unix: Implement time.sleep().

unix/time.c

@@ -1,5 +1,7 @@
 #include <string.h>
 #include <time.h>
+#include <sys/time.h>
+#include <math.h>
 
 #include "misc.h"
 #include "mpconfig.h"
@@ -23,8 +25,24 @@ static mp_obj_t mod_time_clock() {
 }
 static MP_DEFINE_CONST_FUN_OBJ_0(mod_time_clock_obj, mod_time_clock);
 
+static mp_obj_t mod_time_sleep(mp_obj_t arg) {
+#if MICROPY_ENABLE_FLOAT
+    struct timeval tv;
+    machine_float_t val = mp_obj_get_float(arg);
+    double ipart;
+    tv.tv_usec = round(modf(val, &ipart) * 1000000);
+    tv.tv_sec = ipart;
+    select(0, NULL, NULL, NULL, &tv);
+#else
+    sleep(mp_obj_get_int(arg));
+#endif
+    return mp_const_none;
+}
+static MP_DEFINE_CONST_FUN_OBJ_1(mod_time_sleep_obj, mod_time_sleep);
+
 void time_init() {
     mp_obj_t m = mp_obj_new_module(QSTR_FROM_STR_STATIC("time"));
     rt_store_attr(m, QSTR_FROM_STR_STATIC("time"), (mp_obj_t)&mod_time_time_obj);
     rt_store_attr(m, QSTR_FROM_STR_STATIC("clock"), (mp_obj_t)&mod_time_clock_obj);
+    rt_store_attr(m, QSTR_FROM_STR_STATIC("sleep"), (mp_obj_t)&mod_time_sleep_obj);
 }