syscall/js: rename js.Callback to js.Func

The name "Callback" does not fit to all use cases of js.Callback. This commit changes its name to Func. Accordingly NewCallback gets renamed to FuncOf, which matches ValueOf and TypedArrayOf. The package syscall/js is currently exempt from Go's compatibility promise and js.Callback is already affected by a breaking change in this release cycle. See golang#28711 for details. Fixes golang#28711 Change-Id: I2c380970c3822bed6a3893909672c15d0cbe9da3 Reviewed-on: https://go-review.googlesource.com/c/153559 Run-TryBot: Brad Fitzpatrick <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: Brad Fitzpatrick <[email protected]>
freeformz · Dec 13, 2018 · 7d9649b · 7d9649b
1 parent f95578c
commit 7d9649b
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Showing 11 changed files with 158 additions and 159 deletions.
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
@@ -87,8 +87,8 @@
 			this._exitPromise = new Promise((resolve) => {
 				this._resolveExitPromise = resolve;
 			});
-			this._pendingCallback = null;
-			this._callbackTimeouts = new Map();
+			this._pendingEvent = null;
+			this._scheduledTimeouts = new Map();
 			this._nextCallbackTimeoutID = 1;
 
 			const mem = () => {
@@ -204,7 +204,7 @@
 			this.importObject = {
 				go: {
 					// Go's SP does not change as long as no Go code is running. Some operations (e.g. calls, getters and setters)
-					// may trigger a synchronous callback to Go. This makes Go code get executed in the middle of the imported
+					// may synchronously trigger a Go event handler. This makes Go code get executed in the middle of the imported
 					// function. A goroutine can switch to a new stack if the current stack is too small (see morestack function).
 					// This changes the SP, thus we have to update the SP used by the imported function.
 
@@ -238,22 +238,22 @@
 						mem().setInt32(sp + 16, (msec % 1000) * 1000000, true);
 					},
 
-					// func scheduleCallback(delay int64) int32
-					"runtime.scheduleCallback": (sp) => {
+					// func scheduleTimeoutEvent(delay int64) int32
+					"runtime.scheduleTimeoutEvent": (sp) => {
 						const id = this._nextCallbackTimeoutID;
 						this._nextCallbackTimeoutID++;
-						this._callbackTimeouts.set(id, setTimeout(
+						this._scheduledTimeouts.set(id, setTimeout(
 							() => { this._resume(); },
 							getInt64(sp + 8) + 1, // setTimeout has been seen to fire up to 1 millisecond early
 						));
 						mem().setInt32(sp + 16, id, true);
 					},
 
-					// func clearScheduledCallback(id int32)
-					"runtime.clearScheduledCallback": (sp) => {
+					// func clearTimeoutEvent(id int32)
+					"runtime.clearTimeoutEvent": (sp) => {
 						const id = mem().getInt32(sp + 8, true);
-						clearTimeout(this._callbackTimeouts.get(id));
-						this._callbackTimeouts.delete(id);
+						clearTimeout(this._scheduledTimeouts.get(id));
+						this._scheduledTimeouts.delete(id);
 					},
 
 					// func getRandomData(r []byte)
@@ -420,21 +420,21 @@
 
 		_resume() {
 			if (this.exited) {
-				throw new Error("bad callback: Go program has already exited");
+				throw new Error("Go program has already exited");
 			}
 			this._inst.exports.resume();
 			if (this.exited) {
 				this._resolveExitPromise();
 			}
 		}
 
-		_makeCallbackHelper(id) {
+		_makeFuncWrapper(id) {
 			const go = this;
 			return function () {
-				const cb = { id: id, this: this, args: arguments };
-				go._pendingCallback = cb;
+				const event = { id: id, this: this, args: arguments };
+				go._pendingEvent = event;
 				go._resume();
-				return cb.result;
+				return event.result;
 			};
 		}
 	}
@@ -450,10 +450,10 @@
 		go.env = Object.assign({ TMPDIR: require("os").tmpdir() }, process.env);
 		go.exit = process.exit;
 		WebAssembly.instantiate(fs.readFileSync(process.argv[2]), go.importObject).then((result) => {
-			process.on("exit", (code) => { // Node.js exits if no callback is pending
+			process.on("exit", (code) => { // Node.js exits if no event handler is pending
 				if (code === 0 && !go.exited) {
 					// deadlock, make Go print error and stack traces
-					go._pendingCallback = { id: 0 };
+					go._pendingEvent = { id: 0 };
 					go._resume();
 				}
 			});

diff --git a/src/cmd/vet/all/whitelist/wasm.txt b/src/cmd/vet/all/whitelist/wasm.txt
@@ -12,7 +12,7 @@ runtime/asm_wasm.s: [wasm] rt0_go: use of 8(SP) points beyond argument frame
 
