Add infrastructure for reference counts.

OpenSSL has traditionally done reference counting with |int|s and the
|CRYPTO_add| function. Unless a special callback is installed (rare),
this is implemented by doing the reference count operations under a

This change adds infrastructure for handling reference counts and uses
atomic operations when C11 support is available.

Change-Id: Ia023ce432319efd00f77a7340da27d16ee4b63c3
Reviewed-by: Adam Langley <>
8 files changed