bpo-39465: Fix _PyUnicode_FromId() for subinterpreters (GH-20058)
Make _PyUnicode_FromId() function compatible with subinterpreters. Each interpreter now has an array of identifier objects (interned strings decoded from UTF-8). * Add PyInterpreterState.unicode.identifiers: array of identifiers objects. * Add _PyRuntimeState.unicode_ids used to allocate unique indexes to _Py_Identifier. * Rewrite the _Py_Identifier structure. Microbenchmark on _PyUnicode_FromId(&PyId_a) with _Py_IDENTIFIER(a): [ref] 2.42 ns +- 0.00 ns -> [atomic] 3.39 ns +- 0.00 ns: 1.40x slower This change adds 1 ns per _PyUnicode_FromId() call in average.
This commit is contained in:
parent
f0853bcedf
commit
ba3d67c2fb
|
@ -35,12 +35,13 @@ PyAPI_FUNC(Py_ssize_t) _Py_GetRefTotal(void);
|
|||
_PyObject_{Get,Set,Has}AttrId are __getattr__ versions using _Py_Identifier*.
|
||||
*/
|
||||
typedef struct _Py_Identifier {
|
||||
struct _Py_Identifier *next;
|
||||
const char* string;
|
||||
PyObject *object;
|
||||
// Index in PyInterpreterState.unicode.ids.array. It is process-wide
|
||||
// unique and must be initialized to -1.
|
||||
Py_ssize_t index;
|
||||
} _Py_Identifier;
|
||||
|
||||
#define _Py_static_string_init(value) { .next = NULL, .string = value, .object = NULL }
|
||||
#define _Py_static_string_init(value) { .string = value, .index = -1 }
|
||||
#define _Py_static_string(varname, value) static _Py_Identifier varname = _Py_static_string_init(value)
|
||||
#define _Py_IDENTIFIER(varname) _Py_static_string(PyId_##varname, #varname)
|
||||
|
||||
|
|
|
@ -64,6 +64,11 @@ struct _Py_bytes_state {
|
|||
PyBytesObject *characters[256];
|
||||
};
|
||||
|
||||
struct _Py_unicode_ids {
|
||||
Py_ssize_t size;
|
||||
PyObject **array;
|
||||
};
|
||||
|
||||
struct _Py_unicode_state {
|
||||
// The empty Unicode object is a singleton to improve performance.
|
||||
PyObject *empty_string;
|
||||
|
@ -71,6 +76,8 @@ struct _Py_unicode_state {
|
|||
shared as well. */
|
||||
PyObject *latin1[256];
|
||||
struct _Py_unicode_fs_codec fs_codec;
|
||||
// Unicode identifiers (_Py_Identifier): see _PyUnicode_FromId()
|
||||
struct _Py_unicode_ids ids;
|
||||
};
|
||||
|
||||
struct _Py_float_state {
|
||||
|
|
|
@ -49,6 +49,11 @@ typedef struct _Py_AuditHookEntry {
|
|||
void *userData;
|
||||
} _Py_AuditHookEntry;
|
||||
|
||||
struct _Py_unicode_runtime_ids {
|
||||
PyThread_type_lock lock;
|
||||
Py_ssize_t next_index;
|
||||
};
|
||||
|
||||
/* Full Python runtime state */
|
||||
|
||||
typedef struct pyruntimestate {
|
||||
|
@ -106,6 +111,8 @@ typedef struct pyruntimestate {
|
|||
void *open_code_userdata;
|
||||
_Py_AuditHookEntry *audit_hook_head;
|
||||
|
||||
struct _Py_unicode_runtime_ids unicode_ids;
|
||||
|
||||
// XXX Consolidate globals found via the check-c-globals script.
|
||||
} _PyRuntimeState;
|
||||
|
||||
|
|
|
@ -0,0 +1,3 @@
|
|||
Make :c:func:`_PyUnicode_FromId` function compatible with subinterpreters.
|
||||
Each interpreter now has an array of identifier objects (interned strings
|
||||
decoded from UTF-8). Patch by Victor Stinner.
