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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sts=4 et sw=4 tw=99:
* 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/. */
#include "gc/Statistics.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/PodOperations.h"
#include "mozilla/UniquePtr.h"
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include "jsprf.h"
#include "jsutil.h"
#include "gc/Memory.h"
#include "vm/Debugger.h"
#include "vm/HelperThreads.h"
#include "vm/Runtime.h"
#include "vm/Time.h"
#if defined(STARBOARD)
#include "starboard/string.h"
#endif
using namespace js;
using namespace js::gc;
using namespace js::gcstats;
using mozilla::MakeRange;
using mozilla::PodArrayZero;
using mozilla::PodZero;
/* Except for the first and last, slices of less than 10ms are not reported. */
static const int64_t SLICE_MIN_REPORT_TIME = 10 * PRMJ_USEC_PER_MSEC;
/*
* If this fails, then you can either delete this assertion and allow all
* larger-numbered reasons to pile up in the last telemetry bucket, or switch
* to GC_REASON_3 and bump the max value.
*/
JS_STATIC_ASSERT(JS::gcreason::NUM_TELEMETRY_REASONS >= JS::gcreason::NUM_REASONS);
const char*
js::gcstats::ExplainInvocationKind(JSGCInvocationKind gckind)
{
MOZ_ASSERT(gckind == GC_NORMAL || gckind == GC_SHRINK);
if (gckind == GC_NORMAL)
return "Normal";
else
return "Shrinking";
}
const char*
js::gcstats::ExplainReason(JS::gcreason::Reason reason)
{
switch (reason) {
#define SWITCH_REASON(name) \
case JS::gcreason::name: \
return #name;
GCREASONS(SWITCH_REASON)
default:
MOZ_CRASH("bad GC reason");
#undef SWITCH_REASON
}
}
static double
t(int64_t t)
{
return double(t) / PRMJ_USEC_PER_MSEC;
}
struct PhaseInfo
{
Phase index;
const char* name;
Phase parent;
const uint8_t telemetryBucket;
};
// The zeroth entry in the timing arrays is used for phases that have a
// unique lineage.
static const size_t PHASE_DAG_NONE = 0;
// These are really just fields of PhaseInfo, but I have to initialize them
// programmatically, which prevents making phases[] const. (And marking these
// fields mutable does not work on Windows; the whole thing gets created in
// read-only memory anyway.)
struct ExtraPhaseInfo
{
// Depth in the tree of each phase type
size_t depth;
// Index into the set of parallel arrays of timing data, for parents with
// at least one multi-parented child
size_t dagSlot;
};
static const Phase PHASE_NO_PARENT = PHASE_LIMIT;
struct DagChildEdge {
Phase parent;
Phase child;
} dagChildEdges[] = {
{ PHASE_MARK, PHASE_MARK_ROOTS },
{ PHASE_MINOR_GC, PHASE_MARK_ROOTS },
{ PHASE_TRACE_HEAP, PHASE_MARK_ROOTS },
{ PHASE_EVICT_NURSERY, PHASE_MARK_ROOTS },
{ PHASE_COMPACT_UPDATE, PHASE_MARK_ROOTS }
};
/*
* Note that PHASE_MUTATOR, PHASE_GC_BEGIN, and PHASE_GC_END never have any
* child phases. If beginPhase is called while one of these is active, they
* will automatically be suspended and resumed when the phase stack is next
* empty. Timings for these phases are thus exclusive of any other phase.
*/
static const PhaseInfo phases[] = {
{ PHASE_MUTATOR, "Mutator Running", PHASE_NO_PARENT, 0 },
{ PHASE_GC_BEGIN, "Begin Callback", PHASE_NO_PARENT, 1 },
{ PHASE_WAIT_BACKGROUND_THREAD, "Wait Background Thread", PHASE_NO_PARENT, 2 },
{ PHASE_MARK_DISCARD_CODE, "Mark Discard Code", PHASE_NO_PARENT, 3 },
{ PHASE_RELAZIFY_FUNCTIONS, "Relazify Functions", PHASE_NO_PARENT, 4 },
{ PHASE_PURGE, "Purge", PHASE_NO_PARENT, 5 },
{ PHASE_MARK, "Mark", PHASE_NO_PARENT, 6 },
{ PHASE_UNMARK, "Unmark", PHASE_MARK, 7 },
/* PHASE_MARK_ROOTS */
{ PHASE_MARK_DELAYED, "Mark Delayed", PHASE_MARK, 8 },
{ PHASE_SWEEP, "Sweep", PHASE_NO_PARENT, 9 },
{ PHASE_SWEEP_MARK, "Mark During Sweeping", PHASE_SWEEP, 10 },
