kernel: finish implementation of private and shared futexes

libmango/include/mango/syscall.h

@@ -41,5 +41,7 @@
 #define SYS_VM_CONTROLLER_CREATE_OBJECT 0x25u
 #define SYS_VM_CONTROLLER_DETACH_OBJECT 0x26u
 #define SYS_VM_CONTROLLER_SUPPLY_PAGES  0x27u
+#define SYS_FUTEX_WAIT                  0x28u
+#define SYS_FUTEX_WAKE                  0x29u
 
 #endif

libmango/include/mango/types.h

@@ -44,6 +44,13 @@
 #define PAGE_REQUEST_DIRTY      0x02u
 #define PAGE_REQUEST_DETACH     0x03u
 
+/* futex special values */
+#define FUTEX_WAKE_ALL          ((size_t)-1)
+
+/* futex flags */
+#define FUTEX_PRIVATE           0x01u
+#define FUTEX_SHARED            0x02u
+
 #define IOVEC(p, len)                                                          \
 	{                                                                      \
 		.io_base = (virt_addr_t)(p), .io_len = (len),                  \