Re: problem with gc?

[Daniel Kozák via Digitalmars-d-learn]

On Wed, 27 May 2015 05:48:11 +0000
zhmt via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com> wrote:

> I am writing a echoclient, as below:
> 
> Ptr!Conn conn = connect("127.0.0.1",8881);
> ubyte[100] buf;
> for(int i=0; i<N; i++)
> {
>       scope string str = format("%s",i);
>       conn.write((cast(ubyte*)str.ptr)[0..str.length]);
>       conn.read(buf[0..str.length]);
>       n++;
> }
> conn.close();
> 
> 
> When it loops about more than 100000 times,the throughput will 
> fall from 60000request/second to 26request/second.
> 
> If the code changes a little as below:
> 
>   scope string str = format("%s",10000); //changes to a constant
> 
> It will runs normally with speed of 60000request/second. I test 
> for 13minutes, everything seems well.
> 
> 
> 
> What happened when the code changes a little? Who will give an 
> explaination,Thanks a lot?

what happend if you use sformat instead?

Ptr!Conn conn = connect("127.0.0.1",8881);
ubyte[100] buf;
char[100] buf2;
for(int i=0; i<N; i++)
{
        auto str = sformat(buf2, "%s",i);
        conn.write((cast(ubyte*)str.ptr)[0..str.length]);
        conn.read(buf[0..str.length]);
        n++;
}
conn.close();