Merge pull request #985 from tannewt/heap_tweaks3

A few heap related tweaks

5 files changed, 19 insertions, 4 deletions

diff --git a/py/builtinimport.c b/py/builtinimport.c
index 9f7d34dca..c1437da4c 100644..100755
--- a/py/builtinimport.c
+++ b/py/builtinimport.c
@@ -31,6 +31,7 @@
 
 #include "py/compile.h"
 #include "py/gc_long_lived.h"
+#include "py/gc.h"
 #include "py/objmodule.h"
 #include "py/persistentcode.h"
 #include "py/runtime.h"
@@ -468,6 +469,10 @@ mp_obj_t mp_builtin___import__(size_t n_args, const mp_obj_t *args) {
                     // (the module that was just loaded) is not a package.  This will be caught
                     // on the next iteration because the file will not exist.
                 }
+
+                // Loading a module thrashes the heap significantly so we explicitly clean up
+                // afterwards.
+                gc_collect();
             }
             if (outer_module_obj != MP_OBJ_NULL) {
                 qstr s = qstr_from_strn(mod_str + last, i - last);
diff --git a/py/gc.c b/py/gc.c
index 2c2354e4c..2c2354e4c 100644..100755
--- a/py/gc.c
+++ b/py/gc.c
diff --git a/py/gc_long_lived.c b/py/gc_long_lived.c
index d34fde5d9..e30b389fa 100644..100755
--- a/py/gc_long_lived.c
+++ b/py/gc_long_lived.c
@@ -121,7 +121,7 @@ mp_obj_t make_obj_long_lived(mp_obj_t obj, uint8_t max_depth){
     } else if (MP_OBJ_IS_TYPE(obj, &mp_type_property)) {
         mp_obj_property_t *prop = MP_OBJ_TO_PTR(obj);
         return MP_OBJ_FROM_PTR(make_property_long_lived(prop, max_depth));
-    } else if (MP_OBJ_IS_TYPE(obj, &mp_type_str)) {
+    } else if (MP_OBJ_IS_TYPE(obj, &mp_type_str) || MP_OBJ_IS_TYPE(obj, &mp_type_bytes)) {
         mp_obj_str_t *str = MP_OBJ_TO_PTR(obj);
         return MP_OBJ_FROM_PTR(make_str_long_lived(str));
     } else if (MP_OBJ_IS_TYPE(obj, &mp_type_type)) {
diff --git a/py/mpconfig.h b/py/mpconfig.h
index 765ae1e8f..74d7c2c92 100644..100755
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -130,6 +130,12 @@
 #define MICROPY_ALLOC_QSTR_CHUNK_INIT (128)
 #endif
 
+// Max number of entries in newly allocated QSTR pools. Smaller numbers may make QSTR lookups
+// slightly slower but reduce the waste of unused spots.
+#ifndef MICROPY_QSTR_POOL_MAX_ENTRIES
+#define MICROPY_QSTR_POOL_MAX_ENTRIES (64)
+#endif
+
 // Initial amount for lexer indentation level
 #ifndef MICROPY_ALLOC_LEXER_INDENT_INIT
 #define MICROPY_ALLOC_LEXER_INDENT_INIT (10)
diff --git a/py/qstr.c b/py/qstr.c
index 49b2d9daa..de4dc6240 100644..100755
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -144,14 +144,18 @@ STATIC qstr qstr_add(const byte *q_ptr) {
 
     // make sure we have room in the pool for a new qstr
     if (MP_STATE_VM(last_pool)->len >= MP_STATE_VM(last_pool)->alloc) {
-        qstr_pool_t *pool = m_new_ll_obj_var_maybe(qstr_pool_t, const char*, MP_STATE_VM(last_pool)->alloc * 2);
+        uint32_t new_pool_length = MP_STATE_VM(last_pool)->alloc * 2;
+        if (new_pool_length > MICROPY_QSTR_POOL_MAX_ENTRIES) {
+            new_pool_length = MICROPY_QSTR_POOL_MAX_ENTRIES;
+        }
+        qstr_pool_t *pool = m_new_ll_obj_var_maybe(qstr_pool_t, const char*, new_pool_length);
         if (pool == NULL) {
             QSTR_EXIT();
-            m_malloc_fail(MP_STATE_VM(last_pool)->alloc * 2);
+            m_malloc_fail(new_pool_length);
         }
         pool->prev = MP_STATE_VM(last_pool);
         pool->total_prev_len = MP_STATE_VM(last_pool)->total_prev_len + MP_STATE_VM(last_pool)->len;
-        pool->alloc = MP_STATE_VM(last_pool)->alloc * 2;
+        pool->alloc = new_pool_length;
         pool->len = 0;
         MP_STATE_VM(last_pool) = pool;
         DEBUG_printf("QSTR: allocate new pool of size %d\n", MP_STATE_VM(last_pool)->alloc);