[Python-Dev] FW: [Python-Help] Python threads with suncc (Forte 6.1) compiler (original) (raw)

Tim Peters tim.one@home.com
Sun, 5 Aug 2001 18:50:06 -0400

[Michael Hudson]

... (1) Doesn't the Python fileno() method issue leave you open to ridiculous fileno() methods that mutate the list passed in to select()?

Yes, but that's par for the course, and selectmodule is suitably paranoid about it (unfortunately, this is so common in the implementation that it's rarely mentioned in comments -- so there's a real danger of "simplifying" seemingly overly-elaborate code into creating a hole). list2set() is unusual in letting PyList_GetItem catch it, though:

int len = PyList_Size(list);
...
for (i = 0; i < len; i++)  {
    SOCKET v;

    /* any intervening fileno() calls could decr this refcnt */
    if (!(o = PyList_GetItem(list, i)))
                return -1;
    Py_INCREF(o);

It's more common to see

for (i = 0; i < PyList_Size(list); i++)  {

i.e. to recompute the list length on each trip, and so silently ignore length-changing mutations.

(2) AIUI,

New one on me!

at-least-as-i-understand-it-ly y'rs - tim