On Wed, Nov 11, 2009 at 10:22:23AM +0000, Tim Bunce wrote: > The next version of NYTProf supports profiling some 'slow' perl opcodes. > I've included the rand opcode for exactly this reason.
I meant srand (though rand is also included, just in case). Though having just looked at the Configure code and relevant man pages I realise I was misguided. You can't (easily) configure perl to use a random function that uses /dev/random. Tim. > Tim. > > On Tue, Nov 10, 2009 at 07:01:38PM -0800, cr...@animalhead.com wrote: > > Many of you know that the random number generator /dev/random > > is subject to delays when it has "not accumulated enough entropy", > > which is to say randomness. These delays are said to be longer > > on Linux /dev/random that on some other Unices. They occur > > particularly after a system is booted, which I hear is a regular > > occurrence on some smoke-test systems. > > > > But I bet many of you will be surprised by the magnitude of the > > delays that can occur. > > > > Recently one perl tester's Linux system tested my module IPC::MMA > > version 0.58, which used /dev/random to drive testing, to produce > > report 5888084. It took 22320 wallclock seconds to complete the > > tests: 6.2 hours. > > > > A few days later the same system tested version 0.58001, which > > differs from 0.58 mainly in using /dev/urandom which is not subject > > to "entropy delays". Report 5889682 shows that it took 5 wallclock > > seconds. > > > > Anyway, I found it interesting, > > Craig MacKenna > >