 // Calling WebAssembly import. No write from Go assembly.
 runtime/sys_wasm.s: [wasm] nanotime: RET without writing to 8-byte ret+0(FP)
-runtime/sys_wasm.s: [wasm] scheduleCallback: RET without writing to 4-byte ret+8(FP)
+runtime/sys_wasm.s: [wasm] scheduleTimeoutEvent: RET without writing to 4-byte ret+8(FP)
 syscall/js/js_js.s: [wasm] stringVal: RET without writing to 8-byte ret+16(FP)
 syscall/js/js_js.s: [wasm] valueGet: RET without writing to 8-byte ret+24(FP)
 syscall/js/js_js.s: [wasm] valueIndex: RET without writing to 8-byte ret+16(FP)

diff --git a/src/net/http/roundtrip_js.go b/src/net/http/roundtrip_js.go
@@ -93,7 +93,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 		respCh = make(chan *Response, 1)
 		errCh  = make(chan error, 1)
 	)
-	success := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+	success := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 		result := args[0]
 		header := Header{}
 		// https://developer.mozilla.org/en-US/docs/Web/API/Headers/entries
@@ -141,7 +141,7 @@ func (t *Transport) RoundTrip(req *Request) (*Response, error) {
 		return nil
 	})
 	defer success.Release()
-	failure := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+	failure := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 		err := fmt.Errorf("net/http: fetch() failed: %s", args[0].String())
 		select {
 		case errCh <- err:
@@ -190,7 +190,7 @@ func (r *streamReader) Read(p []byte) (n int, err error) {
 			bCh   = make(chan []byte, 1)
 			errCh = make(chan error, 1)
 		)
-		success := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+		success := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 			result := args[0]
 			if result.Get("done").Bool() {
 				errCh <- io.EOF
@@ -204,7 +204,7 @@ func (r *streamReader) Read(p []byte) (n int, err error) {
 			return nil
 		})
 		defer success.Release()
-		failure := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+		failure := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 			// Assumes it's a TypeError. See
 			// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError
 			// for more information on this type. See
@@ -258,7 +258,7 @@ func (r *arrayReader) Read(p []byte) (n int, err error) {
 			bCh   = make(chan []byte, 1)
 			errCh = make(chan error, 1)
 		)
-		success := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+		success := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 			// Wrap the input ArrayBuffer with a Uint8Array
 			uint8arrayWrapper := js.Global().Get("Uint8Array").New(args[0])
 			value := make([]byte, uint8arrayWrapper.Get("byteLength").Int())
@@ -269,7 +269,7 @@ func (r *arrayReader) Read(p []byte) (n int, err error) {
 			return nil
 		})
 		defer success.Release()
-		failure := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+		failure := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 			// Assumes it's a TypeError. See
 			// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypeError
 			// for more information on this type.

diff --git a/src/runtime/lock_js.go b/src/runtime/lock_js.go
@@ -92,15 +92,15 @@ func notetsleepg(n *note, ns int64) bool {
 			delay = 1<<31 - 1 // cap to max int32
 		}
 
-		id := scheduleCallback(delay)
+		id := scheduleTimeoutEvent(delay)
 		mp := acquirem()
 		notes[n] = gp
 		notesWithTimeout[n] = noteWithTimeout{gp: gp, deadline: deadline}
 		releasem(mp)
 
 		gopark(nil, nil, waitReasonSleep, traceEvNone, 1)
 
-		clearScheduledCallback(id) // note might have woken early, clear timeout
+		clearTimeoutEvent(id) // note might have woken early, clear timeout
 		mp = acquirem()
 		delete(notes, n)
 		delete(notesWithTimeout, n)
@@ -134,62 +134,61 @@ func checkTimeouts() {
 	}
 }
 
-var returnedCallback *g
+var returnedEventHandler *g
 
 func init() {
-	// At the toplevel we need an extra goroutine that handles asynchronous callbacks.
+	// At the toplevel we need an extra goroutine that handles asynchronous events.
 	initg := getg()
 	go func() {
-		returnedCallback = getg()
+		returnedEventHandler = getg()
 		goready(initg, 1)
 
 		gopark(nil, nil, waitReasonZero, traceEvNone, 1)
-		returnedCallback = nil
+		returnedEventHandler = nil
 
 		pause(getcallersp() - 16)
 	}()
 	gopark(nil, nil, waitReasonZero, traceEvNone, 1)
 }
 
