Add option to run tests with persistent compilation cache enabled.

This can help us get a lot more coverage of the compilation cache, since all compiles will trigger it, instead of having to write explicit compilation cache tests.

PiperOrigin-RevId: 507898535

jax/_src/test_util.py

@@ -12,15 +12,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from contextlib import contextmanager
+from contextlib import contextmanager, ExitStack
 import inspect
 import io
 import functools
 from functools import partial
 import re
 import os
+import tempfile
 import textwrap
-from typing import Callable, List, Generator, Sequence, Tuple, Union
+from typing import Callable, List, Generator, Optional, Sequence, Tuple, Union
 import unittest
 import warnings
 import zlib
@@ -33,14 +34,17 @@
 
 import jax
 from jax import lax
+from jax.experimental.compilation_cache import compilation_cache
 from jax.interpreters import mlir
 from jax.tree_util import tree_map, tree_all, tree_flatten, tree_unflatten
 from jax._src import api
 from jax._src import pjit as pjit_lib
 from jax._src import core
 from jax._src import dispatch
 from jax._src import dtypes as _dtypes
-from jax._src.config import flags, bool_env, config
+from jax._src.config import (flags, bool_env, config,
+                             raise_persistent_cache_errors,
+                             persistent_cache_min_compile_time_secs)
 from jax._src.numpy.lax_numpy import _promote_dtypes, _promote_dtypes_inexact
 from jax._src.util import prod, unzip2
 from jax._src.lib import xla_bridge
@@ -90,6 +94,12 @@
   'on the test name. If empty or unspecified, run all tests.'
 )
 
+flags.DEFINE_bool(
+    'jax_test_with_persistent_compilation_cache',
+    bool_env('JAX_TEST_WITH_PERSISTENT_COMPILATION_CACHE', False),
+    help='If enabled, the persistent compilation cache will be enabled for all '
+    'test cases. This can be used to increase compilation cache coverage.')
+
 def num_float_bits(dtype):
   return _dtypes.finfo(_dtypes.canonicalize_dtype(dtype)).bits
 
@@ -822,6 +832,8 @@ class JaxTestCase(parameterized.TestCase):
     'jax_traceback_filtering': 'off',
   }
 
+  _compilation_cache_exit_stack: Optional[ExitStack] = None
+
   # TODO(mattjj): this obscures the error messages from failures, figure out how
   # to re-enable it
   # def tearDown(self) -> None:
@@ -844,6 +856,24 @@ def tearDown(self):
       config.update(key, value)
     super().tearDown()
 
+  @classmethod
+  def setUpClass(cls):
+    if FLAGS.jax_test_with_persistent_compilation_cache:
+      cls._compilation_cache_exit_stack = ExitStack()
+      stack = cls._compilation_cache_exit_stack
+      stack.enter_context(raise_persistent_cache_errors(True))
+      stack.enter_context(persistent_cache_min_compile_time_secs(0))
+
+      tmp_dir = stack.enter_context(tempfile.TemporaryDirectory())
+      compilation_cache.initialize_cache(tmp_dir)
+      stack.callback(lambda: compilation_cache.reset_cache()
+                     if compilation_cache.is_initialized() else None)
+
+  @classmethod
+  def tearDownClass(cls):
+    if FLAGS.jax_test_with_persistent_compilation_cache:
+      cls._compilation_cache_exit_stack.close()
+
   def rng(self):
     return self._rng
 

jax/experimental/compilation_cache/compilation_cache.py

@@ -254,3 +254,9 @@ def _hash_int_list(hash_obj, int_list):
 
 def is_initialized():
   return _cache is not None
+
+def reset_cache():
+  global _cache
+  assert is_initialized()
+  logger.info("Resetting cache at %s.", _cache._path)
+  _cache = None

tests/compilation_cache_test.py

@@ -61,9 +61,14 @@ def setUp(self):
       raise SkipTest("serialize executable only works on " +
                      ",".join(supported_platforms))
 
+    # Reset cache if already initialized by JaxTestCase
+    if cc.is_initialized():
+      cc.reset_cache()
+
   def tearDown(self):
-      super().tearDown()
-      cc._cache = None
+    if cc.is_initialized():
+      cc.reset_cache()
+    super().tearDown()
 
   def test_compile_options(self):
     compile_options_not_filled = xla_bridge.get_compile_options(