This removes the XP compatibility code, and switches entirely to SRW
locks, which are available starting at Windows Vista.
This removes CRITICAL_SECTION use, which allows us to add
PTHREAD_MUTEX_INITIALIZER, which will be useful later.
Windows XP is hereby not a supported build target anymore.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Sometimes, if pthread_create() failed, then pthread_cond_wait() could
accidentally be called in the worker threads after the uninit function
had already called pthread_cond_broadcast(), leading to a deadlock.
Don't call pthread_cond_wait() if c->done is set.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>