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process: allow ticker to cross communicate better

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Using external memory values allows for quick communication between js
and cc land, so we can check if the js land callback needs to be run.
(this is where I meant that manually tracking nextTickQueue.length would
be helpful)

Also did some minor cleanup of removing the old Tick and
StartTickSpinner functions, and a few unneeded comments.

Conflicts:

	src/node.cc
This commit is contained in:
Trevor Norris 2013-02-13 06:30:06 -08:00 committed by isaacs
parent 86c0745a5e
commit ec4200068c
2 changed files with 93 additions and 84 deletions
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87
src/node.cc
View File

@ -100,7 +100,7 @@ Persistent<String> process_symbol;
Persistent<String> domain_symbol;
static Persistent<Object> process;
static Persistent<Function> process_tickWDCallback;
static Persistent<Function> process_tickDomainCallback;
static Persistent<Function> process_tickFromSpinner;
static Persistent<Function> process_tickCallback;
@ -144,6 +144,12 @@ static uv_idle_t idle_immediate_dummy;
static bool need_immediate_cb;
static Persistent<String> immediate_callback_sym;
// for quick ref to tickCallback values
struct {
uint32_t length;
uint32_t index;
uint32_t depth;
} tick_infobox;
#ifdef OPENSSL_NPN_NEGOTIATED
static bool use_npn = true;
@ -167,7 +173,10 @@ static uv_async_t dispatch_debug_messages_async;
Isolate* node_isolate = NULL;
static void Tick(void) {
static void Spin(uv_idle_t* handle, int status) {
assert((uv_idle_t*) handle == &tick_spinner);
assert(status == 0);
// Avoid entering a V8 scope.
if (!need_tick_cb) return;
need_tick_cb = false;
@ -196,26 +205,9 @@ static void Tick(void) {
}
static void Spin(uv_idle_t* handle, int status) {
assert((uv_idle_t*) handle == &tick_spinner);
assert(status == 0);
Tick();
}
static void StartTickSpinner() {
need_tick_cb = true;
// TODO: this tick_spinner shouldn't be necessary. An ev_prepare should be
// sufficent, the problem is only in the case of the very last "tick" -
// there is nothing left to do in the event loop and libev will exit. The
// ev_prepare callback isn't called before exiting. Thus we start this
// tick_spinner to keep the event loop alive long enough to handle it.
uv_idle_start(&tick_spinner, Spin);
}
static Handle<Value> NeedTickCallback(const Arguments& args) {
StartTickSpinner();
need_tick_cb = true;
uv_idle_start(&tick_spinner, Spin);
return Undefined(node_isolate);
}
@ -905,19 +897,19 @@ Handle<Value> FromConstructorTemplate(Persistent<FunctionTemplate> t,
Handle<Value>
MCWithDomain(const Handle<Object> object,
MakeDomainCallback(const Handle<Object> object,
const Handle<Function> callback,
int argc,
Handle<Value> argv[]) {
// lazy load _tickWDCallback
if (process_tickWDCallback.IsEmpty()) {
