gecko/dom/workers/test/promise_worker.js
Kyle Huey 1ffb03e8dc Bug 1179909: Refactor stable state handling. r=smaug
This is motivated by three separate but related problems:

1. Our concept of recursion depth is broken for things that run from AfterProcessNextEvent observers (e.g. Promises). We decrement the recursionDepth counter before firing observers, so a Promise callback running at the lowest event loop depth has a recursion depth of 0 (whereas a regular nsIRunnable would be 1). This is a problem because it's impossible to distinguish a Promise running after a sync XHR's onreadystatechange handler from a top-level event (since the former runs with depth 2 - 1 = 1, and the latter runs with just 1).

2. The nsIThreadObserver mechanism that is used by a lot of code to run "after" the current event is a poor fit for anything that runs script. First, the order the observers fire in is the order they were added, not anything fixed by spec. Additionally, running script can cause the event loop to spin, which is a big source of pain here (bholley has some nasty bug caused by this).

3. We run Promises from different points in the code for workers and main thread. The latter runs from XPConnect's nsIThreadObserver callbacks, while the former runs from a hardcoded call to run Promises in the worker event loop. What workers do is particularly problematic because it means we can't get the right recursion depth no matter what we do to nsThread.

The solve this, this patch does the following:

1. Consolidate some handling of microtasks and all handling of stable state from appshell and WorkerPrivate into CycleCollectedJSRuntime.
2. Make the recursionDepth counter only available to CycleCollectedJSRuntime (and its consumers) and remove it from the nsIThreadInternal and nsIThreadObserver APIs.
3. Adjust the recursionDepth counter so that microtasks run with the recursionDepth of the task they are associated with.
4. Introduce the concept of metastable state to replace appshell's RunBeforeNextEvent. Metastable state is reached after every microtask or task is completed. This provides the semantics that bent and I want for IndexedDB, where transactions autocommit at the end of a microtask and do not "spill" from one microtask into a subsequent microtask. This differs from appshell's RunBeforeNextEvent in two ways:
a) It fires between microtasks, which was the motivation for starting this.
b) It no longer ensures that we're at the same event loop depth in the native event queue. bent decided we don't care about this.
5. Reorder stable state to happen after microtasks such as Promises, per HTML. Right now we call the regular thread observers, including appshell, before the main thread observer (XPConnect), so stable state tasks happen before microtasks.
2015-08-11 06:10:46 -07:00

857 lines
22 KiB
JavaScript

function ok(a, msg) {
dump("OK: " + !!a + " => " + a + " " + msg + "\n");
postMessage({type: 'status', status: !!a, msg: a + ": " + msg });
}
function todo(a, msg) {
dump("TODO: " + !a + " => " + a + " " + msg + "\n");
postMessage({type: 'status', status: !a, msg: a + ": " + msg });
}
function is(a, b, msg) {
dump("IS: " + (a===b) + " => " + a + " | " + b + " " + msg + "\n");
postMessage({type: 'status', status: a === b, msg: a + " === " + b + ": " + msg });
}
function isnot(a, b, msg) {
dump("ISNOT: " + (a!==b) + " => " + a + " | " + b + " " + msg + "\n");
postMessage({type: 'status', status: a !== b, msg: a + " !== " + b + ": " + msg });
}
function promiseResolve() {
ok(Promise, "Promise object should exist");
var promise = new Promise(function(resolve, reject) {
ok(resolve, "Promise.resolve exists");
ok(reject, "Promise.reject exists");
resolve(42);
}).then(function(what) {
ok(true, "Then - resolveCb has been called");
is(what, 42, "ResolveCb received 42");
runTest();
}, function() {
ok(false, "Then - rejectCb has been called");
runTest();
});
}
function promiseResolveNoArg() {
var promise = new Promise(function(resolve, reject) {
ok(resolve, "Promise.resolve exists");
ok(reject, "Promise.reject exists");
resolve();
}).then(function(what) {
ok(true, "Then - resolveCb has been called");
is(what, undefined, "ResolveCb received undefined");
runTest();
}, function() {
ok(false, "Then - rejectCb has been called");
runTest();
});
}
function promiseRejectNoHandler() {
// This test only checks that the code that reports unhandled errors in the
// Promises implementation does not crash or leak.
