https://github.com/mozilla/gecko-dev
Tip revision: 373ea7c388c7a2ad93d48298999d9726505e4ead authored by seabld on 21 May 2011, 04:50:50 UTC
Added tag SEAMONKEY_2_1rc2_RELEASE for changeset ac9cf29de0d2. CLOSED TREE a=release
Added tag SEAMONKEY_2_1rc2_RELEASE for changeset ac9cf29de0d2. CLOSED TREE a=release
Tip revision: 373ea7c
jscntxt.cpp
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=80:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* JS execution context.
*/
#include <new>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#ifdef ANDROID
# include <android/log.h>
# include <fstream>
# include <string>
#endif // ANDROID
#include "jsstdint.h"
#include "jstypes.h"
#include "jsarena.h"
#include "jsutil.h"
#include "jsclist.h"
#include "jsprf.h"
#include "jsatom.h"
#include "jscntxt.h"
#include "jsversion.h"
#include "jsdbgapi.h"
#include "jsexn.h"
#include "jsfun.h"
#include "jsgc.h"
#include "jsiter.h"
#include "jslock.h"
#include "jsmath.h"
#include "jsnativestack.h"
#include "jsnum.h"
#include "jsobj.h"
#include "jsopcode.h"
#include "jspubtd.h"
#include "jsscan.h"
#include "jsscope.h"
#include "jsscript.h"
#include "jsstaticcheck.h"
#include "jsstr.h"
#include "jstracer.h"
#ifdef JS_METHODJIT
# include "assembler/assembler/MacroAssembler.h"
#endif
#include "jscntxtinlines.h"
#include "jscompartment.h"
#include "jsinterpinlines.h"
#include "jsobjinlines.h"
#ifdef XP_WIN
# include "jswin.h"
#elif defined(XP_OS2)
# define INCL_DOSMEMMGR
# include <os2.h>
#else
# include <unistd.h>
# include <sys/mman.h>
# if !defined(MAP_ANONYMOUS)
# if defined(MAP_ANON)
# define MAP_ANONYMOUS MAP_ANON
# else
# define MAP_ANONYMOUS 0
# endif
# endif
#endif
using namespace js;
using namespace js::gc;
static const size_t ARENA_HEADER_SIZE_HACK = 40;
static const size_t TEMP_POOL_CHUNK_SIZE = 4096 - ARENA_HEADER_SIZE_HACK;
static void
FreeContext(JSContext *cx);
#ifdef DEBUG
JS_REQUIRES_STACK bool
StackSegment::contains(const JSStackFrame *fp) const
{
JS_ASSERT(inContext());
JSStackFrame *start;
JSStackFrame *stop;
if (isActive()) {
JS_ASSERT(cx->hasfp());
start = cx->fp();
stop = cx->activeSegment()->initialFrame->prev();
} else {
JS_ASSERT(suspendedRegs && suspendedRegs->fp);
start = suspendedRegs->fp;
stop = initialFrame->prev();
}
for (JSStackFrame *f = start; f != stop; f = f->prev()) {
if (f == fp)
return true;
}
return false;
}
#endif
bool
StackSpace::init()
{
void *p;
#ifdef XP_WIN
p = VirtualAlloc(NULL, CAPACITY_BYTES, MEM_RESERVE, PAGE_READWRITE);
if (!p)
return false;
void *check = VirtualAlloc(p, COMMIT_BYTES, MEM_COMMIT, PAGE_READWRITE);
if (p != check)
return false;
base = reinterpret_cast<Value *>(p);
commitEnd = base + COMMIT_VALS;
end = base + CAPACITY_VALS;
#elif defined(XP_OS2)
if (DosAllocMem(&p, CAPACITY_BYTES, PAG_COMMIT | PAG_READ | PAG_WRITE | OBJ_ANY) &&
DosAllocMem(&p, CAPACITY_BYTES, PAG_COMMIT | PAG_READ | PAG_WRITE))
return false;
base = reinterpret_cast<Value *>(p);
end = base + CAPACITY_VALS;
#else
JS_ASSERT(CAPACITY_BYTES % getpagesize() == 0);
p = mmap(NULL, CAPACITY_BYTES, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (p == MAP_FAILED)
return false;
base = reinterpret_cast<Value *>(p);
end = base + CAPACITY_VALS;
#endif
return true;
}
void
StackSpace::finish()
{
#ifdef XP_WIN
VirtualFree(base, (commitEnd - base) * sizeof(Value), MEM_DECOMMIT);
VirtualFree(base, 0, MEM_RELEASE);
#elif defined(XP_OS2)
DosFreeMem(base);
#else
#ifdef SOLARIS
munmap((caddr_t)base, CAPACITY_BYTES);
#else
munmap(base, CAPACITY_BYTES);
#endif
#endif
}
#ifdef XP_WIN
JS_FRIEND_API(bool)
StackSpace::bumpCommit(Value *from, ptrdiff_t nvals) const
{
JS_ASSERT(end - from >= nvals);
Value *newCommit = commitEnd;
Value *request = from + nvals;
/* Use a dumb loop; will probably execute once. */
JS_ASSERT((end - newCommit) % COMMIT_VALS == 0);
do {
newCommit += COMMIT_VALS;
JS_ASSERT((end - newCommit) >= 0);
} while (newCommit < request);
/* The cast is safe because CAPACITY_BYTES is small. */
int32 size = static_cast<int32>(newCommit - commitEnd) * sizeof(Value);
if (!VirtualAlloc(commitEnd, size, MEM_COMMIT, PAGE_READWRITE))
return false;
commitEnd = newCommit;
return true;
}
#endif
void
StackSpace::mark(JSTracer *trc)
{
/*
* The correctness/completeness of marking depends on the continuity
* invariants described by the StackSegment and StackSpace definitions.
*
* NB:
* Stack slots might be torn or uninitialized in the presence of method
* JIT'd code. Arguments are an exception and are always fully synced
* (so they can be read by functions).
*/
Value *end = firstUnused();
for (StackSegment *seg = currentSegment; seg; seg = seg->getPreviousInMemory()) {
STATIC_ASSERT(ubound(end) >= 0);
if (seg->inContext()) {
/* This may be the only pointer to the initialVarObj. */
if (seg->hasInitialVarObj())
MarkObject(trc, seg->getInitialVarObj(), "varobj");
/* Mark slots/args trailing off of the last stack frame. */
JSStackFrame *fp = seg->getCurrentFrame();
MarkStackRangeConservatively(trc, fp->slots(), end);
/* Mark stack frames and slots/args between stack frames. */
JSStackFrame *initial = seg->getInitialFrame();
for (JSStackFrame *f = fp; f != initial; f = f->prev()) {
js_TraceStackFrame(trc, f);
MarkStackRangeConservatively(trc, f->prev()->slots(), (Value *)f);
}
/* Mark initial stack frame and leading args. */
js_TraceStackFrame(trc, initial);
MarkStackRangeConservatively(trc, seg->valueRangeBegin(), (Value *)initial);
} else {
/* Mark slots/args trailing off segment. */
MarkValueRange(trc, seg->valueRangeBegin(), end, "stack");
}
end = (Value *)seg;
}
}
bool
StackSpace::pushSegmentForInvoke(JSContext *cx, uintN argc, InvokeArgsGuard *ag)
{
Value *start = firstUnused();
ptrdiff_t nvals = VALUES_PER_STACK_SEGMENT + 2 + argc;
if (!ensureSpace(cx, start, nvals))
return false;
StackSegment *seg = new(start) StackSegment;
seg->setPreviousInMemory(currentSegment);
currentSegment = seg;
ag->cx = cx;
ag->seg = seg;
ag->argv_ = seg->valueRangeBegin() + 2;
ag->argc_ = argc;
/* Use invokeArgEnd to root [vp, vpend) until the frame is pushed. */
#ifdef DEBUG
ag->prevInvokeSegment = invokeSegment;
invokeSegment = seg;
ag->prevInvokeFrame = invokeFrame;
invokeFrame = NULL;
#endif
ag->prevInvokeArgEnd = invokeArgEnd;
invokeArgEnd = ag->argv() + ag->argc();
return true;
}
void
StackSpace::popSegmentForInvoke(const InvokeArgsGuard &ag)
{
JS_ASSERT(!currentSegment->inContext());
JS_ASSERT(ag.seg == currentSegment);
JS_ASSERT(invokeSegment == currentSegment);
JS_ASSERT(invokeArgEnd == ag.argv() + ag.argc());
currentSegment = currentSegment->getPreviousInMemory();
#ifdef DEBUG
invokeSegment = ag.prevInvokeSegment;
invokeFrame = ag.prevInvokeFrame;
#endif
invokeArgEnd = ag.prevInvokeArgEnd;
}
bool
StackSpace::getSegmentAndFrame(JSContext *cx, uintN vplen, uintN nslots,
FrameGuard *fg) const
{
Value *start = firstUnused();
uintN nvals = VALUES_PER_STACK_SEGMENT + vplen + VALUES_PER_STACK_FRAME + nslots;
if (!ensureSpace(cx, start, nvals))
return false;
fg->seg_ = new(start) StackSegment;
fg->vp_ = start + VALUES_PER_STACK_SEGMENT;
fg->fp_ = reinterpret_cast<JSStackFrame *>(fg->vp() + vplen);
return true;
}
void
StackSpace::pushSegmentAndFrame(JSContext *cx, JSFrameRegs *regs, FrameGuard *fg)
{
/* Caller should have already initialized regs. */
JS_ASSERT(regs->fp == fg->fp());
StackSegment *seg = fg->segment();
/* Register new segment/frame with the context. */
cx->pushSegmentAndFrame(seg, *regs);
/* Officially push the segment/frame on the stack. */
seg->setPreviousInMemory(currentSegment);
currentSegment = seg;
/* Mark as 'pushed' in the guard. */
fg->cx_ = cx;
}
void
StackSpace::popSegmentAndFrame(JSContext *cx)
{
JS_ASSERT(isCurrentAndActive(cx));
JS_ASSERT(cx->hasActiveSegment());
/* Officially pop the segment/frame from the stack. */
currentSegment = currentSegment->getPreviousInMemory();
/* Unregister pushed segment/frame from the context. */
cx->popSegmentAndFrame();
/*
* N.B. This StackSpace should be GC-able without any operations after
* cx->popSegmentAndFrame executes since it can trigger GC.