Local<Value> cb_v = process->Get(String::New("_tickWDCallback"));
// lazy load _tickDomainCallback
if (process_tickDomainCallback.IsEmpty()) {
Local<Value> cb_v = process->Get(String::New("_tickDomainCallback"));
if (!cb_v->IsFunction()) {
fprintf(stderr, "process._tickWDCallback assigned to non-function\n");
fprintf(stderr, "process._tickDomainCallback assigned to non-function\n");
abort();
}
Local<Function> cb = cb_v.As<Function>();
process_tickWDCallback = Persistent<Function>::New(cb);
process_tickDomainCallback = Persistent<Function>::New(cb);
}
// lazy load domain specific symbols
@ -965,8 +957,14 @@ MCWithDomain(const Handle<Object> object,
return Undefined(node_isolate);
}
if (tick_infobox.length == 0) {
tick_infobox.index = 0;
tick_infobox.depth = 0;
return ret;
}
// process nextTicks after call
process_tickWDCallback->Call(process, 0, NULL);
process_tickDomainCallback->Call(process, 0, NULL);
if (try_catch.HasCaught()) {
FatalException(try_catch);
@ -984,17 +982,15 @@ MakeCallback(const Handle<Object> object,
Handle<Value> argv[]) {
HandleScope scope;
Local<Value> callback_v = object->Get(symbol);
if (!callback_v->IsFunction()) {
String::Utf8Value method(symbol);
fprintf(stderr, "Non-function in MakeCallback. method = %s\n", *method);
abort();
}
Local<Function> callback = Local<Function>::Cast(callback_v);
Local<Function> callback = object->Get(symbol).As<Function>();
Local<Value> domain = object->Get(domain_symbol);
// TODO Hook for long stack traces to be made here.
// has domain, off with you
if (!domain->IsNull() && !domain->IsUndefined())
return scope.Close(MakeDomainCallback(object, callback, argc, argv));
// lazy load no domain next tick callbacks
if (process_tickCallback.IsEmpty()) {
Local<Value> cb_v = process->Get(String::New("_tickCallback"));
@ -1006,12 +1002,6 @@ MakeCallback(const Handle<Object> object,
process_tickCallback = Persistent<Function>::New(cb);
}
// has domain, off with you
if (object->Has(domain_symbol) &&
!object->Get(domain_symbol)->IsNull() &&
!object->Get(domain_symbol)->IsUndefined())
return scope.Close(MCWithDomain(object, callback, argc, argv));
TryCatch try_catch;
Local<Value> ret = callback->Call(object, argc, argv);
@ -1021,6 +1011,12 @@ MakeCallback(const Handle<Object> object,
return Undefined(node_isolate);
}
if (tick_infobox.length == 0) {
tick_infobox.index = 0;
tick_infobox.depth = 0;
return scope.Close(ret);
}
// process nextTicks after call
process_tickCallback->Call(process, 0, NULL);
@ -2477,6 +2473,13 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
NODE_SET_METHOD(process, "binding", Binding);
// values use to cross communicate with processNextTick
Local<Object> info_box = Object::New();
info_box->SetIndexedPropertiesToExternalArrayData(&tick_infobox,
kExternalUnsignedIntArray,
3);
process->Set(String::NewSymbol("_tickInfoBox"), info_box);
return process;
}

