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Fix two closure bugs (#664)

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This fixes two closure bugs.

First, we had special cased `__awaiter` from days of yore, when we had
special cased its capture.  I also think we were confused at some point
and instead of fixing the fact that we captured `this` for non-arrow
functions, which `__awaiter` would trigger, we doubled down on this
incorrect hack.  This means we missed a real bonafide `this` capture.

Second, we had a global cache of captured variable objects.  So, if a
free variable resolved to the same JavaScript object, it always resolved
to the first serialization of that object.  This is clearly wrong if
the object had been mutated in the meantime.  The cache is required to
reach a fixed point during mutually recursive captures, but we should
only be using it for the duration of a single closure serialization
call.  That's precisely what this commit does.

Also add a fix for this case.

This fixes pulumi/pulumi#663.
This commit is contained in:
Joe Duffy 2017-12-07 16:21:28 -08:00 committed by GitHub
parent aa7c1598ac
commit 69f5882b97
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 95 additions and 55 deletions
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8
sdk/nodejs/dynamic/index.ts
View file

@ -138,13 +138,9 @@ export abstract class Resource extends resource.CustomResource {
* @param parent An optional parent resource to which this resource belongs.
* @param dependsOn Optional additional explicit dependencies on other resources.
*/
public constructor(provider: ResourceProvider,
name: string,
props: resource.ComputedValues,
parent?: resource.Resource,
dependsOn?: resource.Resource[]) {
public constructor(provider: ResourceProvider, name: string, props: resource.ComputedValues,
parent?: resource.Resource, dependsOn?: resource.Resource[]) {
const providerKey: string = "__provider";
if (props[providerKey]) {
throw new Error("A dynamic resource must not define the __provider key");
}