{ PHASE_SWEEP_MARK_TYPES, "Mark Types During Sweeping", PHASE_SWEEP_MARK, 11 },
{ PHASE_SWEEP_MARK_INCOMING_BLACK, "Mark Incoming Black Pointers", PHASE_SWEEP_MARK, 12 },
{ PHASE_SWEEP_MARK_WEAK, "Mark Weak", PHASE_SWEEP_MARK, 13 },
{ PHASE_SWEEP_MARK_INCOMING_GRAY, "Mark Incoming Gray Pointers", PHASE_SWEEP_MARK, 14 },
{ PHASE_SWEEP_MARK_GRAY, "Mark Gray", PHASE_SWEEP_MARK, 15 },
{ PHASE_SWEEP_MARK_GRAY_WEAK, "Mark Gray and Weak", PHASE_SWEEP_MARK, 16 },
{ PHASE_FINALIZE_START, "Finalize Start Callbacks", PHASE_SWEEP, 17 },
{ PHASE_WEAK_ZONEGROUP_CALLBACK, "Per-Slice Weak Callback", PHASE_FINALIZE_START, 57 },
{ PHASE_WEAK_COMPARTMENT_CALLBACK, "Per-Compartment Weak Callback", PHASE_FINALIZE_START, 58 },
{ PHASE_SWEEP_ATOMS, "Sweep Atoms", PHASE_SWEEP, 18 },
{ PHASE_SWEEP_SYMBOL_REGISTRY, "Sweep Symbol Registry", PHASE_SWEEP, 19 },
{ PHASE_SWEEP_COMPARTMENTS, "Sweep Compartments", PHASE_SWEEP, 20 },
{ PHASE_SWEEP_DISCARD_CODE, "Sweep Discard Code", PHASE_SWEEP_COMPARTMENTS, 21 },
{ PHASE_SWEEP_INNER_VIEWS, "Sweep Inner Views", PHASE_SWEEP_COMPARTMENTS, 22 },
{ PHASE_SWEEP_CC_WRAPPER, "Sweep Cross Compartment Wrappers", PHASE_SWEEP_COMPARTMENTS, 23 },
{ PHASE_SWEEP_BASE_SHAPE, "Sweep Base Shapes", PHASE_SWEEP_COMPARTMENTS, 24 },
{ PHASE_SWEEP_INITIAL_SHAPE, "Sweep Initial Shapes", PHASE_SWEEP_COMPARTMENTS, 25 },
{ PHASE_SWEEP_TYPE_OBJECT, "Sweep Type Objects", PHASE_SWEEP_COMPARTMENTS, 26 },
{ PHASE_SWEEP_BREAKPOINT, "Sweep Breakpoints", PHASE_SWEEP_COMPARTMENTS, 27 },
{ PHASE_SWEEP_REGEXP, "Sweep Regexps", PHASE_SWEEP_COMPARTMENTS, 28 },
{ PHASE_SWEEP_MISC, "Sweep Miscellaneous", PHASE_SWEEP_COMPARTMENTS, 29 },
{ PHASE_SWEEP_TYPES, "Sweep type information", PHASE_SWEEP_COMPARTMENTS, 30 },
{ PHASE_SWEEP_TYPES_BEGIN, "Sweep type tables and compilations", PHASE_SWEEP_TYPES, 31 },
{ PHASE_SWEEP_TYPES_END, "Free type arena", PHASE_SWEEP_TYPES, 32 },
{ PHASE_SWEEP_OBJECT, "Sweep Object", PHASE_SWEEP, 33 },
{ PHASE_SWEEP_STRING, "Sweep String", PHASE_SWEEP, 34 },
{ PHASE_SWEEP_SCRIPT, "Sweep Script", PHASE_SWEEP, 35 },
{ PHASE_SWEEP_SHAPE, "Sweep Shape", PHASE_SWEEP, 36 },
{ PHASE_SWEEP_JITCODE, "Sweep JIT code", PHASE_SWEEP, 37 },
{ PHASE_FINALIZE_END, "Finalize End Callback", PHASE_SWEEP, 38 },
{ PHASE_DESTROY, "Deallocate", PHASE_SWEEP, 39 },
{ PHASE_COMPACT, "Compact", PHASE_NO_PARENT, 40 },
{ PHASE_COMPACT_MOVE, "Compact Move", PHASE_COMPACT, 41 },
{ PHASE_COMPACT_UPDATE, "Compact Update", PHASE_COMPACT, 42 },
/* PHASE_MARK_ROOTS */
{ PHASE_COMPACT_UPDATE_CELLS, "Compact Update Cells", PHASE_COMPACT_UPDATE, 43 },
{ PHASE_GC_END, "End Callback", PHASE_NO_PARENT, 44 },
{ PHASE_MINOR_GC, "All Minor GCs", PHASE_NO_PARENT, 45 },
/* PHASE_MARK_ROOTS */
{ PHASE_EVICT_NURSERY, "Minor GCs to Evict Nursery", PHASE_NO_PARENT, 46 },
/* PHASE_MARK_ROOTS */
{ PHASE_TRACE_HEAP, "Trace Heap", PHASE_NO_PARENT, 47 },
/* PHASE_MARK_ROOTS */
{ PHASE_BARRIER, "Barriers", PHASE_NO_PARENT, 55 },
{ PHASE_UNMARK_GRAY, "Unmark gray", PHASE_BARRIER, 56 },
{ PHASE_MARK_ROOTS, "Mark Roots", PHASE_MULTI_PARENTS, 48 },
{ PHASE_BUFFER_GRAY_ROOTS, "Buffer Gray Roots", PHASE_MARK_ROOTS, 49 },
{ PHASE_MARK_CCWS, "Mark Cross Compartment Wrappers", PHASE_MARK_ROOTS, 50 },
{ PHASE_MARK_ROOTERS, "Mark Rooters", PHASE_MARK_ROOTS, 51 },
{ PHASE_MARK_RUNTIME_DATA, "Mark Runtime-wide Data", PHASE_MARK_ROOTS, 52 },
{ PHASE_MARK_EMBEDDING, "Mark Embedding", PHASE_MARK_ROOTS, 53 },
{ PHASE_MARK_COMPARTMENTS, "Mark Compartments", PHASE_MARK_ROOTS, 54 },
{ PHASE_LIMIT, nullptr, PHASE_NO_PARENT, 58 }
// Current number of telemetryBuckets is 58. If you insert new phases
// somewhere, start at that number and count up. Do not change any existing
// numbers.
