Fix windows

Author: wjsi

shared_memory/_winshmem.py

@@ -0,0 +1,132 @@
+import _winapi
+import ctypes.wintypes
+from ctypes import c_ulong, byref, sizeof
+
+SIZE_T = c_ulong
+
+INVALID_HANDLE_VALUE = ctypes.wintypes.HANDLE(-1)
+
+PAGE_READWRITE = 0x04
+
+FILE_MAP_COPY = 1
+FILE_MAP_WRITE = 2
+FILE_MAP_READ = 4
+
+
+_CreateFileMapping = ctypes.windll.kernel32.CreateFileMappingW
+_CreateFileMapping.argtypes = [
+    ctypes.wintypes.HANDLE,
+    ctypes.wintypes.LPVOID,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.LPWSTR,
+]
+_CreateFileMapping.restype = ctypes.wintypes.HANDLE
+
+
+def CreateFileMapping(hFile, lpFileMappingAttributes, flProtect,
+                      dwMaximumSizeHigh, dwMaximumSizeLow, lpName):
+    handle = _CreateFileMapping(hFile, lpFileMappingAttributes, flProtect,
+                                dwMaximumSizeHigh, dwMaximumSizeLow, lpName)
+    if handle is None:
+        last_err = _winapi.GetLastError()
+        raise OSError(last_err)
+    return handle
+
+
+_OpenFileMapping = ctypes.windll.kernel32.OpenFileMappingW
+_OpenFileMapping.argtypes = [
+    ctypes.wintypes.DWORD,
+    ctypes.wintypes.BOOL,
+    ctypes.wintypes.LPWSTR
+]
+_OpenFileMapping.restype = ctypes.wintypes.HANDLE
+
+
+def OpenFileMapping(dwDesiredAccess, hInheritedHandle, lpName):
+    handle = _OpenFileMapping(dwDesiredAccess, hInheritedHandle, lpName)
+    if handle is None:
+        last_err = _winapi.GetLastError()
+        if last_err == 2:
+            raise FileNotFoundError
+        else:
+            raise OSError(last_err)
+    return handle
+
+
+_MapViewOfFile = ctypes.windll.kernel32.MapViewOfFile
+_MapViewOfFile.argtypes = [
+   ctypes.wintypes.HANDLE,
+   ctypes.wintypes.DWORD,
+   ctypes.wintypes.DWORD,
+   ctypes.wintypes.DWORD,
+   SIZE_T
+]
+_MapViewOfFile.restype = ctypes.wintypes.LPVOID
+
+
+def MapViewOfFile(hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh,
+                  dwFileOffsetLow, dwNumberOfBytesToMap):
+    ptr = _MapViewOfFile(hFileMappingObject, dwDesiredAccess, dwFileOffsetHigh,
+                         dwFileOffsetLow, dwNumberOfBytesToMap)
+    if ptr is None:
+        last_err = _winapi.GetLastError()
+        raise OSError(last_err)
+    return ptr
+
+
+class MEMORY_BASIC_INFORMATION32(ctypes.Structure):
+    """
+    MEMORY_BASIC_INFORMATION contains information about a
+    particular region of memory. A call to kernel32.VirtualQuery()
+    populates this structure
+    """
+    _fields_ = [
+        ("BaseAddress", ctypes.wintypes.LPVOID),
+        ("AllocationBase", ctypes.wintypes.LPVOID),
+        ("AllocationProtect", ctypes.wintypes.DWORD),
+        ("RegionSize", ctypes.wintypes.DWORD),
+        ("State", ctypes.wintypes.DWORD),
+        ("Protect", ctypes.wintypes.DWORD),
+        ("Type", ctypes.wintypes.DWORD),
+    ]
+
+
+class MEMORY_BASIC_INFORMATION64(ctypes.Structure):
+    """
+    MEMORY_BASIC_INFORMATION contains information about a
+    particular region of memory. A call to kernel32.VirtualQuery()
+    populates this structure
+    """
+    _fields_ = [
+        ("BaseAddress", ctypes.wintypes.LPVOID),
+        ("AllocationBase", ctypes.wintypes.LPVOID),
+        ("AllocationProtect", ctypes.wintypes.DWORD),
+        ("__alignment1", ctypes.wintypes.DWORD),
+        ("RegionSize", ctypes.wintypes.DWORD),
+        ("State", ctypes.wintypes.DWORD),
+        ("Protect", ctypes.wintypes.DWORD),
+        ("Type", ctypes.wintypes.DWORD),
+        ("__alignment2", ctypes.wintypes.DWORD),
+    ]
+
+
+MEMORY_BASIC_INFORMATION = MEMORY_BASIC_INFORMATION64 if sizeof(ctypes.c_void_p) == 8 \
+    else MEMORY_BASIC_INFORMATION32
+
+
+VirtualQuery = ctypes.windll.kernel32.VirtualQuery
+VirtualQuery.argtypes = [
+    ctypes.wintypes.LPCVOID,
+    ctypes.POINTER(MEMORY_BASIC_INFORMATION),
+    SIZE_T
+]
+VirtualQuery.restype = SIZE_T
+
+
+def VirtualQuerySize(address):
+    mbi = MEMORY_BASIC_INFORMATION()
+    ret_size = VirtualQuery(address, byref(mbi), sizeof(mbi))
+    assert ret_size == sizeof(mbi)
+    return mbi.RegionSize

shared_memory/shared_memory.py

@@ -16,6 +16,7 @@
 
 if os.name == "nt":
     import _winapi
+    from . import _winshmem
     _USE_POSIX = False
 else:
     from . import _posixshmem
@@ -124,10 +125,10 @@ def __init__(self, name=None, create=False, size=0):
                     temp_name = _make_filename() if name is None else name
                     # Create and reserve shared memory block with this name
                     # until it can be attached to by mmap.
-                    h_map = _winapi.CreateFileMapping(
-                        _winapi.INVALID_HANDLE_VALUE,
+                    h_map = _winshmem.CreateFileMapping(
+                        _winshmem.INVALID_HANDLE_VALUE,
                         _winapi.NULL,
-                        _winapi.PAGE_READWRITE,
+                        _winshmem.PAGE_READWRITE,
                         (size >> 32) & 0xFFFFFFFF,
                         size & 0xFFFFFFFF,
                         temp_name
@@ -154,22 +155,22 @@ def __init__(self, name=None, create=False, size=0):
                 self._name = name
                 # Dynamically determine the existing named shared memory
                 # block's size which is likely a multiple of mmap.PAGESIZE.
-                h_map = _winapi.OpenFileMapping(
-                    _winapi.FILE_MAP_READ,
+                h_map = _winshmem.OpenFileMapping(
+                    _winshmem.FILE_MAP_READ,
                     False,
                     name
                 )
                 try:
-                    p_buf = _winapi.MapViewOfFile(
+                    p_buf = _winshmem.MapViewOfFile(
                         h_map,
-                        _winapi.FILE_MAP_READ,
+                        _winshmem.FILE_MAP_READ,
                         0,
                         0,
                         0
                     )
                 finally:
                     _winapi.CloseHandle(h_map)
-                size = _winapi.VirtualQuerySize(p_buf)
+                size = _winshmem.VirtualQuerySize(p_buf)
                 self._mmap = mmap.mmap(-1, size, tagname=name)
 
         self._size = size

shared_memory/tests/test_shared_memory.py

@@ -11,6 +11,7 @@
 import warnings
 from shared_memory.shared_memory import _USE_POSIX
 
+
 def strip_python_stderr(stderr):
     """Strip the stderr of a Python process from potential debug output
     emitted by the interpreter.