Re: [Haskell-cafe] Mixing C++ and Haskell, OpenSSL thread safety, and using mmap

From: Joel Reymont To: "Branimir Maksimovic" CC: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Mixing C++ and Haskell, OpenSSL thread safety, and using mmap Date: Thu, 8 Dec 2005 09:21:08 +0000

I use OpenSSL in a heavily threaded environment. It works without extra locking. I do not use bound (OS) threads, though.

If code executes concurrently that means you have a problem with OpenSSL for sure. Probably it works now because SSL calls are not concurrent or so, but I wouldn't risk about it as I am sure that you would have problems with that if calls to SSL functions are concurrent. Also, I think that original problem of gethostbyname just hides real SSL problem as you've probably locked around that too, but you can't be really sure. so either lock around every SSL call with global mutex or set locks in C module then call Haskell or setup callbacks from Haskell, whichever way you prefer. Greetings, Bane.

On Dec 8, 2005, at 7:06 AM, Branimir Maksimovic wrote:

...

First I want to say about OpenSSL thread safety. It is not thread safe by default. Who wants to import and use OpenSLL functions with FFI, have to set locking hooks for it, or else spurious crashes with useless stack trace will result. Higher level of concurrency, more likely crash will happen.

-- http://wagerlabs.com/

_________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/