var promise = new Promise(function(res, rej) {
noSuchMethod();
});
runTest();
}
function promiseReject() {
var promise = new Promise(function(resolve, reject) {
reject(42);
}).then(function(what) {
ok(false, "Then - resolveCb has been called");
runTest();
}, function(what) {
ok(true, "Then - rejectCb has been called");
is(what, 42, "RejectCb received 42");
runTest();
});
}
function promiseRejectNoArg() {
var promise = new Promise(function(resolve, reject) {
reject();
}).then(function(what) {
ok(false, "Then - resolveCb has been called");
runTest();
}, function(what) {
ok(true, "Then - rejectCb has been called");
is(what, undefined, "RejectCb received undefined");
runTest();
});
}
function promiseException() {
var promise = new Promise(function(resolve, reject) {
throw 42;
}).then(function(what) {
ok(false, "Then - resolveCb has been called");
runTest();
}, function(what) {
ok(true, "Then - rejectCb has been called");
is(what, 42, "RejectCb received 42");
runTest();
});
}
function promiseAsync_TimeoutResolveThen() {
var handlerExecuted = false;
setTimeout(function() {
ok(handlerExecuted, "Handler should have been called before the timeout.");
// Allow other assertions to run so the test could fail before the next one.
setTimeout(runTest, 0);
}, 0);
Promise.resolve().then(function() {
handlerExecuted = true;
});
ok(!handlerExecuted, "Handlers are not called before 'then' returns.");
}
function promiseAsync_ResolveTimeoutThen() {
var handlerExecuted = false;
var promise = Promise.resolve();
setTimeout(function() {
ok(handlerExecuted, "Handler should have been called before the timeout.");
// Allow other assertions to run so the test could fail before the next one.
setTimeout(runTest, 0);
}, 0);
promise.then(function() {
handlerExecuted = true;
});
ok(!handlerExecuted, "Handlers are not called before 'then' returns.");
}
function promiseAsync_ResolveThenTimeout() {
var handlerExecuted = false;
Promise.resolve().then(function() {
handlerExecuted = true;
});
setTimeout(function() {
ok(handlerExecuted, "Handler should have been called before the timeout.");
// Allow other assertions to run so the test could fail before the next one.
setTimeout(runTest, 0);
}, 0);
ok(!handlerExecuted, "Handlers are not called before 'then' returns.");
}
function promiseAsync_SyncXHRAndImportScripts()
{
var handlerExecuted = false;
Promise.resolve().then(function() {
handlerExecuted = true;
// Allow other assertions to run so the test could fail before the next one.
setTimeout(runTest, 0);
});
ok(!handlerExecuted, "Handlers are not called until the next microtask.");
var xhr = new XMLHttpRequest();
xhr.open("GET", "testXHR.txt", false);
xhr.send(null);
ok(!handlerExecuted, "Sync XHR should not trigger microtask execution.");
importScripts("relativeLoad_import.js");
ok(!handlerExecuted, "importScripts should not trigger microtask execution.");
}
function promiseDoubleThen() {
var steps = 0;
var promise = new Promise(function(r1, r2) {
r1(42);
});
promise.then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 42, "Value == 42");
steps++;
}, function(what) {
ok(false, "Then.reject has been called");
});
promise.then(function(what) {
ok(true, "Then.resolve has been called");
is(steps, 1, "Then.resolve - step == 1");
is(what, 42, "Value == 42");
runTest();
}, function(what) {
ok(false, "Then.reject has been called");
});
}
function promiseThenException() {
var promise = new Promise(function(resolve, reject) {
resolve(42);
});
promise.then(function(what) {
ok(true, "Then.resolve has been called");
throw "booh";
}).catch(function(e) {
ok(true, "Catch has been called!");
runTest();
});
}
function promiseThenCatchThen() {
var promise = new Promise(function(resolve, reject) {
resolve(42);
});
var promise2 = promise.then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 42, "Value == 42");
return what + 1;
}, function(what) {
ok(false, "Then.reject has been called");
});
isnot(promise, promise2, "These 2 promise objs are different");
promise2.then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 43, "Value == 43");
return what + 1;
}, function(what) {
ok(false, "Then.reject has been called");
}).catch(function() {
ok(false, "Catch has been called");
}).then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 44, "Value == 44");
runTest();
}, function(what) {
ok(false, "Then.reject has been called");
});
}
function promiseRejectThenCatchThen() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
var promise2 = promise.then(function(what) {
ok(false, "Then.resolve has been called");
}, function(what) {
ok(true, "Then.reject has been called");
is(what, 42, "Value == 42");
return what + 1;
});
isnot(promise, promise2, "These 2 promise objs are different");
promise2.then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 43, "Value == 43");
return what+1;
}).catch(function(what) {
ok(false, "Catch has been called");
}).then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 44, "Value == 44");
runTest();
});
}