};
static ExtraPhaseInfo phaseExtra[PHASE_LIMIT] = { { 0, 0 } };
// Mapping from all nodes with a multi-parented child to a Vector of all
// multi-parented children and their descendants. (Single-parented children will
// not show up in this list.)
static mozilla::Vector<Phase> dagDescendants[Statistics::NumTimingArrays];
struct AllPhaseIterator {
int current;
int baseLevel;
size_t activeSlot;
mozilla::Vector<Phase>::Range descendants;
explicit AllPhaseIterator(const Statistics::PhaseTimeTable table)
: current(0)
, baseLevel(0)
, activeSlot(PHASE_DAG_NONE)
, descendants(dagDescendants[PHASE_DAG_NONE].all()) /* empty range */
{
}
void get(Phase* phase, size_t* dagSlot, size_t* level = nullptr) {
MOZ_ASSERT(!done());
*dagSlot = activeSlot;
*phase = descendants.empty() ? Phase(current) : descendants.front();
if (level)
*level = phaseExtra[*phase].depth + baseLevel;
}
void advance() {
MOZ_ASSERT(!done());
if (!descendants.empty()) {
descendants.popFront();
if (!descendants.empty())
return;
++current;
activeSlot = PHASE_DAG_NONE;
baseLevel = 0;
return;
}
if (phaseExtra[current].dagSlot != PHASE_DAG_NONE) {
activeSlot = phaseExtra[current].dagSlot;
descendants = dagDescendants[activeSlot].all();
MOZ_ASSERT(!descendants.empty());
baseLevel += phaseExtra[current].depth + 1;
return;
}
++current;
}
bool done() const {
return phases[current].parent == PHASE_MULTI_PARENTS;
}
};
void
Statistics::gcDuration(int64_t* total, int64_t* maxPause) const
{
*total = *maxPause = 0;
for (const SliceData* slice = slices.begin(); slice != slices.end(); slice++) {
*total += slice->duration();
if (slice->duration() > *maxPause)
*maxPause = slice->duration();
}
if (*maxPause > maxPauseInInterval)
maxPauseInInterval = *maxPause;
}
void
Statistics::sccDurations(int64_t* total, int64_t* maxPause)
{
*total = *maxPause = 0;
for (size_t i = 0; i < sccTimes.length(); i++) {
*total += sccTimes[i];
*maxPause = Max(*maxPause, sccTimes[i]);
}
}
typedef Vector<UniqueChars, 8, SystemAllocPolicy> FragmentVector;
static UniqueChars
Join(const FragmentVector& fragments, const char* separator = "") {
const size_t separatorLength = strlen(separator);
size_t length = 0;
for (size_t i = 0; i < fragments.length(); ++i) {
length += fragments[i] ? strlen(fragments[i].get()) : 0;
if (i < (fragments.length() - 1))
length += separatorLength;
}
char* joined = js_pod_malloc<char>(length + 1);
joined[length] = '\0';
char* cursor = joined;
for (size_t i = 0; i < fragments.length(); ++i) {
if (fragments[i])
strcpy(cursor, fragments[i].get());
cursor += fragments[i] ? strlen(fragments[i].get()) : 0;
if (i < (fragments.length() - 1)) {
if (separatorLength)
strcpy(cursor, separator);
cursor += separatorLength;
}
}
return UniqueChars(joined);
}
static int64_t
SumChildTimes(size_t phaseSlot, Phase phase, const Statistics::PhaseTimeTable phaseTimes)
{
// Sum the contributions from single-parented children.
int64_t total = 0;
for (unsigned i = 0; i < PHASE_LIMIT; i++) {
if (phases[i].parent == phase)
total += phaseTimes[phaseSlot][i];
}
// Sum the contributions from multi-parented children.
size_t dagSlot = phaseExtra[phase].dagSlot;
if (dagSlot != PHASE_DAG_NONE) {
for (size_t i = 0; i < mozilla::ArrayLength(dagChildEdges); i++) {
if (dagChildEdges[i].parent == phase) {
Phase child = dagChildEdges[i].child;
total += phaseTimes[dagSlot][child];
}
}
}
return total;
}
UniqueChars
Statistics::formatCompactSliceMessage() const
{
// Skip if we OOM'ed.