*/
}
FrameGuard::~FrameGuard()
{
if (!pushed())
return;
JS_ASSERT(cx_->activeSegment() == segment());
JS_ASSERT(cx_->maybefp() == fp());
cx_->stack().popSegmentAndFrame(cx_);
}
bool
StackSpace::getExecuteFrame(JSContext *cx, JSScript *script, ExecuteFrameGuard *fg) const
{
return getSegmentAndFrame(cx, 2, script->nslots, fg);
}
void
StackSpace::pushExecuteFrame(JSContext *cx, JSObject *initialVarObj, ExecuteFrameGuard *fg)
{
JSStackFrame *fp = fg->fp();
JSScript *script = fp->script();
fg->regs_.pc = script->code;
fg->regs_.fp = fp;
fg->regs_.sp = fp->base();
pushSegmentAndFrame(cx, &fg->regs_, fg);
fg->seg_->setInitialVarObj(initialVarObj);
}
bool
StackSpace::pushDummyFrame(JSContext *cx, JSObject &scopeChain, DummyFrameGuard *fg)
{
if (!getSegmentAndFrame(cx, 0 /*vplen*/, 0 /*nslots*/, fg))
return false;
fg->fp()->initDummyFrame(cx, scopeChain);
fg->regs_.fp = fg->fp();
fg->regs_.pc = NULL;
fg->regs_.sp = fg->fp()->slots();
pushSegmentAndFrame(cx, &fg->regs_, fg);
return true;
}
bool
StackSpace::getGeneratorFrame(JSContext *cx, uintN vplen, uintN nslots, GeneratorFrameGuard *fg)
{
return getSegmentAndFrame(cx, vplen, nslots, fg);
}
void
StackSpace::pushGeneratorFrame(JSContext *cx, JSFrameRegs *regs, GeneratorFrameGuard *fg)
{
JS_ASSERT(regs->fp == fg->fp());
JS_ASSERT(regs->fp->prev() == cx->maybefp());
pushSegmentAndFrame(cx, regs, fg);
}
bool
StackSpace::bumpCommitAndLimit(JSStackFrame *base, Value *sp, uintN nvals, Value **limit) const
{
JS_ASSERT(sp >= firstUnused());
JS_ASSERT(sp + nvals >= *limit);
#ifdef XP_WIN
if (commitEnd <= *limit) {
Value *quotaEnd = (Value *)base + STACK_QUOTA;
if (sp + nvals < quotaEnd) {
if (!ensureSpace(NULL, sp, nvals))
return false;
*limit = Min(quotaEnd, commitEnd);
return true;
}
}
#endif
return false;
}
void
FrameRegsIter::initSlow()
{
if (!curseg) {
curfp = NULL;
cursp = NULL;
curpc = NULL;
return;
}
JS_ASSERT(curseg->isSuspended());
curfp = curseg->getSuspendedFrame();
cursp = curseg->getSuspendedRegs()->sp;
curpc = curseg->getSuspendedRegs()->pc;
}
/*
* Using the invariant described in the js::StackSegment comment, we know that,
* when a pair of prev-linked stack frames are in the same segment, the
* first frame's address is the top of the prev-frame's stack, modulo missing
* arguments.
*/
void
FrameRegsIter::incSlow(JSStackFrame *fp, JSStackFrame *prev)
{
JS_ASSERT(prev);
JS_ASSERT(curpc == curfp->pc(cx, fp));
JS_ASSERT(fp == curseg->getInitialFrame());
/*
* If fp is in cs and the prev-frame is in csprev, it is not necessarily
* the case that |cs->getPreviousInContext == csprev| or that
* |csprev->getSuspendedFrame == prev| (because of indirect eval and
* JS_EvaluateInStackFrame). To compute prev's sp, we need to do a linear
* scan, keeping track of what is immediately after prev in memory.
*/
curseg = curseg->getPreviousInContext();
cursp = curseg->getSuspendedRegs()->sp;
JSStackFrame *f = curseg->getSuspendedFrame();
while (f != prev) {
if (f == curseg->getInitialFrame()) {
curseg = curseg->getPreviousInContext();
cursp = curseg->getSuspendedRegs()->sp;
f = curseg->getSuspendedFrame();
} else {
cursp = f->formalArgsEnd();
f = f->prev();
}
}
}
AllFramesIter::AllFramesIter(JSContext *cx)
: curcs(cx->stack().getCurrentSegment()),
curfp(curcs ? curcs->getCurrentFrame() : NULL)
{
}
AllFramesIter&
AllFramesIter::operator++()
{
JS_ASSERT(!done());
if (curfp == curcs->getInitialFrame()) {
curcs = curcs->getPreviousInMemory();
curfp = curcs ? curcs->getCurrentFrame() : NULL;
} else {
curfp = curfp->prev();
}
return *this;
}
bool
JSThreadData::init()
{
#ifdef DEBUG
/* The data must be already zeroed. */
for (size_t i = 0; i != sizeof(*this); ++i)
JS_ASSERT(reinterpret_cast<uint8*>(this)[i] == 0);
#endif
if (!stackSpace.init())
return false;
dtoaState = js_NewDtoaState();
if (!dtoaState) {
finish();
return false;
}
nativeStackBase = GetNativeStackBase();
#ifdef JS_TRACER
/* Set the default size for the code cache to 16MB. */
maxCodeCacheBytes = 16 * 1024 * 1024;
#endif
return true;
}
void
JSThreadData::finish()
{
if (dtoaState)
js_DestroyDtoaState(dtoaState);
js_FinishGSNCache(&gsnCache);
propertyCache.~PropertyCache();
stackSpace.finish();
}
void
JSThreadData::mark(JSTracer *trc)
{
stackSpace.mark(trc);
}
void
JSThreadData::purge(JSContext *cx)
{
js_PurgeGSNCache(&gsnCache);
/* FIXME: bug 506341. */
propertyCache.purge(cx);
}
#ifdef JS_THREADSAFE
static JSThread *
NewThread(void *id)
{
JS_ASSERT(js_CurrentThreadId() == id);
JSThread *thread = (JSThread *) js_calloc(sizeof(JSThread));
if (!thread)
return NULL;
JS_INIT_CLIST(&thread->contextList);
thread->id = id;
if (!thread->data.init()) {
js_free(thread);
return NULL;
}
return thread;
}
static void
DestroyThread(JSThread *thread)
{
/* The thread must have zero contexts. */
JS_ASSERT(JS_CLIST_IS_EMPTY(&thread->contextList));
/*
* The conservative GC scanner should be disabled when the thread leaves
* the last request.
*/
JS_ASSERT(!thread->data.conservativeGC.hasStackToScan());
thread->data.finish();
js_free(thread);
}
JSThread *
js_CurrentThread(JSRuntime *rt)
{
void *id = js_CurrentThreadId();
JS_LOCK_GC(rt);
/*
* We must not race with a GC that accesses cx->thread for JSContext
* instances on all threads, see bug 476934.
