[Win] Process IO priority constants + high priority

HISTORY.rst

@@ -10,6 +10,9 @@
   the number of physical CPUs in case /proc/cpuinfo does not provide this info.
 - 1458_: provide coloured test output. Also show failures on KeyboardInterrupt.
 - 1464_: various docfixes (always point to python3 doc, fix links, etc.).
+- 1473_: [Windows] process IO priority (ionice()) values are now exposed as 4
+  new constants: IOPRIO_VERYLOW, IOPRIO_LOW, IOPRIO_NORMAL, IOPRIO_HIGH.
+  Also it was not possible to set high I/O priority (not it is).
 - 1478_: add make command to re-run tests failed on last run.
 
 **Bug fixes**

docs/index.rst

@@ -1245,12 +1245,15 @@ Process class
       pionice(ioclass=<IOPriority.IOPRIO_CLASS_IDLE: 3>, value=0)
       >>>
 
-    On Windows only *ioclass* is used and it can be set to ``2`` (normal),
-    ``1`` (low) or ``0`` (very low). Also it returns an integer instead of a
-    named tuple.
+    On Windows only *ioclass* is used and it can be set to ``3`` (high),
+    ``2`` (normal), ``1`` (low) or ``0`` (very low).
+    Also it returns an integer instead of a named tuple.
 
     Availability: Linux and Windows > Vista
 
+    .. versionchanged::
+      Windows accepts ``3`` (high) value.
+
     .. versionchanged::
       3.0.0 on Python >= 3.4 the returned ``ioclass`` constant is an
       `enum <https://docs.python.org/3/library/enum.html#module-enum>`__
@@ -2157,10 +2160,19 @@ Constants
 
   Availability: Linux
 
-  .. versionchanged::
-    3.0.0 on Python >= 3.4 these constants are
-    `enums <https://docs.python.org/3/library/enum.html#module-enum>`__
-    instead of a plain integer.
+.. _const-ioprio:
+.. data:: IOPRIO_VERYLOW
+.. data:: IOPRIO_LOW
+.. data:: IOPRIO_NORMAL
+.. data:: IOPRIO_HIGH
+
+  A set of integers representing the I/O priority of a process on Linux.
+  They can be used in conjunction with :meth:`psutil.Process.ionice()` to get
+  or set process I/O priority.
+
+  Availability: Windows
+
+  .. versionadded:: 5.6.2
 
 .. _const-rlimit:
 .. data:: RLIM_INFINITY

psutil/__init__.py

@@ -146,6 +146,10 @@
     from ._psutil_windows import NORMAL_PRIORITY_CLASS  # NOQA
     from ._psutil_windows import REALTIME_PRIORITY_CLASS  # NOQA
     from ._pswindows import CONN_DELETE_TCB  # NOQA
+    from ._pswindows import IOPRIO_VERYLOW  # NOQA
+    from ._pswindows import IOPRIO_LOW  # NOQA
+    from ._pswindows import IOPRIO_NORMAL  # NOQA
+    from ._pswindows import IOPRIO_HIGH  # NOQA
 
 elif MACOS:
     from . import _psosx as _psplatform

psutil/_psutil_windows.c

@@ -3685,7 +3685,8 @@ void init_psutil_windows(void)
         module, "ERROR_INVALID_NAME", ERROR_INVALID_NAME);
     PyModule_AddIntConstant(
         module, "ERROR_SERVICE_DOES_NOT_EXIST", ERROR_SERVICE_DOES_NOT_EXIST);
-
+    PyModule_AddIntConstant(
+        module, "ERROR_PRIVILEGE_NOT_HELD", ERROR_PRIVILEGE_NOT_HELD);
     PyModule_AddIntConstant(
         module, "WINVER", PSUTIL_WINVER);
     PyModule_AddIntConstant(

psutil/_pswindows.py

@@ -63,11 +63,14 @@
 # http://msdn.microsoft.com/en-us/library/ms686219(v=vs.85).aspx
 __extra__all__ = [
     "win_service_iter", "win_service_get",
+    # Process priority
     "ABOVE_NORMAL_PRIORITY_CLASS", "BELOW_NORMAL_PRIORITY_CLASS",
-    "HIGH_PRIORITY_CLASS", "IDLE_PRIORITY_CLASS",
-    "NORMAL_PRIORITY_CLASS", "REALTIME_PRIORITY_CLASS",
-    "CONN_DELETE_TCB",
-    "AF_LINK",
+    "HIGH_PRIORITY_CLASS", "IDLE_PRIORITY_CLASS", "NORMAL_PRIORITY_CLASS",
+    "REALTIME_PRIORITY_CLASS",
+    # IO priority
+    "IOPRIO_VERYLOW", "IOPRIO_LOW", "IOPRIO_NORMAL", "IOPRIO_HIGH",
+    # others
+    "CONN_DELETE_TCB", "AF_LINK",
 ]
 
 
@@ -112,6 +115,19 @@ class Priority(enum.IntEnum):
 
     globals().update(Priority.__members__)
 