if (slices.length() == 0)
return UniqueChars(nullptr);
const size_t index = slices.length() - 1;
const SliceData& slice = slices[index];
char budgetDescription[200];
slice.budget.describe(budgetDescription, sizeof(budgetDescription) - 1);
const char* format =
"GC Slice %u - Pause: %.3fms of %s budget (@ %.3fms); Reason: %s; Reset: %s%s; Times: ";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format, index,
t(slice.duration()), budgetDescription, t(slice.start - slices[0].start),
ExplainReason(slice.reason),
slice.resetReason ? "yes - " : "no", slice.resetReason ? slice.resetReason : "");
FragmentVector fragments;
if (!fragments.append(make_string_copy(buffer)) ||
!fragments.append(formatCompactSlicePhaseTimes(slices[index].phaseTimes)))
{
return UniqueChars(nullptr);
}
return Join(fragments);
}
UniqueChars
Statistics::formatCompactSummaryMessage() const
{
const double bytesPerMiB = 1024 * 1024;
FragmentVector fragments;
if (!fragments.append(make_string_copy("Summary - ")))
return UniqueChars(nullptr);
int64_t total, longest;
gcDuration(&total, &longest);
const double mmu20 = computeMMU(20 * PRMJ_USEC_PER_MSEC);
const double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
char buffer[1024];
if (!nonincrementalReason_) {
JS_snprintf(buffer, sizeof(buffer),
"Max Pause: %.3fms; MMU 20ms: %.1f%%; MMU 50ms: %.1f%%; Total: %.3fms; ",
t(longest), mmu20 * 100., mmu50 * 100., t(total));
} else {
JS_snprintf(buffer, sizeof(buffer), "Non-Incremental: %.3fms (%s); ",
t(total), nonincrementalReason_);
}
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
JS_snprintf(buffer, sizeof(buffer),
"Zones: %d of %d; Compartments: %d of %d; HeapSize: %.3f MiB; "\
"HeapChange (abs): %+d (%d); ",
zoneStats.collectedZoneCount, zoneStats.zoneCount,
zoneStats.collectedCompartmentCount, zoneStats.compartmentCount,
double(preBytes) / bytesPerMiB,
counts[STAT_NEW_CHUNK] - counts[STAT_DESTROY_CHUNK],
counts[STAT_NEW_CHUNK] + counts[STAT_DESTROY_CHUNK]);
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
MOZ_ASSERT_IF(counts[STAT_ARENA_RELOCATED], gckind == GC_SHRINK);
if (gckind == GC_SHRINK) {
JS_snprintf(buffer, sizeof(buffer),
"Kind: %s; Relocated: %.3f MiB; ",
ExplainInvocationKind(gckind),
double(ArenaSize * counts[STAT_ARENA_RELOCATED]) / bytesPerMiB);
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
}
return Join(fragments);
}
UniqueChars
Statistics::formatCompactSlicePhaseTimes(const PhaseTimeTable phaseTimes) const
{
static const int64_t MaxUnaccountedTimeUS = 100;
FragmentVector fragments;
char buffer[128];
for (AllPhaseIterator iter(phaseTimes); !iter.done(); iter.advance()) {
Phase phase;
size_t dagSlot;
size_t level;
iter.get(&phase, &dagSlot, &level);
MOZ_ASSERT(level < 4);
int64_t ownTime = phaseTimes[dagSlot][phase];
int64_t childTime = SumChildTimes(dagSlot, phase, phaseTimes);
if (ownTime > MaxUnaccountedTimeUS) {
JS_snprintf(buffer, sizeof(buffer), "%s: %.3fms", phases[phase].name, t(ownTime));
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
if (childTime && (ownTime - childTime) > MaxUnaccountedTimeUS) {
MOZ_ASSERT(level < 3);
JS_snprintf(buffer, sizeof(buffer), "%s: %.3fms", "Other", t(ownTime - childTime));
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
}
}
}
return Join(fragments, ", ");
}
UniqueChars
Statistics::formatDetailedMessage()
{
FragmentVector fragments;
if (!fragments.append(formatDetailedDescription()))
return UniqueChars(nullptr);
if (slices.length() > 1) {
for (unsigned i = 0; i < slices.length(); i++) {
if (!fragments.append(formatDetailedSliceDescription(i, slices[i])))
return UniqueChars(nullptr);
if (!fragments.append(formatDetailedPhaseTimes(slices[i].phaseTimes)))
return UniqueChars(nullptr);
}
}
if (!fragments.append(formatDetailedTotals()))
return UniqueChars(nullptr);
if (!fragments.append(formatDetailedPhaseTimes(phaseTimes)))
return UniqueChars(nullptr);
return Join(fragments);
}
UniqueChars
Statistics::formatDetailedDescription()
{
const double bytesPerMiB = 1024 * 1024;
int64_t sccTotal, sccLongest;
sccDurations(&sccTotal, &sccLongest);
double mmu20 = computeMMU(20 * PRMJ_USEC_PER_MSEC);
double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
const char* format =
"=================================================================\n\
Invocation Kind: %s\n\
Reason: %s\n\
Incremental: %s%s\n\
Zones Collected: %d of %d\n\
Compartments Collected: %d of %d\n\
MinorGCs since last GC: %d\n\
Store Buffer Overflows: %d\n\
MMU 20ms:%.1f%%; 50ms:%.1f%%\n\
SCC Sweep Total (MaxPause): %.3fms (%.3fms)\n\
HeapSize: %.3f MiB\n\
Chunk Delta (magnitude): %+d (%d)\n\
Arenas Relocated: %.3f MiB\n\
";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format,
ExplainInvocationKind(gckind),
ExplainReason(slices[0].reason),
nonincrementalReason_ ? "no - " : "yes",
nonincrementalReason_ ? nonincrementalReason_ : "",
