sem_init() is deprecated on OS X, and it actually fails with ENOSYS. Using our
wrapped semaphore object is not an option, as it relies on the thread cleanup
that we can't rely on at this stage.
It is unclear why startup synchronization is required, as we can allocate the
thread ID just before creating the pthread. There is a chance that we allocate
a thread ID for a thread that fails to create, but the risk and consequences
are negligible.
SIGRTMIN is defined as 32 while sigset_t is defined as
unsigned long (i.e. holds 32 signals). Hence, the signal
could never be blocked. Sending the signal still canceled
threads, but sometimes in situations where they shouldn't
have been canceled (e.g. while holding a lock).
Fixes#298.
Within the Android App the library stays loaded in memory and is just
initialized/deinitialized with each connection, the static thread
counter would continuously increase without this patch.
Martin Willi