diff options
| -rw-r--r-- | misc/wasm/wasm_exec.js | 2 | ||||
| -rw-r--r-- | src/runtime/lock_js.go | 78 | ||||
| -rw-r--r-- | src/syscall/js/func.go | 17 |
3 files changed, 68 insertions, 29 deletions
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js index 7f72bee005..bc6f210242 100644 --- a/misc/wasm/wasm_exec.js +++ b/misc/wasm/wasm_exec.js @@ -276,7 +276,7 @@ this._resume(); } }, - getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early + getInt64(sp + 8), )); this.mem.setInt32(sp + 16, id, true); }, diff --git a/src/runtime/lock_js.go b/src/runtime/lock_js.go index ae2bb3db47..fd2abee7c4 100644 --- a/src/runtime/lock_js.go +++ b/src/runtime/lock_js.go @@ -117,7 +117,6 @@ func notetsleepg(n *note, ns int64) bool { gopark(nil, nil, waitReasonSleep, traceBlockSleep, 1) clearTimeoutEvent(id) // note might have woken early, clear timeout - clearIdleID() mp = acquirem() delete(notes, n) @@ -169,8 +168,36 @@ type event struct { returned bool } +type timeoutEvent struct { + id int32 + // The time when this timeout will be triggered. + time int64 +} + +// diff calculates the difference of the event's trigger time and x. +func (e *timeoutEvent) diff(x int64) int64 { + if e == nil { + return 0 + } + + diff := x - idleTimeout.time + if diff < 0 { + diff = -diff + } + return diff +} + +// clear cancels this timeout event. +func (e *timeoutEvent) clear() { + if e == nil { + return + } + + clearTimeoutEvent(e.id) +} + // The timeout event started by beforeIdle. -var idleID int32 +var idleTimeout *timeoutEvent // beforeIdle gets called by the scheduler if no goroutine is awake. // If we are not already handling an event, then we pause for an async event. @@ -183,21 +210,23 @@ var idleID int32 func beforeIdle(now, pollUntil int64) (gp *g, otherReady bool) { delay := int64(-1) if pollUntil != 0 { - delay = pollUntil - now - } - - if delay > 0 { - clearIdleID() - if delay < 1e6 { - delay = 1 - } else if delay < 1e15 { - delay = delay / 1e6 - } else { + // round up to prevent setTimeout being called early + delay = (pollUntil-now-1)/1e6 + 1 + if delay > 1e9 { // An arbitrary cap on how long to wait for a timer. // 1e9 ms == ~11.5 days. delay = 1e9 } - idleID = scheduleTimeoutEvent(delay) + } + + if delay > 0 && (idleTimeout == nil || idleTimeout.diff(pollUntil) > 1e6) { + // If the difference is larger than 1 ms, we should reschedule the timeout. + idleTimeout.clear() + + idleTimeout = &timeoutEvent{ + id: scheduleTimeoutEvent(delay), + time: pollUntil, + } } if len(events) == 0 { @@ -217,12 +246,10 @@ func handleAsyncEvent() { pause(getcallersp() - 16) } -// clearIdleID clears our record of the timeout started by beforeIdle. -func clearIdleID() { - if idleID != 0 { - clearTimeoutEvent(idleID) - idleID = 0 - } +// clearIdleTimeout clears our record of the timeout started by beforeIdle. +func clearIdleTimeout() { + idleTimeout.clear() + idleTimeout = nil } // pause sets SP to newsp and pauses the execution of Go's WebAssembly code until an event is triggered. @@ -250,9 +277,10 @@ func handleEvent() { } events = append(events, e) - eventHandler() - - clearIdleID() + if !eventHandler() { + // If we did not handle a window event, the idle timeout was triggered, so we can clear it. + clearIdleTimeout() + } // wait until all goroutines are idle e.returned = true @@ -265,9 +293,11 @@ func handleEvent() { pause(getcallersp() - 16) } -var eventHandler func() +// eventHandler retrieves and executes handlers for pending JavaScript events. +// It returns true if an event was handled. +var eventHandler func() bool //go:linkname setEventHandler syscall/js.setEventHandler -func setEventHandler(fn func()) { +func setEventHandler(fn func() bool) { eventHandler = fn } diff --git a/src/syscall/js/func.go b/src/syscall/js/func.go index cc94972364..53a4d79a95 100644 --- a/src/syscall/js/func.go +++ b/src/syscall/js/func.go @@ -60,16 +60,19 @@ func (c Func) Release() { } // setEventHandler is defined in the runtime package. -func setEventHandler(fn func()) +func setEventHandler(fn func() bool) func init() { setEventHandler(handleEvent) } -func handleEvent() { +// handleEvent retrieves the pending event (window._pendingEvent) and calls the js.Func on it. +// It returns true if an event was handled. +func handleEvent() bool { + // Retrieve the event from js cb := jsGo.Get("_pendingEvent") if cb.IsNull() { - return + return false } jsGo.Set("_pendingEvent", Null()) @@ -77,14 +80,17 @@ func handleEvent() { if id == 0 { // zero indicates deadlock select {} } + + // Retrieve the associated js.Func funcsMu.Lock() f, ok := funcs[id] funcsMu.Unlock() if !ok { Global().Get("console").Call("error", "call to released function") - return + return true } + // Call the js.Func with arguments this := cb.Get("this") argsObj := cb.Get("args") args := make([]Value, argsObj.Length()) @@ -92,5 +98,8 @@ func handleEvent() { args[i] = argsObj.Index(i) } result := f(this, args) + + // Return the result to js cb.Set("result", result) + return true } |