|
|
@ -41,6 +41,7 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|||
#define PY_SSIZE_T_CLEAN
|
||||
#include "Python.h"
|
||||
#include "pycore_abstract.h" // _PyIndex_Check()
|
||||
#include "pycore_atomic_funcs.h" // _Py_atomic_size_get()
|
||||
#include "pycore_bytes_methods.h" // _Py_bytes_lower()
|
||||
#include "pycore_format.h" // F_LJUST
|
||||
#include "pycore_initconfig.h" // _PyStatus_OK()
|
||||
|
@ -302,9 +303,6 @@ unicode_decode_utf8(const char *s, Py_ssize_t size,
|
|||
_Py_error_handler error_handler, const char *errors,
|
||||
Py_ssize_t *consumed);
|
||||
|
||||
/* List of static strings. */
|
||||
static _Py_Identifier *static_strings = NULL;
|
||||
|
||||
/* Fast detection of the most frequent whitespace characters */
|
||||
const unsigned char _Py_ascii_whitespace[] = {
|
||||
0, 0, 0, 0, 0, 0, 0, 0,
|
||||
|
@ -2312,42 +2310,85 @@ PyUnicode_FromString(const char *u)
|
|||
return PyUnicode_DecodeUTF8Stateful(u, (Py_ssize_t)size, NULL, NULL);
|
||||
}
|
||||
|
||||
|
||||
PyObject *
|
||||
_PyUnicode_FromId(_Py_Identifier *id)
|
||||
{
|
||||
if (id->object) {
|
||||
return id->object;
|
||||
PyInterpreterState *interp = _PyInterpreterState_GET();
|
||||
struct _Py_unicode_ids *ids = &interp->unicode.ids;
|
||||
|
||||
int index = _Py_atomic_size_get(&id->index);
|
||||
if (index < 0) {
|
||||
struct _Py_unicode_runtime_ids *rt_ids = &interp->runtime->unicode_ids;
|
||||
|
||||
PyThread_acquire_lock(rt_ids->lock, WAIT_LOCK);
|
||||
// Check again to detect concurrent access. Another thread can have
|
||||
// initialized the index while this thread waited for the lock.
|
||||
index = _Py_atomic_size_get(&id->index);
|
||||
if (index < 0) {
|
||||
assert(rt_ids->next_index < PY_SSIZE_T_MAX);
|
||||
index = rt_ids->next_index;
|
||||
rt_ids->next_index++;
|
||||
_Py_atomic_size_set(&id->index, index);
|
||||
}
|
||||
PyThread_release_lock(rt_ids->lock);
|
||||
}
|
||||
assert(index >= 0);
|
||||
|
||||
PyObject *obj;
|
||||
obj = PyUnicode_DecodeUTF8Stateful(id->string,
|
||||
strlen(id->string),
|
||||
if (index < ids->size) {
|
||||
obj = ids->array[index];
|
||||
if (obj) {
|
||||
// Return a borrowed reference
|
||||
return obj;
|
||||
}
|
||||
}
|
||||
|
||||
obj = PyUnicode_DecodeUTF8Stateful(id->string, strlen(id->string),
|
||||
NULL, NULL);
|
||||
if (!obj) {
|
||||
return NULL;
|
||||
}
|
||||
PyUnicode_InternInPlace(&obj);
|
||||
|
||||
assert(!id->next);
|
||||
id->object = obj;
|
||||
id->next = static_strings;
|
||||
static_strings = id;
|
||||
return id->object;
|
||||
if (index >= ids->size) {
|
||||
// Overallocate to reduce the number of realloc
|
||||
Py_ssize_t new_size = Py_MAX(index * 2, 16);
|
||||
Py_ssize_t item_size = sizeof(ids->array[0]);
|
||||
PyObject **new_array = PyMem_Realloc(ids->array, new_size * item_size);
|
||||
if (new_array == NULL) {
|
||||
PyErr_NoMemory();
|
||||
return NULL;
|
||||
}
|
||||
memset(&new_array[ids->size], 0, (new_size - ids->size) * item_size);
|
||||
ids->array = new_array;
|
||||
ids->size = new_size;
|
||||
}
|
||||
|
||||
// The array stores a strong reference
|
||||
ids->array[index] = obj;
|
||||
|
||||
// Return a borrowed reference
|
||||
return obj;
|
||||
}
|
||||
|
||||
|
||||
static void
|
||||
unicode_clear_static_strings(void)
|
||||
unicode_clear_identifiers(PyThreadState *tstate)
|
||||
{
|
||||
_Py_Identifier *tmp, *s = static_strings;
|
||||
while (s) {
|
||||
Py_CLEAR(s->object);
|
||||
tmp = s->next;
|
||||
s->next = NULL;
|
||||
s = tmp;
|
||||
PyInterpreterState *interp = _PyInterpreterState_GET();
|
||||
struct _Py_unicode_ids *ids = &interp->unicode.ids;
|
||||
for (Py_ssize_t i=0; i < ids->size; i++) {
|
||||
Py_XDECREF(ids->array[i]);
|
||||
}
|
||||
static_strings = NULL;
|
||||
ids->size = 0;
|
||||
PyMem_Free(ids->array);
|
||||
ids->array = NULL;
|
||||
// Don't reset _PyRuntime next_index: _Py_Identifier.id remains valid
|
||||
// after Py_Finalize().
