First commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 38 insertions, 0 deletions

diff --git a/internal-linux.h b/internal-linux.h
new file mode 100644
index 0000000..4fb2ee3
--- /dev/null
+++ b/internal-linux.h
@@ -0,0 +1,38 @@
+/* See LICENSE file for copyright and license details. */
+
+#include <linux/futex.h>
+#include <sys/syscall.h>
+
+#include "internal-llmutex.h"
+
+
+typedef volatile _Atomic uint32_t MUTEX;
+_Static_assert(sizeof(MUTEX) == sizeof(uint32_t));
+
+
+#define INIT_MUTEX(MUTEX)\
+	((void)0) /* TODO atomic_init(&(MUTEX), 0) */
+
+#define _TRYLOCK(MUTEX)\
+	!atomic_exchange(&(MUTEX), 1)
+
+#define _LOCK(MUTEX)\
+	do {\
+		while (!_TRYLOCK(MUTEX))\
+			_WAIT(MUTEX);\
+	} while (0)
+
+#define _UNLOCK(MUTEX)\
+	do {\
+		atomic_store(&(MUTEX), 0);\
+		if (syscall(SYS_futex, &(MUTEX), FUTEX_PRIVATE_FLAG | FUTEX_WAKE, INT_MAX, NULL, 0, 0) < 0) {\
+			/* TODO */\
+		}\
+	} while (0)
+
+#define _WAIT(MUTEX)\
+	do {\
+		if (syscall(SYS_futex, &(MUTEX), FUTEX_PRIVATE_FLAG | FUTEX_WAIT, 1, NULL, 0, 0) < 0) {\
+			/* TODO */\
+		}\
+	} while (0)