--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/symbian-qemu-0.9.1-12/python-2.6.1/Python/pyarena.c Fri Jul 31 15:01:17 2009 +0100
@@ -0,0 +1,220 @@
+#include "Python.h"
+#include "pyarena.h"
+
+/* A simple arena block structure.
+
+ Measurements with standard library modules suggest the average
+ allocation is about 20 bytes and that most compiles use a single
+ block.
+
+ TODO(jhylton): Think about a realloc API, maybe just for the last
+ allocation?
+*/
+
+#define DEFAULT_BLOCK_SIZE 8192
+#define ALIGNMENT 8
+#define ALIGNMENT_MASK (ALIGNMENT - 1)
+#define ROUNDUP(x) (((x) + ALIGNMENT_MASK) & ~ALIGNMENT_MASK)
+
+typedef struct _block {
+ /* Total number of bytes owned by this block available to pass out.
+ * Read-only after initialization. The first such byte starts at
+ * ab_mem.
+ */
+ size_t ab_size;
+
+ /* Total number of bytes already passed out. The next byte available
+ * to pass out starts at ab_mem + ab_offset.
+ */
+ size_t ab_offset;
+
+ /* An arena maintains a singly-linked, NULL-terminated list of
+ * all blocks owned by the arena. These are linked via the
+ * ab_next member.
+ */
+ struct _block *ab_next;
+
+ /* Pointer to the first allocatable byte owned by this block. Read-
+ * only after initialization.
+ */
+ void *ab_mem;
+} block;
+
+/* The arena manages two kinds of memory, blocks of raw memory
+ and a list of PyObject* pointers. PyObjects are decrefed
+ when the arena is freed.
+*/
+
+struct _arena {
+ /* Pointer to the first block allocated for the arena, never NULL.
+ It is used only to find the first block when the arena is
+ being freed.
+ */
+ block *a_head;
+
+ /* Pointer to the block currently used for allocation. It's
+ ab_next field should be NULL. If it is not-null after a
+ call to block_alloc(), it means a new block has been allocated
+ and a_cur should be reset to point it.
+ */
+ block *a_cur;
+
+ /* A Python list object containing references to all the PyObject
+ pointers associated with this area. They will be DECREFed
+ when the arena is freed.
+ */
+ PyObject *a_objects;
+
+#if defined(Py_DEBUG)
+ /* Debug output */
+ size_t total_allocs;
+ size_t total_size;
+ size_t total_blocks;
+ size_t total_block_size;
+ size_t total_big_blocks;
+#endif
+};
+
+static block *
+block_new(size_t size)
+{
+ /* Allocate header and block as one unit.
+ ab_mem points just past header. */
+ block *b = (block *)malloc(sizeof(block) + size);
+ if (!b)
+ return NULL;
+ b->ab_size = size;
+ b->ab_mem = (void *)(b + 1);
+ b->ab_next = NULL;
+ b->ab_offset = ROUNDUP((Py_uintptr_t)(b->ab_mem)) -
+ (Py_uintptr_t)(b->ab_mem);
+ return b;
+}
+
+static void
+block_free(block *b) {
+ while (b) {
+ block *next = b->ab_next;
+ free(b);
+ b = next;
+ }
+}
+
+static void *
+block_alloc(block *b, size_t size)
+{
+ void *p;
+ assert(b);
+ size = ROUNDUP(size);
+ if (b->ab_offset + size > b->ab_size) {
+ /* If we need to allocate more memory than will fit in
+ the default block, allocate a one-off block that is
+ exactly the right size. */
+ /* TODO(jhylton): Think about space waste at end of block */
+ block *newbl = block_new(
+ size < DEFAULT_BLOCK_SIZE ?
+ DEFAULT_BLOCK_SIZE : size);
+ if (!newbl)
+ return NULL;
+ assert(!b->ab_next);
+ b->ab_next = newbl;
+ b = newbl;
+ }
+
+ assert(b->ab_offset + size <= b->ab_size);
+ p = (void *)(((char *)b->ab_mem) + b->ab_offset);
+ b->ab_offset += size;
+ return p;
+}
+
+PyArena *
+PyArena_New()
+{
+ PyArena* arena = (PyArena *)malloc(sizeof(PyArena));
+ if (!arena)
+ return (PyArena*)PyErr_NoMemory();
+
+ arena->a_head = block_new(DEFAULT_BLOCK_SIZE);
+ arena->a_cur = arena->a_head;
+ if (!arena->a_head) {
+ free((void *)arena);
+ return (PyArena*)PyErr_NoMemory();
+ }
+ arena->a_objects = PyList_New(0);
+ if (!arena->a_objects) {
+ block_free(arena->a_head);
+ free((void *)arena);
+ return (PyArena*)PyErr_NoMemory();
+ }
+#if defined(Py_DEBUG)
+ arena->total_allocs = 0;
+ arena->total_size = 0;
+ arena->total_blocks = 1;
+ arena->total_block_size = DEFAULT_BLOCK_SIZE;
+ arena->total_big_blocks = 0;
+#endif
+ return arena;
+}
+
+void
+PyArena_Free(PyArena *arena)
+{
+ int r;
+ assert(arena);
+#if defined(Py_DEBUG)
+ /*
+ fprintf(stderr,
+ "alloc=%d size=%d blocks=%d block_size=%d big=%d objects=%d\n",
+ arena->total_allocs, arena->total_size, arena->total_blocks,
+ arena->total_block_size, arena->total_big_blocks,
+ PyList_Size(arena->a_objects));
+ */
+#endif
+ block_free(arena->a_head);
+ /* This property normally holds, except when the code being compiled
+ is sys.getobjects(0), in which case there will be two references.
+ assert(arena->a_objects->ob_refcnt == 1);
+ */
+
+ /* Clear all the elements from the list. This is necessary
+ to guarantee that they will be DECREFed. */
+ r = PyList_SetSlice(arena->a_objects,
+ 0, PyList_GET_SIZE(arena->a_objects), NULL);
+ assert(r == 0);
+ assert(PyList_GET_SIZE(arena->a_objects) == 0);
+ Py_DECREF(arena->a_objects);
+ free(arena);
+}
+
+void *
+PyArena_Malloc(PyArena *arena, size_t size)
+{
+ void *p = block_alloc(arena->a_cur, size);
+ if (!p)
+ return PyErr_NoMemory();
+#if defined(Py_DEBUG)
+ arena->total_allocs++;
+ arena->total_size += size;
+#endif
+ /* Reset cur if we allocated a new block. */
+ if (arena->a_cur->ab_next) {
+ arena->a_cur = arena->a_cur->ab_next;
+#if defined(Py_DEBUG)
+ arena->total_blocks++;
+ arena->total_block_size += arena->a_cur->ab_size;
+ if (arena->a_cur->ab_size > DEFAULT_BLOCK_SIZE)
+ ++arena->total_big_blocks;
+#endif
+ }
+ return p;
+}
+
+int
+PyArena_AddPyObject(PyArena *arena, PyObject *obj)
+{
+ int r = PyList_Append(arena->a_objects, obj);
+ if (r >= 0) {
+ Py_DECREF(obj);
+ }
+ return r;
+}