function promiseRejectThenCatchThen2() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
promise.then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 42, "Value == 42");
return what+1;
}).catch(function(what) {
is(what, 42, "Value == 42");
ok(true, "Catch has been called");
return what+1;
}).then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 43, "Value == 43");
runTest();
});
}
function promiseRejectThenCatchExceptionThen() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
promise.then(function(what) {
ok(false, "Then.resolve has been called");
}, function(what) {
ok(true, "Then.reject has been called");
is(what, 42, "Value == 42");
throw(what + 1);
}).catch(function(what) {
ok(true, "Catch has been called");
is(what, 43, "Value == 43");
return what + 1;
}).then(function(what) {
ok(true, "Then.resolve has been called");
is(what, 44, "Value == 44");
runTest();
});
}
function promiseThenCatchOrderingResolve() {
var global = 0;
var f = new Promise(function(r1, r2) {
r1(42);
});
f.then(function() {
f.then(function() {
global++;
});
f.catch(function() {
global++;
});
f.then(function() {
global++;
});
setTimeout(function() {
is(global, 2, "Many steps... should return 2");
runTest();
}, 0);
});
}
function promiseThenCatchOrderingReject() {
var global = 0;
var f = new Promise(function(r1, r2) {
r2(42);
})
f.then(function() {}, function() {
f.then(function() {
global++;
});
f.catch(function() {
global++;
});
f.then(function() {}, function() {
global++;
});
setTimeout(function() {
is(global, 2, "Many steps... should return 2");
runTest();
}, 0);
});
}
function promiseThenNoArg() {
var promise = new Promise(function(resolve, reject) {
resolve(42);
});
var clone = promise.then();
isnot(promise, clone, "These 2 promise objs are different");
promise.then(function(v) {
clone.then(function(cv) {
is(v, cv, "Both resolve to the same value");
runTest();
});
});
}
function promiseThenUndefinedResolveFunction() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
try {
promise.then(undefined, function(v) {
is(v, 42, "Promise rejected with 42");
runTest();
});
} catch (e) {
ok(false, "then should not throw on undefined resolve function");
}
}
function promiseThenNullResolveFunction() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
try {
promise.then(null, function(v) {
is(v, 42, "Promise rejected with 42");
runTest();
});
} catch (e) {
ok(false, "then should not throw on null resolve function");
}
}
function promiseCatchNoArg() {
var promise = new Promise(function(resolve, reject) {
reject(42);
});
var clone = promise.catch();
isnot(promise, clone, "These 2 promise objs are different");
promise.catch(function(v) {
clone.catch(function(cv) {
is(v, cv, "Both reject to the same value");
runTest();
});
});
}
function promiseNestedPromise() {
new Promise(function(resolve, reject) {
resolve(new Promise(function(resolve, reject) {
ok(true, "Nested promise is executed");
resolve(42);
}));
}).then(function(value) {
is(value, 42, "Nested promise is executed and then == 42");
runTest();
});
}
function promiseNestedNestedPromise() {
new Promise(function(resolve, reject) {
resolve(new Promise(function(resolve, reject) {
ok(true, "Nested promise is executed");
resolve(42);
}).then(function(what) { return what+1; }));
}).then(function(value) {
is(value, 43, "Nested promise is executed and then == 43");
runTest();
});
}
function promiseWrongNestedPromise() {
new Promise(function(resolve, reject) {
resolve(new Promise(function(r, r2) {
ok(true, "Nested promise is executed");
r(42);
}));
reject(42);
}).then(function(value) {
is(value, 42, "Nested promise is executed and then == 42");
runTest();
}, function(value) {
ok(false, "This is wrong");
});
}
function promiseLoop() {
new Promise(function(resolve, reject) {
resolve(new Promise(function(r1, r2) {
ok(true, "Nested promise is executed");
r1(new Promise(function(r1, r2) {
ok(true, "Nested nested promise is executed");
r1(42);
}));
}));
}).then(function(value) {
is(value, 42, "Nested nested promise is executed and then == 42");
runTest();
}, function(value) {
ok(false, "This is wrong");
});
}
function promiseStaticReject() {
var promise = Promise.reject(42).then(function(what) {
ok(false, "This should not be called");
}, function(what) {
is(what, 42, "Value == 42");
runTest();
});
}
function promiseStaticResolve() {
var promise = Promise.resolve(42).then(function(what) {
is(what, 42, "Value == 42");
runTest();
}, function() {
ok(false, "This should not be called");
});
}
function promiseResolveNestedPromise() {
var promise = Promise.resolve(new Promise(function(r, r2) {
ok(true, "Nested promise is executed");
r(42);
}, function() {
ok(false, "This should not be called");
})).then(function(what) {
is(what, 42, "Value == 42");
runTest();
}, function() {
ok(false, "This should not be called");
});
}
function promiseRejectNoHandler() {
// This test only checks that the code that reports unhandled errors in the
// Promises implementation does not crash or leak.
