On 02/04/18 05:27 AM, Daniel Stenberg wrote:
On Sat, 31 Mar 2018, Philip Prindeville wrote:
Couple of questions. One is a broader question about tweaking the API
so that it uses fewer “doubles” for get curl_easy_getinfo() call, in
particular using fixed point since you might be running on a platform
such as an embedded router with a MIPS-32 or ARMv6 CPU which doesn’t
have floating-point… but is reasonably capable of 64-bit operations
(shifting, adding, subtracting, etc).
We've slowly been moving in that direction over time. As Harold
mentioned, that easily conflicts with other limitation: not having 64
bit support.
IMO, the most important thing would be to not have floating point
operations in "the critical path" since most systems still have soft
float support.
This same problem shows up in the openssl codebase also. Recently some
usage of things like "fabs()" fell into the codebase. This was caught
in the openssl-1.1.1 beta code but released out to the world in the
openssl-1.1.0h sources. Seems to happen when people go looking for a
diff in time even though the datatypes in the time structs are just
integers. Not sure where the floating point is used in the curl code
but I suspect it may be related to time calcs ?
For the sake of reference the openssl test ct_test.c was fixed in the
beta release of openssl 1.1.1 :
***************
*** 538,556 ****
* Tests that the CT_POLICY_EVAL_CTX default time is approximately now.
* Allow +-10 minutes, as it may compensate for clock skew.
*/
! static int test_default_ct_policy_eval_ctx_time_is_now()
{
int success = 0;
CT_POLICY_EVAL_CTX *ct_policy_ctx = CT_POLICY_EVAL_CTX_new();
const time_t default_time =
CT_POLICY_EVAL_CTX_get_time(ct_policy_ctx) /
! 1000;
const time_t time_tolerance = 600; /* 10 minutes */
! if (fabs(difftime(time(NULL), default_time)) > time_tolerance) {
! fprintf(stderr,
! "Default CT_POLICY_EVAL_CTX time is not approximately
now.\n");
goto end;
- }
success = 1;
end:
--- 496,512 ----
* Tests that the CT_POLICY_EVAL_CTX default time is approximately now.
* Allow +-10 minutes, as it may compensate for clock skew.
*/
! static int test_default_ct_policy_eval_ctx_time_is_now(void)
{
int success = 0;
CT_POLICY_EVAL_CTX *ct_policy_ctx = CT_POLICY_EVAL_CTX_new();
const time_t default_time =
CT_POLICY_EVAL_CTX_get_time(ct_policy_ctx) /
! 1000;
const time_t time_tolerance = 600; /* 10 minutes */
! if (!TEST_time_t_le(abs((int)difftime(time(NULL), default_time)),
! time_tolerance))
goto end;
success = 1;
end:
***************
Lovely .. people are still using difftime for some reason and then
casting it. Anyways .. it happens.
Dennis
ps: why did umich.edu send that post to curl maillist a dozen times?
-------------------------------------------------------------------
Unsubscribe: https://cool.haxx.se/list/listinfo/curl-library
Etiquette: https://curl.haxx.se/mail/etiquette.html
