gh-125196: Add a free list to PyUnicodeWriter (#125227)

python · Oct 10, 2024 · 1639d93 · 1639d93
1 parent 7a10cde
commit 1639d93
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Showing 3 changed files with 12 additions and 4 deletions.
diff --git a/Include/internal/pycore_freelist_state.h b/Include/internal/pycore_freelist_state.h
@@ -20,6 +20,7 @@ extern "C" {
 # define Py_async_gen_asends_MAXFREELIST 80
 # define Py_futureiters_MAXFREELIST 255
 # define Py_object_stack_chunks_MAXFREELIST 4
+# define Py_unicode_writers_MAXFREELIST 1
 
 // A generic freelist of either PyObjects or other data structures.
 struct _Py_freelist {
@@ -44,6 +45,7 @@ struct _Py_freelists {
  struct _Py_freelist async_gen_asends;
  struct _Py_freelist futureiters;
  struct _Py_freelist object_stack_chunks;
+ struct _Py_freelist unicode_writers;
 };
 
 #ifdef __cplusplus

diff --git a/Objects/object.c b/Objects/object.c
@@ -862,6 +862,7 @@ _PyObject_ClearFreeLists(struct _Py_freelists *freelists, int is_finalization)
  // stacks during GC, so emptying the free-list is counterproductive.
  clear_freelist(&freelists->object_stack_chunks, 1, PyMem_RawFree);
  }
+ clear_freelist(&freelists->unicode_writers, is_finalization, PyMem_Free);
 }
 
 /*

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
@@ -46,6 +46,7 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 #include "pycore_codecs.h" // _PyCodec_Lookup()
 #include "pycore_critical_section.h" // Py_*_CRITICAL_SECTION_SEQUENCE_FAST
 #include "pycore_format.h" // F_LJUST
+#include "pycore_freelist.h" // _Py_FREELIST_FREE(), _Py_FREELIST_POP()
 #include "pycore_initconfig.h" // _PyStatus_OK()
 #include "pycore_interp.h" // PyInterpreterState.fs_codec
 #include "pycore_long.h" // _PyLong_FormatWriter()
@@ -13436,9 +13437,13 @@ PyUnicodeWriter_Create(Py_ssize_t length)
  }
 
  const size_t size = sizeof(_PyUnicodeWriter);
- PyUnicodeWriter *pub_writer = (PyUnicodeWriter *)PyMem_Malloc(size);
+ PyUnicodeWriter *pub_writer;
+ pub_writer = _Py_FREELIST_POP_MEM(unicode_writers);
  if (pub_writer == NULL) {
- return (PyUnicodeWriter *)PyErr_NoMemory();
+ pub_writer = (PyUnicodeWriter *)PyMem_Malloc(size);
+ if (pub_writer == NULL) {
+ return (PyUnicodeWriter *)PyErr_NoMemory();
+ }
  }
  _PyUnicodeWriter *writer = (_PyUnicodeWriter *)pub_writer;
 
@@ -13459,7 +13464,7 @@ void PyUnicodeWriter_Discard(PyUnicodeWriter *writer)
  return;
  }
  _PyUnicodeWriter_Dealloc((_PyUnicodeWriter*)writer);
- PyMem_Free(writer);
+ _Py_FREELIST_FREE(unicode_writers, writer, PyMem_Free);
 }
 
 
@@ -13881,7 +13886,7 @@ PyUnicodeWriter_Finish(PyUnicodeWriter *writer)
 {
  PyObject *str = _PyUnicodeWriter_Finish((_PyUnicodeWriter*)writer);
  assert(((_PyUnicodeWriter*)writer)->buffer == NULL);
- PyMem_Free(writer);
+ _Py_FREELIST_FREE(unicode_writers, writer, PyMem_Free);
  return str;
 }