var promise = new Promise(function(res, rej) {
noSuchMethod();
});
runTest();
}
function promiseUtilitiesDefined() {
ok(Promise.all, "Promise.all must be defined when Promise is enabled.");
ok(Promise.race, "Promise.race must be defined when Promise is enabled.");
runTest();
}
function promiseAllArray() {
var p = Promise.all([1, new Date(), Promise.resolve("firefox")]);
ok(p instanceof Promise, "Return value of Promise.all should be a Promise.");
p.then(function(values) {
ok(Array.isArray(values), "Resolved value should be an array.");
is(values.length, 3, "Resolved array length should match iterable's length.");
is(values[0], 1, "Array values should match.");
ok(values[1] instanceof Date, "Array values should match.");
is(values[2], "firefox", "Array values should match.");
runTest();
}, function() {
ok(false, "Promise.all shouldn't fail when iterable has no rejected Promises.");
runTest();
});
}
function promiseAllWaitsForAllPromises() {
var arr = [
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 1), 50);
}),
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 2), 10);
}),
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, new Promise(function(resolve2) {
resolve2(3);
})), 10);
}),
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 4), 20);
})
];
var p = Promise.all(arr);
p.then(function(values) {
ok(Array.isArray(values), "Resolved value should be an array.");
is(values.length, 4, "Resolved array length should match iterable's length.");
is(values[0], 1, "Array values should match.");
is(values[1], 2, "Array values should match.");
is(values[2], 3, "Array values should match.");
is(values[3], 4, "Array values should match.");
runTest();
}, function() {
ok(false, "Promise.all shouldn't fail when iterable has no rejected Promises.");
runTest();
});
}
function promiseAllRejectFails() {
var arr = [
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 1), 50);
}),
new Promise(function(resolve, reject) {
setTimeout(reject.bind(undefined, 2), 10);
}),
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 3), 10);
}),
new Promise(function(resolve) {
setTimeout(resolve.bind(undefined, 4), 20);
})
];
var p = Promise.all(arr);
p.then(function(values) {
ok(false, "Promise.all shouldn't resolve when iterable has rejected Promises.");
runTest();
}, function(e) {
ok(true, "Promise.all should reject when iterable has rejected Promises.");
is(e, 2, "Rejection value should match.");
runTest();
});
}
function promiseRaceEmpty() {
var p = Promise.race([]);
ok(p instanceof Promise, "Should return a Promise.");
// An empty race never resolves!
runTest();
}
function promiseRaceValuesArray() {
var p = Promise.race([true, new Date(), 3]);
ok(p instanceof Promise, "Should return a Promise.");
p.then(function(winner) {
is(winner, true, "First value should win.");
runTest();
}, function(err) {
ok(false, "Should not fail " + err + ".");
runTest();
});
}
function promiseRacePromiseArray() {
var arr = [
new Promise(function(resolve) {
resolve("first");
}),
Promise.resolve("second"),
new Promise(function() {}),
new Promise(function(resolve) {
setTimeout(function() {
setTimeout(function() {
resolve("fourth");
}, 0);
}, 0);
}),
];
var p = Promise.race(arr);
p.then(function(winner) {
is(winner, "first", "First queued resolution should win the race.");
runTest();
});
}
function promiseRaceReject() {
var p = Promise.race([
Promise.reject(new Error("Fail bad!")),
new Promise(function(resolve) {
setTimeout(resolve, 0);
})
]);
p.then(function() {
ok(false, "Should not resolve when winning Promise rejected.");
runTest();
}, function(e) {
ok(true, "Should be rejected");
ok(e instanceof Error, "Should reject with Error.");
ok(e.message == "Fail bad!", "Message should match.");
runTest();
});
}
function promiseRaceThrow() {
var p = Promise.race([
new Promise(function(resolve) {
nonExistent();
}),
new Promise(function(resolve) {
setTimeout(resolve, 0);
})
]);
p.then(function() {
ok(false, "Should not resolve when winning Promise had an error.");
runTest();
}, function(e) {
ok(true, "Should be rejected");
ok(e instanceof ReferenceError, "Should reject with ReferenceError for function nonExistent().");
runTest();
});
}
function promiseResolveArray() {
var p = Promise.resolve([1,2,3]);
ok(p instanceof Promise, "Should return a Promise.");
p.then(function(v) {
ok(Array.isArray(v), "Resolved value should be an Array");
is(v.length, 3, "Length should match");
is(v[0], 1, "Resolved value should match original");
is(v[1], 2, "Resolved value should match original");
is(v[2], 3, "Resolved value should match original");
runTest();
});
}
function promiseResolveThenable() {
var p = Promise.resolve({ then: function(onFulfill, onReject) { onFulfill(2); } });
ok(p instanceof Promise, "Should cast to a Promise.");
p.then(function(v) {
is(v, 2, "Should resolve to 2.");
runTest();
}, function(e) {
ok(false, "promiseResolveThenable should've resolved");
runTest();
});
}
function promiseResolvePromise() {
var original = Promise.resolve(true);
var cast = Promise.resolve(original);
ok(cast instanceof Promise, "Should cast to a Promise.");
is(cast, original, "Should return original Promise.");
cast.then(function(v) {
is(v, true, "Should resolve to true.");
runTest();
});
}
// Bug 1009569.
