Add realloc function to jmem (#2998)

This patch extends jmem functionality by adding a realloc function. This opens up other paths of optimization which can result in smaller peak memory usage and faster execution times, due to not having to duplicate memory when we need to extend blocks. JerryScript-DCO-1.0-Signed-off-by: Dániel Bátyai dbatyai@inf.u-szeged.hu
2019-08-06 17:59:49 +02:00
parent 3b7475b01d
commit 566e81451e
3 changed files with 335 additions and 36 deletions
@@ -0,0 +1,110 @@
+/* Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ecma-init-finalize.h"
+#include "jmem.h"
+
+#include "test-common.h"
+
+#define BASIC_SIZE (64)
+
+int
+main (void)
+{
+  TEST_INIT ();
+
+  jmem_init ();
+  ecma_init ();
+
+  {
+    uint8_t *block1_p = (uint8_t *) jmem_heap_alloc_block (BASIC_SIZE);
+    uint8_t *block2_p = (uint8_t *) jmem_heap_alloc_block (BASIC_SIZE);
+    uint8_t *block3_p = (uint8_t *) jmem_heap_alloc_block (BASIC_SIZE);
+
+    /* [block1 64] [block2 64] [block3 64] [...] */
+
+    for (uint8_t i = 0; i < BASIC_SIZE; i++)
+    {
+      block2_p[i] = i;
+    }
+
+    /* Realloc by moving */
+    block2_p = jmem_heap_realloc_block (block2_p, BASIC_SIZE, BASIC_SIZE * 2);
+
+    /* [block1 64] [free 64] [block3 64] [block2 128] [...] */
+
+    for (uint8_t i = 0; i < BASIC_SIZE; i++)
+    {
+      TEST_ASSERT (block2_p[i] == i);
+    }
+
+    for (uint8_t i = BASIC_SIZE; i < BASIC_SIZE * 2; i++)
+    {
+      block2_p[i] = i;
+    }
+
+    uint8_t *block4_p = (uint8_t *) jmem_heap_alloc_block (BASIC_SIZE * 2);
+
+    /* [block1 64] [free 64] [block3 64] [block2 128] [block4 128] [...] */
+
+    jmem_heap_free_block (block3_p, BASIC_SIZE);
+
+    /* [block1 64] [free 128] [block2 128] [block4 128] [...] */
+
+    /* Realloc by extending front */
+    block2_p = (uint8_t *) jmem_heap_realloc_block (block2_p, BASIC_SIZE * 2, BASIC_SIZE * 3);
+
+    /* [block1 64] [free 64] [block2 192] [block4 128] [...] */
+
+    for (uint8_t i = 0; i < BASIC_SIZE * 2; i++)
+    {
+      TEST_ASSERT (block2_p[i] == i);
+    }
+
+    /* Shrink */
+    block2_p = (uint8_t *) jmem_heap_realloc_block (block2_p, BASIC_SIZE * 3, BASIC_SIZE);
+
+    /* [block1 64] [free 64] [block2 64] [free 128] [block4 128] [...] */
+
+    for (uint8_t i = 0; i < BASIC_SIZE; i++)
+    {
+      TEST_ASSERT (block2_p[i] == i);
+    }
+
+    for (uint8_t i = 0; i < BASIC_SIZE; i++)
+    {
+      block1_p[i] = i;
+    }
+
+    /* Grow in place */
+    block1_p = (uint8_t *) jmem_heap_realloc_block (block1_p, BASIC_SIZE, BASIC_SIZE * 2);
+
+    /* [block1 128] [block2 64] [free 128] [block4 128] [...] */
+
+    for (uint8_t i = 0; i < BASIC_SIZE; i++)
+    {
+      TEST_ASSERT (block1_p[i] == i);
+    }
+
+    jmem_heap_free_block (block1_p, BASIC_SIZE * 2);
+    jmem_heap_free_block (block2_p, BASIC_SIZE);
+    jmem_heap_free_block (block4_p, BASIC_SIZE * 2);
+  }
+
+  ecma_finalize ();
+  jmem_finalize ();
+
+  return 0;
+} /* main */