Add goroutines and function pointers

src/runtime/runtime_unix.go

@@ -10,6 +10,7 @@ import (
 // #include <stdio.h>
 // #include <stdlib.h>
 // #include <unistd.h>
+// #include <time.h>
 import "C"
 
 const Microsecond = 1
@@ -18,10 +19,20 @@ func putchar(c byte) {
 	C.putchar(C.int(c))
 }
 
-func Sleep(d Duration) {
+func sleep(d Duration) {
 	C.usleep(C.useconds_t(d))
 }
 
+// Return monotonic time in microseconds.
+//
+// TODO: use nanoseconds?
+// TODO: noescape
+func monotime() uint64 {
+	var ts C.struct_timespec
+	C.clock_gettime(C.CLOCK_MONOTONIC, &ts)
+	return uint64(ts.tv_sec) * 1000 * 1000 + uint64(ts.tv_nsec) / 1000
+}
+
 func abort() {
 	C.abort()
 }
@@ -35,5 +46,5 @@ func alloc(size uintptr) unsafe.Pointer {
 }
 
 func free(ptr unsafe.Pointer) {
-	C.free(ptr)
+	//C.free(ptr) // TODO
 }