*/
js_WaitForGC(rt);
JSThread *thread;
JSThread::Map::AddPtr p = rt->threads.lookupForAdd(id);
if (p) {
thread = p->value;
/*
* If thread has no contexts, it might be left over from a previous
* thread with the same id but a different stack address.
*/
if (JS_CLIST_IS_EMPTY(&thread->contextList))
thread->data.nativeStackBase = GetNativeStackBase();
} else {
JS_UNLOCK_GC(rt);
thread = NewThread(id);
if (!thread)
return NULL;
JS_LOCK_GC(rt);
js_WaitForGC(rt);
if (!rt->threads.relookupOrAdd(p, id, thread)) {
JS_UNLOCK_GC(rt);
DestroyThread(thread);
return NULL;
}
/* Another thread cannot add an entry for the current thread id. */
JS_ASSERT(p->value == thread);
}
JS_ASSERT(thread->id == id);
#ifdef DEBUG
char* gnsb = (char*) GetNativeStackBase();
JS_ASSERT(gnsb + 0 == (char*) thread->data.nativeStackBase ||
/* Work around apparent glibc bug; see bug 608526. */
gnsb + 0x1000 == (char*) thread->data.nativeStackBase ||
gnsb + 0x2000 == (char*) thread->data.nativeStackBase ||
gnsb + 0x3000 == (char*) thread->data.nativeStackBase);
#endif
return thread;
}
JSBool
js_InitContextThread(JSContext *cx)
{
JSThread *thread = js_CurrentThread(cx->runtime);
if (!thread)
return false;
JS_APPEND_LINK(&cx->threadLinks, &thread->contextList);
cx->thread = thread;
return true;
}
void
js_ClearContextThread(JSContext *cx)
{
JS_ASSERT(CURRENT_THREAD_IS_ME(cx->thread));
JS_REMOVE_AND_INIT_LINK(&cx->threadLinks);
cx->thread = NULL;
}
#endif /* JS_THREADSAFE */
JSThreadData *
js_CurrentThreadData(JSRuntime *rt)
{
#ifdef JS_THREADSAFE
JSThread *thread = js_CurrentThread(rt);
if (!thread)
return NULL;
return &thread->data;
#else
return &rt->threadData;
#endif
}
JSBool
js_InitThreads(JSRuntime *rt)
{
#ifdef JS_THREADSAFE
if (!rt->threads.init(4))
return false;
#else
if (!rt->threadData.init())
return false;
#endif
return true;
}
void
js_FinishThreads(JSRuntime *rt)
{
#ifdef JS_THREADSAFE
if (!rt->threads.initialized())
return;
for (JSThread::Map::Range r = rt->threads.all(); !r.empty(); r.popFront()) {
JSThread *thread = r.front().value;
JS_ASSERT(JS_CLIST_IS_EMPTY(&thread->contextList));
DestroyThread(thread);
}
rt->threads.clear();
#else
rt->threadData.finish();
#endif
}
void
js_PurgeThreads(JSContext *cx)
{
#ifdef JS_THREADSAFE
for (JSThread::Map::Enum e(cx->runtime->threads);
!e.empty();
e.popFront()) {
JSThread *thread = e.front().value;
if (JS_CLIST_IS_EMPTY(&thread->contextList)) {
JS_ASSERT(cx->thread != thread);
DestroyThread(thread);
e.removeFront();
} else {
thread->data.purge(cx);
}
}
#else
cx->runtime->threadData.purge(cx);
#endif
}
JSContext *
js_NewContext(JSRuntime *rt, size_t stackChunkSize)
{
JSContext *cx;
JSBool ok, first;
JSContextCallback cxCallback;
/*
* We need to initialize the new context fully before adding it to the
* runtime list. After that it can be accessed from another thread via
* js_ContextIterator.
*/
void *mem = js_calloc(sizeof *cx);
if (!mem)
return NULL;
cx = new (mem) JSContext(rt);
cx->debugHooks = &rt->globalDebugHooks;
#if JS_STACK_GROWTH_DIRECTION > 0
cx->stackLimit = (jsuword) -1;
#endif
cx->scriptStackQuota = JS_DEFAULT_SCRIPT_STACK_QUOTA;
JS_STATIC_ASSERT(JSVERSION_DEFAULT == 0);
JS_ASSERT(cx->findVersion() == JSVERSION_DEFAULT);
VOUCH_DOES_NOT_REQUIRE_STACK();
JS_InitArenaPool(&cx->tempPool, "temp", TEMP_POOL_CHUNK_SIZE, sizeof(jsdouble),
&cx->scriptStackQuota);
JS_InitArenaPool(&cx->regExpPool, "regExp", TEMP_POOL_CHUNK_SIZE, sizeof(int),
&cx->scriptStackQuota);
JS_ASSERT(cx->resolveFlags == 0);
if (!cx->busyArrays.init()) {
FreeContext(cx);
return NULL;
}
#ifdef JS_THREADSAFE
if (!js_InitContextThread(cx)) {
FreeContext(cx);
return NULL;
}
#endif
/*
* Here the GC lock is still held after js_InitContextThread took it and
* the GC is not running on another thread.
*/
for (;;) {
if (rt->state == JSRTS_UP) {
JS_ASSERT(!JS_CLIST_IS_EMPTY(&rt->contextList));
first = JS_FALSE;
break;
}
if (rt->state == JSRTS_DOWN) {
JS_ASSERT(JS_CLIST_IS_EMPTY(&rt->contextList));
first = JS_TRUE;
rt->state = JSRTS_LAUNCHING;
break;
}
JS_WAIT_CONDVAR(rt->stateChange, JS_NO_TIMEOUT);
/*
* During the above wait after we are notified about the state change
* but before we wake up, another thread could enter the GC from
* js_DestroyContext, bug 478336. So we must wait here to ensure that
* when we exit the loop with the first flag set to true, that GC is
* finished.
*/
js_WaitForGC(rt);
}
JS_APPEND_LINK(&cx->link, &rt->contextList);
JS_UNLOCK_GC(rt);
js_InitRandom(cx);
/*
* If cx is the first context on this runtime, initialize well-known atoms,
* keywords, numbers, and strings. If one of these steps should fail, the
* runtime will be left in a partially initialized state, with zeroes and
* nulls stored in the default-initialized remainder of the struct. We'll
* clean the runtime up under js_DestroyContext, because cx will be "last"
* as well as "first".
*/
if (first) {
#ifdef JS_THREADSAFE
JS_BeginRequest(cx);
#endif
ok = js_InitCommonAtoms(cx);
/*
* scriptFilenameTable may be left over from a previous episode of
* non-zero contexts alive in rt, so don't re-init the table if it's
* not necessary.
