extmod/moduos_dupterm: Reserve buffer bytearray object for dupterm.

pfalcon · pfalcon · commit 426112ce88bf · 2016-07-04T13:32:30.000+03:00
Allocating it for each read/write operation is a memory fragmentation
hazard.
diff --git a/extmod/moduos_dupterm.c b/extmod/moduos_dupterm.c
@@ -69,9 +69,12 @@ STATIC mp_obj_t mp_uos_dupterm(mp_uint_t n_args, const mp_obj_t *args) {
         }
     } else {
         if (args[0] == mp_const_none) {
-            MP_STATE_PORT(term_obj) = NULL;
+            MP_STATE_PORT(term_obj) = MP_OBJ_NULL;
         } else {
             MP_STATE_PORT(term_obj) = args[0];
+            if (MP_STATE_PORT(dupterm_arr_obj) == MP_OBJ_NULL) {
+                MP_STATE_PORT(dupterm_arr_obj) = mp_obj_new_bytearray(1, "");
+            }
         }
         return mp_const_none;
     }
diff --git a/py/mpstate.h b/py/mpstate.h
@@ -143,6 +143,7 @@ typedef struct _mp_state_vm_t {
 
     #if MICROPY_PY_OS_DUPTERM
     mp_obj_t term_obj;
+    mp_obj_t dupterm_arr_obj;
     #endif
 
     #if MICROPY_PY_LWIP_SLIP

Original file line number	Diff line number	Diff line change
`@@ -69,9 +69,12 @@ STATIC mp_obj_t mp_uos_dupterm(mp_uint_t n_args, const mp_obj_t *args) {`
`69`	`69`	`}`
`70`	`70`	`} else {`
`71`	`71`	`if (args[0] == mp_const_none) {`
`72`		`- MP_STATE_PORT(term_obj) = NULL;`
	`72`	`+ MP_STATE_PORT(term_obj) = MP_OBJ_NULL;`
`73`	`73`	`} else {`
`74`	`74`	`MP_STATE_PORT(term_obj) = args[0];`
	`75`	`+ if (MP_STATE_PORT(dupterm_arr_obj) == MP_OBJ_NULL) {`
	`76`	`+ MP_STATE_PORT(dupterm_arr_obj) = mp_obj_new_bytearray(1, "");`
	`77`	`+ }`
`75`	`78`	`}`
`76`	`79`	`return mp_const_none;`
`77`	`80`	`}`