Fix/CFMTech#60 : Allow to set CPU frequency externally

js-dieu · web-flow · commit 32d02354931b · 2022-10-22T15:42:11.000+02:00
Allow to set the CPU frequency from an environment variable.
Additionally, whenever psutil cannot resolve the cpu frequency, we use the same
fallback mechanism.
Added environment variables:
 - PYTEST_MONITOR_FORCE_CPU_FREQ (to overcome psutil)
 - PYTEST_MONITOR_CPU_FREQ (to set a CPU frequency value)
diff --git a/docs/sources/changelog.rst b/docs/sources/changelog.rst
@@ -2,6 +2,9 @@
 Changelog
 =========
 
+* :release:`1.6.5 <2022-10-16>`
+* :bug:`#60` Make sure that when psutil cannot fetch cpu frequency, the fallback mechanism is used.
+
 * :release:`1.6.4 <2022-05-18>`
 * :bug:`#56` Force the CPU frequency to 0 and emit a warning when unable to fetch it from the system.
 * :bug:`#54` Fix a bug that crashes the monitor upon non ASCII characters in commit log under Perforce. Improved P4 change number extraction.
diff --git a/docs/sources/configuration.rst b/docs/sources/configuration.rst
@@ -176,3 +176,19 @@ garbage collector, you just have to set the option `--no-gc` on the command line
 
     bash $> pytest --no-gc
 
+Forcing CPU frequency
+---------------------
+Under some circumstances, you may want to set the CPU frequency instead of asking `pytest-monitor` to compute it.
+To do so, you can either:
+ - ask `pytest-monitor` to use a preset value if it does not manage to compute the CPU frequency
+ - or to not try computing the CPU frequency and use your preset value.
+
+ Two environment variables controls this behaviour:
+ - `PYTEST_MONITOR_CPU_FREQ` allows you to preset a value for the CPU frequency. It must be a float convertible value.
+ This value will be used if `pytest-monitor` cannot compute the CPU frequency. Otherwise, `0.0` will be used as a
+ default value.
+ - `PYTEST_MONITOR_FORCE_CPU_FREQ` instructs `pytest-monitor` to try computing the CPU frequency or not. It expects an
+ integer convertible value. If not set, or if the integer representation of the value is `0`, then `pytest-monitor` will
+ try to compute the cpu frequency and defaults to the usecase describe for the previous environment variable.
+ If it set and not equal to `0`, then we use the value that the environment variable `PYTEST_MONITOR_CPU_FREQ` holds
+ (`0.0` if not set).
diff --git a/docs/sources/installation.rst b/docs/sources/installation.rst
@@ -11,13 +11,8 @@ Supported environments
 
 **You will need pytest 4.4+ to run pytest-monitor.**
 
-The following versions of Python are supported:
+We support all versions of Python >= 3.6.
 
-- Python 3.5
-- Python 3.6
-- Python 3.7
-
-Support for Python 3.8 is still experimental.
 
 From conda
 ----------
diff --git a/pytest_monitor/__init__.py b/pytest_monitor/__init__.py
@@ -1,2 +1,2 @@
-__version__ = "1.6.4"
+__version__ = "1.6.5"
 __author__ = "Jean-Sebastien Dieu"
diff --git a/pytest_monitor/sys_utils.py b/pytest_monitor/sys_utils.py
@@ -68,11 +68,14 @@ class ExecutionContext:
     def __init__(self):
         self.__cpu_count = multiprocessing.cpu_count()
         self.__cpu_vendor = _get_cpu_string()
-        try:
-            self.__cpu_freq_base = psutil.cpu_freq().current
-        except AttributeError:
-            warnings.warn("Unable to fetch CPU frequency. Forcing it to 0.")
-            self.__cpu_freq_base = 0
+        if int(os.environ.get('PYTEST_MONITOR_FORCE_CPU_FREQ', '0')):
+            self._read_cpu_freq_from_env()
+        else:
+            try:
+                self.__cpu_freq_base = psutil.cpu_freq().current
+            except (AttributeError, NotImplementedError, FileNotFoundError):
+                warnings.warn("Unable to fetch CPU frequency. Trying to read it from environment..")
+                self._read_cpu_freq_from_env()
         self.__proc_typ = platform.processor()
         self.__tot_mem = int(psutil.virtual_memory().total / 1024**2)
         self.__fqdn = socket.getfqdn()
@@ -81,6 +84,13 @@ def __init__(self):
         self.__system = '{} - {}'.format(platform.system(), platform.release())
         self.__py_ver = sys.version
 
