[pypy-svn] r30353 - pypy/dist/pypy/module/mmap

[rhymes at codespeak.net]

Author: rhymes
Date: Sat Jul 22 15:22:18 2006
New Revision: 30353

Modified:
   pypy/dist/pypy/module/mmap/interp_mmap.py
Log:
fix flush() under Linux.

Linux has an alignment bug with msync() syscall so the address has to be padded. Also worked around the lack of addressof() in rctypes using the Python API primitive that addressof() in ctypes calls.


Modified: pypy/dist/pypy/module/mmap/interp_mmap.py
==============================================================================
--- pypy/dist/pypy/module/mmap/interp_mmap.py	(original)
+++ pypy/dist/pypy/module/mmap/interp_mmap.py	Sat Jul 22 15:22:18 2006
@@ -14,7 +14,7 @@
 
 _POSIX = os.name == "posix"
 _MS_WINDOWS = os.name == "nt"
-_FREEBSD = "freebsd" in sys.platform
+_LINUX = "linux" in sys.platform
 _64BIT = "64bit" in platform.architecture()[0]
 
 class CConfig:
@@ -70,6 +70,16 @@
 libc.msync.argtypes = [c_char_p, size_t, c_int]
 libc.msync.restype = c_int
 
+## LINUX msync syscall helper stuff
+# you don't have addressof() in rctypes so I looked up the implementation
+# of addressof in ctypes source and come up with this.
+pythonapi.PyLong_FromVoidPtr.argtypes = [c_char_p]
+pythonapi.PyLong_FromVoidPtr.restype = c_int
+# we also need to alias msync to take a c_void_p instead of c_char_p
+linux_msync = libc["msync"]
+linux_msync.argtypes = [c_void_p, size_t, c_int]
+linux_msync.restype = c_int
+
 if _POSIX:
     def _get_page_size():
         return libc.getpagesize()
@@ -374,7 +384,13 @@
             #     res = FlushViewOfFile(data, size)
             #     return res
             if _POSIX:
-                res = libc.msync(data, size, MS_SYNC)
+                if _LINUX:
+                    # padding of the address
+                    value = pythonapi.PyLong_FromVoidPtr(data)
+                    padded_value = value & ~(PAGESIZE - 1)
+                    res = linux_msync(c_void_p(padded_value), size, MS_SYNC)
+                else:
+                    res = libc.msync(data, size, MS_SYNC)
                 if res == -1:
                     raise OperationError(self.space.w_EnvironmentError,
                         self.space.wrap(_get_error_msg()))