*/
if (ok && !rt->scriptFilenameTable)
ok = js_InitRuntimeScriptState(rt);
if (ok)
ok = js_InitRuntimeNumberState(cx);
#ifdef JS_THREADSAFE
JS_EndRequest(cx);
#endif
if (!ok) {
js_DestroyContext(cx, JSDCM_NEW_FAILED);
return NULL;
}
AutoLockGC lock(rt);
rt->state = JSRTS_UP;
JS_NOTIFY_ALL_CONDVAR(rt->stateChange);
}
cxCallback = rt->cxCallback;
if (cxCallback && !cxCallback(cx, JSCONTEXT_NEW)) {
js_DestroyContext(cx, JSDCM_NEW_FAILED);
return NULL;
}
return cx;
}
#if defined DEBUG && defined XP_UNIX
# include <stdio.h>
class JSAutoFile {
public:
JSAutoFile() : mFile(NULL) {}
~JSAutoFile() {
if (mFile)
fclose(mFile);
}
FILE *open(const char *fname, const char *mode) {
return mFile = fopen(fname, mode);
}
operator FILE *() {
return mFile;
}
private:
FILE *mFile;
};
static void
DumpEvalCacheMeter(JSContext *cx)
{
if (const char *filename = getenv("JS_EVALCACHE_STATFILE")) {
struct {
const char *name;
ptrdiff_t offset;
} table[] = {
#define frob(x) { #x, offsetof(JSEvalCacheMeter, x) }
EVAL_CACHE_METER_LIST(frob)
#undef frob
};
JSEvalCacheMeter *ecm = &cx->compartment->evalCacheMeter;
static JSAutoFile fp;
if (!fp && !fp.open(filename, "w"))
return;
fprintf(fp, "eval cache meter (%p):\n",
#ifdef JS_THREADSAFE
(void *) cx->thread
#else
(void *) cx->runtime
#endif
);
for (uintN i = 0; i < JS_ARRAY_LENGTH(table); ++i) {
fprintf(fp, "%-8.8s %llu\n",
table[i].name,
(unsigned long long int) *(uint64 *)((uint8 *)ecm + table[i].offset));
}
fprintf(fp, "hit ratio %g%%\n", ecm->hit * 100. / ecm->probe);
fprintf(fp, "avg steps %g\n", double(ecm->step) / ecm->probe);
fflush(fp);
}
}
# define DUMP_EVAL_CACHE_METER(cx) DumpEvalCacheMeter(cx)
static void
DumpFunctionCountMap(const char *title, JSRuntime::FunctionCountMap &map, FILE *fp)
{
fprintf(fp, "\n%s count map:\n", title);
for (JSRuntime::FunctionCountMap::Range r = map.all(); !r.empty(); r.popFront()) {
JSFunction *fun = r.front().key;
int32 count = r.front().value;
fprintf(fp, "%10d %s:%u\n", count, fun->u.i.script->filename, fun->u.i.script->lineno);
}
}
static void
DumpFunctionMeter(JSContext *cx)
{
if (const char *filename = cx->runtime->functionMeterFilename) {
struct {
const char *name;
ptrdiff_t offset;
} table[] = {
#define frob(x) { #x, offsetof(JSFunctionMeter, x) }
FUNCTION_KIND_METER_LIST(frob)
#undef frob
};
JSFunctionMeter *fm = &cx->runtime->functionMeter;
static JSAutoFile fp;
if (!fp && !fp.open(filename, "w"))
return;
fprintf(fp, "function meter (%s):\n", cx->runtime->lastScriptFilename);
for (uintN i = 0; i < JS_ARRAY_LENGTH(table); ++i)
fprintf(fp, "%-19.19s %d\n", table[i].name, *(int32 *)((uint8 *)fm + table[i].offset));
DumpFunctionCountMap("method read barrier", cx->runtime->methodReadBarrierCountMap, fp);
DumpFunctionCountMap("unjoined function", cx->runtime->unjoinedFunctionCountMap, fp);
putc('\n', fp);
fflush(fp);
}
}
# define DUMP_FUNCTION_METER(cx) DumpFunctionMeter(cx)
#endif /* DEBUG && XP_UNIX */
#ifndef DUMP_EVAL_CACHE_METER
# define DUMP_EVAL_CACHE_METER(cx) ((void) 0)
#endif
#ifndef DUMP_FUNCTION_METER
# define DUMP_FUNCTION_METER(cx) ((void) 0)
#endif
void
js_DestroyContext(JSContext *cx, JSDestroyContextMode mode)
{
JSRuntime *rt;
JSContextCallback cxCallback;
JSBool last;
JS_ASSERT(!cx->enumerators);
rt = cx->runtime;
#ifdef JS_THREADSAFE
/*
* For API compatibility we allow to destroy contexts without a thread in
* optimized builds. We assume that the embedding knows that an OOM error
* cannot happen in JS_SetContextThread.
*/
JS_ASSERT(cx->thread && CURRENT_THREAD_IS_ME(cx->thread));
if (!cx->thread)
JS_SetContextThread(cx);
/*
* For API compatibility we support destroying contexts with non-zero
* cx->outstandingRequests but we assume that all JS_BeginRequest calls
* on this cx contributes to cx->thread->data.requestDepth and there is no
* JS_SuspendRequest calls that set aside the counter.
*/
JS_ASSERT(cx->outstandingRequests <= cx->thread->data.requestDepth);
#endif
if (mode != JSDCM_NEW_FAILED) {
cxCallback = rt->cxCallback;
if (cxCallback) {
/*
* JSCONTEXT_DESTROY callback is not allowed to fail and must
* return true.
*/
#ifdef DEBUG
JSBool callbackStatus =
#endif
cxCallback(cx, JSCONTEXT_DESTROY);
JS_ASSERT(callbackStatus);
}
}
JS_LOCK_GC(rt);
JS_ASSERT(rt->state == JSRTS_UP || rt->state == JSRTS_LAUNCHING);
#ifdef JS_THREADSAFE
/*
* Typically we are called outside a request, so ensure that the GC is not
* running before removing the context from rt->contextList, see bug 477021.
*/
if (cx->thread->data.requestDepth == 0)
js_WaitForGC(rt);
#endif
JS_REMOVE_LINK(&cx->link);
last = (rt->contextList.next == &rt->contextList);
if (last)
rt->state = JSRTS_LANDING;
if (last || mode == JSDCM_FORCE_GC || mode == JSDCM_MAYBE_GC
#ifdef JS_THREADSAFE
|| cx->outstandingRequests != 0
#endif
) {
JS_ASSERT(!rt->gcRunning);
JS_UNLOCK_GC(rt);
if (last) {
#ifdef JS_THREADSAFE
/*
* If this thread is not in a request already, begin one now so
* that we wait for any racing GC started on a not-last context to
* finish, before we plow ahead and unpin atoms. Note that even
* though we begin a request here if necessary, we end all
* thread's requests before forcing a final GC. This lets any
* not-last context destruction racing in another thread try to
* force or maybe run the GC, but by that point, rt->state will
* not be JSRTS_UP, and that GC attempt will return early.
*/
if (cx->thread->data.requestDepth == 0)
JS_BeginRequest(cx);
#endif
js_FinishRuntimeNumberState(cx);
/* Unpin all common atoms before final GC. */
js_FinishCommonAtoms(cx);
/* Clear debugging state to remove GC roots. */
JS_ClearAllTraps(cx);
JS_ClearAllWatchPoints(cx);
}
#ifdef JS_THREADSAFE
/*
* Destroying a context implicitly calls JS_EndRequest(). Also, we must
* end our request here in case we are "last" -- in that event, another
* js_DestroyContext that was not last might be waiting in the GC for our
* request to end. We'll let it run below, just before we do the truly
* final GC and then free atom state.
*/
while (cx->outstandingRequests != 0)
JS_EndRequest(cx);
#endif
if (last) {
js_GC(cx, NULL, GC_LAST_CONTEXT);
DUMP_EVAL_CACHE_METER(cx);
DUMP_FUNCTION_METER(cx);
/* Take the runtime down, now that it has no contexts or atoms. */
JS_LOCK_GC(rt);
rt->state = JSRTS_DOWN;
JS_NOTIFY_ALL_CONDVAR(rt->stateChange);
} else {
if (mode == JSDCM_FORCE_GC)
js_GC(cx, NULL, GC_NORMAL);
else if (mode == JSDCM_MAYBE_GC)
JS_MaybeGC(cx);
JS_LOCK_GC(rt);
js_WaitForGC(rt);
}
}
#ifdef JS_THREADSAFE
#ifdef DEBUG
JSThread *t = cx->thread;
#endif
js_ClearContextThread(cx);
JS_ASSERT_IF(JS_CLIST_IS_EMPTY(&t->contextList), !t->data.requestDepth);
#endif
#ifdef JS_METER_DST_OFFSET_CACHING
cx->dstOffsetCache.dumpStats();
#endif
JS_UNLOCK_GC(rt);
FreeContext(cx);
}
static void
FreeContext(JSContext *cx)
{
#ifdef JS_THREADSAFE
JS_ASSERT(!cx->thread);
#endif
/* Free the stuff hanging off of cx. */
VOUCH_DOES_NOT_REQUIRE_STACK();
JS_FinishArenaPool(&cx->tempPool);
JS_FinishArenaPool(&cx->regExpPool);
if (cx->lastMessage)
js_free(cx->lastMessage);
/* Remove any argument formatters. */
JSArgumentFormatMap *map = cx->argumentFormatMap;
while (map) {
JSArgumentFormatMap *temp = map;
map = map->next;
cx->free(temp);
}
/* Destroy the resolve recursion damper. */
if (cx->resolvingTable) {
JS_DHashTableDestroy(cx->resolvingTable);
cx->resolvingTable = NULL;
}
/* Finally, free cx itself. */
cx->~JSContext();