zoneStats.collectedZoneCount, zoneStats.zoneCount,
zoneStats.collectedCompartmentCount, zoneStats.compartmentCount,
counts[STAT_MINOR_GC],
counts[STAT_STOREBUFFER_OVERFLOW],
mmu20 * 100., mmu50 * 100.,
t(sccTotal), t(sccLongest),
double(preBytes) / bytesPerMiB,
counts[STAT_NEW_CHUNK] - counts[STAT_DESTROY_CHUNK], counts[STAT_NEW_CHUNK] +
counts[STAT_DESTROY_CHUNK],
double(ArenaSize * counts[STAT_ARENA_RELOCATED]) / bytesPerMiB);
return make_string_copy(buffer);
}
UniqueChars
Statistics::formatDetailedSliceDescription(unsigned i, const SliceData& slice)
{
char budgetDescription[200];
slice.budget.describe(budgetDescription, sizeof(budgetDescription) - 1);
const char* format =
"\
---- Slice %u ----\n\
Reason: %s\n\
Reset: %s%s\n\
Page Faults: %ld\n\
Pause: %.3fms of %s budget (@ %.3fms)\n\
";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format, i,
ExplainReason(slice.reason),
slice.resetReason ? "yes - " : "no", slice.resetReason ? slice.resetReason : "",
uint64_t(slice.endFaults - slice.startFaults),
t(slice.duration()), budgetDescription, t(slice.start - slices[0].start));
return make_string_copy(buffer);
}
UniqueChars
Statistics::formatDetailedPhaseTimes(const PhaseTimeTable phaseTimes)
{
static const char* LevelToIndent[] = { "", " ", " ", " " };
static const int64_t MaxUnaccountedChildTimeUS = 50;
FragmentVector fragments;
char buffer[128];
for (AllPhaseIterator iter(phaseTimes); !iter.done(); iter.advance()) {
Phase phase;
size_t dagSlot;
size_t level;
iter.get(&phase, &dagSlot, &level);
MOZ_ASSERT(level < 4);
int64_t ownTime = phaseTimes[dagSlot][phase];
int64_t childTime = SumChildTimes(dagSlot, phase, phaseTimes);
if (ownTime > 0) {
JS_snprintf(buffer, sizeof(buffer), " %s%s: %.3fms\n",
LevelToIndent[level], phases[phase].name, t(ownTime));
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
if (childTime && (ownTime - childTime) > MaxUnaccountedChildTimeUS) {
MOZ_ASSERT(level < 3);
JS_snprintf(buffer, sizeof(buffer), " %s%s: %.3fms\n",
LevelToIndent[level + 1], "Other", t(ownTime - childTime));
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
}
}
}
return Join(fragments);
}
UniqueChars
Statistics::formatDetailedTotals()
{
int64_t total, longest;
gcDuration(&total, &longest);
const char* format =
"\
---- Totals ----\n\
Total Time: %.3fms\n\
Max Pause: %.3fms\n\
";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format, t(total), t(longest));
return make_string_copy(buffer);
}
UniqueChars
Statistics::formatJsonMessage(uint64_t timestamp)
{
MOZ_ASSERT(!aborted);
FragmentVector fragments;
if (!fragments.append(make_string_copy("{")) ||
!fragments.append(formatJsonDescription(timestamp)) ||
!fragments.append(make_string_copy("\"slices\":[")))
{
return UniqueChars(nullptr);
}
for (unsigned i = 0; i < slices.length(); i++) {
if (!fragments.append(make_string_copy("{")) ||
!fragments.append(formatJsonSliceDescription(i, slices[i])) ||
!fragments.append(make_string_copy("\"times\":{")) ||
!fragments.append(formatJsonPhaseTimes(slices[i].phaseTimes)) ||
!fragments.append(make_string_copy("}}")) ||
(i < (slices.length() - 1) && !fragments.append(make_string_copy(","))))
{
return UniqueChars(nullptr);
}
}
if (!fragments.append(make_string_copy("],\"totals\":{")) ||
!fragments.append(formatJsonPhaseTimes(phaseTimes)) ||
!fragments.append(make_string_copy("}}")))
{
return UniqueChars(nullptr);
}
return Join(fragments);
}
UniqueChars
Statistics::formatJsonDescription(uint64_t timestamp)
{
int64_t total, longest;
gcDuration(&total, &longest);
int64_t sccTotal, sccLongest;
sccDurations(&sccTotal, &sccLongest);
double mmu20 = computeMMU(20 * PRMJ_USEC_PER_MSEC);
double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
const char *format =
"\"timestamp\":%llu,"
"\"max_pause\":%llu.%03llu,"
"\"total_time\":%llu.%03llu,"
"\"zones_collected\":%d,"
"\"total_zones\":%d,"
"\"total_compartments\":%d,"
"\"minor_gcs\":%d,"
"\"store_buffer_overflows\":%d,"
"\"mmu_20ms\":%d,"
"\"mmu_50ms\":%d,"
"\"scc_sweep_total\":%llu.%03llu,"
"\"scc_sweep_max_pause\":%llu.%03llu,"
"\"nonincremental_reason\":\"%s\","
"\"allocated\":%u,"
"\"added_chunks\":%d,"
"\"removed_chunks\":%d,";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format,
(unsigned long long)timestamp,
longest / 1000, longest % 1000,
total / 1000, total % 1000,
zoneStats.collectedZoneCount,
zoneStats.zoneCount,
zoneStats.compartmentCount,
counts[STAT_MINOR_GC],
counts[STAT_STOREBUFFER_OVERFLOW],
int(mmu20 * 100),
int(mmu50 * 100),
sccTotal / 1000, sccTotal % 1000,
sccLongest / 1000, sccLongest % 1000,
nonincrementalReason_ ? nonincrementalReason_ : "none",
unsigned(preBytes / 1024 / 1024),
counts[STAT_NEW_CHUNK],
counts[STAT_DESTROY_CHUNK]);
return make_string_copy(buffer);
}
UniqueChars
Statistics::formatJsonSliceDescription(unsigned i, const SliceData& slice)