+if enum is None:
+    IOPRIO_VERYLOW = 0
+    IOPRIO_LOW = 1
+    IOPRIO_NORMAL = 2
+    IOPRIO_HIGH = 3
+else:
+    class IOPriority(enum.IntEnum):
+        IOPRIO_VERYLOW = 0
+        IOPRIO_LOW = 1
+        IOPRIO_NORMAL = 2
+        IOPRIO_HIGH = 3
+    globals().update(IOPriority.__members__)
+
 pinfo_map = dict(
     num_handles=0,
     ctx_switches=1,
@@ -656,8 +672,12 @@ def as_dict(self):
 def is_permission_err(exc):
     """Return True if this is a permission error."""
     assert isinstance(exc, OSError), exc
+    # On Python 2 OSError doesn't always have 'winerror'. Sometimes
+    # it does, in which case the original exception was WindowsError
+    # (which is a subclass of OSError).
     return exc.errno in (errno.EPERM, errno.EACCES) or \
-        exc.winerror == cext.ERROR_ACCESS_DENIED
+        getattr(exc, "winerror", -1) in (cext.ERROR_ACCESS_DENIED,
+                                         cext.ERROR_PRIVILEGE_NOT_HELD)
 
 
 def convert_oserror(exc, pid=None, name=None):
@@ -981,17 +1001,19 @@ def nice_set(self, value):
     if HAS_PROC_IO_PRIORITY:
         @wrap_exceptions
         def ionice_get(self):
-            return cext.proc_io_priority_get(self.pid)
+            ret = cext.proc_io_priority_get(self.pid)
+            if enum is not None:
+                ret = IOPriority(ret)
+            return ret
 
         @wrap_exceptions
-        def ionice_set(self, value, _):
-            if _:
-                raise TypeError("set_proc_ionice() on Windows takes only "
-                                "1 argument (2 given)")
-            if value not in (2, 1, 0):
-                raise ValueError("value must be 2 (normal), 1 (low) or 0 "
-                                 "(very low); got %r" % value)
-            return cext.proc_io_priority_set(self.pid, value)
+        def ionice_set(self, ioclass, value):
+            if value:
+                raise TypeError("value argument not accepted on Windows")
+            if ioclass not in (IOPRIO_VERYLOW, IOPRIO_LOW, IOPRIO_NORMAL,
+                               IOPRIO_HIGH):
+                raise ValueError("%s is not a valid priority" % ioclass)
+            cext.proc_io_priority_set(self.pid, ioclass)
 
     @wrap_exceptions
     def io_counters(self):

psutil/tests/test_process.py

@@ -380,29 +380,7 @@ def test_ionice_linux(self):
                                  (psutil.IOPRIO_CLASS_RT, 7))
                 with self.assertRaises(ValueError):
                     p.ionice(psutil.IOPRIO_CLASS_IDLE, value=8)
-        finally:
-            p.ionice(psutil.IOPRIO_CLASS_BE)
-
-    @unittest.skipIf(not HAS_IONICE, "not supported")
-    @unittest.skipIf(not WINDOWS, 'not supported on this win version')
-    def test_ionice_win(self):
-        p = psutil.Process()
-        original = p.ionice()
-        self.assertIsInstance(original, int)
-        try:
-            value = 0  # very low
-            if original == value:
-                value = 1  # low
-            p.ionice(value)
-            self.assertEqual(p.ionice(), value)
-        finally:
-            p.ionice(original)
-
-    @unittest.skipIf(not HAS_IONICE, "not supported")
-    def test_ionice_errs(self):
-        sproc = get_test_subprocess()
-        p = psutil.Process(sproc.pid)
-        if LINUX:
+            # errs
             self.assertRaises(ValueError, p.ionice, 2, 10)
             self.assertRaises(ValueError, p.ionice, 2, -1)
             self.assertRaises(ValueError, p.ionice, 4)
@@ -416,9 +394,36 @@ def test_ionice_errs(self):
             self.assertRaisesRegex(
                 ValueError, "'ioclass' argument must be specified",
                 p.ionice, value=1)
-        else:
-            self.assertRaises(ValueError, p.ionice, 3)
-            self.assertRaises(TypeError, p.ionice, 2, 1)
+        finally:
+            p.ionice(psutil.IOPRIO_CLASS_BE)
+
+    @unittest.skipIf(not HAS_IONICE, "not supported")
+    @unittest.skipIf(not WINDOWS, 'not supported on this win version')
+    def test_ionice_win(self):
+        p = psutil.Process()
+        self.assertEqual(p.ionice(), psutil.IOPRIO_NORMAL)
+        try:
+            # base
+            p.ionice(psutil.IOPRIO_VERYLOW)
+            self.assertEqual(p.ionice(), psutil.IOPRIO_VERYLOW)
+            p.ionice(psutil.IOPRIO_LOW)
+            self.assertEqual(p.ionice(), psutil.IOPRIO_LOW)
+            try:
+                p.ionice(psutil.IOPRIO_HIGH)
+            except psutil.AccessDenied:
+                pass
+            else:
+                self.assertEqual(p.ionice(), psutil.IOPRIO_HIGH)
+            # errs
+            self.assertRaisesRegex(
+                TypeError, "value argument not accepted on Windows",
+                p.ionice, psutil.IOPRIO_NORMAL, value=1)
+            self.assertRaisesRegex(
+                ValueError, "is not a valid priority",
+                p.ionice, psutil.IOPRIO_HIGH + 1)
+        finally:
+            p.ionice(psutil.IOPRIO_NORMAL)
+            self.assertEqual(p.ionice(), psutil.IOPRIO_NORMAL)
 
     @unittest.skipIf(not HAS_RLIMIT, "not supported")
     def test_rlimit_get(self):