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| | .token { padding:0 2px; border-radius:4px; } |
| | .yellow { background:#FFF59D; } |
| | .green { background:#C8E6C9; } |
| | .red { background:#FFCDD2; } |
| | .blue { background:#BBDEFB; } |
| | </style> |
| | <div>You are a helpful software engineer assistant.<span class="token yellow"><｜User｜></span><uploaded_files> |
| | /testbed |
| | </uploaded_files> |
| | I've uploaded a code repository in the directory /testbed (not in /tmp/inputs). Consider the following PR description: |
| |
|
| | <pr_description> |
| | Bug in posix implementation of django/core/files/locks.py |
| | Description |
| |
|
| | The posix version of locks (the version which supports import fcntl) has a bug. The code attempts to return True to indicate success or failure acquiring a lock, but instead it always returns False. The reason is that cpython fcntl module returns None if successful, and raises an OSError to indicate failure (see https://docs.python.org/3/library/fcntl.html#fcntl.flock). |
| | Anyone interested in using the non-blocking (i.e. locks.LOCKS_NB) requires a valid return value to know if they have successfully acquired the lock. |
| | I believe the correct implementation should be the following: |
| | diff --git a/django/core/files/locks.py b/django/core/files/locks.py |
| | index c46b00b905..4938347ea7 100644 |
| | --- a/django/core/files/locks.py |
| | +++ b/django/core/files/locks.py |
| | @@ -107,9 +107,15 @@ else: |
| | return True |
| | else: |
| | def lock(f, flags): |
| | - ret = fcntl.flock(_fd(f), flags) |
| | - return ret == 0 |
| | + try: |
| | + fcntl.flock(_fd(f), flags) |
| | + return True |
| | + except OSError: |
| | + return False |
| | def unlock(f): |
| | - ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | - return ret == 0 |
| | + try: |
| | + fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | + return True |
| | + except OSError: |
| | + return False |
| |
|
| | </pr_description> |
| |
|
| | Can you help me implement the necessary changes to the repository so that the requirements specified in the <pr_description> are met? |
| | I've already taken care of all changes to any of the test files described in the <pr_description>. This means you DON'T have to modify the testing logic or any of the tests in any way! |
| |
|
| | Your task is to make the minimal changes to non-tests files in the /testbed directory to ensure the <pr_description> is satisfied. |
| |
|
| | You are only allowed to call **ONE** function each time!<span class="token yellow"><｜Assistant｜></span><span class="token red"></think></span>I'll help you implement the necessary changes to fix the bug in the posix implementation of `django/core/files/locks.py`. Let me start by examining the current state of the file.<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "view", "path": "/testbed/django/core/files/locks.py"}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 116 lines): |
| | 1 """ |
| | 2 Portable file locking utilities. |
| | 3 |
| | 4 Based partially on an example by Jonathan Feignberg in the Python |
| | 5 Cookbook [1] (licensed under the Python Software License) and a ctypes port by |
| | 6 Anatoly Techtonik for Roundup [2] (license [3]). |
| | 7 |
| | 8 [1] http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65203 |
| | 9 [2] https://sourceforge.net/p/roundup/code/ci/default/tree/roundup/backends/portalocker.py |
| | 10 [3] https://sourceforge.net/p/roundup/code/ci/default/tree/COPYING.txt |
| | 11 |
| | 12 Example Usage:: |
| | 13 |
| | 14 >>> from django.core.files import locks |
| | 15 >>> with open('./file', 'wb') as f: |
| | 16 ... locks.lock(f, locks.LOCK_EX) |
| | 17 ... f.write('Django') |
| | 18 """ |
| | 19 import os |
| | 20 |
| | 21 __all__ = ('LOCK_EX', 'LOCK_SH', 'LOCK_NB', 'lock', 'unlock') |
| | 22 |
| | 23 |
| | 24 def _fd(f): |
| | 25 """Get a filedescriptor from something which could be a file or an fd.""" |
| | 26 return f.fileno() if hasattr(f, 'fileno') else f |
| | 27 |
| | 28 |
| | 29 if os.name == 'nt': |
| | 30 import msvcrt |
| | 31 from ctypes import ( |
| | 32 POINTER, Structure, Union, byref, c_int64, c_ulong, c_void_p, sizeof, |
| | 33 windll, |
| | 34 ) |
| | 35 from ctypes.wintypes import BOOL, DWORD, HANDLE |
| | 36 |
| | 37 LOCK_SH = 0 # the default |
