Fix setTimeout ID collisions.

src/workerd/api/global-scope.c++

@@ -687,7 +687,6 @@ TimeoutId::NumberType ServiceWorkerGlobalScope::setTimeoutInternal(
     jsg::Function<void()> function,
     double msDelay) {
   auto timeoutId = IoContext::current().setTimeoutImpl(
-      timeoutIdGenerator,
       /** repeats = */ false,
       kj::mv(function),
       msDelay);
@@ -707,7 +706,6 @@ TimeoutId::NumberType ServiceWorkerGlobalScope::setTimeout(
     function(js, kj::mv(args));
   };
   auto timeoutId = IoContext::current().setTimeoutImpl(
-      timeoutIdGenerator,
       /* repeats = */ false,
       [function = kj::mv(fn)](jsg::Lock& js) mutable {
     function(js);
@@ -737,7 +735,6 @@ TimeoutId::NumberType ServiceWorkerGlobalScope::setInterval(
     function(js, jsg::Arguments(kj::mv(argv)));
   };
   auto timeoutId = IoContext::current().setTimeoutImpl(
-      timeoutIdGenerator,
       /* repeats = */ true,
       [function = kj::mv(fn)](jsg::Lock& js) mutable {
     function(js);

src/workerd/api/gpu/gpu-async-runner.c++

@@ -30,7 +30,7 @@ void AsyncRunner::QueueTick() {
   tick_queued_ = true;
 
   IoContext::current().setTimeoutImpl(
-      timeoutIdGenerator, false,
+      false,
       [this](jsg::Lock& js) mutable {
         this->tick_queued_ = false;
         if (this->count_ > 0) {

src/workerd/api/gpu/gpu-async-runner.h

@@ -33,7 +33,6 @@ class AsyncRunner : public kj::Refcounted {
   wgpu::Device const device_;
   uint64_t count_ = 0;
   bool tick_queued_ = false;
-  TimeoutId::Generator timeoutIdGenerator;
 };
 
 // AsyncTask is a RAII helper for calling AsyncRunner::Begin() on construction,

src/workerd/api/gpu/webgpu-buffer-test.js

@@ -6,6 +6,11 @@ export class DurableObjectExample {
   }
 
   async fetch() {
+    // Some WebGPU APIs use setTimeout under the hood. There used to be a bug whereby webGPU would
+    // try to use a timeout ID that was already in use by a call to a JS timer API (or vice versa).
+    // We set a timeout here as a regression test.
+    setTimeout(() => { console.log("timeout fired"); }, 30000);
+
     ok(navigator.gpu);
     const adapter = await navigator.gpu.requestAdapter();
     ok(adapter);

src/workerd/io/io-context.c++

@@ -31,8 +31,8 @@ public:
   KJ_DISALLOW_COPY_AND_MOVE(TimeoutManagerImpl);
 
   TimeoutId setTimeout(
-      IoContext& context, TimeoutId::Generator& generator, TimeoutParameters params) override {
-    auto [id, it] = addState(generator, kj::mv(params));
+      IoContext& context, TimeoutParameters params) override {
+    auto [id, it] = addState(kj::mv(params));
     setTimeoutImpl(context, it);
     return id;
   }
@@ -56,7 +56,7 @@ private:
     TimeoutId id;
     Iterator it;
   };
-  IdAndIterator addState(TimeoutId::Generator& generator, TimeoutParameters params);
+  IdAndIterator addState(TimeoutParameters params);
 
   void setTimeoutImpl(IoContext& context, Iterator it);
 
@@ -75,6 +75,8 @@ private:
     }
   };
 
+  TimeoutId::Generator timeoutIdGenerator;
+
   // Tracks registered timeouts sorted by the next time the timeout is expected to fire.
   //
   // The associated fulfiller should be fulfilled when the time has been reached AND all previous
@@ -591,13 +593,12 @@ void IoContext::TimeoutManagerImpl::TimeoutState::cancel() {
   ++manager.timeoutsFinished;
 }
 
-auto IoContext::TimeoutManagerImpl::addState(
-    TimeoutId::Generator& generator, TimeoutParameters params) -> IdAndIterator {
+auto IoContext::TimeoutManagerImpl::addState(TimeoutParameters params) -> IdAndIterator {
   JSG_REQUIRE(getTimeoutCount() < MAX_TIMEOUTS, DOMQuotaExceededError,
               "You have exceeded the number of timeouts you may set.",
               MAX_TIMEOUTS);
 
-  auto id = generator.getNext();
+  auto id = timeoutIdGenerator.getNext();
   auto [it, wasEmplaced] = timeouts.try_emplace(id, *this, kj::mv(params));
   if (!wasEmplaced) {
     // We shouldn't have reached here because the `TimeoutId::Generator` throws if it reaches
@@ -763,7 +764,6 @@ void IoContext::TimeoutManagerImpl::clearTimeout(
 }
 
 TimeoutId IoContext::setTimeoutImpl(
-    TimeoutId::Generator& generator,
     bool repeat,
     jsg::Function<void()> function,
     double msDelay) {
@@ -775,7 +775,7 @@ TimeoutId IoContext::setTimeoutImpl(
       msDelay <= 0 || std::isnan(msDelay) ? 0 :
       msDelay >= static_cast<double>(max) ? max : static_cast<int64_t>(msDelay);
   auto params = TimeoutManager::TimeoutParameters(repeat, delay, kj::mv(function));
-  return timeoutManager->setTimeout(*this, generator, kj::mv(params));
+  return timeoutManager->setTimeout(*this, kj::mv(params));
 }
 
 void IoContext::clearTimeoutImpl(TimeoutId id) {

src/workerd/io/io-context.h

@@ -548,7 +548,6 @@ class IoContext final: public kj::Refcounted, private kj::TaskSet::ErrorHandler
   // Used to implement setTimeout(). We don't expose the timer directly because the
   // promises it returns need to live in this I/O context, anyway.
   TimeoutId setTimeoutImpl(
-    TimeoutId::Generator& generator,
     bool repeat,
     jsg::Function<void()> function,
     double msDelay);

src/workerd/io/io-timers.h

@@ -79,11 +79,10 @@ class TimeoutManager {
     kj::Maybe<jsg::Function<void()>> function;
   };
 
-  virtual TimeoutId setTimeout(
-      IoContext& context, TimeoutId::Generator& generator, TimeoutParameters params) = 0;
+  virtual TimeoutId setTimeout(IoContext& context, TimeoutParameters params) = 0;
   virtual void clearTimeout(IoContext& context, TimeoutId id) = 0;
   virtual size_t getTimeoutCount() const = 0;
   virtual kj::Maybe<kj::Date> getNextTimeout() const = 0;
 };
 
-}  // namespace workerd
+} // namespace workerd