{
int64_t duration = slices[i].duration();
int64_t when = slices[i].start - slices[0].start;
char budgetDescription[200];
slice.budget.describe(budgetDescription, sizeof(budgetDescription) - 1);
int64_t pageFaults = slices[i].endFaults - slices[i].startFaults;
const char* format =
"\"slice\":%d,"
"\"pause\":%llu.%03llu,"
"\"when\":%llu.%03llu,"
"\"reason\":\"%s\","
"\"budget\":\"%s\","
"\"page_faults\":%llu,"
"\"start_timestamp\":%llu,"
"\"end_timestamp\":%llu,";
char buffer[1024];
memset(buffer, 0, sizeof(buffer));
JS_snprintf(buffer, sizeof(buffer), format,
i,
duration / 1000, duration % 1000,
when / 1000, when % 1000,
ExplainReason(slices[i].reason),
budgetDescription,
pageFaults,
slices[i].start,
slices[i].end);
return make_string_copy(buffer);
}
UniqueChars
FilterJsonKey(const char*const buffer)
{
#if defined(STARBOARD)
char* mut = SbStringDuplicate(buffer);
#else
char* mut = strdup(buffer);
#endif
char* c = mut;
while (*c) {
if (!isalpha(*c))
*c = '_';
else if (isupper(*c))
*c = tolower(*c);
++c;
}
return UniqueChars(mut);
}
UniqueChars
Statistics::formatJsonPhaseTimes(const PhaseTimeTable phaseTimes)
{
FragmentVector fragments;
char buffer[128];
for (AllPhaseIterator iter(phaseTimes); !iter.done(); iter.advance()) {
Phase phase;
size_t dagSlot;
iter.get(&phase, &dagSlot);
UniqueChars name = FilterJsonKey(phases[phase].name);
int64_t ownTime = phaseTimes[dagSlot][phase];
JS_snprintf(buffer, sizeof(buffer), "\"%s\":%llu.%03llu",
name.get(), ownTime / 1000, ownTime % 1000);
if (!fragments.append(make_string_copy(buffer)))
return UniqueChars(nullptr);
}
return Join(fragments, ",");
}
Statistics::Statistics(JSRuntime* rt)
: runtime(rt),
startupTime(PRMJ_Now()),
fp(nullptr),
gcDepth(0),
nonincrementalReason_(nullptr),
timedGCStart(0),
preBytes(0),
maxPauseInInterval(0),
phaseNestingDepth(0),
activeDagSlot(PHASE_DAG_NONE),
suspendedPhaseNestingDepth(0),
sliceCallback(nullptr),
aborted(false)
{
PodArrayZero(phaseTotals);
PodArrayZero(counts);
PodArrayZero(phaseStartTimes);
for (auto d : MakeRange(NumTimingArrays))
PodArrayZero(phaseTimes[d]);
static bool initialized = false;
if (!initialized) {
initialized = true;
for (size_t i = 0; i < PHASE_LIMIT; i++) {
MOZ_ASSERT(phases[i].index == i);
for (size_t j = 0; j < PHASE_LIMIT; j++)
MOZ_ASSERT_IF(i != j, phases[i].telemetryBucket != phases[j].telemetryBucket);
}
// Create a static table of descendants for every phase with multiple
// children. This assumes that all descendants come linearly in the
// list, which is reasonable since full dags are not supported; any
// path from the leaf to the root must encounter at most one node with
// multiple parents.
size_t dagSlot = 0;
for (size_t i = 0; i < mozilla::ArrayLength(dagChildEdges); i++) {
Phase parent = dagChildEdges[i].parent;
if (!phaseExtra[parent].dagSlot)
phaseExtra[parent].dagSlot = ++dagSlot;
Phase child = dagChildEdges[i].child;
MOZ_ASSERT(phases[child].parent == PHASE_MULTI_PARENTS);
int j = child;
do {
dagDescendants[phaseExtra[parent].dagSlot].append(Phase(j));
j++;
} while (j != PHASE_LIMIT && phases[j].parent != PHASE_MULTI_PARENTS);
}
MOZ_ASSERT(dagSlot <= MaxMultiparentPhases - 1);
// Fill in the depth of each node in the tree. Multi-parented nodes
// have depth 0.
mozilla::Vector<Phase> stack;
stack.append(PHASE_LIMIT); // Dummy entry to avoid special-casing the first node
for (int i = 0; i < PHASE_LIMIT; i++) {
if (phases[i].parent == PHASE_NO_PARENT ||
phases[i].parent == PHASE_MULTI_PARENTS)
{
stack.clear();
} else {
while (stack.back() != phases[i].parent)
stack.popBack();
}
phaseExtra[i].depth = stack.length();
stack.append(Phase(i));
}
}
char* env = js_sb_getenv("MOZ_GCTIMER");
if (env) {
if (strcmp(env, "none") == 0) {
fp = nullptr;
} else if (strcmp(env, "stdout") == 0) {
fp = stdout;
} else if (strcmp(env, "stderr") == 0) {
fp = stderr;
} else {
fp = fopen(env, "a");
if (!fp)
MOZ_CRASH("Failed to open MOZ_GCTIMER log file.");
}
}
}
Statistics::~Statistics()
{
if (fp && fp != stdout && fp != stderr)
fclose(fp);
}
JS::GCSliceCallback
Statistics::setSliceCallback(JS::GCSliceCallback newCallback)
{
JS::GCSliceCallback oldCallback = sliceCallback;
sliceCallback = newCallback;
return oldCallback;
}
int64_t
Statistics::clearMaxGCPauseAccumulator()
{
int64_t prior = maxPauseInInterval;
maxPauseInInterval = 0;
return prior;
}
int64_t
Statistics::getMaxGCPauseSinceClear()
{
return maxPauseInInterval;
}
static int64_t
SumPhase(Phase phase, const Statistics::PhaseTimeTable times)
{
int64_t sum = 0;
for (auto i : MakeRange(Statistics::NumTimingArrays))
sum += times[i][phase];
return sum;
}
static Phase
LongestPhase(const Statistics::PhaseTimeTable times)
{
int64_t longestTime = 0;
Phase longestPhase = PHASE_NONE;
for (size_t i = 0; i < PHASE_LIMIT; ++i) {
int64_t phaseTime = SumPhase(Phase(i), times);
if (phaseTime > longestTime) {
