1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jsutil.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,237 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/* Various JS utility functions. */
1.11 +
1.12 +#include "jsutil.h"
1.13 +
1.14 +#include "mozilla/Assertions.h"
1.15 +#include "mozilla/MathAlgorithms.h"
1.16 +#include "mozilla/PodOperations.h"
1.17 +
1.18 +#include <stdio.h>
1.19 +
1.20 +#include "jstypes.h"
1.21 +
1.22 +#ifdef WIN32
1.23 +# include "jswin.h"
1.24 +#endif
1.25 +
1.26 +#include "js/Utility.h"
1.27 +
1.28 +using namespace js;
1.29 +
1.30 +using mozilla::CeilingLog2Size;
1.31 +using mozilla::PodArrayZero;
1.32 +
1.33 +#if defined(DEBUG) || defined(JS_OOM_BREAKPOINT)
1.34 +/* For JS_OOM_POSSIBLY_FAIL in jsutil.h. */
1.35 +JS_PUBLIC_DATA(uint32_t) OOM_maxAllocations = UINT32_MAX;
1.36 +JS_PUBLIC_DATA(uint32_t) OOM_counter = 0;
1.37 +#endif
1.38 +
1.39 +/*
1.40 + * Checks the assumption that JS_FUNC_TO_DATA_PTR and JS_DATA_TO_FUNC_PTR
1.41 + * macros uses to implement casts between function and data pointers.
1.42 + */
1.43 +JS_STATIC_ASSERT(sizeof(void *) == sizeof(void (*)()));
1.44 +
1.45 +JS_PUBLIC_API(void)
1.46 +JS_Assert(const char *s, const char *file, int ln)
1.47 +{
1.48 + MOZ_ReportAssertionFailure(s, file, ln);
1.49 + MOZ_CRASH();
1.50 +}
1.51 +
1.52 +#ifdef __linux__
1.53 +
1.54 +#include <malloc.h>
1.55 +#include <stdlib.h>
1.56 +
1.57 +namespace js {
1.58 +
1.59 +// This function calls all the vanilla heap allocation functions. It is never
1.60 +// called, and exists purely to help config/check_vanilla_allocations.py. See
1.61 +// that script for more details.
1.62 +extern void
1.63 +AllTheNonBasicVanillaNewAllocations()
1.64 +{
1.65 + // posix_memalign and aligned_alloc aren't available on all Linux
1.66 + // configurations.
1.67 + //char *q;
1.68 + //posix_memalign((void**)&q, 16, 16);
1.69 +
1.70 + intptr_t p =
1.71 + intptr_t(malloc(16)) +
1.72 + intptr_t(calloc(1, 16)) +
1.73 + intptr_t(realloc(nullptr, 16)) +
1.74 + intptr_t(new char) +
1.75 + intptr_t(new char) +
1.76 + intptr_t(new char) +
1.77 + intptr_t(new char[16]) +
1.78 + intptr_t(memalign(16, 16)) +
1.79 + //intptr_t(q) +
1.80 + //intptr_t(aligned_alloc(16, 16)) +
1.81 + intptr_t(valloc(4096)) +
1.82 + intptr_t(strdup("dummy"));
1.83 +
1.84 + printf("%u\n", uint32_t(p)); // make sure |p| is not optimized away
1.85 +
1.86 + free((int*)p); // this would crash if ever actually called
1.87 +
1.88 + MOZ_CRASH();
1.89 +}
1.90 +
1.91 +} // namespace js
1.92 +
1.93 +#endif // __linux__
1.94 +
1.95 +#ifdef JS_BASIC_STATS
1.96 +
1.97 +#include <math.h>
1.98 +
1.99 +/*
1.100 + * Histogram bins count occurrences of values <= the bin label, as follows:
1.101 + *
1.102 + * linear: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more
1.103 + * 2**x: 0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 or more
1.104 + * 10**x: 0, 1, 10, 100, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9 or more
1.105 + *
1.106 + * We wish to count occurrences of 0 and 1 values separately, always.