90
src/node.js
View File

@ -309,17 +309,24 @@
startup.processNextTick = function() {
var _needTickCallback = process._needTickCallback;
var nextTickQueue = [];
var nextTickQueueLength = 0;
var nextTickIndex = 0;
var tickDepth = 0;
var usingDomains = false;
var needSpinner = true;
var inTick = false;
// this infobox thing is used so that the C++ code in src/node.cc
// can have easy accesss to our nextTick state, and avoid unnecessary
// calls into process._tickCallback.
// order is [length, index, depth]
// Never write code like this without very good reason!
var infoBox = process._tickInfoBox;
var length = 0;
var index = 1;
var depth = 2;
process._tickCallback = _tickCallback;
process._tickFromSpinner = _tickFromSpinner;
// needs to be accessible from cc land
process._tickWDCallback = _tickWDCallback;
process._tickDomainCallback = _tickDomainCallback;
process.nextTick = nextTick;
// the maximum number of times it'll process something like
@ -332,13 +339,13 @@
process.maxTickDepth = 1000;
function tickDone(tickDepth_) {
if (nextTickQueueLength !== 0) {
if (nextTickQueueLength <= nextTickIndex) {
if (infoBox[length] !== 0) {
if (infoBox[length] <= infoBox[index]) {
nextTickQueue = [];
nextTickQueueLength = 0;
infoBox[length] = 0;
} else {
nextTickQueue.splice(0, nextTickIndex);
nextTickQueueLength = nextTickQueue.length;
nextTickQueue.splice(0, infoBox[index]);
infoBox[length] = nextTickQueue.length;
if (needSpinner) {
_needTickCallback();
needSpinner = false;
@ -346,8 +353,8 @@
}
}
inTick = false;
nextTickIndex = 0;
tickDepth = tickDepth_;
infoBox[index] = 0;
infoBox[depth] = tickDepth_;
}
function maxTickWarn() {
@ -364,44 +371,43 @@
function _tickFromSpinner() {
needSpinner = true;
// coming from spinner, reset!
if (tickDepth !== 0)
tickDepth = 0;
if (infoBox[depth] !== 0)
infoBox[depth] = 0;
// no callbacks to run
if (nextTickQueueLength === 0)
return nextTickIndex = tickDepth = 0;
if (nextTickQueue[nextTickQueueLength - 1].domain)
_tickWDCallback();
if (infoBox[length] === 0)
return infoBox[index] = infoBox[depth] = 0;
if (nextTickQueue[infoBox[length] - 1].domain)
_tickDomainCallback();
else
_tickCallback();
}
// run callback that have no domain
// this is very hot, so has been super optimized
// this will be overridden if user uses domains
// run callbacks that have no domain
// using domains will cause this to be overridden
function _tickCallback() {
var callback, nextTickLength, threw;
if (inTick) return;
if (nextTickQueueLength === 0) {
nextTickIndex = 0;
tickDepth = 0;
if (infoBox[length] === 0) {
infoBox[index] = 0;
infoBox[depth] = 0;
return;
}
inTick = true;
while (tickDepth++ < process.maxTickDepth) {
nextTickLength = nextTickQueueLength;
if (nextTickIndex === nextTickLength)
while (infoBox[depth]++ < process.maxTickDepth) {
nextTickLength = infoBox[length];
if (infoBox[index] === nextTickLength)
return tickDone(0);
while (nextTickIndex < nextTickLength) {
callback = nextTickQueue[nextTickIndex++].callback;
while (infoBox[index] < nextTickLength) {
callback = nextTickQueue[infoBox[index]++].callback;
threw = true;
try {
callback();
threw = false;
} finally {
if (threw) tickDone(tickDepth);
if (threw) tickDone(infoBox[depth]);
}
}
}
@ -409,7 +415,7 @@
tickDone(0);
}
function _tickWDCallback() {
function _tickDomainCallback() {
var nextTickLength, tock, callback, threw;
// if you add a nextTick in a domain's error handler, then
@ -418,7 +424,7 @@
// that error handler ALSO triggers multiple MakeCallbacks, then
// it'll try to keep clearing the queue, since the finally block
// fires *before* the error hits the top level and is handled.
if (tickDepth >= process.maxTickDepth)
if (infoBox[depth] >= process.maxTickDepth)
return _needTickCallback();
if (inTick) return;
@ -426,15 +432,15 @@
// always do this at least once. otherwise if process.maxTickDepth
// is set to some negative value, or if there were repeated errors
// preventing tickDepth from being cleared, we'd never process any
// preventing depth from being cleared, we'd never process any
// of them.
while (tickDepth++ < process.maxTickDepth) {
nextTickLength = nextTickQueueLength;
if (nextTickIndex === nextTickLength)
while (infoBox[depth]++ < process.maxTickDepth) {
nextTickLength = infoBox[length];
if (infoBox[index] === nextTickLength)
return tickDone(0);
while (nextTickIndex < nextTickLength) {
tock = nextTickQueue[nextTickIndex++];
while (infoBox[index] < nextTickLength) {
tock = nextTickQueue[infoBox[index]++];
callback = tock.callback;
if (tock.domain) {
if (tock.domain._disposed) continue;
@ -446,8 +452,8 @@
threw = false;
} finally {
// finally blocks fire before the error hits the top level,
// so we can't clear the tickDepth at this point.
if (threw) tickDone(tickDepth);
// so we can't clear the depth at this point.
if (threw) tickDone(infoBox[depth]);
}
if (tock.domain) {
tock.domain.exit();
@ -462,7 +468,7 @@
// on the way out, don't bother. it won't get fired anyway.
if (process._exiting)
return;
if (tickDepth >= process.maxTickDepth)
if (infoBox[depth] >= process.maxTickDepth)
maxTickWarn();
var obj = { callback: callback };
@ -470,13 +476,13 @@
obj.domain = process.domain;
// user has opt'd to use domains, so override default functionality
if (!usingDomains) {
process._tickCallback = _tickWDCallback;
process._tickCallback = _tickDomainCallback;
usingDomains = true;
}
}
nextTickQueue.push(obj);
nextTickQueueLength++;
infoBox[length]++;
}
};