ENH: Add mutex for global instance

pyopenjtalk/__init__.py

@@ -1,10 +1,15 @@
+from __future__ import annotations
+
 import atexit
 import os
 import sys
 import tarfile
 import tempfile
-from contextlib import ExitStack
+from collections.abc import Callable, Generator
+from contextlib import ExitStack, contextmanager
 from os.path import exists
+from threading import Lock
+from typing import TypeVar
 from urllib.request import urlopen
 
 if sys.version_info >= (3, 9):
@@ -44,14 +49,6 @@
     )
 ).encode("utf-8")
 
-# Global instance of OpenJTalk
-_global_jtalk = None
-# Global instance of HTSEngine
-# mei_normal.voice is used as default
-_global_htsengine = None
-# Global instance of Marine
-_global_marine = None
-
 
 def _extract_dic():
     from tqdm.auto import tqdm
@@ -78,6 +75,49 @@ def _lazy_init():
         _extract_dic()
 
 
+_T = TypeVar("_T")
+
+
+def _global_instance_manager(
+    instance_factory: Callable[[], _T] | None = None, instance: _T | None = None
+) -> Callable[[], Generator[_T, None, None]]:
+    assert instance_factory is not None or instance is not None
+    _instance = instance
+    mutex = Lock()
+
+    @contextmanager
+    def manager() -> Generator[_T, None, None]:
+        nonlocal _instance
+        with mutex:
+            if _instance is None:
+                _instance = instance_factory()
+            yield _instance
+
+    return manager
+
+
+def _jtalk_factory() -> OpenJTalk:
+    _lazy_init()
+    return OpenJTalk(dn_mecab=OPEN_JTALK_DICT_DIR)
+
+
+def _marine_factory():
+    try:
+        from marine.predict import Predictor
+    except ImportError:
+        raise ImportError("Please install marine by `pip install pyopenjtalk[marine]`")
+    return Predictor()
+
+
+# Global instance of OpenJTalk
+_global_jtalk = _global_instance_manager(_jtalk_factory)
+# Global instance of HTSEngine
+# mei_normal.voice is used as default
+_global_htsengine = _global_instance_manager(lambda: HTSEngine(DEFAULT_HTS_VOICE))
+# Global instance of Marine
+_global_marine = _global_instance_manager(_marine_factory)
+
+
 def g2p(*args, **kwargs):
     """Grapheme-to-phoeneme (G2P) conversion
 
@@ -93,11 +133,8 @@ def g2p(*args, **kwargs):
     Returns:
         str or list: G2P result in 1) str if join is True 2) list if join is False.
     """
-    global _global_jtalk
-    if _global_jtalk is None:
-        _lazy_init()
-        _global_jtalk = OpenJTalk(dn_mecab=OPEN_JTALK_DICT_DIR)
-    return _global_jtalk.g2p(*args, **kwargs)
+    with _global_jtalk() as jtalk:
+        return jtalk.g2p(*args, **kwargs)
 
 
 def estimate_accent(njd_features):
@@ -111,21 +148,13 @@ def estimate_accent(njd_features):
     Returns:
         list: features for NJDNode with estimation results by marine.
     """
-    global _global_marine
-    if _global_marine is None:
-        try:
-            from marine.predict import Predictor
-        except BaseException:
-            raise ImportError(
-                "Please install marine by `pip install pyopenjtalk[marine]`"
-            )
-        _global_marine = Predictor()
-    from marine.utils.openjtalk_util import convert_njd_feature_to_marine_feature
+    with _global_marine() as marine:
+        from marine.utils.openjtalk_util import convert_njd_feature_to_marine_feature
 
-    marine_feature = convert_njd_feature_to_marine_feature(njd_features)
-    marine_results = _global_marine.predict(
-        [marine_feature], require_open_jtalk_format=True
-    )
+        marine_feature = convert_njd_feature_to_marine_feature(njd_features)
+        marine_results = marine.predict(
+            [marine_feature], require_open_jtalk_format=True
+        )
     njd_features = merge_njd_marine_features(njd_features, marine_results)
     return njd_features
 
@@ -164,13 +193,11 @@ def synthesize(labels, speed=1.0, half_tone=0.0):
     if isinstance(labels, tuple) and len(labels) == 2:
         labels = labels[1]
 
-    global _global_htsengine
-    if _global_htsengine is None:
-        _global_htsengine = HTSEngine(DEFAULT_HTS_VOICE)
-    sr = _global_htsengine.get_sampling_frequency()
-    _global_htsengine.set_speed(speed)
-    _global_htsengine.add_half_tone(half_tone)
-    return _global_htsengine.synthesize(labels), sr
+    with _global_htsengine() as htsengine:
+        sr = htsengine.get_sampling_frequency()
+        htsengine.set_speed(speed)
+        htsengine.add_half_tone(half_tone)
+        return htsengine.synthesize(labels), sr
 
 
 def tts(text, speed=1.0, half_tone=0.0, run_marine=False):
@@ -202,11 +229,8 @@ def run_frontend(text):
     Returns:
         list: features for NJDNode.
     """
-    global _global_jtalk
-    if _global_jtalk is None:
-        _lazy_init()
-        _global_jtalk = OpenJTalk(dn_mecab=OPEN_JTALK_DICT_DIR)
-    return _global_jtalk.run_frontend(text)
+    with _global_jtalk() as jtalk:
+        return jtalk.run_frontend(text)
 
 
 def make_label(njd_features):
@@ -218,11 +242,8 @@ def make_label(njd_features):
     Returns:
         list: full-context labels.
     """
-    global _global_jtalk
-    if _global_jtalk is None:
-        _lazy_init()
-        _global_jtalk = OpenJTalk(dn_mecab=OPEN_JTALK_DICT_DIR)
-    return _global_jtalk.make_label(njd_features)
+    with _global_jtalk() as jtalk:
+        return jtalk.make_label(njd_features)
 
 
 def mecab_dict_index(path, out_path, dn_mecab=None):
@@ -233,12 +254,11 @@ def mecab_dict_index(path, out_path, dn_mecab=None):
         out_path (str): path to output dictionary
         dn_mecab (optional. str): path to mecab dictionary
     """
-    global _global_jtalk
-    if _global_jtalk is None:
-        _lazy_init()
     if not exists(path):
         raise FileNotFoundError("no such file or directory: %s" % path)
     if dn_mecab is None:
+        with _global_jtalk():  # call _lazy_init()
+            pass
         dn_mecab = OPEN_JTALK_DICT_DIR
     r = _mecab_dict_index(dn_mecab, path.encode("utf-8"), out_path.encode("utf-8"))
 
@@ -257,10 +277,11 @@ def update_global_jtalk_with_user_dict(path):
         path (str): path to user dictionary
     """
     global _global_jtalk
-    if _global_jtalk is None:
-        _lazy_init()
-    if not exists(path):
-        raise FileNotFoundError("no such file or directory: %s" % path)
-    _global_jtalk = OpenJTalk(
-        dn_mecab=OPEN_JTALK_DICT_DIR, userdic=path.encode("utf-8")
-    )
+    with _global_jtalk():
+        if not exists(path):
+            raise FileNotFoundError("no such file or directory: %s" % path)
+        _global_jtalk = _global_instance_manager(
+            instance=OpenJTalk(
+                dn_mecab=OPEN_JTALK_DICT_DIR, userdic=path.encode("utf-8")
+            )
+        )