Add a magic field to the pthread structure to help recognize valid

threads from invalid ones. The pthread structure is opaque to the user
so this change does not cause any incompatibilities.

Hopefully this change will help code that was written for draft 4
fail gracefully if the programmer ignores the compiler warning about
the change in the level of indirection for the argument passed to
pthread_detach(). I got burnt, so I fixed then (expletive deleted)
thing.

These functions comply with the revised standard. That should shut
Terry up!

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/libkse/thread/thr_join.c b/lib/libkse/thread/thr_join.c
index 63d0d58..9e86a01 100644
--- a/lib/libkse/thread/thr_join.c
+++ b/lib/libkse/thread/thr_join.c
@@ -42,6 +42,16 @@ pthread_join(pthread_t pthread, void **thread_return)
 	int             status;
 	pthread_t	pthread1;
 
+	/* Check if the caller has specified an invalid thread: */
+	if (pthread == NULL || pthread->magic != PTHREAD_MAGIC)
+		/* Invalid thread: */
+		return(EINVAL);
+
+	/* Check if the caller has specified itself: */
+	if (pthread == _thread_run)
+		/* Avoid a deadlock condition: */
+		return(EDEADLK);
+
 	/* Block signals: */
 	_thread_kern_sig_block(&status);