https://github.com/git/git
Revision 5843080c85ae9d13f77442bec7bbec8e84a18100 authored by Junio C Hamano on 02 March 2023, 16:44:16 UTC, committed by Johannes Schindelin on 22 March 2023, 16:58:29 UTC
In http.c, the run_active_slot() function allows the given "slot" to make progress by calling step_active_slots() in a loop repeatedly, and the loop is not left until the request held in the slot completes. Ages ago, we used to use the slot->in_use member to get out of the loop, which misbehaved when the request in "slot" completes (at which time, the result of the request is copied away from the slot, and the in_use member is cleared, making the slot ready to be reused), and the "slot" gets reused to service a different request (at which time, the "slot" becomes in_use again, even though it is for a different request). The loop terminating condition mistakenly thought that the original request has yet to be completed. Today's code, after baa7b67d (HTTP slot reuse fixes, 2006-03-10) fixed this issue, uses a separate "slot->finished" member that is set in run_active_slot() to point to an on-stack variable, and the code that completes the request in finish_active_slot() clears the on-stack variable via the pointer to signal that the particular request held by the slot has completed. It also clears the in_use member (as before that fix), so that the slot itself can safely be reused for an unrelated request. One thing that is not quite clean in this arrangement is that, unless the slot gets reused, at which point the finished member is reset to NULL, the member keeps the value of &finished, which becomes a dangling pointer into the stack when run_active_slot() returns. Clear the finished member before the control leaves the function, which has a side effect of unconfusing compilers like recent GCC 12 that is over-eager to warn against such an assignment. Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 321854a
Tip revision: 5843080c85ae9d13f77442bec7bbec8e84a18100 authored by Junio C Hamano on 02 March 2023, 16:44:16 UTC
http.c: clear the 'finished' member once we are done with it
http.c: clear the 'finished' member once we are done with it
Tip revision: 5843080
versioncmp.c
#include "cache.h"
#include "config.h"
#include "string-list.h"
/*
* versioncmp(): copied from string/strverscmp.c in glibc commit
* ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding
* style. The implementation is under LGPL-2.1 and Git relicenses it
* to GPLv2.
*/
/*
* states: S_N: normal, S_I: comparing integral part, S_F: comparing
* fractionnal parts, S_Z: idem but with leading Zeroes only
*/
#define S_N 0x0
#define S_I 0x3
#define S_F 0x6
#define S_Z 0x9
/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
#define CMP 2
#define LEN 3
static const struct string_list *prereleases;
static int initialized;
struct suffix_match {
int conf_pos;
int start;
int len;
};
static void find_better_matching_suffix(const char *tagname, const char *suffix,
int suffix_len, int start, int conf_pos,
struct suffix_match *match)
{
/*
* A better match either starts earlier or starts at the same offset
* but is longer.
*/
int end = match->len < suffix_len ? match->start : match->start-1;
int i;
for (i = start; i <= end; i++)
if (starts_with(tagname + i, suffix)) {
match->conf_pos = conf_pos;
match->start = i;
match->len = suffix_len;
break;
}
}
/*
* off is the offset of the first different character in the two strings
* s1 and s2. If either s1 or s2 contains a prerelease suffix containing
* that offset or a suffix ends right before that offset, then that
* string will be forced to be on top.
*
* If both s1 and s2 contain a (different) suffix around that position,
* their order is determined by the order of those two suffixes in the
* configuration.
* If any of the strings contains more than one different suffixes around
* that position, then that string is sorted according to the contained
* suffix which starts at the earliest offset in that string.
* If more than one different contained suffixes start at that earliest
* offset, then that string is sorted according to the longest of those
* suffixes.
*
* Return non-zero if *diff contains the return value for versioncmp()
*/
static int swap_prereleases(const char *s1,
const char *s2,
int off,
int *diff)
{
int i;
struct suffix_match match1 = { -1, off, -1 };
struct suffix_match match2 = { -1, off, -1 };
for (i = 0; i < prereleases->nr; i++) {
const char *suffix = prereleases->items[i].string;
int start, suffix_len = strlen(suffix);
if (suffix_len < off)
start = off - suffix_len;
else
start = 0;
find_better_matching_suffix(s1, suffix, suffix_len, start,
i, &match1);
find_better_matching_suffix(s2, suffix, suffix_len, start,
i, &match2);
}
if (match1.conf_pos == -1 && match2.conf_pos == -1)
return 0;
if (match1.conf_pos == match2.conf_pos)
/* Found the same suffix in both, e.g. "-rc" in "v1.0-rcX"
* and "v1.0-rcY": the caller should decide based on "X"
* and "Y". */
return 0;
if (match1.conf_pos >= 0 && match2.conf_pos >= 0)
*diff = match1.conf_pos - match2.conf_pos;
else if (match1.conf_pos >= 0)
*diff = -1;
else /* if (match2.conf_pos >= 0) */
*diff = 1;
return 1;
}
/*
* Compare S1 and S2 as strings holding indices/version numbers,
* returning less than, equal to or greater than zero if S1 is less
* than, equal to or greater than S2 (for more info, see the texinfo
* doc).
*/
int versioncmp(const char *s1, const char *s2)
{
const unsigned char *p1 = (const unsigned char *) s1;
const unsigned char *p2 = (const unsigned char *) s2;
unsigned char c1, c2;
int state, diff;
/*
* Symbol(s) 0 [1-9] others
* Transition (10) 0 (01) d (00) x
*/
static const uint8_t next_state[] = {
/* state x d 0 */
/* S_N */ S_N, S_I, S_Z,
/* S_I */ S_N, S_I, S_I,
/* S_F */ S_N, S_F, S_F,
/* S_Z */ S_N, S_F, S_Z
};
static const int8_t result_type[] = {
/* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
/* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
/* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
/* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
/* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
};
if (p1 == p2)
return 0;
c1 = *p1++;
c2 = *p2++;
/* Hint: '0' is a digit too. */
state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
while ((diff = c1 - c2) == 0) {
if (c1 == '\0')
return diff;
state = next_state[state];
c1 = *p1++;
c2 = *p2++;
state += (c1 == '0') + (isdigit (c1) != 0);
}
if (!initialized) {
const struct string_list *deprecated_prereleases;
initialized = 1;
prereleases = git_config_get_value_multi("versionsort.suffix");
deprecated_prereleases = git_config_get_value_multi("versionsort.prereleasesuffix");
if (prereleases) {
if (deprecated_prereleases)
warning("ignoring versionsort.prereleasesuffix because versionsort.suffix is set");
} else
prereleases = deprecated_prereleases;
}
if (prereleases && swap_prereleases(s1, s2, (const char *) p1 - s1 - 1,
&diff))
return diff;
state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
switch (state) {
case CMP:
return diff;
case LEN:
while (isdigit (*p1++))
if (!isdigit (*p2++))
return 1;
return isdigit (*p2) ? -1 : diff;
default:
return state;
}
}
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