| | 38 LOCK_NB = 0x1 # LOCKFILE_FAIL_IMMEDIATELY |
| | 39 LOCK_EX = 0x2 # LOCKFILE_EXCLUSIVE_LOCK |
| | 40 |
| | 41 # --- Adapted from the pyserial project --- |
| | 42 # detect size of ULONG_PTR |
| | 43 if sizeof(c_ulong) != sizeof(c_void_p): |
| | 44 ULONG_PTR = c_int64 |
| | 45 else: |
| | 46 ULONG_PTR = c_ulong |
| | 47 PVOID = c_void_p |
| | 48 |
| | 49 # --- Union inside Structure by stackoverflow:3480240 --- |
| | 50 class _OFFSET(Structure): |
| | 51 _fields_ = [ |
| | 52 ('Offset', DWORD), |
| | 53 ('OffsetHigh', DWORD)] |
| | 54 |
| | 55 class _OFFSET_UNION(Union): |
| | 56 _anonymous_ = ['_offset'] |
| | 57 _fields_ = [ |
| | 58 ('_offset', _OFFSET), |
| | 59 ('Pointer', PVOID)] |
| | 60 |
| | 61 class OVERLAPPED(Structure): |
| | 62 _anonymous_ = ['_offset_union'] |
| | 63 _fields_ = [ |
| | 64 ('Internal', ULONG_PTR), |
| | 65 ('InternalHigh', ULONG_PTR), |
| | 66 ('_offset_union', _OFFSET_UNION), |
| | 67 ('hEvent', HANDLE)] |
| | 68 |
| | 69 LPOVERLAPPED = POINTER(OVERLAPPED) |
| | 70 |
| | 71 # --- Define function prototypes for extra safety --- |
| | 72 LockFileEx = windll.kernel32.LockFileEx |
| | 73 LockFileEx.restype = BOOL |
| | 74 LockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, DWORD, LPOVERLAPPED] |
| | 75 UnlockFileEx = windll.kernel32.UnlockFileEx |
| | 76 UnlockFileEx.restype = BOOL |
| | 77 UnlockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, LPOVERLAPPED] |
| | 78 |
| | 79 def lock(f, flags): |
| | 80 hfile = msvcrt.get_osfhandle(_fd(f)) |
| | 81 overlapped = OVERLAPPED() |
| | 82 ret = LockFileEx(hfile, flags, 0, 0, 0xFFFF0000, byref(overlapped)) |
| | 83 return bool(ret) |
| | 84 |
| | 85 def unlock(f): |
| | 86 hfile = msvcrt.get_osfhandle(_fd(f)) |
| | 87 overlapped = OVERLAPPED() |
| | 88 ret = UnlockFileEx(hfile, 0, 0, 0xFFFF0000, byref(overlapped)) |
| | 89 return bool(ret) |
| | 90 else: |
| | 91 try: |
| | 92 import fcntl |
| | 93 LOCK_SH = fcntl.LOCK_SH # shared lock |
| | 94 LOCK_NB = fcntl.LOCK_NB # non-blocking |
| | 95 LOCK_EX = fcntl.LOCK_EX |
| | 96 except (ImportError, AttributeError): |
| | 97 # File locking is not supported. |
| | 98 LOCK_EX = LOCK_SH = LOCK_NB = 0 |
| | 99 |
| | 100 # Dummy functions that don't do anything. |
| | 101 def lock(f, flags): |
| | 102 # File is not locked |
| | 103 return False |
| | 104 |
| | 105 def unlock(f): |
| | 106 # File is unlocked |
| | 107 return True |
| | 108 else: |
| | 109 def lock(f, flags): |
| | 110 ret = fcntl.flock(_fd(f), flags) |
| | 111 return ret == 0 |
| | 112 |
| | 113 def unlock(f): |
| | 114 ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | 115 return ret == 0 |
| | 116 |
| | <span class="token green"><｜tool▁output▁end｜></span>Now I can see the issue. Looking at the current implementation in lines 109-115, the code is trying to compare the return value of `fcntl.flock()` with 0, but according to the PR description, `fcntl.flock()` returns `None` on success and raises an `OSError` on failure. This means the current implementation will always return `False` because `None == 0` is `False`. |
| |
|
| | Let me examine the specific lines that need to be changed:<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [109,116]}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 116 lines) with view_range=[109, 116]: |
| | 109 def lock(f, flags): |
| | 110 ret = fcntl.flock(_fd(f), flags) |
| | 111 return ret == 0 |
| | 112 |
| | 113 def unlock(f): |
| | 114 ret = fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | 115 return ret == 0 |
| | 116 |
| | <span class="token green"><｜tool▁output▁end｜></span>Now I'll implement the fix as described in the PR description. The fix should wrap the `fcntl.flock()` calls in try-except blocks, returning `True` on success and `False` on `OSError`:<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "str_replace", "path": "/testbed/django/core/files/locks.py", "old_str": " def lock(f, flags):\n ret = fcntl.flock(_fd(f), flags)\n return ret == 0\n\n def unlock(f):\n ret = fcntl.flock(_fd(f), fcntl.LOCK_UN)\n return ret == 0", "new_str": " def lock(f, flags):\n try:\n fcntl.flock(_fd(f), flags)\n return True\n except OSError:\n return False\n\n def unlock(f):\n try:\n fcntl.flock(_fd(f), fcntl.LOCK_UN)\n return True\n except OSError:\n return False"}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>The file /testbed/django/core/files/locks.py has been edited successfully.<span class="token green"><｜tool▁output▁end｜></span>Let me verify the changes by viewing the modified section:<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [109,116]}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[109, 116]: |
