Trac #33213: remove sage.interfaces.cleaner.

With sage-cleaner gone, it's a bit weird to leave this interface lying
around. Part of it is still used: our expect interface allows
instances to register themselves to be killed with the
expect_quitall() function in sage.interfaces.quit. To keep that
working (for the time being), I've moved/renamed the function that
registers a a process to register_spawned_process() in the module
sage.interfaces.quit.

src/doc/en/reference/interfaces/index.rst

@@ -108,7 +108,6 @@ and testing to make sure nothing funny is going on).
    sage/interfaces/tachyon
    sage/interfaces/tides
 
-   sage/interfaces/cleaner
    sage/interfaces/quit
    sage/interfaces/read_data
 

src/sage/interfaces/expect.py

@@ -48,7 +48,6 @@
 import time
 import gc
 from . import quit
-from . import cleaner
 from random import randrange
 
 import pexpect
@@ -515,7 +514,7 @@ def _start(self, alt_message=None, block_during_init=True):
             os.chdir(currentdir)
 
         if self._do_cleaner():
-            cleaner.cleaner(self._expect.pid, cmd)
+            quit.register_spawned_process(self._expect.pid, cmd)
 
         try:
             self._expect.expect(self._prompt)

src/sage/interfaces/qsieve.py

@@ -129,7 +129,7 @@ def data_to_list(out, n, time):
 
 from sage.interfaces.sagespawn import SageSpawn
 import pexpect
-from . import cleaner
+from . import quit
 class qsieve_nonblock:
     """
     A non-blocking version of Hart's quadratic sieve.
@@ -165,7 +165,7 @@ def __init__(self, n, time):
         env = os.environ.copy()
         env['TMPDIR'] = tmp_dir('qsieve')
         self._p = SageSpawn(cmd, env=env)
-        cleaner.cleaner(self._p.pid, 'QuadraticSieve')
+        quit.register_spawned_process(self._p.pid, 'QuadraticSieve')
         self._p.sendline(str(self._n)+'\n\n\n')
         self._done = False
         self._out = ''

src/sage/interfaces/quit.py

@@ -13,8 +13,27 @@
 
 import os
 
-expect_objects = []
+import atexit, tempfile
+_spd = tempfile.TemporaryDirectory()
+SAGE_SPAWNED_PROCESS_FILE = os.path.join(_spd.name, "spawned_processes")
+atexit.register(lambda: _spd.cleanup())
+
+def register_spawned_process(pid, cmd=''):
+    """
+    Write a line to the ``spawned_processes`` file with the given
+    ``pid`` and ``cmd``.
+    """
+    if cmd != '':
+        cmd = cmd.strip().split()[0]
+    # This is safe, since only this process writes to this file.
+    try:
+        with open(SAGE_SPAWNED_PROCESS_FILE, 'a') as o:
+            o.write('%s %s\n'%(pid, cmd))
+    except IOError:
+        pass
+
 
+expect_objects = []
 
 def expect_quitall(verbose=False):
     """
@@ -63,8 +82,6 @@ def kill_spawned_jobs(verbose=False):
 
         sage: sage.interfaces.quit.expect_quitall()
     """
-    from sage.interfaces.cleaner import SAGE_SPAWNED_PROCESS_FILE
-
     if not os.path.exists(SAGE_SPAWNED_PROCESS_FILE):
         return
     with open(SAGE_SPAWNED_PROCESS_FILE) as f:

src/sage/interfaces/rubik.py

@@ -34,7 +34,7 @@
 
 import pexpect
 import time
-from . import cleaner
+from . import quit
 
 from sage.cpython.string import bytes_to_str
 from sage.groups.perm_gps.cubegroup import index2singmaster
@@ -108,7 +108,7 @@ def __init__(self, verbose=False, wait=True):
 
     def start(self):
         child = pexpect.spawn(self.__cmd)
-        cleaner.cleaner(child.pid, self.__cmd)
+        quit.register_spawned_process(child.pid, self.__cmd)
         child.timeout = None
         self.child = child
         self._ready = False