upstream/mercurial-mirror Files · mercurial/cext/util.h

bookmark: add a test for a race condition on push...

bookmark: add a test for a race condition on push Bookmark pointing to unknown nodes are ignored. Later these ignored bookmarks are dropped when writing the file back on disk. On paper, this behavior should be fine, but with the current implementation, it can lead to unexpected bookmark deletions. In theory, to make sure writer as a consistent view, taking the lock also invalidate bookmark data we already loaded into memory. However this invalidation is incomplete. The data are stored in a `filecache` that preserve them if the bookmark related file are untouched. In practice, the bookmark data in memory also depends of the changelog content, because of the step checking if the bookmarks refers to a node known to the changelog. So if the bookmark data were loaded from an up to date bookmark file but filtered with an outdated changelog file this go undetected. This condition is fairly specific, but can occurs very often in practice. We introduce a test recreating the situation. The test comes in an independant changeset to show it actually reproduce the situation. The fix will come soon after. A large share of the initial investigation of this race condition was made by Valentin Gatien-Baron <valentin.gatienbaron@gmail.com>.

Augie Fackler - - Load All Authors

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      /*

       util.h - utility functions for interfacing with the various python APIs.

       This software may be used and distributed according to the terms of

       the GNU General Public License, incorporated herein by reference.

      */

      #ifndef _HG_UTIL_H_

      #define _HG_UTIL_H_

      #include "compat.h"

      #if PY_MAJOR_VERSION >= 3

      #define IS_PY3K

      #endif

      /* helper to switch things like string literal depending on Python version */

      #ifdef IS_PY3K

      #define PY23(py2, py3) py3

      #else

      #define PY23(py2, py3) py2

      #endif

      /* clang-format off */

      typedef struct {

      	PyObject_HEAD

      	char state;

      	int mode;

      	int size;

      	int mtime;

      } dirstateTupleObject;

      /* clang-format on */

      extern PyTypeObject dirstateTupleType;

      #define dirstate_tuple_check(op) (Py_TYPE(op) == &dirstateTupleType)

      #ifndef MIN

      #define MIN(a, b) (((a) < (b)) ? (a) : (b))

      #endif

      /* VC9 doesn't include bool and lacks stdbool.h based on my searching */

      #if defined(_MSC_VER) || __STDC_VERSION__ < 199901L

      #define true 1

      #define false 0

      typedef unsigned char bool;

      #else

      #include <stdbool.h>

      #endif

      static inline PyObject *_dict_new_presized(Py_ssize_t expected_size)

      {

      	/* _PyDict_NewPresized expects a minused parameter, but it actually

      	   creates a dictionary that's the nearest power of two bigger than the

      	   parameter. For example, with the initial minused = 1000, the

      	   dictionary created has size 1024. Of course in a lot of cases that

      	   can be greater than the maximum load factor Python's dict object

      	   expects (= 2/3), so as soon as we cross the threshold we'll resize

      	   anyway. So create a dictionary that's at least 3/2 the size. */

      	return _PyDict_NewPresized(((1 + expected_size) / 2) * 3);

      }

      /* Convert a PyInt or PyLong to a long. Returns false if there is an

         error, in which case an exception will already have been set. */

      static inline bool pylong_to_long(PyObject *pylong, long *out)

      {

      	*out = PyLong_AsLong(pylong);

      	/* Fast path to avoid hitting PyErr_Occurred if the value was obviously

      	 * not an error. */

      	if (*out != -1) {

      		return true;

      	}

      	return PyErr_Occurred() == NULL;

      }

      #endif /* _HG_UTIL_H_ */

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				/*
				util.h - utility functions for interfacing with the various python APIs.

				This software may be used and distributed according to the terms of
				the GNU General Public License, incorporated herein by reference.
				*/

				#ifndef _HG_UTIL_H_
				#define _HG_UTIL_H_

				#include "compat.h"

				#if PY_MAJOR_VERSION >= 3
				#define IS_PY3K
				#endif

				/* helper to switch things like string literal depending on Python version */
				#ifdef IS_PY3K
				#define PY23(py2, py3) py3
				#else
				#define PY23(py2, py3) py2
				#endif

				/* clang-format off */
				typedef struct {
				PyObject_HEAD
				char state;
				int mode;
				int size;
				int mtime;
				} dirstateTupleObject;
				/* clang-format on */

				extern PyTypeObject dirstateTupleType;
				#define dirstate_tuple_check(op) (Py_TYPE(op) == &dirstateTupleType)

				#ifndef MIN
				#define MIN(a, b) (((a) < (b)) ? (a) : (b))
				#endif
				/* VC9 doesn't include bool and lacks stdbool.h based on my searching */
				#if defined(_MSC_VER) \|\| __STDC_VERSION__ < 199901L
				#define true 1
				#define false 0
				typedef unsigned char bool;
				#else
				#include <stdbool.h>
				#endif

				static inline PyObject *_dict_new_presized(Py_ssize_t expected_size)
				{
				/* _PyDict_NewPresized expects a minused parameter, but it actually
				creates a dictionary that's the nearest power of two bigger than the
				parameter. For example, with the initial minused = 1000, the
				dictionary created has size 1024. Of course in a lot of cases that
				can be greater than the maximum load factor Python's dict object
				expects (= 2/3), so as soon as we cross the threshold we'll resize
				anyway. So create a dictionary that's at least 3/2 the size. */
				return _PyDict_NewPresized(((1 + expected_size) / 2) * 3);
				}

				/* Convert a PyInt or PyLong to a long. Returns false if there is an
				error, in which case an exception will already have been set. */
				static inline bool pylong_to_long(PyObject pylong, long out)
				{
				*out = PyLong_AsLong(pylong);
				/* Fast path to avoid hitting PyErr_Occurred if the value was obviously
				* not an error. */
				if (*out != -1) {
				return true;
				}
				return PyErr_Occurred() == NULL;
				}

				#endif /* _HG_UTIL_H_ */