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Diffstat (limited to 'docs/hazmat/bindings/openssl.rst')
| -rw-r--r-- | docs/hazmat/bindings/openssl.rst | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/docs/hazmat/bindings/openssl.rst b/docs/hazmat/bindings/openssl.rst index 373fe472..77623b22 100644 --- a/docs/hazmat/bindings/openssl.rst +++ b/docs/hazmat/bindings/openssl.rst @@ -22,6 +22,26 @@ These are `CFFI`_ bindings to the `OpenSSL`_ C library. This is a ``cffi`` library. It can be used to call OpenSSL functions, and access constants. + .. classmethod:: init_static_locks + + Enables the best available locking callback for OpenSSL. + See :ref:`openssl-threading`. + +.. _openssl-threading: + +Threading +--------- + +`cryptography` enables OpenSSLs `thread safety facilities`_ in two different +ways depending on the configuration of your system. Normally the locking +callbacks provided by your Python implementation specifically for OpenSSL will +be used. However if you have linked `cryptography` to a different version of +OpenSSL than that used by your Python implementation we enable an alternative +locking callback. This version is implemented in Python and so may result in +lower performance in some situations. In particular parallelism is reduced +because it has to acquire the GIL whenever any lock operations occur within +OpenSSL. .. _`CFFI`: https://cffi.readthedocs.org/ .. _`OpenSSL`: https://www.openssl.org/ +.. _`thread safety facilities`: http://www.openssl.org/docs/crypto/threads.html |