackInternal_Push(this, size, alignment, false);
return result;
}
void *DqnMemStack::Push(isize size, u8 alignment)
{
void *result = DqnMemStackInternal_Push(this, size, alignment, true);
return result;
}
FILE_SCOPE void DqnMemStackInternal_KillMetadataPtrsExistingInBlock(DqnAllocatorMetadata *metadata, FILE_SCOPE void DqnMemStackInternal_KillMetadataPtrsExistingInBlock(DqnAllocatorMetadata *metadata,
DqnMemStack::Block const *block) DqnMemStack::Block const *block)
{ {
@ -3606,20 +3724,34 @@ void DqnMemStack::Pop(void *const ptr, bool zeroClear)
myMetadata->RemoveAllocation(bytePtr); myMetadata->RemoveAllocation(bytePtr);
} }
usize size = *(myMetadata->PtrToAllocAmount(bytePtr)); isize const size = *(myMetadata->PtrToAllocAmount(bytePtr));
u8 alignment = *(myMetadata->PtrToAlignment(bytePtr)); u8 const alignment = *(myMetadata->PtrToAlignment(bytePtr));
u8 offsetToSrc = *(myMetadata->PtrToOffsetToSrc(bytePtr)); u8 const offsetToSrc = *(myMetadata->PtrToOffsetToSrc(bytePtr));
usize actualSize = myMetadata->GetAllocationSize(size, alignment); isize actualSize = myMetadata->GetAllocationSize(size, alignment);
u8 *start = bytePtr - offsetToSrc; u8 *const start = bytePtr - offsetToSrc;
u8 *end = start + actualSize; u8 *const end = start + actualSize;
u8 const *const blockEnd = this->block->memory + this->block->size;
u8 const *blockUsedUpTo = this->block->memory + this->block->used; if (bytePtr >= this->block->memory && bytePtr < this->block->head)
DQN_ASSERTM(end == blockUsedUpTo, "Pointer to pop was not the last allocation! %p != %p", end, {
blockUsedUpTo); DQN_ASSERTM(end == this->block->head, "Pointer to pop was not the last allocation! %p != %p", end, this->block->head);
this->block->used -= actualSize; this->block->head -= actualSize;
DQN_ASSERT(this->block->used >= 0); DQN_ASSERT(this->block->head >= this->block->memory);
}
else if (bytePtr >= this->block->tail && bytePtr < blockEnd)
{
DQN_ASSERTM(start == this->block->tail, "Pointer to pop was not the last allocation! %p != %p", start,
this->block->tail);
this->block->tail += actualSize;
DQN_ASSERT(this->block->tail <= blockEnd);
}
else
{
DQN_ASSERTM(DQN_INVALID_CODE_PATH, "Pointer to free does not belong to current block!");
}
if (zeroClear) if (zeroClear)
DqnMem_Set(start, 0, end - start); DqnMem_Set(start, 0, end - start);
@ -3661,7 +3793,7 @@ bool DqnMemStack::FreeMemBlock(DqnMemStack::Block *memBlock)
DqnMemStackInternal_KillMetadataPtrsExistingInBlock(&this->metadata, blockToFree); DqnMemStackInternal_KillMetadataPtrsExistingInBlock(&this->metadata, blockToFree);
} }
usize realSize = blockToFree->size + sizeof(DqnMemStack::Block); isize realSize = blockToFree->size + sizeof(DqnMemStack::Block);
this->memAPI->Free(blockToFree, realSize); this->memAPI->Free(blockToFree, realSize);
// No more blocks, then last block has been freed // No more blocks, then last block has been freed
@ -3687,7 +3819,8 @@ void DqnMemStack::ClearCurrBlock(bool zeroClear)
DqnMemStackInternal_KillMetadataPtrsExistingInBlock(&this->metadata, this->block); DqnMemStackInternal_KillMetadataPtrsExistingInBlock(&this->metadata, this->block);
} }
this->block->used = 0; this->block->head = this->block->memory;
this->block->tail = this->block->memory + this->block->size;
if (zeroClear) if (zeroClear)
{ {