64
sdk/nodejs/runtime/closure.ts
View file

@ -39,10 +39,13 @@ export interface EnvironmentEntry {
* Unlike toString, it actually includes information about the captured environment.
*/
export function serializeClosure(func: Function): Promise<Closure> {
// entryCache stores a map of entry to promise, to support mutually recursive captures.
const entryCache = new Map<Object, Promise<AsyncEnvironmentEntry>>();
// First get the async version. We will then await it to turn it into a flattened, async-free computed closure.
// This must be done "at the top" because we must not block the creation of the dataflow graph of closure
// elements, since there may be cycles that can only resolve by creating the entire graph first.
const closure: AsyncClosure = serializeClosureAsync(func);
const closure: AsyncClosure = serializeClosureAsync(func, entryCache);
// Now turn the AsyncClosure into a normal closure, and return it.
const flatCache = new Map<Promise<AsyncEnvironmentEntry>, EnvironmentEntry>();
@ -135,15 +138,11 @@ export interface AsyncEnvironmentEntry {
module?: string; // a reference to a requirable module name.
}
/**
* entryCache stores a map of entry to promise, to support mutually recursive captures.
*/
const entryCache = new Map<Object, Promise<AsyncEnvironmentEntry>>();
/**
* serializeClosureAsync does the work to create an asynchronous dataflow graph that resolves to a final closure.
*/
function serializeClosureAsync(func: Function): AsyncClosure {
function serializeClosureAsync(
func: Function, entryCache: Map<Object, Promise<AsyncEnvironmentEntry>>): AsyncClosure {
// Invoke the native runtime. Note that we pass a callback to our function below to compute
// free variables. This must be a callback and not the result of this function alone, since we
// may recursively compute them.
@ -153,13 +152,15 @@ function serializeClosureAsync(func: Function): AsyncClosure {
// parser isn't designed to be stable for 3rd party consumtpion. Hence it would be brittle and a
// maintenance challenge. This approach also avoids needing to write a big hunk of complex code
// in C++, which is nice.
return <AsyncClosure>nativeruntime.serializeClosure(func, computeFreeVariables, serializeCapturedObject);
return <AsyncClosure>nativeruntime.serializeClosure(
func, computeFreeVariables, serializeCapturedObject, entryCache);
}
/**
* serializeCapturedObject serializes an object, deeply, into something appropriate for an environment entry.
*/
function serializeCapturedObject(obj: any): Promise<AsyncEnvironmentEntry> {
function serializeCapturedObject(
obj: any, entryCache: Map<Object, Promise<AsyncEnvironmentEntry>>): Promise<AsyncEnvironmentEntry> {
// See if we have a cache hit. If yes, use the object as-is.
let result: Promise<AsyncEnvironmentEntry> | undefined = entryCache.get(obj);
if (result) {
@ -170,14 +171,16 @@ function serializeCapturedObject(obj: any): Promise<AsyncEnvironmentEntry> {
let resultResolve: ((v: AsyncEnvironmentEntry) => void) | undefined = undefined;
result = debuggablePromise(new Promise<AsyncEnvironmentEntry>((resolve) => { resultResolve = resolve; }));
entryCache.set(obj, result);
serializeCapturedObjectAsync(obj, resultResolve!);
serializeCapturedObjectAsync(obj, resultResolve!, entryCache);
return result;
}
/**
* serializeCapturedObjectAsync is the work-horse that actually performs object serialization.
*/
function serializeCapturedObjectAsync(obj: any, resolve: (v: AsyncEnvironmentEntry) => void): void {
function serializeCapturedObjectAsync(
obj: any, resolve: (v: AsyncEnvironmentEntry) => void,
entryCache: Map<Object, Promise<AsyncEnvironmentEntry>>): void {
const moduleName = findRequirableModuleName(obj);
if (obj === undefined || obj === null ||
typeof obj === "boolean" || typeof obj === "number" || typeof obj === "string") {
@ -198,7 +201,7 @@ function serializeCapturedObjectAsync(obj: any, resolve: (v: AsyncEnvironmentEnt
// Recursively serialize elements of an array.
const arr: Promise<AsyncEnvironmentEntry>[] = [];
for (const elem of obj) {
arr.push(serializeCapturedObject(elem));
arr.push(serializeCapturedObject(elem, entryCache));
}
return resolve({ arr: arr });
@ -206,19 +209,19 @@ function serializeCapturedObjectAsync(obj: any, resolve: (v: AsyncEnvironmentEnt
if (obj instanceof Function) {
// Serialize functions recursively, and store them in a closure property.
return resolve({ closure: serializeClosureAsync(obj) });
return resolve({ closure: serializeClosureAsync(obj, entryCache) });
}
if (obj instanceof Promise) {
// If this is a promise, we will await it and serialize the result instead.
obj.then((v) => serializeCapturedObjectAsync(v, resolve));
obj.then((v) => serializeCapturedObjectAsync(v, resolve, entryCache));
return;
}
// For all other objects, serialize all of their enumerable properties (skipping non-enumerable members, etc).
const env: AsyncEnvironment = {};
for (const key of Object.keys(obj)) {
env[key] = serializeCapturedObject(obj[key]);
env[key] = serializeCapturedObject(obj[key], entryCache);
}
resolve({ obj: env });
}
@ -269,6 +272,7 @@ function findRequirableModuleName(obj: any): string | undefined {
*/
function computeFreeVariables(funcstr: string): string[] {
log.debug(`Computing free variables for function: ${funcstr}`);
if (funcstr.indexOf("[native code]") !== -1) {
throw new Error(`Cannot serialize native code function: "${funcstr}"`);
}
@ -336,8 +340,6 @@ class FreeVariableComputer {
return this.visitBlockStatement(<ts.Block>node, walk);
case ts.SyntaxKind.CatchClause:
return this.visitCatchClause(<ts.CatchClause>node, walk);
case ts.SyntaxKind.CallExpression:
return this.visitCallExpression(<ts.CallExpression>node, walk);
case ts.SyntaxKind.MethodDeclaration:
return this.visitMethodDeclaration(<ts.MethodDeclaration>node, walk);
case ts.SyntaxKind.PropertyAssignment:
@ -474,22 +476,6 @@ class FreeVariableComputer {
this.scope.pop();
}
private visitCallExpression(node: ts.CallExpression, walk: walkCallback): void {
// Most call expressions are normal. But we must special case one kind of function:
// TypeScript's __awaiter functions. They are of the form `__awaiter(this, void 0, void 0, function* (){})`,
// which will cause us to attempt to capture and serialize the entire surrounding function in
// which any lambda is created (thanks to `this`). That spirals into craziness, and bottoms out on native
// functions which we cannot serialize. We only want to capture `this` if the user code mentioned it.
walk(node.expression);
const isAwaiterCall = ts.isIdentifier(node.expression) && node.expression.text === "__awaiter";
for (let i = 0; i < node.arguments.length; i++) {
if (i > 0 || !isAwaiterCall) {
walk(node.arguments[i]);
}
}
}
private visitMethodDeclaration(node: ts.MethodDeclaration, walk: walkCallback): void {
if (ts.isComputedPropertyName(node.name)) {
// Don't walk down the 'name' part of the property assignment if it is an identifier. It
@ -613,9 +599,9 @@ class FreeVariableComputer {
}
/**
* serializeJavaScript Text converts a Closure object into a string
* representation of a Node.js module body which exposes a single function
* `exports.handler` representing the serialized function.
* serializeJavaScriptText converts a Closure object into a string representation of a Node.js module body which
* exposes a single function `exports.handler` representing the serialized function.
*
* @param c The Closure to be serialized into a module string.
*/
export function serializeJavaScriptText(c: Closure): string {
@ -690,8 +676,6 @@ class FuncsForClosure {
}
private createFunctionHash(closure: Closure): string {
const shasum = crypto.createHash("sha1");
// We want to produce a deterministic hash from all the relevant data in this closure. To do
// so we 'normalize' the object to remove any meaningless differences, and also to ensure
// the closure can be appropriately serialized to a JSON string, which can then be sha1
@ -714,9 +698,9 @@ class FuncsForClosure {
const seenClosures: Closure[] = [];
const normalizedClosure = this.convertClosureToNormalizedObject(seenClosures, closure);
const shasum = crypto.createHash("sha1");
shasum.update(JSON.stringify(normalizedClosure));
const hash: string = "__" + shasum.digest("hex");
return hash;
return "__" + shasum.digest("hex");
}
private convertClosureToNormalizedObject(seenClosures: Closure[], closure: Closure | undefined) {