longestTime = phaseTime;
longestPhase = Phase(i);
}
}
return longestPhase;
}
void
Statistics::printStats()
{
if (aborted) {
fprintf(fp, "OOM during GC statistics collection. The report is unavailable for this GC.\n");
} else {
UniqueChars msg = formatDetailedMessage();
if (msg)
fprintf(fp, "GC(T+%.3fs) %s\n", t(slices[0].start - startupTime) / 1000.0, msg.get());
}
fflush(fp);
}
void
Statistics::beginGC(JSGCInvocationKind kind)
{
slices.clearAndFree();
sccTimes.clearAndFree();
gckind = kind;
nonincrementalReason_ = nullptr;
preBytes = runtime->gc.usage.gcBytes();
}
void
Statistics::endGC()
{
for (auto j : MakeRange(NumTimingArrays))
for (int i = 0; i < PHASE_LIMIT; i++)
phaseTotals[j][i] += phaseTimes[j][i];
int64_t total, longest;
gcDuration(&total, &longest);
int64_t sccTotal, sccLongest;
sccDurations(&sccTotal, &sccLongest);
runtime->addTelemetry(JS_TELEMETRY_GC_IS_COMPARTMENTAL, !zoneStats.isCollectingAllZones());
runtime->addTelemetry(JS_TELEMETRY_GC_MS, t(total));
runtime->addTelemetry(JS_TELEMETRY_GC_MAX_PAUSE_MS, t(longest));
int64_t markTotal = SumPhase(PHASE_MARK, phaseTimes);
int64_t markRootsTotal = SumPhase(PHASE_MARK_ROOTS, phaseTimes);
runtime->addTelemetry(JS_TELEMETRY_GC_MARK_MS, t(markTotal));
runtime->addTelemetry(JS_TELEMETRY_GC_SWEEP_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP]));
runtime->addTelemetry(JS_TELEMETRY_GC_MARK_ROOTS_MS, t(markRootsTotal));
runtime->addTelemetry(JS_TELEMETRY_GC_MARK_GRAY_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP_MARK_GRAY]));
runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL, !!nonincrementalReason_);
runtime->addTelemetry(JS_TELEMETRY_GC_INCREMENTAL_DISABLED, !runtime->gc.isIncrementalGCAllowed());
runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS, t(sccTotal));
runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS, t(sccLongest));
if (!aborted) {
double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
runtime->addTelemetry(JS_TELEMETRY_GC_MMU_50, mmu50 * 100);
}
if (fp)
printStats();
// Clear the timers at the end of a GC because we accumulate time in
// between GCs for some (which come before PHASE_GC_BEGIN in the list.)
PodZero(&phaseStartTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
for (size_t d = PHASE_DAG_NONE; d < NumTimingArrays; d++)
PodZero(&phaseTimes[d][PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
// Clear the OOM flag but only if we are not in a nested GC.
if (gcDepth == 1)
aborted = false;
}
void
Statistics::beginSlice(const ZoneGCStats& zoneStats, JSGCInvocationKind gckind,
SliceBudget budget, JS::gcreason::Reason reason)
{
gcDepth++;
this->zoneStats = zoneStats;
bool first = !runtime->gc.isIncrementalGCInProgress();
if (first)
beginGC(gckind);
SliceData data(budget, reason, PRMJ_Now(), JS_GetCurrentEmbedderTime(), GetPageFaultCount());
if (!slices.append(data)) {
// If we are OOM, set a flag to indicate we have missing slice data.
aborted = true;
return;
}
runtime->addTelemetry(JS_TELEMETRY_GC_REASON, reason);
// Slice callbacks should only fire for the outermost level.
if (gcDepth == 1) {
bool wasFullGC = zoneStats.isCollectingAllZones();
if (sliceCallback)
(*sliceCallback)(runtime, first ? JS::GC_CYCLE_BEGIN : JS::GC_SLICE_BEGIN,
JS::GCDescription(!wasFullGC, gckind, reason));
}
}
void
Statistics::endSlice()
{
if (!aborted) {
slices.back().end = PRMJ_Now();
slices.back().endTimestamp = JS_GetCurrentEmbedderTime();
slices.back().endFaults = GetPageFaultCount();
int64_t sliceTime = slices.back().end - slices.back().start;
runtime->addTelemetry(JS_TELEMETRY_GC_SLICE_MS, t(sliceTime));
runtime->addTelemetry(JS_TELEMETRY_GC_RESET, !!slices.back().resetReason);
if (slices.back().budget.isTimeBudget()) {
int64_t budget_ms = slices.back().budget.timeBudget.budget;
runtime->addTelemetry(JS_TELEMETRY_GC_BUDGET_MS, budget_ms);
if (budget_ms == runtime->gc.defaultSliceBudget())
runtime->addTelemetry(JS_TELEMETRY_GC_ANIMATION_MS, t(sliceTime));
// Record any phase that goes more than 2x over its budget.
if (sliceTime > 2 * budget_ms * 1000) {
Phase longest = LongestPhase(slices.back().phaseTimes);
runtime->addTelemetry(JS_TELEMETRY_GC_SLOW_PHASE, phases[longest].telemetryBucket);
}
}
}
bool last = !runtime->gc.isIncrementalGCInProgress();
if (last)
endGC();
// Slice callbacks should only fire for the outermost level.
if (gcDepth == 1 && !aborted) {
bool wasFullGC = zoneStats.isCollectingAllZones();
if (sliceCallback)
(*sliceCallback)(runtime, last ? JS::GC_CYCLE_END : JS::GC_SLICE_END,
JS::GCDescription(!wasFullGC, gckind, slices.back().reason));
}
/* Do this after the slice callback since it uses these values. */
if (last)
PodArrayZero(counts);
gcDepth--;
MOZ_ASSERT(gcDepth >= 0);
}
bool
Statistics::startTimingMutator()
{
if (phaseNestingDepth != 0) {
// Should only be called from outside of GC.
