pthread_once() is portable but it does not allow passing any parameters to
the initialization function, which is often inconvenient, because it means
that the function can only access data declared at file scope. This commit
introduces an alternative with a more convenient interface.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
POSIX defines a portable pthread_key_t API for per-thread data. GCC and
C11 have two different forms of per-thread data that are generally faster
than the POSIX API, where they are available. This commit adds a
macro-based wrapper, DEFINE_PER_THREAD_DATA, that takes advantage of these
features where they are available and falls back to the POSIX API
otherwise.
The Clang compiler implements C11 thread_local in its <threads.h>.
This commit also adds a convenience wrapper for the POSIX API, via the
DEFINE_PER_THREAD_MALLOCED_DATA macro.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
The only tricky part here is that I'm throwing in annotations to allow
"sparse" to report unbalanced locking.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