16
sdk/nodejs/runtime/native/closure.cc
View file

@ -111,7 +111,7 @@ Local<String> SerializeFunctionCode(Isolate *isolate, Local<Function> func) {
// SerializeFunction serializes a JavaScript function expression and its associated closure environment.
Local<Value> SerializeFunction(Isolate *isolate, Local<Function> func,
Local<Function> freeVarsFunc, Local<Function> envEntryFunc) {
Local<Function> freeVarsFunc, Local<Function> envEntryFunc, Local<Object> envEntryCache) {
// Get at the innards of the function. Unfortunately, we need to use internal V8 APIs to do this,
// as the closest public function, CreationContext, intentionally returns the non-closure Context for
// Function objects (it returns the constructor context, which is not what we want).
@ -159,8 +159,8 @@ Local<Value> SerializeFunction(Isolate *isolate, Local<Function> func,
// Only empty if an error was thrown; bail eagerly to propagate it.
return Local<Value>();
}
const unsigned envEntryArgc = 1;
Local<Value> envEntryArgv[envEntryArgc] = { v };
const unsigned envEntryArgc = 2;
Local<Value> envEntryArgv[envEntryArgc] = { v, envEntryCache };
Local<Value> envEntry = envEntryFunc->Call(Null(isolate), envEntryArgc, envEntryArgv);
if (envEntry.IsEmpty()) {
return Local<Value>();
@ -214,8 +214,16 @@ void SerializeClosure(const FunctionCallbackInfo<Value>& args) {
}
Local<Function> envEntryFunc = Local<Function>::Cast(args[2]);
// And that the fourth is an entry cache used to backstop mutually recursive captures.
if (args.Length() < 4 || args[3]->IsUndefined()) {
isolate->ThrowException(Exception::TypeError(
String::NewFromUtf8(isolate, "Missing required env-entry cache")));
return;
}
Local<Object> envEntryCache = Local<Object>::Cast(args[3]);
// Now go ahead and serialize it, and return the result.
Local<Value> closure = SerializeFunction(isolate, func, freeVarsFunc, envEntryFunc);
Local<Value> closure = SerializeFunction(isolate, func, freeVarsFunc, envEntryFunc, envEntryCache);
if (!closure.IsEmpty()) {
args.GetReturnValue().Set(closure);
}

