View source for API Design Considerations: Initialization Functions Hurt

=== Automatic Self-Initialization is the Solution ===

The solution to the above problems is simple: the OpenSSL libcrypto and
libssl libraries must self-initialize automatically.

Note that relying on run-time linker-loader functionality for self-
initialization (e.g., .init/.fini sections, DllMain()) is generally
frowned upon.  The correct way to automatically self-initialize is to
use pthread_once() or InitOnceExecuteOnce(), or to construct a similar
once initializer.

Explicit initialization functions are OK, as long as they are optional
(these may be useful for applications that will chroot, for example).

Finalization should not be required and may not be possible.