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fixed nasty AV in FastFreeMem w/UseReleaseStack #9

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merged 2 commits into from Feb 23, 2016
Merged

fixed nasty AV in FastFreeMem w/UseReleaseStack #9

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fd1d119
fixed nasty AV in FastFreeMem w/UseReleaseStack
gabr42 Feb 23, 2016
0f926ec
added support for per-CPU release stacks
gabr42 Feb 23, 2016
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67 changes: 52 additions & 15 deletions FastMM4.pas
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Expand Up @@ -1563,6 +1563,10 @@ procedure free(__ptr:pointer);cdecl;external clib name 'free';
function usleep(__useconds:dword):longint;cdecl;external clib name 'usleep';
{$endif}

{$ifdef PerCPUReleaseStack}
function GetCurrentProcessorNumber: DWORD; stdcall; external 'kernel32.dll' delayed;
{$endif}

{Fixed size move procedures. The 64-bit versions assume 16-byte alignment.}
procedure Move4(const ASource; var ADest; ACount: NativeInt); forward;
procedure Move12(const ASource; var ADest; ACount: NativeInt); forward;
Expand Down Expand Up @@ -1802,13 +1806,13 @@ TSmallBlockType = record
{$else}
Reserved1: Pointer;
{$endif}
{$ifdef UseReleaseStack}
ReleaseStack: TLFStack;
{$endif}
{$ifdef 64Bit}
{Pad to 64 bytes for 64-bit}
Reserved2: Pointer;
{$endif}
{$ifdef UseReleaseStack}
ReleaseStack: {$ifdef PerCPUReleaseStack}array [0..63] of{$endif} TLFStack;
{$endif}
{$ifdef LogLockContention}
BlockCollector: TStaticCollector;
{$endif}
Expand Down Expand Up @@ -4579,6 +4583,9 @@ function FastGetMem(ASize: {$ifdef XE2AndUp}NativeInt{$else}{$ifdef fpc}NativeUI
LStackTrace: TStackTrace;
{$endif}
{$endif}
{$ifdef UseReleaseStack}
LPReleaseStack: ^TLFStack;
{$endif}
begin
{$ifdef LogLockContention}
ACollector := nil;
Expand All @@ -4594,7 +4601,8 @@ function FastGetMem(ASize: {$ifdef XE2AndUp}NativeInt{$else}{$ifdef fpc}NativeUI
* (SizeOf(TSmallBlockType) div 4)
+ UIntPtr(@SmallBlockTypes));
{$ifdef UseReleaseStack}
if (not LPSmallBlockType.ReleaseStack.IsEmpty) and LPSmallBlockType.ReleaseStack.Pop(Result) then
LPReleaseStack := @LPSmallBlockType.ReleaseStack{$ifdef PerCPUReleaseStack}[GetCurrentProcessorNumber]{$endif};
if (not LPReleaseStack^.IsEmpty) and LPReleaseStack^.Pop(Result) then
Exit;
{$endif}
{Lock the block type}
Expand Down Expand Up @@ -6047,9 +6055,11 @@ function FastFreeMem(APointer: Pointer): {$ifdef fpc}NativeUInt{$else}Integer{$e
LDidSleep: Boolean;
LStackTrace: TStackTrace;
{$endif}
count: integer;
{$ifdef UseReleaseStack}
LReleaseCount: integer;
LPReleaseStack: ^TLFStack;
{$endif}
begin
count := 0;
{$ifdef fpc}
if APointer = nil then
begin
Expand Down Expand Up @@ -6080,7 +6090,8 @@ function FastFreeMem(APointer: Pointer): {$ifdef fpc}NativeUInt{$else}Integer{$e
while (LockCmpxchg(0, 1, @LPSmallBlockType.BlockTypeLocked) <> 0) do
begin
{$ifdef UseReleaseStack}
if (not LPSmallBlockType.ReleaseStack.IsFull) and LPSmallBlockType.ReleaseStack.Push(APointer) then begin
LPReleaseStack := @LPSmallBlockType.ReleaseStack{$ifdef PerCPUReleaseStack}[GetCurrentProcessorNumber]{$endif};
