I am using OpenSSL 1.0.1l in Win32 environment. In the main section of the program I initialize the SSL library and load the error strings. Then I create two threads that run concurrently. One sends GET requests to a website and the other sends POST requests to a website using SSL -- both threads do this in an infinite loop with a 100 millisecond pause. No variables are shared between the two threads. Everything is declared locally. I use a mutex to make sure it is impossible for the two threads to be running at the time (so basically each thread does its work between a WaitForSingleObject and ReleaseMutex call) In this situation, am I correct that there is no need to use CRYPTO_set_locking_callback ? My program has been running for 3+ days and never had a crash or error. Although the documention says this CRYPTO_set_locking_callback function is needed for mufti-threaded programs, I don't see why in the above situation it would be. Please advise. Thanks, -Avery -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20150123/d12fdb70/attachment.html>