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POWhy doesn't my program's memory usage return to normal after I free memory?
 

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    <p>consider the next sample application</p> <pre><code>program TestMemory; {$APPTYPE CONSOLE} uses PsAPI, Windows, SysUtils; function GetUsedMemoryFastMem: cardinal; var st: TMemoryManagerState; sb: TSmallBlockTypeState; begin GetMemoryManagerState(st); result := st.TotalAllocatedMediumBlockSize + st.TotalAllocatedLargeBlockSize; for sb in st.SmallBlockTypeStates do begin result := result + sb.UseableBlockSize * sb.AllocatedBlockCount; end; end; function GetUsedMemoryWindows: longint; var ProcessMemoryCounters: TProcessMemoryCounters; begin Result:=0; ProcessMemoryCounters.cb := SizeOf(TProcessMemoryCounters); if GetProcessMemoryInfo(GetCurrentProcess(), @ProcessMemoryCounters, ProcessMemoryCounters.cb) then Result:= ProcessMemoryCounters.WorkingSetSize else RaiseLastOSError; end; procedure Test; const Size = 1024*1024; var P : Pointer; begin GetMem(P,Size); Writeln('Inside'); Writeln('FastMem '+FormatFloat('#,', GetUsedMemoryFastMem)); Writeln('Windows '+FormatFloat('#,', GetUsedMemoryWindows)); Writeln(''); FreeMem(P); end; begin Writeln('Before'); Writeln('FastMem '+FormatFloat('#,', GetUsedMemoryFastMem)); Writeln('Windows '+FormatFloat('#,', GetUsedMemoryWindows)); Writeln(''); Test; Writeln('After'); Writeln('FastMem '+FormatFloat('#,', GetUsedMemoryFastMem)); Writeln('Windows '+FormatFloat('#,', GetUsedMemoryWindows)); Writeln(''); Readln; end. </code></pre> <p>the results returned by the app are </p> <pre><code>Before FastMem 1.844 Windows 3.633.152 Inside FastMem 1.050.612 Windows 3.637.248 After FastMem 2.036 Windows 3.633.152 </code></pre> <p>I wanna know why the results of the memory usage are different in the <code>Before</code> and <code>After</code>:</p>
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    1. CO@Optimal Cynic - is it really clever? Seems that my application does not return about 160MB. On computers with 1GB or RAM (or less) isn't this a waste of RAM? Details: http://stackoverflow.com/questions/4463979/my-program-never-releases-the-memory-back-why
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      1. USRigel
 

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