https://github.com/mozilla/gecko-dev
Tip revision: ee7c0fafa76542e6d927912dab783084012c4408 authored by ffxbld on 21 August 2012, 23:54:31 UTC
Added FENNEC_15_0b6_RELEASE FENNEC_15_0b6_BUILD1 tag(s) for changeset 6e334cd5152e. DONTBUILD CLOSED TREE a=release
Added FENNEC_15_0b6_RELEASE FENNEC_15_0b6_BUILD1 tag(s) for changeset 6e334cd5152e. DONTBUILD CLOSED TREE a=release
Tip revision: ee7c0fa
jsutil.cpp
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* Various JS utility functions. */
#include "mozilla/Attributes.h"
#include <stdio.h>
#include <stdlib.h>
#include "jstypes.h"
#include "jsutil.h"
#ifdef WIN32
# include "jswin.h"
#else
# include <signal.h>
#endif
#include "js/TemplateLib.h"
using namespace js;
#ifdef DEBUG
/* For JS_OOM_POSSIBLY_FAIL in jsutil.h. */
JS_PUBLIC_DATA(uint32_t) OOM_maxAllocations = UINT32_MAX;
JS_PUBLIC_DATA(uint32_t) OOM_counter = 0;
#endif
/*
* Checks the assumption that JS_FUNC_TO_DATA_PTR and JS_DATA_TO_FUNC_PTR
* macros uses to implement casts between function and data pointers.
*/
JS_STATIC_ASSERT(sizeof(void *) == sizeof(void (*)()));
static JS_NEVER_INLINE void
CrashInJS()
{
/*
* We write 123 here so that the machine code for this function is
* unique. Otherwise the linker, trying to be smart, might use the
* same code for CrashInJS and for some other function. That
* messes up the signature in minidumps.
*/
#if defined(WIN32)
/*
* We used to call DebugBreak() on Windows, but amazingly, it causes
* the MSVS 2010 debugger not to be able to recover a call stack.
*/
*((volatile int *) NULL) = 123;
exit(3);
#elif defined(__APPLE__)
/*
* On Mac OS X, Breakpad ignores signals. Only real Mach exceptions are
* trapped.
*/
*((volatile int *) NULL) = 123; /* To continue from here in GDB: "return" then "continue". */
raise(SIGABRT); /* In case above statement gets nixed by the optimizer. */
#else
raise(SIGABRT); /* To continue from here in GDB: "signal 0". */
#endif
}
JS_PUBLIC_API(void)
JS_Assert(const char *s, const char *file, int ln)
{
fprintf(stderr, "Assertion failure: %s, at %s:%d\n", s, file, ln);
fflush(stderr);
CrashInJS();
}
#ifdef JS_BASIC_STATS
#include <math.h>
#include <string.h>
/*
* Histogram bins count occurrences of values <= the bin label, as follows:
*
* linear: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more
* 2**x: 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 or more
* 10**x: 0, 1, 10, 100, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9 or more
*
* We wish to count occurrences of 0 and 1 values separately, always.
*/
static uint32_t
BinToVal(unsigned logscale, unsigned bin)
{
JS_ASSERT(bin <= 10);
if (bin <= 1 || logscale == 0)
return bin;
--bin;
if (logscale == 2)
return JS_BIT(bin);
JS_ASSERT(logscale == 10);
return uint32_t(pow(10.0, (double) bin));
}
static unsigned
ValToBin(unsigned logscale, uint32_t val)
{
unsigned bin;
if (val <= 1)
return val;
bin = (logscale == 10)
? (unsigned) ceil(log10((double) val))
: (logscale == 2)
? (unsigned) JS_CEILING_LOG2W(val)
: val;
return JS_MIN(bin, 10);
}
void
JS_BasicStatsAccum(JSBasicStats *bs, uint32_t val)
{
unsigned oldscale, newscale, bin;
double mean;
++bs->num;
if (bs->max < val)
bs->max = val;
bs->sum += val;
bs->sqsum += (double)val * val;
oldscale = bs->logscale;
if (oldscale != 10) {
mean = bs->sum / bs->num;
if (bs->max > 16 && mean > 8) {
newscale = (bs->max > 1e6 && mean > 1000) ? 10 : 2;
if (newscale != oldscale) {
uint32_t newhist[11], newbin;
PodArrayZero(newhist);
for (bin = 0; bin <= 10; bin++) {
newbin = ValToBin(newscale, BinToVal(oldscale, bin));
newhist[newbin] += bs->hist[bin];
}
js_memcpy(bs->hist, newhist, sizeof bs->hist);
bs->logscale = newscale;
}
}
}
bin = ValToBin(bs->logscale, val);
++bs->hist[bin];
}
double
JS_MeanAndStdDev(uint32_t num, double sum, double sqsum, double *sigma)
{
double var;
if (num == 0 || sum == 0) {
*sigma = 0;
return 0;
}
var = num * sqsum - sum * sum;
if (var < 0 || num == 1)
var = 0;
else
var /= (double)num * (num - 1);
/* Windows says sqrt(0.0) is "-1.#J" (?!) so we must test. */
*sigma = (var != 0) ? sqrt(var) : 0;
return sum / num;
}
void
JS_DumpBasicStats(JSBasicStats *bs, const char *title, FILE *fp)
{
double mean, sigma;
mean = JS_MeanAndStdDevBS(bs, &sigma);
fprintf(fp, "\nmean %s %g, std. deviation %g, max %lu\n",
title, mean, sigma, (unsigned long) bs->max);
JS_DumpHistogram(bs, fp);
}
void
JS_DumpHistogram(JSBasicStats *bs, FILE *fp)
{
unsigned bin;
uint32_t cnt, max;
double sum, mean;
for (bin = 0, max = 0, sum = 0; bin <= 10; bin++) {
cnt = bs->hist[bin];
if (max < cnt)
max = cnt;
sum += cnt;
}
mean = sum / cnt;
for (bin = 0; bin <= 10; bin++) {
unsigned val = BinToVal(bs->logscale, bin);
unsigned end = (bin == 10) ? 0 : BinToVal(bs->logscale, bin + 1);
cnt = bs->hist[bin];
if (val + 1 == end)
fprintf(fp, " [%6u]", val);
else if (end != 0)
fprintf(fp, "[%6u, %6u]", val, end - 1);
else
fprintf(fp, "[%6u, +inf]", val);
fprintf(fp, ": %8u ", cnt);
if (cnt != 0) {
if (max > 1e6 && mean > 1e3)
cnt = uint32_t(ceil(log10((double) cnt)));
else if (max > 16 && mean > 8)
cnt = JS_CEILING_LOG2W(cnt);
for (unsigned i = 0; i < cnt; i++)
putc('*', fp);
}
putc('\n', fp);
}
}
#endif /* JS_BASIC_STATS */