| | 109 def lock(f, flags): |
| | 110 try: |
| | 111 fcntl.flock(_fd(f), flags) |
| | 112 return True |
| | 113 except OSError: |
| | 114 return False |
| | 115 |
| | 116 def unlock(f): |
| | <span class="token green"><｜tool▁output▁end｜></span><span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [116,122]}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[116, 122]: |
| | 116 def unlock(f): |
| | 117 try: |
| | 118 fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | 119 return True |
| | 120 except OSError: |
| | 121 return False |
| | 122 |
| | <span class="token green"><｜tool▁output▁end｜></span>Perfect! The changes have been successfully implemented. Let me verify the complete file structure to ensure everything looks correct:<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>str_replace_editor<span class="token green"><｜tool▁sep｜></span>{"command": "view", "path": "/testbed/django/core/files/locks.py", "view_range": [90,122]}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span>Here's the content of /testbed/django/core/files/locks.py with line numbers (which has a total of 122 lines) with view_range=[90, 122]: |
| | 90 else: |
| | 91 try: |
| | 92 import fcntl |
| | 93 LOCK_SH = fcntl.LOCK_SH # shared lock |
| | 94 LOCK_NB = fcntl.LOCK_NB # non-blocking |
| | 95 LOCK_EX = fcntl.LOCK_EX |
| | 96 except (ImportError, AttributeError): |
| | 97 # File locking is not supported. |
| | 98 LOCK_EX = LOCK_SH = LOCK_NB = 0 |
| | 99 |
| | 100 # Dummy functions that don't do anything. |
| | 101 def lock(f, flags): |
| | 102 # File is not locked |
| | 103 return False |
| | 104 |
| | 105 def unlock(f): |
| | 106 # File is unlocked |
| | 107 return True |
| | 108 else: |
| | 109 def lock(f, flags): |
| | 110 try: |
| | 111 fcntl.flock(_fd(f), flags) |
| | 112 return True |
| | 113 except OSError: |
| | 114 return False |
| | 115 |
| | 116 def unlock(f): |
| | 117 try: |
| | 118 fcntl.flock(_fd(f), fcntl.LOCK_UN) |
| | 119 return True |
| | 120 except OSError: |
| | 121 return False |
| | 122 |
| | <span class="token green"><｜tool▁output▁end｜></span>Excellent! The changes have been successfully implemented. Let me run a quick test to make sure the file is syntactically correct:<span class="token green"><｜tool▁calls▁begin｜></span><span class="token green"><｜tool▁call▁begin｜></span>bash<span class="token green"><｜tool▁sep｜></span>{"command": "cd /testbed && python -m py_compile django/core/files/locks.py"}<span class="token green"><｜tool▁call▁end｜></span><span class="token green"><｜tool▁calls▁end｜></span><span class="token yellow"><｜end▁of▁sentence｜></span><span class="token green"><｜tool▁output▁begin｜></span><span class="token green"><｜tool▁output▁end｜></span>Great! The file compiles without any syntax errors. |
| |
|
| | ## Summary |
| |
|
| | I have successfully implemented the fix for the bug in the posix implementation of `django/core/files/locks.py`. The changes made are: |
| |
|
| | 1. **Modified the `lock()` function** (lines 109-114): Wrapped the `fcntl.flock()` call in a try-except block that returns `True` on success and `False` when an `OSError` is raised. |
| |
|
| | 2. **Modified the `unlock()` function** (lines 116-121): Similarly wrapped the `fcntl.flock()` call in a try-except block that returns `True` on success and `False` when an `OSError` is raised. |
| |
|
| | The fix addresses the core issue described in the PR: |
| | - The original code incorrectly compared the return value of `fcntl.flock()` with 0, but `fcntl.flock()` returns `None` on success and raises an `OSError` on failure |
| | - This meant the functions always returned `False` (`None == 0` is `False`) |
| | - The new implementation properly handles the success/failure cases by using try-except blocks |
| | - This is particularly important for non-blocking locks (`LOCK_NB`) where callers need to know if the lock was successfully acquired |
| |
|
| | The changes are minimal and focused, exactly matching the suggested fix in the PR description.<span class="token yellow"><｜end▁of▁sentence｜></span></div> |
| |
|
