5f97e81a69
Thread locking callbacks into the interpreter impose considerable overhead. The standard library's ssl module registers its own thread locking and id callback functions. Registration of the latter can be detected by a call to the OpenSSL library. In this case, do not set the Python callback function and therefore keep using the more efficient ssl module functions.
41 lines
1.2 KiB
Python
41 lines
1.2 KiB
Python
# TLock: OpenSSL lock support on thread-enabled systems. Written by Ray Brown.
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"""TLock
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This module provides the callbacks required by the OpenSSL library in situations
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where it is being entered concurrently by multiple threads. This module is
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enagaged automatically by the PyDTLS package on systems that have Python
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threading support. It does not have client-visible components.
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"""
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from logging import getLogger
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from openssl import *
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try:
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import threading
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except ImportError:
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pass
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_logger = getLogger(__name__)
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DO_DEBUG_LOG = False
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def tlock_init():
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if not globals().has_key("threading"):
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return # nothing to configure
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# The standard library ssl module's lock implementation is more efficient;
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# do not override it if it has been established
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if CRYPTO_get_id_callback():
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return
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global _locks
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num_locks = CRYPTO_num_locks()
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_locks = tuple(threading.Lock() for _ in range(num_locks))
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CRYPTO_set_locking_callback(_locking_function)
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def _locking_function(mode, n, file, line):
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if DO_DEBUG_LOG:
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_logger.debug("Thread lock: mode: %d, n: %d, file: %s, line: %d",
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mode, n, file, line)
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if mode & CRYPTO_LOCK:
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_locks[n].acquire()
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else:
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_locks[n].release()
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