commit: 6b08846736ebf8a224f8aad2a5b17baf66fec1e0
Author: Zac Medico <zmedico <AT> gentoo <DOT> org>
AuthorDate: Sat Aug 8 02:19:31 2020 +0000
Commit: Zac Medico <zmedico <AT> gentoo <DOT> org>
CommitDate: Sun Aug 9 00:48:12 2020 +0000
URL: https://gitweb.gentoo.org/proj/portage.git/commit/?id=6b088467
Add cached portage.getpid() function
Since getpid is a syscall, cache results, and update them
via an after fork hook.
Signed-off-by: Zac Medico <zmedico <AT> gentoo.org>
lib/portage/__init__.py | 16 ++++++++++++++++
lib/portage/tests/process/test_AsyncFunction.py | 24 ++++++++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/lib/portage/__init__.py b/lib/portage/__init__.py
index 916c93510..4d4b590a8 100644
--- a/lib/portage/__init__.py
+++ b/lib/portage/__init__.py
@@ -14,6 +14,7 @@ try:
if not hasattr(errno, 'ESTALE'):
# ESTALE may not be defined on some systems, such as interix.
errno.ESTALE = -1
+ import multiprocessing.util
import re
import types
import platform
@@ -368,6 +369,21 @@ _internal_caller = False
_sync_mode = False
+class _ForkWatcher:
+ @staticmethod
+ def hook(_ForkWatcher):
+ _ForkWatcher.current_pid = _os.getpid()
+
+_ForkWatcher.hook(_ForkWatcher)
+
+multiprocessing.util.register_after_fork(_ForkWatcher, _ForkWatcher.hook)
+
+def getpid():
+ """
+ Cached version of os.getpid(). ForkProcess updates the cache.
+ """
+ return _ForkWatcher.current_pid
+
def _get_stdin():
"""
Buggy code in python's multiprocessing/process.py closes sys.stdin
diff --git a/lib/portage/tests/process/test_AsyncFunction.py
b/lib/portage/tests/process/test_AsyncFunction.py
index 55857026d..3b360e02f 100644
--- a/lib/portage/tests/process/test_AsyncFunction.py
+++ b/lib/portage/tests/process/test_AsyncFunction.py
@@ -3,6 +3,7 @@
import sys
+import portage
from portage import os
from portage.tests import TestCase
from portage.util._async.AsyncFunction import AsyncFunction
@@ -36,3 +37,26 @@ class AsyncFunctionTestCase(TestCase):
def testAsyncFunctionStdin(self):
loop = asyncio._wrap_loop()
loop.run_until_complete(self._testAsyncFunctionStdin(loop))
+
+ def _test_getpid_fork(self):
+ """
+ Verify that portage.getpid() cache is updated in a forked child
process.
+ """
+ loop = asyncio._wrap_loop()
+ proc = AsyncFunction(scheduler=loop, target=portage.getpid)
+ proc.start()
+ proc.wait()
+ self.assertEqual(proc.pid, proc.result)
+
+ def test_getpid_fork(self):
+ self._test_getpid_fork()
+
+ def test_getpid_double_fork(self):
+ """
+ Verify that portage.getpid() cache is updated correctly after
+ two forks.
+ """
+ loop = asyncio._wrap_loop()
+ proc = AsyncFunction(scheduler=loop,
target=self._test_getpid_fork)
+ proc.start()
+ self.assertEqual(proc.wait(), 0)
