implement robust mutexes

some of this code should be cleaned up, e.g. using macros for some of
the bit flags, masks, etc. nonetheless, the code is believed to be
working and correct at this point.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/thread/pthread_mutex_consistent.c b/src/thread/pthread_mutex_consistent.c
new file mode 100644
index 00000000..7dfb904f
--- /dev/null
+++ b/src/thread/pthread_mutex_consistent.c
@@ -0,0 +1,10 @@
+#include "pthread_impl.h"
+
+int pthread_mutex_consistent(pthread_mutex_t *m)
+{
+	if (m->_m_type < 8) return EINVAL;
+	if ((m->_m_lock & 0x3fffffff) != pthread_self()->tid)
+		return EPERM;
+	m->_m_type -= 8;
+	return 0;
+}