SetHeapExtraInfo
Store extra information in blocks.
Declaration
Source position: heaptrc.pp line 49
procedure SetHeapExtraInfo(size: PtrUInt; fillproc: tFillExtraInfoProc;
displayproc: tdisplayextrainfoProc);
Description
You can use SetHeapExtraInfo to store extra info in the blocks that the heaptrc unit reserves when tracing getmem calls. Size indicates the size (in bytes) that the trace mechanism should reserve for your extra information. For each call to getmem, FillProc will be called, and passed a pointer to the memory reserved.
When dumping the memory summary, the extra info is shown by calling displayproc and passing it the memory location which was filled by fillproc. It should write the information in readable form to the text file provided in the call to displayproc
Errors
You can only call SetHeapExtraInfo if no memory has been allocated yet. If memory was already allocated prior to the call to SetHeapExtraInfo, then an error will be displayed on standard error output, and a DumpHeap is executed.
See also
Name | Description |
---|---|
DumpHeap | Dump memory usage report to stderr. |
SetHeapTraceOutput | Specify filename for heap trace output. |
Example
Program heapex;
{ Program used to demonstrate the usage of heaptrc unit }
Uses heaptrc;
Var P1 : ^Longint;
P2 : Pointer;
I : longint;
Marker : Longint;
Procedure SetMarker (P : pointer);
Type PLongint = ^Longint;
begin
PLongint(P)^:=Marker;
end;
Procedure Part1;
begin
// Blocks allocated here are marked with $FFAAFFAA = -5570646
Marker := $FFAAFFAA;
New(P1);
New(P1);
Dispose(P1);
For I:=1 to 10 do
begin
GetMem (P2,128);
If (I mod 2) = 0 Then FreeMem(P2,128);
end;
GetMem(P2,128);
end;
Procedure Part2;
begin
// Blocks allocated here are marked with $FAFAFAFA = -84215046
Marker := $FAFAFAFA;
New(P1);
New(P1);
Dispose(P1);
For I:=1 to 10 do
begin
GetMem (P2,128);
If (I mod 2) = 0 Then FreeMem(P2,128);
end;
GetMem(P2,128);
end;
begin
SetExtraInfo(SizeOf(Marker),@SetMarker);
Writeln ('Part 1');
part1;
Writeln('Part 2');
part2;
end.