js_free(cx);
}
JSContext *
js_ContextIterator(JSRuntime *rt, JSBool unlocked, JSContext **iterp)
{
JSContext *cx = *iterp;
Conditionally<AutoLockGC> lockIf(!!unlocked, rt);
cx = js_ContextFromLinkField(cx ? cx->link.next : rt->contextList.next);
if (&cx->link == &rt->contextList)
cx = NULL;
*iterp = cx;
return cx;
}
JS_FRIEND_API(JSContext *)
js_NextActiveContext(JSRuntime *rt, JSContext *cx)
{
JSContext *iter = cx;
#ifdef JS_THREADSAFE
while ((cx = js_ContextIterator(rt, JS_FALSE, &iter)) != NULL) {
if (cx->outstandingRequests && cx->thread->data.requestDepth)
break;
}
return cx;
#else
return js_ContextIterator(rt, JS_FALSE, &iter);
#endif
}
static JSDHashNumber
resolving_HashKey(JSDHashTable *table, const void *ptr)
{
const JSResolvingKey *key = (const JSResolvingKey *)ptr;
return (JSDHashNumber(uintptr_t(key->obj)) >> JS_GCTHING_ALIGN) ^ JSID_BITS(key->id);
}
static JSBool
resolving_MatchEntry(JSDHashTable *table,
const JSDHashEntryHdr *hdr,
const void *ptr)
{
const JSResolvingEntry *entry = (const JSResolvingEntry *)hdr;
const JSResolvingKey *key = (const JSResolvingKey *)ptr;
return entry->key.obj == key->obj && entry->key.id == key->id;
}
static const JSDHashTableOps resolving_dhash_ops = {
JS_DHashAllocTable,
JS_DHashFreeTable,
resolving_HashKey,
resolving_MatchEntry,
JS_DHashMoveEntryStub,
JS_DHashClearEntryStub,
JS_DHashFinalizeStub,
NULL
};
JSBool
js_StartResolving(JSContext *cx, JSResolvingKey *key, uint32 flag,
JSResolvingEntry **entryp)
{
JSDHashTable *table;
JSResolvingEntry *entry;
table = cx->resolvingTable;
if (!table) {
table = JS_NewDHashTable(&resolving_dhash_ops, NULL,
sizeof(JSResolvingEntry),
JS_DHASH_MIN_SIZE);
if (!table)
goto outofmem;
cx->resolvingTable = table;
}
entry = (JSResolvingEntry *)
JS_DHashTableOperate(table, key, JS_DHASH_ADD);
if (!entry)
goto outofmem;
if (entry->flags & flag) {
/* An entry for (key, flag) exists already -- dampen recursion. */
entry = NULL;
} else {
/* Fill in key if we were the first to add entry, then set flag. */
if (!entry->key.obj)
entry->key = *key;
entry->flags |= flag;
}
*entryp = entry;
return JS_TRUE;
outofmem:
JS_ReportOutOfMemory(cx);
return JS_FALSE;
}
void
js_StopResolving(JSContext *cx, JSResolvingKey *key, uint32 flag,
JSResolvingEntry *entry, uint32 generation)
{
JSDHashTable *table;
/*
* Clear flag from entry->flags and return early if other flags remain.
* We must take care to re-lookup entry if the table has changed since
* it was found by js_StartResolving.
*/
table = cx->resolvingTable;
if (!entry || table->generation != generation) {
entry = (JSResolvingEntry *)
JS_DHashTableOperate(table, key, JS_DHASH_LOOKUP);
}
JS_ASSERT(JS_DHASH_ENTRY_IS_BUSY(&entry->hdr));
entry->flags &= ~flag;
if (entry->flags)
return;
/*
* Do a raw remove only if fewer entries were removed than would cause
* alpha to be less than .5 (alpha is at most .75). Otherwise, we just
* call JS_DHashTableOperate to re-lookup the key and remove its entry,
* compressing or shrinking the table as needed.
*/
if (table->removedCount < JS_DHASH_TABLE_SIZE(table) >> 2)
JS_DHashTableRawRemove(table, &entry->hdr);
else
JS_DHashTableOperate(table, key, JS_DHASH_REMOVE);
}
static void
ReportError(JSContext *cx, const char *message, JSErrorReport *reportp,
JSErrorCallback callback, void *userRef)
{
/*
* Check the error report, and set a JavaScript-catchable exception
* if the error is defined to have an associated exception. If an
* exception is thrown, then the JSREPORT_EXCEPTION flag will be set
* on the error report, and exception-aware hosts should ignore it.
*/
JS_ASSERT(reportp);
if ((!callback || callback == js_GetErrorMessage) &&
reportp->errorNumber == JSMSG_UNCAUGHT_EXCEPTION)
reportp->flags |= JSREPORT_EXCEPTION;
/*
* Call the error reporter only if an exception wasn't raised.
*
* If an exception was raised, then we call the debugErrorHook
* (if present) to give it a chance to see the error before it
* propagates out of scope. This is needed for compatability
* with the old scheme.
*/
if (!JS_IsRunning(cx) ||
!js_ErrorToException(cx, message, reportp, callback, userRef)) {
js_ReportErrorAgain(cx, message, reportp);
} else if (cx->debugHooks->debugErrorHook && cx->errorReporter) {
JSDebugErrorHook hook = cx->debugHooks->debugErrorHook;
/* test local in case debugErrorHook changed on another thread */
if (hook)
hook(cx, message, reportp, cx->debugHooks->debugErrorHookData);
}
}
/* The report must be initially zeroed. */
static void
PopulateReportBlame(JSContext *cx, JSErrorReport *report)
{
/*
* Walk stack until we find a frame that is associated with some script
* rather than a native frame.
*/
for (JSStackFrame *fp = js_GetTopStackFrame(cx); fp; fp = fp->prev()) {
if (fp->pc(cx)) {
report->filename = fp->script()->filename;
report->lineno = js_FramePCToLineNumber(cx, fp);
break;
}
}
}
/*
* We don't post an exception in this case, since doing so runs into
* complications of pre-allocating an exception object which required
* running the Exception class initializer early etc.
* Instead we just invoke the errorReporter with an "Out Of Memory"
* type message, and then hope the process ends swiftly.
*/
void
js_ReportOutOfMemory(JSContext *cx)
{
#ifdef JS_TRACER
/*
* If we are in a builtin called directly from trace, don't report an
* error. We will retry in the interpreter instead.
*/
if (JS_ON_TRACE(cx) && !JS_TRACE_MONITOR_ON_TRACE(cx)->bailExit)
return;
#endif
JSErrorReport report;
JSErrorReporter onError = cx->errorReporter;
/* Get the message for this error, but we won't expand any arguments. */
const JSErrorFormatString *efs =
js_GetLocalizedErrorMessage(cx, NULL, NULL, JSMSG_OUT_OF_MEMORY);
const char *msg = efs ? efs->format : "Out of memory";
/* Fill out the report, but don't do anything that requires allocation. */
PodZero(&report);
report.flags = JSREPORT_ERROR;
report.errorNumber = JSMSG_OUT_OF_MEMORY;
PopulateReportBlame(cx, &report);
/*
* If debugErrorHook is present then we give it a chance to veto sending
* the error on to the regular ErrorReporter. We also clear a pending
* exception if any now so the hooks can replace the out-of-memory error
* by a script-catchable exception.
*/
cx->clearPendingException();
if (onError) {
JSDebugErrorHook hook = cx->debugHooks->debugErrorHook;
if (hook &&
!hook(cx, msg, &report, cx->debugHooks->debugErrorHookData)) {
onError = NULL;
}
}
if (onError)
onError(cx, msg, &report);
}
void
js_ReportOutOfScriptQuota(JSContext *cx)
{
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_SCRIPT_STACK_QUOTA);
}
JS_FRIEND_API(void)
js_ReportOverRecursed(JSContext *cx)
{
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_OVER_RECURSED);
}
void
js_ReportAllocationOverflow(JSContext *cx)
{
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_ALLOC_OVERFLOW);
}
/*
* Given flags and the state of cx, decide whether we should report an
* error, a warning, or just continue execution normally. Return
* true if we should continue normally, without reporting anything;
* otherwise, adjust *flags as appropriate and return false.
*/
static bool
checkReportFlags(JSContext *cx, uintN *flags)
{
if (JSREPORT_IS_STRICT_MODE_ERROR(*flags)) {
/*
* Error in strict code; warning with strict option; okay otherwise.
* We assume that if the top frame is a native, then it is strict if
* the nearest scripted frame is strict, see bug 536306.