1.107 + */
1.108 +static uint32_t
1.109 +BinToVal(unsigned logscale, unsigned bin)
1.110 +{
1.111 + JS_ASSERT(bin <= 10);
1.112 + if (bin <= 1 || logscale == 0)
1.113 + return bin;
1.114 + --bin;
1.115 + if (logscale == 2)
1.116 + return JS_BIT(bin);
1.117 + JS_ASSERT(logscale == 10);
1.118 + return uint32_t(pow(10.0, (double) bin));
1.119 +}
1.120 +
1.121 +static unsigned
1.122 +ValToBin(unsigned logscale, uint32_t val)
1.123 +{
1.124 + unsigned bin;
1.125 +
1.126 + if (val <= 1)
1.127 + return val;
1.128 + bin = (logscale == 10)
1.129 + ? (unsigned) ceil(log10((double) val))
1.130 + : (logscale == 2)
1.131 + ? (unsigned) CeilingLog2Size(val)
1.132 + : val;
1.133 + return Min(bin, 10U);
1.134 +}
1.135 +
1.136 +void
1.137 +JS_BasicStatsAccum(JSBasicStats *bs, uint32_t val)
1.138 +{
1.139 + unsigned oldscale, newscale, bin;
1.140 + double mean;
1.141 +
1.142 + ++bs->num;
1.143 + if (bs->max < val)
1.144 + bs->max = val;
1.145 + bs->sum += val;
1.146 + bs->sqsum += (double)val * val;
1.147 +
1.148 + oldscale = bs->logscale;
1.149 + if (oldscale != 10) {
1.150 + mean = bs->sum / bs->num;
1.151 + if (bs->max > 16 && mean > 8) {
1.152 + newscale = (bs->max > 1e6 && mean > 1000) ? 10 : 2;
1.153 + if (newscale != oldscale) {
1.154 + uint32_t newhist[11], newbin;
1.155 +
1.156 + PodArrayZero(newhist);
1.157 + for (bin = 0; bin <= 10; bin++) {
1.158 + newbin = ValToBin(newscale, BinToVal(oldscale, bin));
1.159 + newhist[newbin] += bs->hist[bin];
1.160 + }
1.161 + js_memcpy(bs->hist, newhist, sizeof bs->hist);
1.162 + bs->logscale = newscale;
1.163 + }
1.164 + }
1.165 + }
1.166 +
1.167 + bin = ValToBin(bs->logscale, val);
1.168 + ++bs->hist[bin];
1.169 +}
1.170 +
1.171 +double
1.172 +JS_MeanAndStdDev(uint32_t num, double sum, double sqsum, double *sigma)
1.173 +{
1.174 + double var;
1.175 +
1.176 + if (num == 0 || sum == 0) {
1.177 + *sigma = 0;
1.178 + return 0;
1.179 + }
1.180 +
1.181 + var = num * sqsum - sum * sum;
1.182 + if (var < 0 || num == 1)
1.183 + var = 0;
1.184 + else
1.185 + var /= (double)num * (num - 1);
1.186 +
1.187 + /* Windows says sqrt(0.0) is "-1.#J" (?!) so we must test. */
1.188 + *sigma = (var != 0) ? sqrt(var) : 0;
1.189 + return sum / num;
1.190 +}
1.191 +
1.192 +void
1.193 +JS_DumpBasicStats(JSBasicStats *bs, const char *title, FILE *fp)
1.194 +{
1.195 + double mean, sigma;
1.196 +
1.197 + mean = JS_MeanAndStdDevBS(bs, &sigma);
1.198 + fprintf(fp, "\nmean %s %g, std. deviation %g, max %lu\n",
1.199 + title, mean, sigma, (unsigned long) bs->max);
1.200 + JS_DumpHistogram(bs, fp);
1.201 +}
1.202 +
1.203 +void
1.204 +JS_DumpHistogram(JSBasicStats *bs, FILE *fp)
1.205 +{
1.206 + unsigned bin;
1.207 + uint32_t cnt, max;
1.208 + double sum, mean;
1.209 +
1.210 + for (bin = 0, max = 0, sum = 0; bin <= 10; bin++) {
1.211 + cnt = bs->hist[bin];
1.212 + if (max < cnt)
1.213 + max = cnt;
1.214 + sum += cnt;
1.215 + }
1.216 + mean = sum / cnt;
1.217 + for (bin = 0; bin <= 10; bin++) {
1.218 + unsigned val = BinToVal(bs->logscale, bin);
1.219 + unsigned end = (bin == 10) ? 0 : BinToVal(bs->logscale, bin + 1);
1.220 + cnt = bs->hist[bin];
1.221 + if (val + 1 == end)
1.222 + fprintf(fp, " [%6u]", val);
1.223 + else if (end != 0)
1.224 + fprintf(fp, "[%6u, %6u]", val, end - 1);
1.225 + else
1.226 + fprintf(fp, "[%6u, +inf]", val);
1.227 + fprintf(fp, ": %8u ", cnt);
1.228 + if (cnt != 0) {
1.229 + if (max > 1e6 && mean > 1e3)
1.230 + cnt = uint32_t(ceil(log10((double) cnt)));
1.231 + else if (max > 16 && mean > 8)
1.232 + cnt = CeilingLog2Size(cnt);
1.233 + for (unsigned i = 0; i < cnt; i++)
1.234 + putc('*', fp);
1.235 + }
1.236 + putc('\n', fp);
1.237 + }
1.238 +}
1.239 +
1.240 +#endif /* JS_BASIC_STATS */
