diff -r 000000000000 -r ae805ac0140d python-2.5.2/win32/Tools/Scripts/combinerefs.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/python-2.5.2/win32/Tools/Scripts/combinerefs.py Fri Apr 03 17:19:34 2009 +0100 @@ -0,0 +1,127 @@ +#! /usr/bin/env python + +""" +combinerefs path + +A helper for analyzing PYTHONDUMPREFS output. + +When the PYTHONDUMPREFS envar is set in a debug build, at Python shutdown +time Py_Finalize() prints the list of all live objects twice: first it +prints the repr() of each object while the interpreter is still fully intact. +After cleaning up everything it can, it prints all remaining live objects +again, but the second time just prints their addresses, refcounts, and type +names (because the interpreter has been torn down, calling repr methods at +this point can get into infinite loops or blow up). + +Save all this output into a file, then run this script passing the path to +that file. The script finds both output chunks, combines them, then prints +a line of output for each object still alive at the end: + + address refcnt typename repr + +address is the address of the object, in whatever format the platform C +produces for a %p format code. + +refcnt is of the form + + "[" ref "]" + +when the object's refcount is the same in both PYTHONDUMPREFS output blocks, +or + + "[" ref_before "->" ref_after "]" + +if the refcount changed. + +typename is object->ob_type->tp_name, extracted from the second PYTHONDUMPREFS +output block. + +repr is repr(object), extracted from the first PYTHONDUMPREFS output block. +CAUTION: If object is a container type, it may not actually contain all the +objects shown in the repr: the repr was captured from the first output block, +and some of the containees may have been released since then. For example, +it's common for the line showing the dict of interned strings to display +strings that no longer exist at the end of Py_Finalize; this can be recognized +(albeit painfully) because such containees don't have a line of their own. + +The objects are listed in allocation order, with most-recently allocated +printed first, and the first object allocated printed last. + + +Simple examples: + + 00857060 [14] str '__len__' + +The str object '__len__' is alive at shutdown time, and both PYTHONDUMPREFS +output blocks said there were 14 references to it. This is probably due to +C modules that intern the string "__len__" and keep a reference to it in a +file static. + + 00857038 [46->5] tuple () + +46-5 = 41 references to the empty tuple were removed by the cleanup actions +between the times PYTHONDUMPREFS produced output. + + 00858028 [1025->1456] str '' + +The string '', which is used in dictobject.c to overwrite a real +key that gets deleted, grew several hundred references during cleanup. It +suggests that stuff did get removed from dicts by cleanup, but that the dicts +themselves are staying alive for some reason. """ + +import re +import sys + +# Generate lines from fileiter. If whilematch is true, continue reading +# while the regexp object pat matches line. If whilematch is false, lines +# are read so long as pat doesn't match them. In any case, the first line +# that doesn't match pat (when whilematch is true), or that does match pat +# (when whilematch is false), is lost, and fileiter will resume at the line +# following it. +def read(fileiter, pat, whilematch): + for line in fileiter: + if bool(pat.match(line)) == whilematch: + yield line + else: + break + +def combine(fname): + f = file(fname) + fi = iter(f) + + for line in read(fi, re.compile(r'^Remaining objects:$'), False): + pass + + crack = re.compile(r'([a-zA-Z\d]+) \[(\d+)\] (.*)') + addr2rc = {} + addr2guts = {} + before = 0 + for line in read(fi, re.compile(r'^Remaining object addresses:$'), False): + m = crack.match(line) + if m: + addr, addr2rc[addr], addr2guts[addr] = m.groups() + before += 1 + else: + print '??? skipped:', line + + after = 0 + for line in read(fi, crack, True): + after += 1 + m = crack.match(line) + assert m + addr, rc, guts = m.groups() # guts is type name here + if addr not in addr2rc: + print '??? new object created while tearing down:', line.rstrip() + continue + print addr, + if rc == addr2rc[addr]: + print '[%s]' % rc, + else: + print '[%s->%s]' % (addr2rc[addr], rc), + print guts, addr2guts[addr] + + f.close() + print "%d objects before, %d after" % (before, after) + +if __name__ == '__main__': + combine(sys.argv[1])