Interface Patch
Tomash Brechko
tomash.brechko at gmail.com
Mon Feb 4 07:37:11 UTC 2008
On Sun, Feb 03, 2008 at 13:33:24 -0800, Brian Aker wrote:
> BTW if you can resend the patch for your no-op stuff I'd be happy to
> review that.
I guess you mean 'noreply' patch. It may be found here:
http://git.openhack.ru/?p=memcached-patched.git;a=commitdiff;h=7dd54ac11da58690a64fbefcf5dcc81af4fe664b
On Sun, Feb 03, 2008 at 16:18:53 -0800, Brian Aker wrote:
> This is the second interface patch. It answers Tomash's questions, and
> comes after a conversation with Dormando.
> @@ -381,6 +380,7 @@ conn *conn_new(const int sfd, const int
> if (conn_add_to_freelist(c)) {
> conn_free(c);
> }
> + perror("event_add");
> return NULL;
> }
event_add() is not a system call, perror() may or may not return
something meaningful, depending on whether the failure happened in a
syscall executed from event_add(), or in the event_add()'s own logic.
> + sfd_list= (int *)calloc(*count, sizeof(int));
> + if (sfd_list == NULL) {
> + perror("calloc()");
> + return NULL;
> + }
> + memset(sfd_list, -1, sizeof(int) * (*count));
Likewise, malloc() and friends are not system calls, and do not set errno.
Back then I meant it's either calloc() (zeroing), or initialization
with -1, or no initialization at all (and after your explanation only
"-1" seemed to be the right thing to do). So no need to call calloc()
and then overwriting zeroes with -1, you may use malloc().
On a larger scale, you are storing the array size now along with the
array. Instead of using 'success' counter in the binding code, you
could store in *count the number of _initialized_ sockets. Then the
whole thing will be
- malloc() the array
- initialize continuous number of elements from the start, set
*count to the number of initialized elements, leaving the rest
uninitialized.
With this, no initialization and later tests against -1 will be
required, you will always know that first *count elems are valid.
> + if (bind(sfd, next->ai_addr, next->ai_addrlen) == -1) {
> + if (errno != EADDRINUSE) {
> + int *sfd_ptr;
> + int x;
> +
> + perror("bind()");
> + for (sfd_ptr= sfd_list, x = 0; x < *count; sfd_ptr++) {
> + if (*sfd_ptr > -1 )
> + close(sfd);
> + }
Looks like an infinite loop (x is never increased), and wrong sfd is
closed. Instead it can be
if (errno != EADDRINUSE) {
perror("bind()");
++sfd_ptr;
while (sfd_ptr != sfd_list) {
--sfd_ptr;
close(*sfd_ptr);
}
The trick with initial increment of sfd_ptr, and decrement before the
close() is not a mistake. This is required because pointer to the
element one past the last is defined, while to one before the first is
not.
> + for (sfd_ptr= sfd_list, x = 0; x < *count; sfd_ptr++) {
> + if (*sfd_ptr > -1 )
> + close(sfd);
> + }
Copy-pastes are evil ;).
--
Tomash Brechko
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