DqnMem_Clear(this->block->memory, 0, this->block->size); DqnMem_Clear(this->block->memory, 0, this->block->size);
@ -3701,12 +3834,21 @@ DqnMemStack::Info DqnMemStack::GetInfo() const
Info result = {}; Info result = {};
for (Block *block_ = this->block; block_; block_ = block_->prevBlock) for (Block *block_ = this->block; block_; block_ = block_->prevBlock)
{ {
result.totalUsed += block_->used; u8 const *blockEnd = block_->memory + block_->size;
isize usageFromHead = block_->head - block_->memory;
isize usageFromTail = blockEnd - block_->tail;
result.totalUsed += usageFromHead + usageFromTail;
result.totalSize += block_->size; result.totalSize += block_->size;
result.wastedSize += block_->size - block_->used; result.wastedSize += (block_->size - usageFromHead - usageFromTail);
result.numBlocks++; result.numBlocks++;
} }
result.wastedSize -= this->block->size - this->block->used; // Don't include the curr block
u8 const *blockEnd = this->block->memory + this->block->size;
isize usageFromHead = this->block->head - this->block->memory;
isize usageFromTail = blockEnd - this->block->tail;
result.wastedSize -= (this->block->size - usageFromHead - usageFromTail); // Don't include the curr block
return result; return result;
} }
@ -3715,7 +3857,8 @@ DqnMemStack::TempRegion DqnMemStack::TempRegionBegin()
TempRegion result = {}; TempRegion result = {};
result.stack = this; result.stack = this;
result.startingBlock = this->block; result.startingBlock = this->block;
result.used = this->block->used; result.startingBlockHead = (this->block) ? this->block->head : nullptr;
result.startingBlockTail = (this->block) ? this->block->tail : nullptr;
if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard)) if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard))
{ {
@ -3737,8 +3880,16 @@ void DqnMemStack::TempRegionEnd(TempRegion region)
if (this->block) if (this->block)
{ {
DQN_ASSERT(this->block->used >= region.used); // Debug checks
this->block->used = region.used; {
u8 const *const start = this->block->memory;
u8 const *const end = start + this->block->size;
DQN_ASSERT(region.startingBlockHead >= start && region.startingBlockHead <= end);
DQN_ASSERT(region.startingBlockTail >= start && region.startingBlockTail <= end);
}
this->block->head = region.startingBlockHead;
this->block->tail = region.startingBlockTail;
} }
if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard)) if (Dqn_BitIsSet(this->flags, Flag::BoundsGuard))

32
dqn_unit_test.cpp
View File

@ -2354,7 +2354,6 @@ FILE_SCOPE void DqnMemStack_Test()
{ {
DqnMemStack stack = {}; DqnMemStack stack = {};
DQN_ASSERT(stack.Init(DQN_MEGABYTE(1), true, DqnMemStack::Flag::BoundsGuard)); DQN_ASSERT(stack.Init(DQN_MEGABYTE(1), true, DqnMemStack::Flag::BoundsGuard));
stack.Free();
i32 const ALIGN64 = 64; i32 const ALIGN64 = 64;
i32 const ALIGN16 = 16; i32 const ALIGN16 = 16;
@ -2384,6 +2383,7 @@ FILE_SCOPE void DqnMemStack_Test()
stack.Pop(result1); stack.Pop(result1);
} }
stack.Free();
Log(Status::Ok, "Check allocated alignment to 4, 16, 64"); Log(Status::Ok, "Check allocated alignment to 4, 16, 64");
} }
@ -2410,7 +2410,8 @@ FILE_SCOPE void DqnMemStack_Test()
auto *oldBlock = stack.block; auto *oldBlock = stack.block;
DQN_ASSERT(oldBlock); DQN_ASSERT(oldBlock);
DQN_ASSERT(oldBlock->size == DQN_MEGABYTE(1)); DQN_ASSERT(oldBlock->size == DQN_MEGABYTE(1));
