Memory leak in request readline()

• Key: MODPYTHON-182
• Type: Bug
• Status: Closed
• Resolution: Fixed
• Priority: Major
• Assignee: Jim Gallacher
• Reporter: Jim Gallacher
• Component/s: core
• Affects Version/s: 3.2.x, 3.3.x, 3.2.10
• Fix Version/s: 3.3.1

Description

There is at least one memory leak request.readline(). I'm currently auditing the code so there may well be others.

I think the leak will only occur when the request body is incompletely read with readline, which is likely an unusual corner case. The following demostrates the leak:

Consider a request body consisting of:

'\n'.join([ 'a'*100 for i in xrange(0, 100) ])

and using this handler:


def handler(req):
    # Handler reads 20 lines but request contains 100 lines.
    # Since the body is not completely read, the buffer allocated
    # in requestobject.c req_readline is never freed.
    req.content_type = 'text/plain'
    count = 0
    for i in range(0, 20):
        line = req.readline()
        count += 1

    req.write('ok readline_partial: %d lines read' % count)
    return apache.OK

With this test setup I'm seeing a leak of approx 10k bytes per request.

Comments

[Graham Dumpleton]

Do the patches which been made on this cover all the problems that are known? If yes and we can mark as resolved, still need to add entry into change list of documentation.