mozilla-config.h.in
author Tom Ritter <tom@mozilla.com>
Fri, 12 Jan 2018 13:36:04 -0600
changeset 399590 17bf5819b42fa3b656f2d3c565bc4fb0ca050066
parent 397410 e9c5541886e8b7cb9960751e25e3b05f0780f6b4
child 401897 c0de1027fbdab6f93e38854be19bbb936012339c
permissions -rw-r--r--
Bug 1429764 Do not call ReduceTimerPrecision twice for DOM Navigation timers r=bkelly,timhuang Bug 1429764 details a test failure that was asserting that the performance navigation timers were strictly increasing (or equal). fetchStart should have a timestamp before domainLookupStart. But it didn't. The problem is two-fold. This corrects the test and the issue by addressing one part of the problem, the second part of the problem needs to be written up in a new bug and addressed there. (That bug is not yet filed at writing, but see dependencies of 1429764 in the future to find it.) The second, and underlying, problem is that calling ReduceTimerPrecision with the same value multiple times may continually reduce it. Meaning that the first you call it with, say, .75, (and a precision of .20), it will be reduced to .6. The second time you call it (with .6), instead of staying at .6 it will be reduced to .4. This is because floats are fuzzy. Inside ReduceTimerPrecision we are multiplying a decimal by a decimal, so while floor(.6 / .20) should equal 3, sometimes it's actually 2.999... which gets floors to 2, gets multiplied again by .2, and which results in .4 If that's the underlying problem, the first, and surface, problem is - why are we calling ReduceTimerPrecision multiple times? We shouldn't be. That's what this patch fixes. TimeStampToDOMHighResOrFetchStart will return either TimeStampToDOMHighRes() or FetchStartHighRes(). FetchStartHighRes() internally calls TimeStampToDOMHighRes and then ReduceTimerPrecision - this is where (some of) the two reduction calls happen - because TimeStampToDOMHighRes itself calls ReduceTimerPrecision also. I remove the ReduceTimerPrecision from TimeStampToDOMHighRes. FetchStartHighRes will now only call ReduceTimerPrecision once, at the end of the return. But we have to fix places we call TimeStampToDOMHighResOrFetchStart, because the callers of that function also call ReduceTimerPrecision. So if TimeStampToDOMHighResOrFetchStart returned FetchStartHighRes, we'd be calling ReduceTimerPrecision twice for those callers. So inside first off, we remove the outer call to ReduceTimerPrecision. that surrounds the 5 or so callsites of TimeStampToDOMHighResOrFetchStart. Then inside of TimeStampToDOMHighResOrFetchStart we return either FetchStartHighRes (which is has already called ReduceTimerPrecision) or we call ReduceTimerPrecision with the value. Now. TimeStampToDOMHighRes was used in more places than just FetchStartHighRes - there were several other places where we were doing double rounding, and this fixed those as well. AsyncOpenHighRes, WorkerStartHighRes, DomainLookupEndHighRes, ConnectStartHighRes, SecureConnectionStartHighRes, ConnectEndHighRes, and ResponseEndHighRes. MozReview-Commit-ID: K5nHql135rb

/* List of defines generated by configure. Included with preprocessor flag,
 * -include, to avoid long list of -D defines on the compile command-line.
 * Do not edit.
 */

#ifndef MOZILLA_CONFIG_H
#define MOZILLA_CONFIG_H

#if defined(__clang__)
#pragma clang diagnostic push
#if __has_warning("-Wreserved-id-macro")
#pragma clang diagnostic ignored "-Wreserved-id-macro"
#endif
#endif

/* Expands to all the defines from configure. */
#undef ALLDEFINES

/*
 * The c99 defining the limit macros (UINT32_MAX for example), says:
 *
 *   C++ implementations should define these macros only when
 *   __STDC_LIMIT_MACROS is defined before <stdint.h> is included.
 *
 * The same also occurs with __STDC_CONSTANT_MACROS for the constant macros
 * (INT8_C for example) used to specify a literal constant of the proper type,
 * and with __STDC_FORMAT_MACROS for the format macros (PRId32 for example) used
 * with the fprintf function family.
 */
#define __STDC_LIMIT_MACROS
#define __STDC_CONSTANT_MACROS
#if !defined(__STDC_FORMAT_MACROS)
#define __STDC_FORMAT_MACROS
#endif

#if defined(__clang__)
#pragma clang diagnostic pop
#endif

/*
 * Force-include hunspell_alloc_hooks.h and hunspell_fopen_hooks.h for hunspell,
 * so that we don't need to modify them directly.
 *
 * HUNSPELL_STATIC is defined in extensions/spellcheck/hunspell/src/Makefile.in,
 * unless --enable-system-hunspell is defined.
 */
#if defined(HUNSPELL_STATIC)
#include "hunspell_alloc_hooks.h"
#include "hunspell_fopen_hooks.h"
#endif

/*
 * Force-include sdkdecls.h for building the chromium sandbox code.
 *
 * CHROMIUM_SANDBOX_BUILD is defined in security/sandbox/moz.build.
 * Note that this include path relies on the LOCAL_INCLUDES in that file.
 */
#if defined(CHROMIUM_SANDBOX_BUILD) && defined(XP_WIN)
#include "base/win/sdkdecls.h"
#endif

#endif /* MOZILLA_CONFIG_H */