Best,

-Matt

On Tuesday, Aug 25, 2015 at 12:46 AM, Ken Thomases <ken@codeweavers.com>, wrote:

Thanks for continuing to work on this. By no means a thorough review:

> On Aug 24, 2015, at 10:49 PM, Matt Durgavich <mattdurgavich@gmail.com> wrote:

> +#define CACHE_SIZE 256
> +#define CACHE_DEPTH 16
> +static SOCKET socket_cache[CACHE_SIZE][CACHE_DEPTH];
> +
> +/* Cache support */
> +static void add_to_cache(SOCKET s);
> +static BOOL remove_from_cache(SOCKET s);
> +static BOOL socket_in_cache(SOCKET s);

I'm not sure this is a "cache", per se. It's a hash table, but naming issues are fairly minor.

Let's go with socket_table

> @@ -1470,8 +1479,24 @@ int WINAPI WSAStartup(WORD wVersionRequested, LPWSADATA lpWSAData)
> INT WINAPI WSACleanup(void)
> {
> if (num_startup) {
> - num_startup--;
> - TRACE("pending cleanups: %d\n", num_startup);
> + /* WS_closesocket needs num_startup to be non-zero, so decrement afterwards */
> + if (num_startup - 1 == 0) {

Why not "if (num_startup == 1)"?

> +static void add_to_cache(SOCKET s)
> +{
> + int index, depth;
> + SOCKET old;
> + LONG *dest;
> + index = socket_to_index(s) % CACHE_SIZE;

If you always mod the result of socket_to_index() by CACHE_SIZE, why not do that in that function?

Point taken.

> + for (depth = 0; depth < CACHE_DEPTH; ++depth) {
> + if (socket_cache[index][depth] == 0)
> + break;
> + }
> +
> + if (depth == CACHE_DEPTH) {
> + ERR("Socket hash table collision\n");

This should exit here or you access beyond the end of socket_cache[index] just below.

Good catch.

> + }
> +
> + dest = (PLONG)&socket_cache[index][depth];

Don't use PLONG, just use LONG*.

> + old = InterlockedExchange(dest, s);
> +
> + if (old != 0) {
> + ERR("Socket hash table internal corruption");

Reporting corruption isn't right. You should use InterlockedCompareExchange() with 0 as the comparand to _avoid_ corruption. If it fails, loop back to the depth loop and try again. The only error possible should be filling the hash table bucket.

Right. Makes sense. Will fix.

> + }
> +}
> +
> +static BOOL remove_from_cache(SOCKET s)
> +{
> + int index,depth;
> + SOCKET old;
> + LONG *dest;
> + index = socket_to_index(s) % CACHE_SIZE;
> + for (depth = 0; depth < CACHE_DEPTH; ++depth) {
> + if (socket_cache[index][depth] == s)
> + break;
> + }
> +
> + if (depth == CACHE_DEPTH) {
> + return FALSE;
> + }
> +
> + dest = (PLONG)&socket_cache[index][depth];
> + old = InterlockedExchange(dest, 0);
> + return (old == s);

Under what circumstances could old not equal s? If that can happen, then this should also use InterlockedCompareExchange(), otherwise you've removed some other socket.

If I fork a child, I'll inherit their sockets right? So some paranoia in the remove is needed. Unless wine doesn't work that way. I'll write it as the analog to add.

-Ken

Thanks! I appreciate the feedback.