DQN_ASSERT(oldBlock->used == 0); DQN_ASSERT(oldBlock->head == oldBlock->head);
DQN_ASSERT(oldBlock->tail == oldBlock->tail);
DQN_ASSERT(oldBlock->prevBlock == nullptr); DQN_ASSERT(oldBlock->prevBlock == nullptr);
auto *result1 = stack.Push(DQN_MEGABYTE(2)); auto *result1 = stack.Push(DQN_MEGABYTE(2));
@ -2432,7 +2433,8 @@ FILE_SCOPE void DqnMemStack_Test()
if (1) if (1)
{ {
DqnMemStack::Block *blockToReturnTo = stack.block; DqnMemStack::Block *blockToReturnTo = stack.block;
auto usedBefore = blockToReturnTo->used; auto headBefore = blockToReturnTo->head;
auto tailBefore = blockToReturnTo->tail;
if (1) if (1)
{ {
auto memGuard1 = stack.TempRegionGuard(); auto memGuard1 = stack.TempRegionGuard();
@ -2440,7 +2442,8 @@ FILE_SCOPE void DqnMemStack_Test()
auto *result3 = stack.Push(100); auto *result3 = stack.Push(100);
auto *result4 = stack.Push(100); auto *result4 = stack.Push(100);
DQN_ASSERT(result2 && result3 && result4); DQN_ASSERT(result2 && result3 && result4);
DQN_ASSERT(stack.block->used > usedBefore); DQN_ASSERT(stack.block->head != headBefore);
DQN_ASSERT(stack.block->tail == tailBefore);
DQN_ASSERT(stack.block->memory == blockToReturnTo->memory); DQN_ASSERT(stack.block->memory == blockToReturnTo->memory);
// Force allocation of new block // Force allocation of new block
@ -2451,14 +2454,16 @@ FILE_SCOPE void DqnMemStack_Test()
} }
DQN_ASSERT(stack.block == blockToReturnTo); DQN_ASSERT(stack.block == blockToReturnTo);
DQN_ASSERT(stack.block->used == usedBefore); DQN_ASSERT(stack.block->head == headBefore);
DQN_ASSERT(stack.block->tail == tailBefore);
} }
// Check temporary regions keep state // Check temporary regions keep state
if (1) if (1)
{ {
DqnMemStack::Block *blockToReturnTo = stack.block; DqnMemStack::Block *blockToReturnTo = stack.block;
auto usedBefore = blockToReturnTo->used; auto headBefore = blockToReturnTo->head;
auto tailBefore = blockToReturnTo->tail;
if (1) if (1)
{ {
auto memGuard1 = stack.TempRegionGuard(); auto memGuard1 = stack.TempRegionGuard();
@ -2466,7 +2471,8 @@ FILE_SCOPE void DqnMemStack_Test()
auto *result3 = stack.Push(100); auto *result3 = stack.Push(100);
auto *result4 = stack.Push(100); auto *result4 = stack.Push(100);
DQN_ASSERT(result2 && result3 && result4); DQN_ASSERT(result2 && result3 && result4);
DQN_ASSERT(stack.block->used > usedBefore); DQN_ASSERT(stack.block->head != headBefore);
DQN_ASSERT(stack.block->tail == tailBefore);
DQN_ASSERT(stack.block->memory == blockToReturnTo->memory); DQN_ASSERT(stack.block->memory == blockToReturnTo->memory);
// Force allocation of new block // Force allocation of new block
@ -2597,8 +2603,20 @@ FILE_SCOPE void DqnMemStack_Test()
DQN_ASSERT(*head == DqnAllocatorMetadata::HEAD_GUARD_VALUE); DQN_ASSERT(*head == DqnAllocatorMetadata::HEAD_GUARD_VALUE);
DQN_ASSERT(*tail == DqnAllocatorMetadata::TAIL_GUARD_VALUE); DQN_ASSERT(*tail == DqnAllocatorMetadata::TAIL_GUARD_VALUE);
stack.Free();
Log(Status::Ok, "Bounds guards are placed adjacent and have magic values."); Log(Status::Ok, "Bounds guards are placed adjacent and have magic values.");
} }
// Push to tail and head
if (1)
{
DqnMemStack stack = {};
DQN_ASSERT(stack.Init(DQN_MEGABYTE(1), true, DqnMemStack::Flag::BoundsGuard));
auto *result1 = stack.Push(100);
auto *result2 = stack.PushOnTail(100);
stack.Free();
}
} }
int main(void) int main(void)