*/
JSStackFrame *fp = js_GetScriptedCaller(cx, NULL);
if (fp && fp->script()->strictModeCode)
*flags &= ~JSREPORT_WARNING;
else if (cx->hasStrictOption())
*flags |= JSREPORT_WARNING;
else
return true;
} else if (JSREPORT_IS_STRICT(*flags)) {
/* Warning/error only when JSOPTION_STRICT is set. */
if (!cx->hasStrictOption())
return true;
}
/* Warnings become errors when JSOPTION_WERROR is set. */
if (JSREPORT_IS_WARNING(*flags) && cx->hasWErrorOption())
*flags &= ~JSREPORT_WARNING;
return false;
}
JSBool
js_ReportErrorVA(JSContext *cx, uintN flags, const char *format, va_list ap)
{
char *message;
jschar *ucmessage;
size_t messagelen;
JSErrorReport report;
JSBool warning;
if (checkReportFlags(cx, &flags))
return JS_TRUE;
message = JS_vsmprintf(format, ap);
if (!message)
return JS_FALSE;
messagelen = strlen(message);
PodZero(&report);
report.flags = flags;
report.errorNumber = JSMSG_USER_DEFINED_ERROR;
report.ucmessage = ucmessage = js_InflateString(cx, message, &messagelen);
PopulateReportBlame(cx, &report);
warning = JSREPORT_IS_WARNING(report.flags);
ReportError(cx, message, &report, NULL, NULL);
js_free(message);
cx->free(ucmessage);
return warning;
}
/*
* The arguments from ap need to be packaged up into an array and stored
* into the report struct.
*
* The format string addressed by the error number may contain operands
* identified by the format {N}, where N is a decimal digit. Each of these
* is to be replaced by the Nth argument from the va_list. The complete
* message is placed into reportp->ucmessage converted to a JSString.
*
* Returns true if the expansion succeeds (can fail if out of memory).
*/
JSBool
js_ExpandErrorArguments(JSContext *cx, JSErrorCallback callback,
void *userRef, const uintN errorNumber,
char **messagep, JSErrorReport *reportp,
bool charArgs, va_list ap)
{
const JSErrorFormatString *efs;
int i;
int argCount;
*messagep = NULL;
/* Most calls supply js_GetErrorMessage; if this is so, assume NULL. */
if (!callback || callback == js_GetErrorMessage)
efs = js_GetLocalizedErrorMessage(cx, userRef, NULL, errorNumber);
else
efs = callback(userRef, NULL, errorNumber);
if (efs) {
size_t totalArgsLength = 0;
size_t argLengths[10]; /* only {0} thru {9} supported */
argCount = efs->argCount;
JS_ASSERT(argCount <= 10);
if (argCount > 0) {
/*
* Gather the arguments into an array, and accumulate
* their sizes. We allocate 1 more than necessary and
* null it out to act as the caboose when we free the
* pointers later.
*/
reportp->messageArgs = (const jschar **)
cx->malloc(sizeof(jschar *) * (argCount + 1));
if (!reportp->messageArgs)
return JS_FALSE;
reportp->messageArgs[argCount] = NULL;
for (i = 0; i < argCount; i++) {
if (charArgs) {
char *charArg = va_arg(ap, char *);
size_t charArgLength = strlen(charArg);
reportp->messageArgs[i]
= js_InflateString(cx, charArg, &charArgLength);
if (!reportp->messageArgs[i])
goto error;
} else {
reportp->messageArgs[i] = va_arg(ap, jschar *);
}
argLengths[i] = js_strlen(reportp->messageArgs[i]);
totalArgsLength += argLengths[i];
}
/* NULL-terminate for easy copying. */
reportp->messageArgs[i] = NULL;
}
/*
* Parse the error format, substituting the argument X
* for {X} in the format.
*/
if (argCount > 0) {
if (efs->format) {
jschar *buffer, *fmt, *out;
int expandedArgs = 0;
size_t expandedLength;
size_t len = strlen(efs->format);
buffer = fmt = js_InflateString (cx, efs->format, &len);
if (!buffer)
goto error;
expandedLength = len
- (3 * argCount) /* exclude the {n} */
+ totalArgsLength;
/*
* Note - the above calculation assumes that each argument
* is used once and only once in the expansion !!!
*/
reportp->ucmessage = out = (jschar *)
cx->malloc((expandedLength + 1) * sizeof(jschar));
if (!out) {
cx->free(buffer);
goto error;
}
while (*fmt) {
if (*fmt == '{') {
if (isdigit(fmt[1])) {
int d = JS7_UNDEC(fmt[1]);
JS_ASSERT(d < argCount);
js_strncpy(out, reportp->messageArgs[d],
argLengths[d]);
out += argLengths[d];
fmt += 3;
expandedArgs++;
continue;
}
}
*out++ = *fmt++;
}
JS_ASSERT(expandedArgs == argCount);
*out = 0;
cx->free(buffer);
*messagep =
js_DeflateString(cx, reportp->ucmessage,
(size_t)(out - reportp->ucmessage));
if (!*messagep)
goto error;
}
} else {
/*
* Zero arguments: the format string (if it exists) is the
* entire message.
*/
if (efs->format) {
size_t len;
*messagep = JS_strdup(cx, efs->format);
if (!*messagep)
goto error;
len = strlen(*messagep);
reportp->ucmessage = js_InflateString(cx, *messagep, &len);
if (!reportp->ucmessage)
goto error;
}
}
}
if (*messagep == NULL) {
/* where's the right place for this ??? */
const char *defaultErrorMessage
= "No error message available for error number %d";
size_t nbytes = strlen(defaultErrorMessage) + 16;
*messagep = (char *)cx->malloc(nbytes);
if (!*messagep)
goto error;
JS_snprintf(*messagep, nbytes, defaultErrorMessage, errorNumber);
}
return JS_TRUE;
error:
if (reportp->messageArgs) {
/* free the arguments only if we allocated them */
if (charArgs) {
i = 0;
while (reportp->messageArgs[i])
cx->free((void *)reportp->messageArgs[i++]);
}
cx->free((void *)reportp->messageArgs);
reportp->messageArgs = NULL;
}
if (reportp->ucmessage) {
cx->free((void *)reportp->ucmessage);
reportp->ucmessage = NULL;
}
if (*messagep) {
cx->free((void *)*messagep);
*messagep = NULL;
}
return JS_FALSE;
}
JSBool
js_ReportErrorNumberVA(JSContext *cx, uintN flags, JSErrorCallback callback,
void *userRef, const uintN errorNumber,
JSBool charArgs, va_list ap)
{
JSErrorReport report;
char *message;
JSBool warning;
if (checkReportFlags(cx, &flags))
return JS_TRUE;
warning = JSREPORT_IS_WARNING(flags);
PodZero(&report);
report.flags = flags;
report.errorNumber = errorNumber;
PopulateReportBlame(cx, &report);
if (!js_ExpandErrorArguments(cx, callback, userRef, errorNumber,
&message, &report, !!charArgs, ap)) {
return JS_FALSE;
}
ReportError(cx, message, &report, callback, userRef);
if (message)
cx->free(message);
if (report.messageArgs) {
/*
* js_ExpandErrorArguments owns its messageArgs only if it had to
* inflate the arguments (from regular |char *|s).
*/
if (charArgs) {
int i = 0;
while (report.messageArgs[i])
cx->free((void *)report.messageArgs[i++]);
}
cx->free((void *)report.messageArgs);
}
if (report.ucmessage)
cx->free((void *)report.ucmessage);
return warning;
}
JS_FRIEND_API(void)
js_ReportErrorAgain(JSContext *cx, const char *message, JSErrorReport *reportp)
{
JSErrorReporter onError;
if (!message)
return;
if (cx->lastMessage)
js_free(cx->lastMessage);
cx->lastMessage = JS_strdup(cx, message);
if (!cx->lastMessage)
return;
onError = cx->errorReporter;
/*
* If debugErrorHook is present then we give it a chance to veto
* sending the error on to the regular ErrorReporter.
