在此之前,这里(几乎)是您需要的一切:[Python 3.Docs]:ctypes- Python的外部函数库。没有解释 ctypes.wintypes ,但是您可以通过dir(ctypes.wintypes)
在 Python 控制台中运行来查看其导出。请注意,所有这些类型都是简单的 CTypes 类型,仅出于约定/一致性/可读性的目的而使用它们。
您更新的代码( code00.py ):
import sys
import ctypes as ct
import ctypes.wintypes as wt
import mmap
import msvcrt
def main(*argv):
FILE_MAP_ALL_ACCESS = 0x000F001F
INVALID_HANDLE_VALUE = -1
SHMEMSIZE = 0x100
PAGE_READWRITE = 0x04
kernel32_dll = ct.windll.kernel32
msvcrt_dll = ct.cdll.msvcrt # To be avoided
CreateFileMapping = kernel32_dll.CreateFileMappingW
CreateFileMapping.argtypes = (wt.HANDLE, wt.LPVOID, wt.DWORD, wt.DWORD, wt.DWORD, wt.LPCWSTR)
CreateFileMapping.restype = wt.HANDLE
MapViewOfFile = kernel32_dll.MapViewOfFile
MapViewOfFile.argtypes = (wt.HANDLE, wt.DWORD, wt.DWORD, wt.DWORD, ct.c_ulonglong)
MapViewOfFile.restype = wt.LPVOID
memcpy = msvcrt_dll.memcpy
memcpy.argtypes = (ct.c_void_p, ct.c_void_p, ct.c_size_t)
memcpy.restype = wt.LPVOID
RtlCopyMemory = kernel32_dll.RtlCopyMemory
RtlCopyMemory.argtypes = (wt.LPVOID, wt.LPCVOID, ct.c_ulonglong)
UnmapViewOfFile = kernel32_dll.UnmapViewOfFile
UnmapViewOfFile.argtypes = (wt.LPCVOID,)
UnmapViewOfFile.restype = wt.BOOL
CloseHandle = kernel32_dll.CloseHandle
CloseHandle.argtypes = (wt.HANDLE,)
CloseHandle.restype = wt.BOOL
GetLastError = kernel32_dll.GetLastError
file_mapping_name_ptr = ct.c_wchar_p("MyFileMappingObject")
msg = "Message from Python(ctypes) process"
msg_ptr = ct.c_wchar_p(msg)
mapping_handle = CreateFileMapping(INVALID_HANDLE_VALUE, 0, PAGE_READWRITE, 0, SHMEMSIZE, file_mapping_name_ptr)
print("Mapping object handle: 0x{:016X}".format(mapping_handle))
if not mapping_handle:
print("Could not open file mapping object: {:d}".format(GetLastError()))
raise ct.WinError()
mapped_view_ptr = MapViewOfFile(mapping_handle, FILE_MAP_ALL_ACCESS, 0, 0, SHMEMSIZE)
print("Mapped view addr: 0x{:016X}".format(mapped_view_ptr))
if not mapped_view_ptr:
print("Could not map view of file: {:d}".format(GetLastError()))
CloseHandle(mapping_handle)
raise ct.WinError()
byte_len = len(msg) * ct.sizeof(ct.c_wchar)
print("Message length: {:d} chars ({:d} bytes)".format(len(msg), byte_len))
memcpy(mapped_view_ptr, msg_ptr, byte_len) # Comment this line
RtlCopyMemory(mapped_view_ptr, msg_ptr, byte_len)
# Python vriant
shmem = mmap.mmap(0, 256, "MyFileMappingObject_ctypes", mmap.ACCESS_WRITE)
shmem.write(b"Message Python process")
print("Hit a key to clean all memory maps and exit...")
msvcrt.getch()
UnmapViewOfFile(mapped_view_ptr)
CloseHandle(mapping_handle)
shmem.close()
if __name__ == "__main__":
print("Python {0:s} {1:d}bit on {2:s}\n".format(" ".join(item.strip() for item in sys.version.split("\n")), 64 if sys.maxsize > 0x100000000 else 32, sys.platform))
main(*sys.argv[1:])
print("\nDone.")
:
为函数添加了 argtypes 和 restype 。详细信息可以在“ 指定所需的参数类型(函数原型) ”和“ 返回类型 ”部分中找到,当然也可以在函数声明的MS.Docs中看到。这是 ( UB ),尤其是在 64位上 :[[SO]:通过ctypes从Python调用的C函数返回错误值
的memcpy 的2次参数是一个 字符串,它是 相同的 字符* 地址(更不用说在 Python 3中 ,字符串 为wchar_t 基于),其 的memcpy 预计,这将可能也产生 UB
常数:
FILE_MAP_ALL_ACCESS 的值为 0x000F001F (从 VStu@R_502_2369@ 2015 打印出该值), 0x04 对应于 FILE_MAP_READ
将 INVALID_HANDLE_VALUE 的旧值转换为 HANDLE时 出错,将其更改为-1(如 handleapi.h所示 )
您正在使用 c_wchar_p 调用 CreateFileMappingA 。,将设置仅由1个的名ST从该映射对象提供的字符串的字符,因为每个 wchar_t的 由2个字节: 0×00 加上相应的 字符 值- “ 甲* ”将被表示为 0×00 0×41 (通常这是 正确-尤其是 0x00 部分,但在我们的例子中是)-因此 lpName 参数中的第二个 字符 (由于 little-endianness )将为 0x00 ( NUL ) __ *** _____
根据上面的页面:
通过访问标准C库cdll.msvcrt
将使用该库的过时版本,该版本可能与Python所使用的版本不兼容。
因此,我还添加了[MS.Docs]:RtlCopyMemory函数来替换 memcpy (您可以注释掉其行,我在此处保留它只是为了表明它可以工作),如示例中所示([MS.Docs]:创建命名共享内存),你采取了从代码,并试图将其转换([minwinbase.h : #36 ] #define CopyMemory RtlCopyMemory
)
将命名约定更改为与 Python 兼容([Python]:PEP 8-Python代码样式指南)
其他(非关键)更改(输出格式,为了更好的结构而移动代码行等等)
:
[cfati@CFATI-5510-0:e:\Work\Dev\StackOverflow\q048788549]>
“e:\Work\Dev\VEnvs\py_pc064_03.07.06_test0\Scripts\python.exe” code00.py Python 3.7.6 (tags/v3.7.6:43364a7ae0, Dec 19 2019, 00:42:30) [MSC v.1916 64 bit (AMD64)] 64bit on win32
Mapping object handle: 0x000000000000022C
Mapped view addr: 0x00000192912B0000
Message length: 35 chars (70 bytes)
Hit a key to clean all memory maps and exit...
Done.