// Ensure that thenables are run on a clean stack asynchronously.
// Test case adopted from
// https://gist.github.com/getify/d64bb01751b50ed6b281#file-bug1-js.
function promiseResolveThenableCleanStack() {
function immed(s) { x++; s(); }
function incX(){ x++; }
var x = 0;
var thenable = { then: immed };
var results = [];
var p = Promise.resolve(thenable).then(incX);
results.push(x);
// check what happens after all "next cycle" steps
// have had a chance to complete
setTimeout(function(){
// Result should be [0, 2] since `thenable` will be called async.
is(results[0], 0, "Expected thenable to be called asynchronously");
// See Bug 1023547 comment 13 for why this check has to be gated on p.
p.then(function() {
results.push(x);
is(results[1], 2, "Expected thenable to be called asynchronously");
runTest();
});
},1000);
}
// Bug 1062323
function promiseWrapperAsyncResolution()
{
var p = new Promise(function(resolve, reject){
resolve();
});
var results = [];
var q = p.then(function () {
results.push("1-1");
}).then(function () {
results.push("1-2");
}).then(function () {
results.push("1-3");
});
var r = p.then(function () {
results.push("2-1");
}).then(function () {
results.push("2-2");
}).then(function () {
results.push("2-3");
});
Promise.all([q, r]).then(function() {
var match = results[0] == "1-1" &&
results[1] == "2-1" &&
results[2] == "1-2" &&
results[3] == "2-2" &&
results[4] == "1-3" &&
results[5] == "2-3";
ok(match, "Chained promises should resolve asynchronously.");
runTest();
}, function() {
ok(false, "promiseWrapperAsyncResolution: One of the promises failed.");
runTest();
});
}
var tests = [
promiseResolve,
promiseReject,
promiseException,
promiseAsync_TimeoutResolveThen,
promiseAsync_ResolveTimeoutThen,
promiseAsync_ResolveThenTimeout,
promiseAsync_SyncXHRAndImportScripts,
promiseDoubleThen,
promiseThenException,
promiseThenCatchThen,
promiseRejectThenCatchThen,
promiseRejectThenCatchThen2,
promiseRejectThenCatchExceptionThen,
promiseThenCatchOrderingResolve,
promiseThenCatchOrderingReject,
promiseNestedPromise,
promiseNestedNestedPromise,
promiseWrongNestedPromise,
promiseLoop,
promiseStaticReject,
promiseStaticResolve,
promiseResolveNestedPromise,
promiseResolveNoArg,
promiseRejectNoArg,
promiseThenNoArg,
promiseThenUndefinedResolveFunction,
promiseThenNullResolveFunction,
promiseCatchNoArg,
promiseRejectNoHandler,
promiseUtilitiesDefined,
promiseAllArray,
promiseAllWaitsForAllPromises,
promiseAllRejectFails,
promiseRaceEmpty,
promiseRaceValuesArray,
promiseRacePromiseArray,
promiseRaceReject,
promiseRaceThrow,
promiseResolveArray,
promiseResolveThenable,
promiseResolvePromise,
promiseResolveThenableCleanStack,
promiseWrapperAsyncResolution,
];
function runTest() {
if (!tests.length) {
postMessage({ type: 'finish' });
return;
}
var test = tests.shift();
test();
}
onmessage = function() {
runTest();
}