+    def _read_cpu_freq_from_env(self):
+        try:
+            self.__cpu_freq_base = float(os.environ.get('PYTEST_MONITOR_CPU_FREQ', '0.'))
+        except (ValueError, TypeError):
+            warnings.warn("Wrong type/value while reading cpu frequency from environment. Forcing to 0.0.")
+            self.__cpu_freq_base = 0.0
+
     def to_dict(self):
         return dict(cpu_count=self.cpu_count,
                     cpu_frequency=self.cpu_frequency,
diff --git a/tests/test_monitor_context.py b/tests/test_monitor_context.py
@@ -1,42 +1,135 @@
 import mock
+import os
 import pathlib
+import pytest
 import sqlite3
 
 
-@mock.patch('pytest_monitor.sys_utils.psutil.cpu_freq', return_value=None)
-def test_when_cpu_freq_cannot_fetch_frequency(cpu_freq_mock, testdir):
-    """Make sure that pytest-monitor does the job when we have issue in collecing context resources"""
+CPU_FREQ_PATH = 'pytest_monitor.sys_utils.psutil.cpu_freq'
+
+TEST_CONTENT = """
+import time
+
+
+def test_ok():
+    time.sleep(0.5)
+    x = ['a' * i for i in range(100)]
+    assert len(x) == 100
+"""
+
+def get_nb_metrics_with_cpu_freq(path):
+    pymon_path = pathlib.Path(str(path)) / '.pymon'
+    db = sqlite3.connect(path.as_posix())
+    cursor = db.cursor()
+    cursor.execute('SELECT ITEM FROM TEST_METRICS;')
+    nb_metrics = len(cursor.fetchall())
+    cursor = db.cursor()
+    cursor.execute('SELECT CPU_FREQUENCY_MHZ FROM EXECUTION_CONTEXTS;')
+    rows = cursor.fetchall()
+    assert 1 == len(rows)
+    cpu_freq = rows[0][0]
+    return nb_metrics, cpu_freq
+
+
+def test_force_cpu_freq_set_0_use_psutil(testdir):
+    """Test that when force mode is set, we do not call psutil to fetch CPU's frequency"""
+
     # create a temporary pytest test module
-    testdir.makepyfile("""
-    import time
+    testdir.makepyfile(TEST_CONTENT)
 
+    with mock.patch(CPU_FREQ_PATH, return_value=1500) as cpu_freq_mock:
+        os.environ['PYTEST_MONITOR_FORCE_CPU_FREQ'] = '0'
+        os.environ['PYTEST_MONITOR_CPU_FREQ'] = '3000'
+        # run pytest with the following cmd args
+        result = testdir.runpytest('-vv')
+        del os.environ['PYTEST_MONITOR_FORCE_CPU_FREQ']
+        del os.environ['PYTEST_MONITOR_CPU_FREQ']
+        cpu_freq_mock.assert_called()
 
-    def test_ok():
-        time.sleep(0.5)
-        x = ['a' * i for i in range(100)]
-        assert len(x) == 100
+    # fnmatch_lines does an assertion internally
+    result.stdout.fnmatch_lines(['*::test_ok PASSED*'])
+    # make sure that that we get a '0' exit code for the test suite
+    result.assert_outcomes(passed=1)
 
-""")
+    assert 1, 3000 == get_nb_metrics_with_cpu_freq(testdir)
 
-    # run pytest with the following cmd args
-    result = testdir.runpytest('-vv')
+
+def test_force_cpu_freq(testdir):
+    """Test that when force mode is set, we do not call psutil to fetch CPU's frequency"""
+
+    # create a temporary pytest test module
+    testdir.makepyfile(TEST_CONTENT)
+
+    with mock.patch(CPU_FREQ_PATH, return_value=1500) as cpu_freq_mock:
+        os.environ['PYTEST_MONITOR_FORCE_CPU_FREQ'] = '1'
+        os.environ['PYTEST_MONITOR_CPU_FREQ'] = '3000'
+        # run pytest with the following cmd args
+        result = testdir.runpytest('-vv')
+        del os.environ['PYTEST_MONITOR_FORCE_CPU_FREQ']
+        del os.environ['PYTEST_MONITOR_CPU_FREQ']
+        cpu_freq_mock.assert_not_called()
 
