I found the following inconsistencies while looking at PID-related code in libbson and libmongoc:

• _bson_getpid() uses GetCurrentProcessId() on Windows and getpid() on other operating systems.
• _mongoc_counters_cleanup() uses getpid() on Unix platforms.
• mongoc_log_default_handler() uses syscall(SYS_gettid) on Linux, _getpid() on Windows, and getpid() on other operating systems.

This is trivial, but it may be worth making the Windows and Linux cases consistent with each other.