Removed 'join_count' from pthread_internal_t and switched to using the flag
PTHREAD_ATTR_FLAG_JOINED to indicate if a thread is being joined. Combined with
a switch to a while loop in pthread_join, this fixes spurious wake-ups but
prevents a thread from being joined multiple times. This is fine for
two reasons:
1) The pthread_join specification allows for undefined behavior when multiple
threads try to join a single thread.
2) There is no thread safe way to allow multiple threads to join a single
thread with the pthread interface. The second thread calling pthread_join
could be pre-empted until the thread is destroyed and its handle reused for
a different thread. Therefore multi-join is always an error.
Bug: https://code.google.com/p/android/issues/detail?id=52255
Change-Id: I8b6784d47620ffdcdbfb14524e7402e21d46c5f7
imgtec pointed out that pthread_kill(3) was broken, but most of the
other functions that ought to return ESRCH for invalid/exited threads
were equally broken.
Change-Id: I96347f6195549aee0c72dc39063e6c5d06d2e01f
