[Qt-interest] QTcpServer - ThreadedFortuneServer memory going up

[Stephen Collyer]

On 20 May 2010 19:56, Tarandeep Singh <tarandeep at gmail.com> wrote:

> Hi,
>
> I am using QT 4.6.1 on Ubuntu Linux.
> I ran ThreadedFortuneServer example. I started multiple clients to talk to
> the server. Each client sends several requests serially.
>
> I found that the memory footprint of ThreadedFortuneServer goes up as more
> and more clients connect (as expected) but it does not come down even when
> clients have disconnected.
> In other words, the more the number of connections the server is handling
> at any given time, the more memory is used but not freed.
>

This is standard memory allocation behaviour for Unix systems.
When a program allocates memory via malloc/new, it may have
to request more virtual memory from the OS, via a system call
(sbrk()). However, when the same program releases memory
via free/delete, the program does not reduce its virtual memory
requirement. So programs generally have monotonically
increasing virtual memory sizes, as reported by VSZ.

That is probably all that you are seeing.

-- 
Stephen Collyer
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