if (not LPReleaseStack^.IsFull) and LPReleaseStack^.Push(APointer) then begin
{Block will be released later.}
Result := 0;
Exit;
Expand All @@ -6107,6 +6118,9 @@ function FastFreeMem(APointer: Pointer): {$ifdef fpc}NativeUInt{$else}Integer{$e
GetStackTrace(@LStackTrace, StackTraceDepth, 1);
LPSmallBlockType.BlockCollector.Add(@LStackTrace[0], StackTraceDepth);
end;
{$endif}
{$ifdef UseReleaseStack}
LReleaseCount := 0;
{$endif}
repeat
{Get the old first free block}
Expand Down Expand Up @@ -6154,17 +6168,23 @@ function FastFreeMem(APointer: Pointer): {$ifdef fpc}NativeUInt{$else}Integer{$e
begin
{$endif}
{$ifdef UseReleaseStack}
if (count = (ReleaseStackSize div 2)) or
LPSmallBlockType.ReleaseStack.IsEmpty or
(not LPSmallBlockType.ReleaseStack.Pop(APointer)) then
LPReleaseStack := @LPSmallBlockType.ReleaseStack{$ifdef PerCPUReleaseStack}[GetCurrentProcessorNumber]{$endif};
if (LReleaseCount < (ReleaseStackSize div 2)) and
(not LPReleaseStack^.IsEmpty) and
LPReleaseStack^.Pop(APointer) then
begin
LBlockHeader := PNativeUInt(PByte(APointer) - BlockHeaderSize)^;
LPSmallBlockPool := PSmallBlockPoolHeader(LBlockHeader);
Inc(LReleaseCount);
end
else
begin
{$endif}
APointer := nil;
{Unlock this block type}
LPSmallBlockType.BlockTypeLocked := False;
{$ifdef UseReleaseStack}
end;
Inc(count);
{$endif}
{$ifndef FullDebugMode}
end;
Expand Down Expand Up @@ -11978,6 +11998,9 @@ procedure InitializeMemoryManager;
LInd, LSizeInd, LMinimumPoolSize, LOptimalPoolSize, LGroupNumber,
LBlocksPerPool, LPreviousBlockSize: Cardinal;
LPMediumFreeBlock: PMediumFreeBlock;
{$ifdef PerCPUReleaseStack}
LCPU: integer;
{$endif}
begin
{$ifdef FullDebugMode}
{$ifdef LoadDebugDLLDynamically}
Expand Down Expand Up @@ -12061,7 +12084,10 @@ procedure InitializeMemoryManager;
SmallBlockTypes[LInd].OptimalBlockPoolSize :=
((LBlocksPerPool * SmallBlockTypes[LInd].BlockSize + SmallBlockPoolHeaderSize + MediumBlockGranularity - 1 - MediumBlockSizeOffset) and -MediumBlockGranularity) + MediumBlockSizeOffset;
{$ifdef UseReleaseStack}
SmallBlockTypes[LInd].ReleaseStack.Initialize(ReleaseStackSize, SizeOf(pointer));
{$ifdef PerCPUReleaseStack}
for LCPU := 0 to 63 do
{$endif}
SmallBlockTypes[LInd].ReleaseStack{$ifdef PerCPUReleaseStack}[LCPU]{$endif}.Initialize(ReleaseStackSize, SizeOf(pointer));
{$endif}
{$ifdef CheckHeapForCorruption}
{Debug checks}
Expand Down Expand Up @@ -12373,11 +12399,22 @@ procedure CleanupReleaseStacks;
var
LInd: integer;
LMemory: pointer;
{$ifdef PerCPUReleaseStack}
LCPU: Integer;
{$endif}
begin
for LInd := 0 to High(SmallBlockTypes) do begin
while SmallBlockTypes[LInd].ReleaseStack.Pop(LMemory) do
FastFreeMem(LMemory);
SmallBlockTypes[LInd].ReleaseStack.Finalize;
{$ifdef PerCPUReleaseStack}
for LCPU := 0 to 63 do
{$endif}
while SmallBlockTypes[LInd].ReleaseStack{$ifdef PerCPUReleaseStack}[LCPU]{$endif}.Pop(LMemory) do
FastFreeMem(LMemory);
{Finalize all stacks only after all memory for this block has been freed.}
{Otherwise, FastFreeMem could try to access a stack that was already finalized.}
{$ifdef PerCPUReleaseStack}
for LCPU := 0 to 63 do
{$endif}
SmallBlockTypes[LInd].ReleaseStack{$ifdef PerCPUReleaseStack}[LCPU]{$endif}.Finalize;
end;
end;
{$endif}
Expand Down