jax.debug.callback now passes arguments as jax.Arrays

Prior to this change the behavior in eager and under jax.jit was inconsistent

    >>> (lambda *args: jax.debug.callback(print, *args))([42])
    [42]
    >>> jax.jit(lambda *args: jax.debug.callback(print, *args))([42])
    [array(42, dtype=int32)]

It was also inconsistent with other callback APIs, which cast the arguments
to jax.Arrays.

Closes #20627.

PiperOrigin-RevId: 626461904

CHANGELOG.md

@@ -14,10 +14,11 @@ Remember to align the itemized text with the first line of an item within a list
     adopted by NumPy.
 
 * Changes
-  * {func}`jax.pure_callback` and {func}`jax.experimental.io_callback`
-    now use {class}`jax.Array` instead of {class}`np.ndarray`. You can recover
-    the old behavior by transforming the arguments via
-    `jax.tree.map(np.asarray, args)` before passing them to the callback.
+  * {func}`jax.pure_callback`, {func}`jax.experimental.io_callback`
+    and {func}`jax.debug.callback` now use {class}`jax.Array` instead
+    of {class}`np.ndarray`. You can recover the old behavior by transforming
+    the arguments via `jax.tree.map(np.asarray, args)` before passing them
+    to the callback.
   * `complex_arr.astype(bool)` now follows the same semantics as NumPy, returning
     False where `complex_arr` is equal to `0 + 0j`, and True otherwise.
   * Async dispatch expensive computations on the CPU backend. This only applies

jax/_src/debugging.py

@@ -18,6 +18,7 @@ from __future__ import annotations
 import importlib.util
 from collections.abc import Sequence
 import functools
+import logging
 import string
 import sys
 from typing import Any, Callable, Union
@@ -25,6 +26,7 @@ import weakref
 
 import numpy as np
 
+import jax
 import jax.numpy as jnp
 from jax import lax
 
@@ -45,6 +47,8 @@ from jax._src.lib.mlir.dialects import hlo
 from jax._src.sharding import Sharding
 from jax._src.sharding_impls import NamedSharding, parse_flatten_op_sharding
 
+logger = logging.getLogger(__name__)
+
 class DebugEffect(effects.Effect):
   __str__ = lambda self: "Debug"
 debug_effect = DebugEffect()
@@ -73,7 +77,14 @@ map, unsafe_map = util.safe_map, map
 def debug_callback_impl(*args, callback: Callable[..., Any],
                         effect: DebugEffect):
   del effect
-  callback(*args)
+  cpu_device, *_ = jax.local_devices(backend="cpu")
+  args = jax.device_put(args, cpu_device)
+  with jax.default_device(cpu_device):
+    try:
+      callback(*args)
+    except BaseException:
+      logger.exception("jax.debug_callback failed")
+      raise
   return ()
 
 @debug_callback_p.def_effectful_abstract_eval

tests/debugger_test.py

@@ -110,7 +110,7 @@ class CliDebuggerTest(jtu.JaxTestCase):
       return y
     expected = _format_multiline(r"""
     Entering jdb:
-    (jdb) array(2., dtype=float32)
+    (jdb) Array(2., dtype=float32)
     (jdb) """)
     f(jnp.array(2., jnp.float32))
     jax.effects_barrier()
@@ -126,7 +126,7 @@ class CliDebuggerTest(jtu.JaxTestCase):
       return y
     expected = _format_multiline(r"""
     Entering jdb:
-    (jdb) (array(2., dtype=float32), array(3., dtype=float32))
+    (jdb) (Array(2., dtype=float32), Array(3., dtype=float32))
     (jdb) """)
     f(jnp.array(2., jnp.float32))
     jax.effects_barrier()
@@ -196,7 +196,7 @@ class CliDebuggerTest(jtu.JaxTestCase):
     ->        y = f\(x\)
               return jnp\.exp\(y\)
     .*
-    \(jdb\) array\(2\., dtype=float32\)
+    \(jdb\) Array\(2\., dtype=float32\)
     \(jdb\) > .*debugger_test\.py\([0-9]+\)
             def f\(x\):
               y = jnp\.sin\(x\)
@@ -225,9 +225,9 @@ class CliDebuggerTest(jtu.JaxTestCase):
       return jnp.exp(y)
     expected = _format_multiline(r"""
     Entering jdb:
-    (jdb) array(3., dtype=float32)
+    (jdb) Array(3., dtype=float32)
     (jdb) Entering jdb:
-    (jdb) array(6., dtype=float32)
+    (jdb) Array(6., dtype=float32)
     (jdb) """)
     g(jnp.array(2., jnp.float32))
     jax.effects_barrier()
@@ -249,9 +249,9 @@ class CliDebuggerTest(jtu.JaxTestCase):
       return jnp.exp(y)
     expected = _format_multiline(r"""
     Entering jdb:
-    (jdb) array(1., dtype=float32)
+    (jdb) Array(1., dtype=float32)
     (jdb) Entering jdb:
-    (jdb) array(2., dtype=float32)
+    (jdb) Array(2., dtype=float32)
     (jdb) """)
     g(jnp.arange(2., dtype=jnp.float32))
     jax.effects_barrier()
@@ -274,9 +274,9 @@ class CliDebuggerTest(jtu.JaxTestCase):
       return jnp.exp(y)
     expected = _format_multiline(r"""
     Entering jdb:
-    \(jdb\) array\(.*, dtype=float32\)
+    \(jdb\) Array\(.*, dtype=float32\)
     \(jdb\) Entering jdb:
-    \(jdb\) array\(.*, dtype=float32\)
+    \(jdb\) Array\(.*, dtype=float32\)
     \(jdb\) """)
     g(jnp.arange(2., dtype=jnp.float32))
     jax.effects_barrier()
@@ -302,7 +302,7 @@ class CliDebuggerTest(jtu.JaxTestCase):
         out_shardings=jax.sharding.PartitionSpec("dev"),
     )
     with jax.sharding.Mesh(np.array(jax.devices()), ["dev"]):
-      arr = (1 + np.arange(8)).astype(np.int32)
+      arr = (1 + jnp.arange(8)).astype(np.int32)
       expected = _format_multiline(r"""
       Entering jdb:
       \(jdb\) {}

tests/debugging_primitives_test.py

@@ -170,7 +170,7 @@ class DebugPrintTest(jtu.JaxTestCase):
     with jtu.capture_stdout() as output:
       f(np.array(2, np.int32))
       jax.effects_barrier()
-    self.assertEqual(output(), f"x: {str(dict(foo=np.array(2, np.int32)))}\n")
+    self.assertEqual(output(), f"x: {str(dict(foo=jnp.array(2, np.int32)))}\n")
 
   def test_debug_print_should_use_default_layout(self):
     data = np.array(