*/
if (onError) {
JSDebugErrorHook hook = cx->debugHooks->debugErrorHook;
if (hook &&
!hook(cx, cx->lastMessage, reportp,
cx->debugHooks->debugErrorHookData)) {
onError = NULL;
}
}
if (onError)
onError(cx, cx->lastMessage, reportp);
}
void
js_ReportIsNotDefined(JSContext *cx, const char *name)
{
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_NOT_DEFINED, name);
}
JSBool
js_ReportIsNullOrUndefined(JSContext *cx, intN spindex, const Value &v,
JSString *fallback)
{
char *bytes;
JSBool ok;
bytes = DecompileValueGenerator(cx, spindex, v, fallback);
if (!bytes)
return JS_FALSE;
if (strcmp(bytes, js_undefined_str) == 0 ||
strcmp(bytes, js_null_str) == 0) {
ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
js_GetErrorMessage, NULL,
JSMSG_NO_PROPERTIES, bytes,
NULL, NULL);
} else if (v.isUndefined()) {
ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
js_GetErrorMessage, NULL,
JSMSG_UNEXPECTED_TYPE, bytes,
js_undefined_str, NULL);
} else {
JS_ASSERT(v.isNull());
ok = JS_ReportErrorFlagsAndNumber(cx, JSREPORT_ERROR,
js_GetErrorMessage, NULL,
JSMSG_UNEXPECTED_TYPE, bytes,
js_null_str, NULL);
}
cx->free(bytes);
return ok;
}
void
js_ReportMissingArg(JSContext *cx, const Value &v, uintN arg)
{
char argbuf[11];
char *bytes;
JSAtom *atom;
JS_snprintf(argbuf, sizeof argbuf, "%u", arg);
bytes = NULL;
if (IsFunctionObject(v)) {
atom = GET_FUNCTION_PRIVATE(cx, &v.toObject())->atom;
bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK,
v, ATOM_TO_STRING(atom));
if (!bytes)
return;
}
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL,
JSMSG_MISSING_FUN_ARG, argbuf,
bytes ? bytes : "");
cx->free(bytes);
}
JSBool
js_ReportValueErrorFlags(JSContext *cx, uintN flags, const uintN errorNumber,
intN spindex, const Value &v, JSString *fallback,
const char *arg1, const char *arg2)
{
char *bytes;
JSBool ok;
JS_ASSERT(js_ErrorFormatString[errorNumber].argCount >= 1);
JS_ASSERT(js_ErrorFormatString[errorNumber].argCount <= 3);
bytes = DecompileValueGenerator(cx, spindex, v, fallback);
if (!bytes)
return JS_FALSE;
ok = JS_ReportErrorFlagsAndNumber(cx, flags, js_GetErrorMessage,
NULL, errorNumber, bytes, arg1, arg2);
cx->free(bytes);
return ok;
}
#if defined DEBUG && defined XP_UNIX
/* For gdb usage. */
void js_logon(JSContext *cx) { cx->logfp = stderr; cx->logPrevPc = NULL; }
void js_logoff(JSContext *cx) { cx->logfp = NULL; }
#endif
JSErrorFormatString js_ErrorFormatString[JSErr_Limit] = {
#define MSG_DEF(name, number, count, exception, format) \
{ format, count, exception } ,
#include "js.msg"
#undef MSG_DEF
};
JS_FRIEND_API(const JSErrorFormatString *)
js_GetErrorMessage(void *userRef, const char *locale, const uintN errorNumber)
{
if ((errorNumber > 0) && (errorNumber < JSErr_Limit))
return &js_ErrorFormatString[errorNumber];
return NULL;
}
JSBool
js_InvokeOperationCallback(JSContext *cx)
{
JSRuntime *rt = cx->runtime;
JSThreadData *td = JS_THREAD_DATA(cx);
JS_ASSERT_REQUEST_DEPTH(cx);
JS_ASSERT(td->interruptFlags != 0);
/*
* Reset the callback counter first, then run GC and yield. If another
* thread is racing us here we will accumulate another callback request
* which will be serviced at the next opportunity.
*/
JS_LOCK_GC(rt);
td->interruptFlags = 0;
#ifdef JS_THREADSAFE
JS_ATOMIC_DECREMENT(&rt->interruptCounter);
#endif
JS_UNLOCK_GC(rt);
if (rt->gcIsNeeded) {
js_GC(cx, rt->gcTriggerCompartment, GC_NORMAL);
/*
* On trace we can exceed the GC quota, see comments in NewGCArena. So
* we check the quota and report OOM here when we are off trace.
*/
bool delayedOutOfMemory;
JS_LOCK_GC(rt);
delayedOutOfMemory = (rt->gcBytes > rt->gcMaxBytes);
JS_UNLOCK_GC(rt);
if (delayedOutOfMemory) {
js_ReportOutOfMemory(cx);
return false;
}
}
#ifdef JS_THREADSAFE
/*
* We automatically yield the current context every time the operation
* callback is hit since we might be called as a result of an impending
* GC on another thread, which would deadlock if we do not yield.
* Operation callbacks are supposed to happen rarely (seconds, not
* milliseconds) so it is acceptable to yield at every callback.
*
* As the GC can be canceled before it does any request checks we yield
* even if rt->gcIsNeeded was true above. See bug 590533.
*/
JS_YieldRequest(cx);
#endif
JSOperationCallback cb = cx->operationCallback;
/*
* Important: Additional callbacks can occur inside the callback handler
* if it re-enters the JS engine. The embedding must ensure that the
* callback is disconnected before attempting such re-entry.
*/
return !cb || cb(cx);
}
JSBool
js_HandleExecutionInterrupt(JSContext *cx)
{
JSBool result = JS_TRUE;
if (JS_THREAD_DATA(cx)->interruptFlags)
result = js_InvokeOperationCallback(cx) && result;
return result;
}
namespace js {
void
TriggerOperationCallback(JSContext *cx)
{
/*
* We allow for cx to come from another thread. Thus we must deal with
* possible JS_ClearContextThread calls when accessing cx->thread. But we
* assume that the calling thread is in a request so JSThread cannot be
* GC-ed.
*/
JSThreadData *td;
#ifdef JS_THREADSAFE
JSThread *thread = cx->thread;
if (!thread)
return;
td = &thread->data;
#else
td = JS_THREAD_DATA(cx);
#endif
td->triggerOperationCallback(cx->runtime);
}
void
TriggerAllOperationCallbacks(JSRuntime *rt)
{
for (ThreadDataIter i(rt); !i.empty(); i.popFront())
i.threadData()->triggerOperationCallback(rt);
}
} /* namespace js */
JSStackFrame *
js_GetScriptedCaller(JSContext *cx, JSStackFrame *fp)
{
if (!fp)
fp = js_GetTopStackFrame(cx);
while (fp && fp->isDummyFrame())
fp = fp->prev();
JS_ASSERT_IF(fp, fp->isScriptFrame());
return fp;
}
jsbytecode*
js_GetCurrentBytecodePC(JSContext* cx)
{
jsbytecode *pc, *imacpc;
#ifdef JS_TRACER
if (JS_ON_TRACE(cx)) {
pc = JS_TRACE_MONITOR_ON_TRACE(cx)->bailExit->pc;
imacpc = JS_TRACE_MONITOR_ON_TRACE(cx)->bailExit->imacpc;
} else
#endif
{
JS_ASSERT_NOT_ON_TRACE(cx); /* for static analysis */
pc = cx->regs ? cx->regs->pc : NULL;
if (!pc)
return NULL;
imacpc = cx->fp()->maybeImacropc();
}
/*
* If we are inside GetProperty_tn or similar, return a pointer to the
* current instruction in the script, not the CALL instruction in the
* imacro, for the benefit of callers doing bytecode inspection.
*/
return (*pc == JSOP_CALL && imacpc) ? imacpc : pc;
}
bool
js_CurrentPCIsInImacro(JSContext *cx)
{
#ifdef JS_TRACER
VOUCH_DOES_NOT_REQUIRE_STACK();
if (JS_ON_TRACE(cx))
return JS_TRACE_MONITOR_ON_TRACE(cx)->bailExit->imacpc != NULL;
return cx->fp()->hasImacropc();
#else
return false;
#endif
}
void
DSTOffsetCache::purge()
{
/*
* NB: The initial range values are carefully chosen to result in a cache
* miss on first use given the range of possible values. Be careful
* to keep these values and the caching algorithm in sync!
*/
offsetMilliseconds = 0;
rangeStartSeconds = rangeEndSeconds = INT64_MIN;
oldOffsetMilliseconds = 0;
oldRangeStartSeconds = oldRangeEndSeconds = INT64_MIN;
#ifdef JS_METER_DST_OFFSET_CACHING
totalCalculations = 0;
hit = 0;
missIncreasing = missDecreasing = 0;
missIncreasingOffsetChangeExpand = missIncreasingOffsetChangeUpper = 0;
missDecreasingOffsetChangeExpand = missDecreasingOffsetChangeLower = 0;
missLargeIncrease = missLargeDecrease = 0;
#endif
sanityCheck();
}
/*
* Since getDSTOffsetMilliseconds guarantees that all times seen will be
* positive, we can initialize the range at construction time with large
* negative numbers to ensure the first computation is always a cache miss and
* doesn't return a bogus offset.
*/
DSTOffsetCache::DSTOffsetCache()
{
purge();
}
JSContext::JSContext(JSRuntime *rt)
: hasVersionOverride(false),
runtime(rt),
compartment(NULL),
regs(NULL),
busyArrays()
{}
void
JSContext::resetCompartment()
{
JSObject *scopeobj;
if (hasfp()) {
scopeobj = &fp()->scopeChain();
} else {
scopeobj = globalObject;
if (!scopeobj)
goto error;
/*
* Innerize. Assert, but check anyway, that this succeeds. (It
* can only fail due to bugs in the engine or embedding.)