 // beforeIdle gets called by the scheduler if no goroutine is awake.
-// If a callback has returned, then we resume the callback handler which
-// will pause the execution.
+// We resume the event handler (if available) which will pause the execution.
 func beforeIdle() bool {
-	if returnedCallback != nil {
-		goready(returnedCallback, 1)
+	if returnedEventHandler != nil {
+		goready(returnedEventHandler, 1)
 		return true
 	}
 	return false
 }
 
-// pause sets SP to newsp and pauses the execution of Go's WebAssembly code until a callback is triggered.
+// pause sets SP to newsp and pauses the execution of Go's WebAssembly code until an event is triggered.
 func pause(newsp uintptr)
 
-// scheduleCallback tells the WebAssembly environment to trigger a callback after ms milliseconds.
-// It returns a timer id that can be used with clearScheduledCallback.
-func scheduleCallback(ms int64) int32
+// scheduleTimeoutEvent tells the WebAssembly environment to trigger an event after ms milliseconds.
+// It returns a timer id that can be used with clearTimeoutEvent.
+func scheduleTimeoutEvent(ms int64) int32
 
-// clearScheduledCallback clears a callback scheduled by scheduleCallback.
-func clearScheduledCallback(id int32)
+// clearTimeoutEvent clears a timeout event scheduled by scheduleTimeoutEvent.
+func clearTimeoutEvent(id int32)
 
-func handleCallback() {
-	prevReturnedCallback := returnedCallback
-	returnedCallback = nil
+func handleEvent() {
+	prevReturnedEventHandler := returnedEventHandler
+	returnedEventHandler = nil
 
 	checkTimeouts()
-	callbackHandler()
+	eventHandler()
 
-	returnedCallback = getg()
+	returnedEventHandler = getg()
 	gopark(nil, nil, waitReasonZero, traceEvNone, 1)
 
-	returnedCallback = prevReturnedCallback
+	returnedEventHandler = prevReturnedEventHandler
 
 	pause(getcallersp() - 16)
 }
 
-var callbackHandler func()
+var eventHandler func()
 
-//go:linkname setCallbackHandler syscall/js.setCallbackHandler
-func setCallbackHandler(fn func()) {
-	callbackHandler = fn
+//go:linkname setEventHandler syscall/js.setEventHandler
+func setEventHandler(fn func()) {
+	eventHandler = fn
 }
diff --git a/src/runtime/rt0_js_wasm.s b/src/runtime/rt0_js_wasm.s
@@ -15,7 +15,7 @@ TEXT _rt0_wasm_js(SB),NOSPLIT,$0
 	Drop
 
 // wasm_export_run gets called from JavaScript. It initializes the Go runtime and executes Go code until it needs
-// to wait for a callback. It does NOT follow the Go ABI. It has two WebAssembly parameters:
+// to wait for an event. It does NOT follow the Go ABI. It has two WebAssembly parameters:
 // R0: argc (i32)
 // R1: argv (i32)
 TEXT wasm_export_run(SB),NOSPLIT,$0
@@ -44,9 +44,9 @@ TEXT wasm_export_run(SB),NOSPLIT,$0
 	Return
 
 // wasm_export_resume gets called from JavaScript. It resumes the execution of Go code until it needs to wait for
-// a callback.
+// an event.
 TEXT wasm_export_resume(SB),NOSPLIT,$0
-	I32Const $runtime·handleCallback(SB)
+	I32Const $runtime·handleEvent(SB)
 	I32Const $16
 	I32ShrU
 	Set PC_F

diff --git a/src/runtime/sys_wasm.s b/src/runtime/sys_wasm.s
@@ -187,11 +187,11 @@ TEXT ·walltime(SB), NOSPLIT, $0
 	CallImport
 	RET
 
-TEXT ·scheduleCallback(SB), NOSPLIT, $0
+TEXT ·scheduleTimeoutEvent(SB), NOSPLIT, $0
 	CallImport
 	RET
 
-TEXT ·clearScheduledCallback(SB), NOSPLIT, $0
+TEXT ·clearTimeoutEvent(SB), NOSPLIT, $0
 	CallImport
 	RET
 

diff --git a/src/syscall/fs_js.go b/src/syscall/fs_js.go
@@ -474,7 +474,7 @@ func fsCall(name string, args ...interface{}) (js.Value, error) {
 	}
 
 	c := make(chan callResult, 1)
-	jsFS.Call(name, append(args, js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+	jsFS.Call(name, append(args, js.FuncOf(func(this js.Value, args []js.Value) interface{} {
 		var res callResult
 
 		if len(args) >= 1 { // on Node.js 8, fs.utimes calls the callback without any arguments

diff --git a/src/syscall/js/callback.go b/src/syscall/js/callback.go