Good coverage of this topic is in the chapter "4 Support Infrastructure", section "4.1 Multithread Support"
http://my.safaribooksonline.com/book/networking/security/059600270x/support-infrastructure/openssl-chp-4-sect-1 from the book Network Security with OpenSSL By: John Viega; Matt Messier; Pravir Chandra Publisher: O'Reilly Media, Inc. Pub. Date: June 17, 2002 Print ISBN-13: 978-0-596-00270-1 The book's sample code contains common.h, common.c, reentrant.h, and reentrant.c which attempts to setup the static and dynamic threading callbacks for WIN32 and POSIX. http://examples.oreilly.com/9780596002701/ Just for completeness, the source reference for the static and dynamic thread primitive callbacks is http://www.openssl.org/docs/crypto/threads.html If you have a Association for Computing Machinery membership, you can access this book with http://acmsel.safaribooksonline.com/book/networking/security/059600270x/support-infrastructure/openssl-chp-4-sect-1 --- Brian Brooks Senior Software Engineer Rockwell Collins Satellite Communications Systems 2205 Northmont Parkway Duluth, GA 30096 bebro...@rockwellcollins.com office: (678) 252-4498 "Vladimir Belov" <ml.vladimbe...@gmail.com> Sent by: owner-openssl-us...@openssl.org 05/13/2012 02:04 PM Please respond to openssl-users@openssl.org To <openssl-users@openssl.org> cc Subject Re: Multi-threaded applications, locking_function, threadid_func, dynamic locks From: Dr. Stephen Henson Sent: Sunday, May 13, 2012 5:53 PM > Yes because some structures need to be locked internally. An example is > the > error queue. I draw a conclusion: in multi-threaded application using of locking_function and threadid_func is mandatory. Ok. > Currently dynamical locks aren't used for much. The only example I can > immediately think of is the CHIL ENGINE. > At some point dynamic locks might be used more generally. The reason they > could increase performance is that currently locks are global and related > to > structures. I don't understand precisely, Steve. All locking is done by OpenSSL itself, we only set platform-specific callback functions such as locking_function, CRYPTO_set_dynlock_lock_callback. We don't speak about locking programmer's objects but about internal objects of OpenSSL that must be done by OpenSSL itself not by programmer. If you also say that "dynamical locks aren't used for much" I really don't understand can we use safely only dynamic locks in multi-threaded applications instead of locking_function and threadid_func or no? Or if we want to use dynamic locks we must set callback functions for "static" and dynamic locks both and OpenSSL already choose what callback it want to use in concrete case? How OpenSSL works here? > So if you need to perform locking on an X509 structure you lock > *all* X509 structures while this is going on. It would be more efficient > if > only the single affected X509 structure was locked. Yes, it would be more efficient if only the single affected X509 structure was locked, I understood now about performance. ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