*/
OBJ_TO_INNER_OBJECT(this, scopeobj);
if (!scopeobj)
goto error;
}
compartment = scopeobj->compartment();
if (isExceptionPending())
wrapPendingException();
return;
error:
/*
* If we try to use the context without a selected compartment,
* we will crash.
*/
compartment = NULL;
}
/*
* Since this function is only called in the context of a pending exception,
* the caller must subsequently take an error path. If wrapping fails, it will
* set a new (uncatchable) exception to be used in place of the original.
*/
void
JSContext::wrapPendingException()
{
Value v = getPendingException();
clearPendingException();
if (compartment->wrap(this, &v))
setPendingException(v);
}
void
JSContext::pushSegmentAndFrame(js::StackSegment *newseg, JSFrameRegs &newregs)
{
JS_ASSERT(regs != &newregs);
if (hasActiveSegment())
currentSegment->suspend(regs);
newseg->setPreviousInContext(currentSegment);
currentSegment = newseg;
setCurrentRegs(&newregs);
newseg->joinContext(this, newregs.fp);
}
void
JSContext::popSegmentAndFrame()
{
/*
* NB: This function calls resetCompartment, which may GC, so the stack needs
* to be in a GC-able state by that point.
*/
JS_ASSERT(currentSegment->maybeContext() == this);
JS_ASSERT(currentSegment->getInitialFrame() == regs->fp);
currentSegment->leaveContext();
currentSegment = currentSegment->getPreviousInContext();
if (currentSegment) {
if (currentSegment->isSaved()) {
setCurrentRegs(NULL);
resetCompartment();
} else {
setCurrentRegs(currentSegment->getSuspendedRegs());
currentSegment->resume();
}
} else {
JS_ASSERT(regs->fp->prev() == NULL);
setCurrentRegs(NULL);
resetCompartment();
}
maybeMigrateVersionOverride();
}
void
JSContext::saveActiveSegment()
{
JS_ASSERT(hasActiveSegment());
currentSegment->save(regs);
setCurrentRegs(NULL);
resetCompartment();
}
void
JSContext::restoreSegment()
{
js::StackSegment *ccs = currentSegment;
setCurrentRegs(ccs->getSuspendedRegs());
ccs->restore();
resetCompartment();
}
JSGenerator *
JSContext::generatorFor(JSStackFrame *fp) const
{
JS_ASSERT(stack().contains(fp) && fp->isGeneratorFrame());
JS_ASSERT(!fp->isFloatingGenerator());
JS_ASSERT(!genStack.empty());
if (JS_LIKELY(fp == genStack.back()->liveFrame()))
return genStack.back();
/* General case; should only be needed for debug APIs. */
for (size_t i = 0; i < genStack.length(); ++i) {
if (genStack[i]->liveFrame() == fp)
return genStack[i];
}
JS_NOT_REACHED("no matching generator");
return NULL;
}
StackSegment *
JSContext::containingSegment(const JSStackFrame *target)
{
/* The context may have nothing running. */
StackSegment *seg = currentSegment;
if (!seg)
return NULL;
/* The active segments's top frame is cx->regs->fp. */
if (regs) {
JS_ASSERT(regs->fp);
JS_ASSERT(activeSegment() == seg);
JSStackFrame *f = regs->fp;
JSStackFrame *stop = seg->getInitialFrame()->prev();
for (; f != stop; f = f->prev()) {
if (f == target)
return seg;
}
seg = seg->getPreviousInContext();
}
/* A suspended segment's top frame is its suspended frame. */
for (; seg; seg = seg->getPreviousInContext()) {
JSStackFrame *f = seg->getSuspendedFrame();
JSStackFrame *stop = seg->getInitialFrame()->prev();
for (; f != stop; f = f->prev()) {
if (f == target)
return seg;
}
}
return NULL;
}
JS_FRIEND_API(void)
JSRuntime::onTooMuchMalloc()
{
#ifdef JS_THREADSAFE
AutoLockGC lock(this);
/*
* We can be called outside a request and can race against a GC that
* mutates the JSThread set during the sweeping phase.
*/
js_WaitForGC(this);
#endif
TriggerGC(this);
}
JS_FRIEND_API(void *)
JSRuntime::onOutOfMemory(void *p, size_t nbytes, JSContext *cx)
{
#ifdef JS_THREADSAFE
gcHelperThread.waitBackgroundSweepEnd(this);
if (!p)
p = ::js_malloc(nbytes);
else if (p == reinterpret_cast<void *>(1))
p = ::js_calloc(nbytes);
else
p = ::js_realloc(p, nbytes);
if (p)
return p;
#endif
if (cx)
js_ReportOutOfMemory(cx);
return NULL;
}
/*
* Release pool's arenas if the stackPool has existed for longer than the
* limit specified by gcEmptyArenaPoolLifespan.
*/
inline void
FreeOldArenas(JSRuntime *rt, JSArenaPool *pool)
{
JSArena *a = pool->current;
if (a == pool->first.next && a->avail == a->base + sizeof(int64)) {
int64 age = JS_Now() - *(int64 *) a->base;
if (age > int64(rt->gcEmptyArenaPoolLifespan) * 1000)
JS_FreeArenaPool(pool);
}
}
void
JSContext::purge()
{
FreeOldArenas(runtime, ®ExpPool);
}
static bool
ComputeIsJITBroken()
{
#ifndef ANDROID
return false;
#else // ANDROID
if (getenv("JS_IGNORE_JIT_BROKENNESS")) {
return false;
}
std::string line;
// Check for the known-bad kernel version (2.6.29).
std::ifstream osrelease("/proc/sys/kernel/osrelease");
std::getline(osrelease, line);
__android_log_print(ANDROID_LOG_INFO, "Gecko", "Detected osrelease `%s'",
line.c_str());
if (line.npos == line.find("2.6.29")) {
// We're using something other than 2.6.29, so the JITs should work.
__android_log_print(ANDROID_LOG_INFO, "Gecko", "JITs are not broken");
return false;
}
// We're using 2.6.29, and this causes trouble with the JITs on i9000.
line = "";
bool broken = false;
std::ifstream cpuinfo("/proc/cpuinfo");
do {
if (0 == line.find("Hardware")) {
const char* blacklist[] = {
"SGH-T959", // Samsung i9000, Vibrant device
"SGH-I897", // Samsung i9000, Captivate device
"SCH-I500", // Samsung i9000, Fascinate device
"SPH-D700", // Samsung i9000, Epic device
"GT-I9000", // Samsung i9000, UK/Europe device
NULL
};
for (const char** hw = &blacklist[0]; *hw; ++hw) {
if (line.npos != line.find(*hw)) {
__android_log_print(ANDROID_LOG_INFO, "Gecko",
"Blacklisted device `%s'", *hw);
broken = true;
break;
}
}
break;
}
std::getline(cpuinfo, line);
} while(!cpuinfo.fail() && !cpuinfo.eof());
__android_log_print(ANDROID_LOG_INFO, "Gecko", "JITs are %sbroken",
broken ? "" : "not ");
return broken;
#endif // ifndef ANDROID
}
static bool
IsJITBrokenHere()
{
static bool computedIsBroken = false;
static bool isBroken = false;
if (!computedIsBroken) {
isBroken = ComputeIsJITBroken();
computedIsBroken = true;
}
return isBroken;
}
void
JSContext::updateJITEnabled()
{
#ifdef JS_TRACER
traceJitEnabled = ((runOptions & JSOPTION_JIT) &&
!IsJITBrokenHere() &&
(debugHooks == &js_NullDebugHooks ||
(debugHooks == &runtime->globalDebugHooks &&
!runtime->debuggerInhibitsJIT())));
#endif
#ifdef JS_METHODJIT
methodJitEnabled = (runOptions & JSOPTION_METHODJIT) &&
!IsJITBrokenHere()
# if defined JS_CPU_X86 || defined JS_CPU_X64
&& JSC::MacroAssemblerX86Common::getSSEState() >=
JSC::MacroAssemblerX86Common::HasSSE2
# endif
;
#ifdef JS_TRACER
profilingEnabled = (runOptions & JSOPTION_PROFILING) && traceJitEnabled && methodJitEnabled;
#endif
#endif
}
namespace js {
JS_FORCES_STACK JS_FRIEND_API(void)
LeaveTrace(JSContext *cx)
{
#ifdef JS_TRACER
if (JS_ON_TRACE(cx))
DeepBail(cx);
#endif
}
} /* namespace js */
