diff options
| -rw-r--r-- | Lib/_android_support.py | 5 | ||||
| -rw-r--r-- | Lib/test/test_android.py | 32 |
2 files changed, 30 insertions, 7 deletions
diff --git a/Lib/_android_support.py b/Lib/_android_support.py index 066e547..353b34f 100644 --- a/Lib/_android_support.py +++ b/Lib/_android_support.py @@ -165,7 +165,10 @@ class Logcat: now = time() self._bucket_level += ( (now - self._prev_write_time) * MAX_BYTES_PER_SECOND) - self._bucket_level = min(self._bucket_level, BUCKET_SIZE) + + # If the bucket level is still below zero, the clock must have gone + # backwards, so reset it to zero and continue. + self._bucket_level = max(0, min(self._bucket_level, BUCKET_SIZE)) self._prev_write_time = now self._bucket_level -= PER_MESSAGE_OVERHEAD + len(tag) + len(message) diff --git a/Lib/test/test_android.py b/Lib/test/test_android.py index 09fa21c..2ef9f10 100644 --- a/Lib/test/test_android.py +++ b/Lib/test/test_android.py @@ -10,7 +10,7 @@ from array import array from contextlib import ExitStack, contextmanager from threading import Thread from test.support import LOOPBACK_TIMEOUT -from time import sleep, time +from time import time from unittest.mock import patch @@ -42,7 +42,8 @@ class TestAndroidOutput(unittest.TestCase): for line in self.logcat_process.stdout: self.logcat_queue.put(line.rstrip("\n")) self.logcat_process.stdout.close() - Thread(target=logcat_thread).start() + self.logcat_thread = Thread(target=logcat_thread) + self.logcat_thread.start() from ctypes import CDLL, c_char_p, c_int android_log_write = getattr(CDLL("liblog.so"), "__android_log_write") @@ -78,6 +79,7 @@ class TestAndroidOutput(unittest.TestCase): def tearDown(self): self.logcat_process.terminate() self.logcat_process.wait(LOOPBACK_TIMEOUT) + self.logcat_thread.join(LOOPBACK_TIMEOUT) @contextmanager def unbuffered(self, stream): @@ -369,6 +371,8 @@ class TestAndroidOutput(unittest.TestCase): ): stream.write(obj) + +class TestAndroidRateLimit(unittest.TestCase): def test_rate_limit(self): # https://cs.android.com/android/platform/superproject/+/android-14.0.0_r1:system/logging/liblog/include/log/log_read.h;l=39 PER_MESSAGE_OVERHEAD = 28 @@ -387,6 +391,19 @@ class TestAndroidOutput(unittest.TestCase): 1024 - PER_MESSAGE_OVERHEAD - len(tag) - len(message.format(0)) ) + "\n" + # To avoid depending on the performance of the test device, we mock the + # passage of time. + mock_now = time() + + def mock_time(): + # Avoid division by zero by simulating a small delay. + mock_sleep(0.0001) + return mock_now + + def mock_sleep(duration): + nonlocal mock_now + mock_now += duration + # See _android_support.py. The default values of these parameters work # well across a wide range of devices, but we'll use smaller values to # ensure a quick and reliable test that doesn't flood the log too much. @@ -395,21 +412,24 @@ class TestAndroidOutput(unittest.TestCase): with ( patch("_android_support.MAX_BYTES_PER_SECOND", MAX_KB_PER_SECOND * 1024), patch("_android_support.BUCKET_SIZE", BUCKET_KB * 1024), + patch("_android_support.sleep", mock_sleep), + patch("_android_support.time", mock_time), ): # Make sure the token bucket is full. - sleep(BUCKET_KB / MAX_KB_PER_SECOND) + stream.write("Initial message to reset _prev_write_time") + mock_sleep(BUCKET_KB / MAX_KB_PER_SECOND) line_num = 0 # Write BUCKET_KB messages, and return the rate at which they were # accepted in KB per second. def write_bucketful(): nonlocal line_num - start = time() + start = mock_time() max_line_num = line_num + BUCKET_KB while line_num < max_line_num: stream.write(message.format(line_num)) line_num += 1 - return BUCKET_KB / (time() - start) + return BUCKET_KB / (mock_time() - start) # The first bucketful should be written with minimal delay. The # factor of 2 here is not arbitrary: it verifies that the system can @@ -427,5 +447,5 @@ class TestAndroidOutput(unittest.TestCase): ) # Once the token bucket refills, we should go back to full speed. - sleep(BUCKET_KB / MAX_KB_PER_SECOND) + mock_sleep(BUCKET_KB / MAX_KB_PER_SECOND) self.assertGreater(write_bucketful(), MAX_KB_PER_SECOND * 2) |