|
||||
}
|
||||
|
||||
|
||||
/* Internal function, doesn't check maximum character */
|
||||
|
||||
PyObject*
|
||||
|
@ -16238,9 +16279,7 @@ _PyUnicode_Fini(PyThreadState *tstate)
|
|||
Py_CLEAR(state->latin1[i]);
|
||||
}
|
||||
|
||||
if (_Py_IsMainInterpreter(tstate)) {
|
||||
unicode_clear_static_strings();
|
||||
}
|
||||
unicode_clear_identifiers(tstate);
|
||||
|
||||
_PyUnicode_FiniEncodings(&tstate->interp->unicode.fs_codec);
|
||||
}
|
||||
|
|
|
@ -73,18 +73,24 @@ _PyRuntimeState_Init_impl(_PyRuntimeState *runtime)
|
|||
|
||||
runtime->interpreters.mutex = PyThread_allocate_lock();
|
||||
if (runtime->interpreters.mutex == NULL) {
|
||||
return _PyStatus_ERR("Can't initialize threads for interpreter");
|
||||
return _PyStatus_NO_MEMORY();
|
||||
}
|
||||
runtime->interpreters.next_id = -1;
|
||||
|
||||
runtime->xidregistry.mutex = PyThread_allocate_lock();
|
||||
if (runtime->xidregistry.mutex == NULL) {
|
||||
return _PyStatus_ERR("Can't initialize threads for cross-interpreter data registry");
|
||||
return _PyStatus_NO_MEMORY();
|
||||
}
|
||||
|
||||
// Set it to the ID of the main thread of the main interpreter.
|
||||
runtime->main_thread = PyThread_get_thread_ident();
|
||||
|
||||
runtime->unicode_ids.lock = PyThread_allocate_lock();
|
||||
if (runtime->unicode_ids.lock == NULL) {
|
||||
return _PyStatus_NO_MEMORY();
|
||||
}
|
||||
runtime->unicode_ids.next_index = 0;
|
||||
|
||||
return _PyStatus_OK();
|
||||
}
|
||||
|
||||
|
@ -108,17 +114,17 @@ _PyRuntimeState_Fini(_PyRuntimeState *runtime)
|
|||
/* Force the allocator used by _PyRuntimeState_Init(). */
|
||||
PyMemAllocatorEx old_alloc;
|
||||
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
|
||||
|
||||
if (runtime->interpreters.mutex != NULL) {
|
||||
PyThread_free_lock(runtime->interpreters.mutex);
|
||||
runtime->interpreters.mutex = NULL;
|
||||
#define FREE_LOCK(LOCK) \
|
||||
if (LOCK != NULL) { \
|
||||
PyThread_free_lock(LOCK); \
|
||||
LOCK = NULL; \
|
||||
}
|
||||
|
||||
if (runtime->xidregistry.mutex != NULL) {
|
||||
PyThread_free_lock(runtime->xidregistry.mutex);
|
||||
runtime->xidregistry.mutex = NULL;
|
||||
}
|
||||
FREE_LOCK(runtime->interpreters.mutex);
|
||||
FREE_LOCK(runtime->xidregistry.mutex);
|
||||
FREE_LOCK(runtime->unicode_ids.lock);
|
||||
|
||||
#undef FREE_LOCK
|
||||
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
|
||||
}
|
||||
|
||||
|
@ -139,12 +145,14 @@ _PyRuntimeState_ReInitThreads(_PyRuntimeState *runtime)
|
|||
int reinit_interp = _PyThread_at_fork_reinit(&runtime->interpreters.mutex);
|
||||
int reinit_main_id = _PyThread_at_fork_reinit(&runtime->interpreters.main->id_mutex);
|
||||
int reinit_xidregistry = _PyThread_at_fork_reinit(&runtime->xidregistry.mutex);
|
||||
int reinit_unicode_ids = _PyThread_at_fork_reinit(&runtime->unicode_ids.lock);
|
||||
|
||||
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
|
||||
|
||||
if (reinit_interp < 0
|
||||
|| reinit_main_id < 0
|
||||
|| reinit_xidregistry < 0)
|
||||
|| reinit_xidregistry < 0
|
||||
|| reinit_unicode_ids < 0)
|
||||
{
|
||||
return _PyStatus_ERR("Failed to reinitialize runtime locks");
|
||||
|
||||
|
|
Loading…
Reference in New Issue