Use setproctitle if available to show state (#696)

Co-authored-by: Bruno Oliveira <nicoddemus@gmail.com>

Author: eqvinox

.github/workflows/main.yml

@@ -17,6 +17,7 @@ jobs:
           - "py39-pytestlatest"
           - "py38-pytestmain"
           - "py38-psutil"
+          - "py38-setproctitle"
 
         os: [ubuntu-latest, windows-latest]
         include:
@@ -32,6 +33,8 @@ jobs:
             python: "3.8"
           - tox_env: "py38-psutil"
             python: "3.8"
+          - tox_env: "py38-setproctitle"
+            python: "3.8"
 
     steps:
     - uses: actions/checkout@v1

README.rst

@@ -317,6 +317,26 @@ Since version 2.0, the following functions are also available in the ``xdist`` m
         """
 
 
+Identifying workers from the system environment
+-----------------------------------------------
+
+*New in version UNRELEASED TBD FIXME*
+
+If the `setproctitle`_ package is installed, ``pytest-xdist`` will use it to
+update the process title (command line) on its workers to show their current
+state.  The titles used are ``[pytest-xdist running] file.py/node::id`` and
+``[pytest-xdist idle]``, visible in standard tools like ``ps`` and ``top`` on
+Linux, Mac OS X and BSD systems.  For Windows, please follow `setproctitle`_'s
+pointer regarding the Process Explorer tool.
+
+This is intended purely as an UX enhancement, e.g. to track down issues with
+long-running or CPU intensive tests.  Errors in changing the title are ignored
+silently.  Please try not to rely on the title format or title changes in
+external scripts.
+
+.. _`setproctitle`: https://pypi.org/project/setproctitle/
+
+
 Uniquely identifying the current test run
 -----------------------------------------
 

changelog/696.feature.rst

@@ -0,0 +1,3 @@
+On Linux, the process title now changes to indicate the current worker state (running/idle).
+
+Depends on the `setproctitle <https://pypi.org/project/setproctitle/>`__ package, which can be installed with ``pip install pytest-xdist[setproctitle]``.

setup.py

@@ -18,7 +18,11 @@
     platforms=["linux", "osx", "win32"],
     packages=find_packages(where="src"),
     package_dir={"": "src"},
-    extras_require={"testing": ["filelock"], "psutil": ["psutil>=3.0"]},
+    extras_require={
+        "testing": ["filelock"],
+        "psutil": ["psutil>=3.0"],
+        "setproctitle": ["setproctitle"],
+    },
     entry_points={
         "pytest11": ["xdist = xdist.plugin", "xdist.looponfail = xdist.looponfail"]
     },

src/xdist/remote.py

@@ -16,6 +16,21 @@
 
 from _pytest.config import _prepareconfig, Config
 
+try:
+    from setproctitle import setproctitle
+except ImportError:
+
+    def setproctitle(title):
+        pass
+
+
+def worker_title(title):
+    try:
+        setproctitle(title)
+    except Exception:
+        # changing the process name is very optional, no errors please
+        pass
+
 
 class WorkerInteractor:
     def __init__(self, config, channel):
@@ -85,9 +100,14 @@ def run_one_test(self, torun):
         else:
             nextitem = None
 
+        worker_title("[pytest-xdist running] %s" % item.nodeid)
+
         start = time.time()
         self.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
         duration = time.time() - start
+
+        worker_title("[pytest-xdist idle]")
+
         self.sendevent(
             "runtest_protocol_complete", item_index=self.item_index, duration=duration
         )

tox.ini

@@ -4,6 +4,7 @@ envlist=
   py{36,37,38,39}-pytestlatest
   py38-pytestmain
   py38-psutil
+  py38-setproctitle
 
 [testenv]
 extras = testing
@@ -21,6 +22,14 @@ deps = pytest
 commands =
   pytest {posargs:-k psutil}
 
+[testenv:py38-setproctitle]
+extras =
+  testing
+  setproctitle
+deps = pytest
+commands =
+  pytest {posargs}
+
 [testenv:release]
 changedir=
 decription = do a release, required posarg of the version number