MOZ_ASSERT(phaseNestingDepth == 1);
MOZ_ASSERT(phaseNesting[0] == PHASE_MUTATOR);
return false;
}
MOZ_ASSERT(suspendedPhaseNestingDepth == 0);
timedGCTime = 0;
phaseStartTimes[PHASE_MUTATOR] = 0;
phaseTimes[PHASE_DAG_NONE][PHASE_MUTATOR] = 0;
timedGCStart = 0;
beginPhase(PHASE_MUTATOR);
return true;
}
bool
Statistics::stopTimingMutator(double& mutator_ms, double& gc_ms)
{
// This should only be called from outside of GC, while timing the mutator.
if (phaseNestingDepth != 1 || phaseNesting[0] != PHASE_MUTATOR)
return false;
endPhase(PHASE_MUTATOR);
mutator_ms = t(phaseTimes[PHASE_DAG_NONE][PHASE_MUTATOR]);
gc_ms = t(timedGCTime);
return true;
}
void
Statistics::beginPhase(Phase phase)
{
Phase parent = phaseNestingDepth ? phaseNesting[phaseNestingDepth - 1] : PHASE_NO_PARENT;
// Re-entry is allowed during callbacks, so pause callback phases while
// other phases are in progress, auto-resuming after they end. As a result,
// nested GC time will not be accounted against the callback phases.
//
// Reuse this mechanism for managing PHASE_MUTATOR.
if (parent == PHASE_GC_BEGIN || parent == PHASE_GC_END || parent == PHASE_MUTATOR) {
MOZ_ASSERT(suspendedPhaseNestingDepth < mozilla::ArrayLength(suspendedPhases));
suspendedPhases[suspendedPhaseNestingDepth++] = parent;
recordPhaseEnd(parent);
parent = phaseNestingDepth ? phaseNesting[phaseNestingDepth - 1] : PHASE_NO_PARENT;
}
// Guard against any other re-entry.
MOZ_ASSERT(!phaseStartTimes[phase]);
MOZ_ASSERT(phases[phase].index == phase);
MOZ_ASSERT(phaseNestingDepth < MAX_NESTING);
MOZ_ASSERT(phases[phase].parent == parent || phases[phase].parent == PHASE_MULTI_PARENTS);
phaseNesting[phaseNestingDepth] = phase;
phaseNestingDepth++;
if (phases[phase].parent == PHASE_MULTI_PARENTS)
activeDagSlot = phaseExtra[parent].dagSlot;
phaseStartTimes[phase] = PRMJ_Now();
}
void
Statistics::recordPhaseEnd(Phase phase)
{
int64_t now = PRMJ_Now();
if (phase == PHASE_MUTATOR)
timedGCStart = now;
phaseNestingDepth--;
int64_t t = now - phaseStartTimes[phase];
if (!slices.empty())
slices.back().phaseTimes[activeDagSlot][phase] += t;
phaseTimes[activeDagSlot][phase] += t;
phaseStartTimes[phase] = 0;
}
void
Statistics::endPhase(Phase phase)
{
recordPhaseEnd(phase);
if (phases[phase].parent == PHASE_MULTI_PARENTS)
activeDagSlot = PHASE_DAG_NONE;
// When emptying the stack, we may need to resume a callback phase
// (PHASE_GC_BEGIN/END) or return to timing the mutator (PHASE_MUTATOR).
if (phaseNestingDepth == 0 && suspendedPhaseNestingDepth > 0) {
Phase resumePhase = suspendedPhases[--suspendedPhaseNestingDepth];
if (resumePhase == PHASE_MUTATOR)
timedGCTime += PRMJ_Now() - timedGCStart;
beginPhase(resumePhase);
}
}
void
Statistics::endParallelPhase(Phase phase, const GCParallelTask* task)
{
phaseNestingDepth--;
if (!slices.empty())
slices.back().phaseTimes[PHASE_DAG_NONE][phase] += task->duration();
phaseTimes[PHASE_DAG_NONE][phase] += task->duration();
phaseStartTimes[phase] = 0;
}
int64_t
Statistics::beginSCC()
{
return PRMJ_Now();
}
void
Statistics::endSCC(unsigned scc, int64_t start)
{
if (scc >= sccTimes.length() && !sccTimes.resize(scc + 1))
return;
sccTimes[scc] += PRMJ_Now() - start;
}
/*
* MMU (minimum mutator utilization) is a measure of how much garbage collection
* is affecting the responsiveness of the system. MMU measurements are given
* with respect to a certain window size. If we report MMU(50ms) = 80%, then
* that means that, for any 50ms window of time, at least 80% of the window is
* devoted to the mutator. In other words, the GC is running for at most 20% of
* the window, or 10ms. The GC can run multiple slices during the 50ms window
* as long as the total time it spends is at most 10ms.
*/
double
Statistics::computeMMU(int64_t window) const
{
MOZ_ASSERT(!slices.empty());
int64_t gc = slices[0].end - slices[0].start;
int64_t gcMax = gc;
if (gc >= window)
return 0.0;
int startIndex = 0;
for (size_t endIndex = 1; endIndex < slices.length(); endIndex++) {
gc += slices[endIndex].end - slices[endIndex].start;
while (slices[endIndex].end - slices[startIndex].end >= window) {
gc -= slices[startIndex].end - slices[startIndex].start;
startIndex++;
}
int64_t cur = gc;
if (slices[endIndex].end - slices[startIndex].start > window)
cur -= (slices[endIndex].end - slices[startIndex].start - window);
if (cur > gcMax)
gcMax = cur;
}
return double(window - gcMax) / window;
}