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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* 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/. */
#ifdef JS_GC_TRACE
#include "gc/GCTrace.h"
#include <stdio.h>
#include <string.h>
#include "gc/GCTraceFormat.h"
#include "js/HashTable.h"
using namespace js;
using namespace js::gc;
JS_STATIC_ASSERT(AllocKinds == unsigned(AllocKind::LIMIT));
JS_STATIC_ASSERT(LastObjectAllocKind == unsigned(AllocKind::OBJECT_LAST));
static FILE* gcTraceFile = nullptr;
static HashSet<const Class*, DefaultHasher<const Class*>, SystemAllocPolicy> tracedClasses;
static HashSet<const ObjectGroup*, DefaultHasher<const ObjectGroup*>, SystemAllocPolicy> tracedGroups;
static inline void
WriteWord(uint64_t data)
{
if (gcTraceFile)
fwrite(&data, sizeof(data), 1, gcTraceFile);
}
static inline void
TraceEvent(GCTraceEvent event, uint64_t payload = 0, uint8_t extra = 0)
{
MOZ_ASSERT(event < GCTraceEventCount);
MOZ_ASSERT((payload >> TracePayloadBits) == 0);
WriteWord((uint64_t(event) << TraceEventShift) |
(uint64_t(extra) << TraceExtraShift) | payload);
}
static inline void
TraceAddress(const void* p)
{
TraceEvent(TraceDataAddress, uint64_t(p));
}
static inline void
TraceInt(uint32_t data)
{
TraceEvent(TraceDataInt, data);
}
static void
TraceString(const char* string)
{
JS_STATIC_ASSERT(sizeof(char) == 1);
size_t length = strlen(string);
const unsigned charsPerWord = sizeof(uint64_t);
unsigned wordCount = (length + charsPerWord - 1) / charsPerWord;
TraceEvent(TraceDataString, length);
for (unsigned i = 0; i < wordCount; ++i) {
union
{
uint64_t word;
char chars[charsPerWord];
} data;
strncpy(data.chars, string + (i * charsPerWord), charsPerWord);
WriteWord(data.word);
}
}
bool
js::gc::InitTrace(GCRuntime& gc)
{
/* This currently does not support multiple runtimes. */
MOZ_ALWAYS_TRUE(!gcTraceFile);
char* filename = getenv("JS_GC_TRACE");
if (!filename)
return true;
if (!tracedClasses.init() || !tracedTypes.init()) {
FinishTrace();
return false;
}
gcTraceFile = fopen(filename, "w");
if (!gcTraceFile) {
FinishTrace();
return false;
}
TraceEvent(TraceEventInit, 0, TraceFormatVersion);
/* Trace information about thing sizes. */
for (auto kind : AllAllocKinds())
TraceEvent(TraceEventThingSize, Arena::thingSize(kind));
return true;
}
void
js::gc::FinishTrace()
{
if (gcTraceFile) {
fclose(gcTraceFile);
gcTraceFile = nullptr;
}
tracedClasses.finish();
tracedTypes.finish();
}
bool
js::gc::TraceEnabled()
{
return gcTraceFile != nullptr;
}
void
js::gc::TraceNurseryAlloc(Cell* thing, size_t size)
{
if (thing) {
/* We don't have AllocKind here, but we can work it out from size. */
unsigned slots = (size - sizeof(JSObject)) / sizeof(JS::Value);
AllocKind kind = GetBackgroundAllocKind(GetGCObjectKind(slots));
TraceEvent(TraceEventNurseryAlloc, uint64_t(thing), kind);
}
}
void
js::gc::TraceTenuredAlloc(Cell* thing, AllocKind kind)
{
if (thing)
TraceEvent(TraceEventTenuredAlloc, uint64_t(thing), kind);
}
static void
MaybeTraceClass(const Class* clasp)
{
if (tracedClasses.has(clasp))
return;
TraceEvent(TraceEventClassInfo, uint64_t(clasp));
TraceString(clasp->name);
TraceInt(clasp->flags);
TraceInt(clasp->finalize != nullptr);
MOZ_ALWAYS_TRUE(tracedClasses.put(clasp));
}
static void
MaybeTraceGroup(ObjectGroup* group)
{
if (tracedGroups.has(group))
return;
MaybeTraceClass(group->clasp());
TraceEvent(TraceEventGroupInfo, uint64_t(group));
TraceAddress(group->clasp());
TraceInt(group->flags());
MOZ_ALWAYS_TRUE(tracedGroups.put(group));
}
void
js::gc::TraceTypeNewScript(ObjectGroup* group)
{
const size_t bufLength = 128;
static char buffer[bufLength];
MOZ_ASSERT(group->hasNewScript());
JSAtom* funName = group->newScript()->fun->displayAtom();
if (!funName)
return;
size_t length = funName->length();
MOZ_ALWAYS_TRUE(length < bufLength);
CopyChars(reinterpret_cast<Latin1Char*>(buffer), *funName);
buffer[length] = 0;
TraceEvent(TraceEventTypeNewScript, uint64_t(group));
TraceString(buffer);
}
void
js::gc::TraceCreateObject(JSObject* object)
{
if (!gcTraceFile)
return;
ObjectGroup* group = object->group();
MaybeTraceGroup(group);
TraceEvent(TraceEventCreateObject, uint64_t(object));
TraceAddress(group);
}
void
js::gc::TraceMinorGCStart()
{
TraceEvent(TraceEventMinorGCStart);
}
void
js::gc::TracePromoteToTenured(Cell* src, Cell* dst)
{
TraceEvent(TraceEventPromoteToTenured, uint64_t(src));
TraceAddress(dst);
}
void
js::gc::TraceMinorGCEnd()
{
TraceEvent(TraceEventMinorGCEnd);
}
void
js::gc::TraceMajorGCStart()
{
TraceEvent(TraceEventMajorGCStart);
}
void
js::gc::TraceTenuredFinalize(Cell* thing)
{
if (!gcTraceFile)
return;
if (thing->tenuredGetAllocKind() == AllocKind::OBJECT_GROUP)
tracedGroups.remove(static_cast<const ObjectGroup*>(thing));
TraceEvent(TraceEventTenuredFinalize, uint64_t(thing));
}
void
js::gc::TraceMajorGCEnd()
{
TraceEvent(TraceEventMajorGCEnd);
}
#endif
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