Use in-memory notifications for workers

gunicorn/arbiter.py

@@ -556,7 +556,6 @@ def reap_workers(self):
                     worker = self.WORKERS.pop(wpid, None)
                     if not worker:
                         continue
-                    worker.tmp.close()
                     self.cfg.child_exit(self, worker)
         except OSError as e:
             if e.errno != errno.ECHILD:
@@ -596,10 +595,6 @@ def spawn_worker(self):
             self.WORKERS[pid] = worker
             return pid
 
-        # Do not inherit the temporary files of other workers
-        for sibling in self.WORKERS.values():
-            sibling.tmp.close()
-
         # Process Child
         worker.pid = os.getpid()
         try:
@@ -624,7 +619,6 @@ def spawn_worker(self):
         finally:
             self.log.info("Worker exiting (pid: %s)", worker.pid)
             try:
-                worker.tmp.close()
                 self.cfg.worker_exit(self, worker)
             except Exception:
                 self.log.warning("Exception during worker exit:\n%s",
@@ -664,7 +658,6 @@ def kill_worker(self, pid, sig):
             if e.errno == errno.ESRCH:
                 try:
                     worker = self.WORKERS.pop(pid)
-                    worker.tmp.close()
                     self.cfg.worker_exit(self, worker)
                     return
                 except (KeyError, OSError):

gunicorn/config.py

@@ -1113,28 +1113,6 @@ class Pidfile(Setting):
         """
 
 
-class WorkerTmpDir(Setting):
-    name = "worker_tmp_dir"
-    section = "Server Mechanics"
-    cli = ["--worker-tmp-dir"]
-    meta = "DIR"
-    validator = validate_string
-    default = None
-    desc = """\
-        A directory to use for the worker heartbeat temporary file.
-
-        If not set, the default temporary directory will be used.
-
-        .. note::
-           The current heartbeat system involves calling ``os.fchmod`` on
-           temporary file handlers and may block a worker for arbitrary time
-           if the directory is on a disk-backed filesystem.
-
-           See :ref:`blocking-os-fchmod` for more detailed information
-           and a solution for avoiding this problem.
-        """
-
-
 class User(Setting):
     name = "user"
     section = "Server Mechanics"

gunicorn/workers/base.py

@@ -61,7 +61,7 @@ def __init__(self, age, ppid, sockets, app, timeout, cfg, log):
 
         self.alive = True
         self.log = log
-        self.tmp = WorkerTmp(cfg)
+        self.tmp = WorkerTmp()
 
     def __str__(self):
         return "<Worker %s>" % self.pid
@@ -109,7 +109,6 @@ def init_process(self):
         # Prevent fd inheritance
         for s in self.sockets:
             util.close_on_exec(s)
-        util.close_on_exec(self.tmp.fileno())
 
         self.wait_fds = self.sockets + [self.PIPE[0]]
 

gunicorn/workers/workertmp.py

@@ -3,52 +3,16 @@
 # This file is part of gunicorn released under the MIT license.
 # See the NOTICE for more information.
 
-import os
+import multiprocessing
 import time
-import platform
-import tempfile
-
-from gunicorn import util
-
-PLATFORM = platform.system()
-IS_CYGWIN = PLATFORM.startswith('CYGWIN')
 
 
 class WorkerTmp(object):
-
-    def __init__(self, cfg):
-        old_umask = os.umask(cfg.umask)
-        fdir = cfg.worker_tmp_dir
-        if fdir and not os.path.isdir(fdir):
-            raise RuntimeError("%s doesn't exist. Can't create workertmp." % fdir)
-        fd, name = tempfile.mkstemp(prefix="wgunicorn-", dir=fdir)
-        os.umask(old_umask)
-
-        # change the owner and group of the file if the worker will run as
-        # a different user or group, so that the worker can modify the file
-        if cfg.uid != os.geteuid() or cfg.gid != os.getegid():
-            util.chown(name, cfg.uid, cfg.gid)
-
-        # unlink the file so we don't leak temporary files
-        try:
-            if not IS_CYGWIN:
-                util.unlink(name)
-            # In Python 3.8, open() emits RuntimeWarning if buffering=1 for binary mode.
-            # Because we never write to this file, pass 0 to switch buffering off.
-            self._tmp = os.fdopen(fd, 'w+b', 0)
-        except Exception:
-            os.close(fd)
-            raise
+    def __init__(self):
+        self._val = multiprocessing.Value('d', lock=False)
 
     def notify(self):
-        new_time = time.monotonic()
-        os.utime(self._tmp.fileno(), (new_time, new_time))
+        self._val.value = time.monotonic()
 
     def last_update(self):
-        return os.fstat(self._tmp.fileno()).st_mtime
-
-    def fileno(self):
-        return self._tmp.fileno()
-
-    def close(self):
-        return self._tmp.close()
+        return self._val.value

tests/test_arbiter.py

@@ -144,7 +144,6 @@ def test_arbiter_reap_workers(mock_os_waitpid):
     mock_worker = mock.Mock()
     arbiter.WORKERS = {42: mock_worker}
     arbiter.reap_workers()
-    mock_worker.tmp.close.assert_called_with()
     arbiter.cfg.child_exit.assert_called_with(arbiter, mock_worker)