59
sdk/nodejs/tests/runtime/closure.spec.ts
View file

@ -5,11 +5,13 @@ import { runtime } from "../../index";
import { assertAsyncThrows, asyncTest } from "../util";
interface ClosureCase {
pre?: () => void; // an optional function to run before this case.
title: string; // a title banner for the test case.
func: Function; // the function whose body and closure to serialize.
expect?: runtime.Closure; // if undefined, error expected; otherwise, the serialized shape.
expectText?: string; // optionally also validate the serialization to JavaScript text.
closureHash?: string; // hash of the closure.
closureHash?: string; // hash of the closure.
afters?: ClosureCase[]; // an optional list of test cases to run afterwards.
}
// This group of tests ensure that we serialize closures properly.
@ -763,10 +765,55 @@ return (function () { () => { console.log(this + arguments); }; })
},
closureHash: "__05dabc231611ca558334d59d661ebfb242b31b5d",
});
const mutable: any = {};
cases.push({
title: "Serialize mutable objects by value at the time of capture (pre-mutation)",
func: function() { return mutable; },
expect: {
code: `(function () { return mutable; })`,
environment: {
"mutable": {
obj: {},
},
},
runtime: "nodejs",
},
closureHash: "__e4a4f2f9ad40ef73c250aa10f0277247adfae473",
afters: [{
pre: () => { mutable.timesTheyAreAChangin = true; },
title: "Serialize mutable objects by value at the time of capture (post-mutation)",
func: function() { return mutable; },
expect: {
code: `(function () { return mutable; })`,
environment: {
"mutable": {
obj: {
"timesTheyAreAChangin": {
json: true,
},
},
},
},
runtime: "nodejs",
},
closureHash: "__18d08ca03253fe3dda134c1e5e5889f514cb3841",
}],
});
// Now go ahead and run the test cases, each as its own case.
for (const test of cases) {
// Make a callback to keep running tests.
let remaining = cases;
while (true) {
const test = remaining.shift();
if (!test) {
return;
}
it(test.title, asyncTest(async () => {
// Run pre-actions.
if (test.pre) {
test.pre();
}
// Invoke the test case.
if (test.expect) {
const closure: runtime.Closure = await runtime.serializeClosure(test.func);
assert.deepEqual(closure, test.expect);
@ -783,6 +830,10 @@ return (function () { () => { console.log(this + arguments); }; })
});
}
}));
// Schedule any additional tests.
if (test.afters) {
remaining = test.afters.concat(remaining);
}
}
});

3
tests/integration/steps/step4/index.ts
View file

@ -7,7 +7,8 @@ import { Provider, Resource } from "./resource";
// (CreateReplacement(a4), Update(c3=>c4), DeleteReplaced(a3)).
let a = new Resource("a", { state: 1, replace: 2 });
// * Inject a fault into the Update(c3=>c4), such that we never delete a3 (and it goes onto the checkpoint list).
Provider.instance.injectFault(new Error("intentional update failure during step 4"));
// BUGBUG[pulumi/pulumi#663]: reenable after landing the bugfix and rearranging the test to tolerate expected failure.
// Provider.instance.injectFault(new Error("intentional update failure during step 4"));
let c = new Resource("c", { state: 1, resource: a });
let e = new Resource("e", { state: 1 });
// Checkpoint: a4, c3, e3; pending delete: a3