[pull] main from python:main

Doc/c-api/exceptions.rst

@@ -673,28 +673,46 @@ Signal Handling
       single: SIGINT (C macro)
       single: KeyboardInterrupt (built-in exception)
 
-   This function interacts with Python's signal handling.
+   Handle external interruptions, such as signals or activating a debugger,
+   whose processing has been delayed until it is safe
+   to run Python code and/or raise exceptions.
 
-   If the function is called from the main thread and under the main Python
-   interpreter, it checks whether a signal has been sent to the processes
-   and if so, invokes the corresponding signal handler.  If the :mod:`signal`
-   module is supported, this can invoke a signal handler written in Python.
+   For example, pressing :kbd:`Ctrl-C` causes a terminal to send the
+   :py:data:`signal.SIGINT` signal.
+   This function executes the corresponding Python signal handler, which,
+   by default, raises the :exc:`KeyboardInterrupt` exception.
 
-   The function attempts to handle all pending signals, and then returns ``0``.
-   However, if a Python signal handler raises an exception, the error
-   indicator is set and the function returns ``-1`` immediately (such that
-   other pending signals may not have been handled yet: they will be on the
-   next :c:func:`PyErr_CheckSignals()` invocation).
+   :c:func:`!PyErr_CheckSignals` should be called by long-running C code
+   frequently enough so that the response appears immediate to humans.
 
-   If the function is called from a non-main thread, or under a non-main
-   Python interpreter, it does nothing and returns ``0``.
+   Handlers invoked by this function currently include:
 
-   This function can be called by long-running C code that wants to
-   be interruptible by user requests (such as by pressing Ctrl-C).
+   - Signal handlers, including Python functions registered using
+     the :mod:`signal` module.
 
-   .. note::
-      The default Python signal handler for :c:macro:`!SIGINT` raises the
-      :exc:`KeyboardInterrupt` exception.
+     Signal handlers are only run in the main thread of the main interpreter.
+
+     (This is where the function got the name: originally, signals
+     were the only way to interrupt the interpreter.)
+
+   - Running the garbage collector, if necessary.
+
+   - Executing a pending :ref:`remote debugger <remote-debugging>` script.
+
+   If any handler raises an exception, immediately return ``-1`` with that
+   exception set.
+   Any remaining interruptions are left to be processed on the next
+   :c:func:`PyErr_CheckSignals()` invocation, if appropriate.
+
+   If all handlers finish successfully, or there are no handlers to run,
+   return ``0``.
+
+   .. versionchanged:: 3.12
+      This function may now invoke the garbage collector.
+
+   .. versionchanged:: 3.14
+      This function may now execute a remote debugger script, if remote
+      debugging is enabled.
 
 
 .. c:function:: void PyErr_SetInterrupt()

Lib/test/test_hashlib.py

@@ -134,8 +134,11 @@ def __init__(self, *args, **kwargs):
             algorithms.add(algorithm.lower())
 
         _blake2 = self._conditional_import_module('_blake2')
+        blake2_hashes = {'blake2b', 'blake2s'}
         if _blake2:
-            algorithms.update({'blake2b', 'blake2s'})
+            algorithms.update(blake2_hashes)
+        else:
+            algorithms.difference_update(blake2_hashes)
 
         self.constructors_to_test = {}
         for algorithm in algorithms:
@@ -232,7 +235,12 @@ def test_algorithms_available(self):
         # all available algorithms must be loadable, bpo-47101
         self.assertNotIn("undefined", hashlib.algorithms_available)
         for name in hashlib.algorithms_available:
-            digest = hashlib.new(name, usedforsecurity=False)
+            with self.subTest(name):
+                try:
+                    _ = hashlib.new(name, usedforsecurity=False)
+                except ValueError as exc:
+                    self.skip_if_blake2_not_builtin(name, exc)
+                    raise
 
     def test_usedforsecurity_true(self):
         hashlib.new("sha256", usedforsecurity=True)
@@ -504,6 +512,7 @@ def test_sha3_256_update_over_4gb(self):
         self.assertEqual(h.hexdigest(), "e2d4535e3b613135c14f2fe4e026d7ad8d569db44901740beffa30d430acb038")
 
     @requires_resource('cpu')
+    @requires_blake2
     def test_blake2_update_over_4gb(self):
         # blake2s or blake2b doesn't matter based on how our C code is structured, this tests the
         # common loop macro logic.
@@ -798,6 +807,12 @@ def test_case_sha512_3(self):
           "e718483d0ce769644e2e42c7bc15b4638e1f98b13b2044285632a803afa973eb"+
           "de0ff244877ea60a4cb0432ce577c31beb009c5c2c49aa2e4eadb217ad8cc09b")
 
+    def skip_if_blake2_not_builtin(self, name, skip_reason):
+        # blake2 builtins may be absent if python built with
+        # a subset of --with-builtin-hashlib-hashes or none.
+        if "blake2" in name and "blake2" not in builtin_hashes:
+            self.skipTest(skip_reason)
+
     def check_blake2(self, constructor, salt_size, person_size, key_size,
                      digest_size, max_offset):
         self.assertEqual(constructor.SALT_SIZE, salt_size)
@@ -1080,10 +1095,16 @@ def test_sha256_gil(self):
     def test_threaded_hashing_fast(self):
         # Same as test_threaded_hashing_slow() but only tests some functions
         # since otherwise test_hashlib.py becomes too slow during development.
-        for name in ['md5', 'sha1', 'sha256', 'sha3_256', 'blake2s']:
+        algos = ['md5', 'sha1', 'sha256', 'sha3_256', 'blake2s']
+        for name in algos:
             if constructor := getattr(hashlib, name, None):
                 with self.subTest(name):
-                    self.do_test_threaded_hashing(constructor, is_shake=False)
+                    try:
+                        self.do_test_threaded_hashing(constructor, is_shake=False)
+                    except ValueError as exc:
+                        self.skip_if_blake2_not_builtin(name, exc)
+                        raise
+
         if shake_128 := getattr(hashlib, 'shake_128', None):
             self.do_test_threaded_hashing(shake_128, is_shake=True)