     # fnmatch_lines does an assertion internally
     result.stdout.fnmatch_lines(['*::test_ok PASSED*'])
+    # make sure that that we get a '0' exit code for the test suite
+    result.assert_outcomes(passed=1)
+
+    assert 1, 3000 == get_nb_metrics_with_cpu_freq(testdir)
+    
+
+@pytest.mark.parametrize('effect', [AttributeError, NotImplementedError, FileNotFoundError])
+def test_when_cpu_freq_cannot_fetch_frequency_set_freq_by_using_fallback(effect, testdir):
+    """Make sure that pytest-monitor fallback takes value of CPU FREQ from special env var"""
+    # create a temporary pytest test module
+    testdir.makepyfile(TEST_CONTENT)
 
-    pymon_path = pathlib.Path(str(testdir)) / '.pymon'
-    assert pymon_path.exists()
+    with mock.patch(CPU_FREQ_PATH, side_effect=effect) as cpu_freq_mock:
+        os.environ['PYTEST_MONITOR_CPU_FREQ'] = '3000'
+        # run pytest with the following cmd args
+        result = testdir.runpytest('-vv')
+        del os.environ['PYTEST_MONITOR_CPU_FREQ']
+        cpu_freq_mock.assert_called()
 
+    # fnmatch_lines does an assertion internally
+    result.stdout.fnmatch_lines(['*::test_ok PASSED*'])
     # make sure that that we get a '0' exit code for the test suite
     result.assert_outcomes(passed=1)
 
-    db = sqlite3.connect(str(pymon_path))
-    cursor = db.cursor()
-    cursor.execute('SELECT ITEM FROM TEST_METRICS;')
-    assert 1 == len(cursor.fetchall())  # current test
-    cursor = db.cursor()
-    cursor.execute('SELECT CPU_FREQUENCY_MHZ FROM EXECUTION_CONTEXTS;')
-    rows = cursor.fetchall()
-    assert 1 == len(rows)
-    assert rows[0][0] == 0
+    assert 1, 3000 == get_nb_metrics_with_cpu_freq(testdir)
+
+    
+@pytest.mark.parametrize('effect', [AttributeError, NotImplementedError, FileNotFoundError])
+def test_when_cpu_freq_cannot_fetch_frequency_set_freq_to_0(effect, testdir):
+    """Make sure that pytest-monitor's fallback mechanism is efficient enough. """
+    # create a temporary pytest test module
+    testdir.makepyfile(TEST_CONTENT)
+
+    with mock.patch(CPU_FREQ_PATH, side_effect=effect) as cpu_freq_mock:
+        # run pytest with the following cmd args
+        result = testdir.runpytest('-vv')
+        cpu_freq_mock.assert_called()
+
+    # fnmatch_lines does an assertion internally
+    result.stdout.fnmatch_lines(['*::test_ok PASSED*'])
+    # make sure that that we get a '0' exit code for the test suite
+    result.assert_outcomes(passed=1)
+
+    assert 1, 0 == get_nb_metrics_with_cpu_freq(testdir)
     
+
+@mock.patch('pytest_monitor.sys_utils.psutil.cpu_freq', return_value=None)
+def test_when_cpu_freq_cannot_fetch_frequency(cpu_freq_mock, testdir):
+    """Make sure that pytest-monitor does the job when we have issue in collecing context resources"""
+    # create a temporary pytest test module
+    testdir.makepyfile(TEST_CONTENT)
+
+    # run pytest with the following cmd args
+    result = testdir.runpytest('-vv')
+
+    # fnmatch_lines does an assertion internally
+    result.stdout.fnmatch_lines(['*::test_ok PASSED*'])
+    # make sure that that we get a '0' exit code for the test suite
+    result.assert_outcomes(passed=1)
+
+    assert 1, 0 == get_nb_metrics_with_cpu_freq(testdir)
+

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`		`-__version__ = "1.6.4"`
	`1`	`+__version__ = "1.6.5"`
`2`	`2`	`__author__ = "Jean-Sebastien Dieu"`