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 #28711 for details.
Fixes #28711
Change-Id: I2c380970c3822bed6a3893909672c15d0cbe9da3
Reviewed-on: https://go-review.googlesource.com/c/153559
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/misc/wasm/wasm_exec.js b/misc/wasm/wasm_exec.js
index 743eaf7..165d567 100644
--- 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)
@@ -420,7 +420,7 @@
_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) {
@@ -428,13 +428,13 @@
}
}
- _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
index a3f8c29..45496ed 100644
--- a/src/cmd/vet/all/whitelist/wasm.txt
+++ b/src/cmd/vet/all/whitelist/wasm.txt
@@ -12,7 +12,7 @@
// 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
index 7959816..1e38b90 100644
--- a/src/net/http/roundtrip_js.go
+++ b/src/net/http/roundtrip_js.go
@@ -93,7 +93,7 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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
index 98aed87..b04ccdb 100644
--- a/src/runtime/lock_js.go
+++ b/src/runtime/lock_js.go
@@ -92,7 +92,7 @@
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}
@@ -100,7 +100,7 @@
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)
@@ -134,17 +134,17 @@
}
}
-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)
}()
@@ -152,44 +152,43 @@
}
// 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
index 8b92fcb..50adbe2 100644
--- a/src/runtime/rt0_js_wasm.s
+++ b/src/runtime/rt0_js_wasm.s
@@ -15,7 +15,7 @@
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 @@
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
index 3ca844a..6e28656 100644
--- a/src/runtime/sys_wasm.s
+++ b/src/runtime/sys_wasm.s
@@ -187,11 +187,11 @@
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
index 58d8216..fcc5f03 100644
--- a/src/syscall/fs_js.go
+++ b/src/syscall/fs_js.go
@@ -474,7 +474,7 @@
}
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
deleted file mode 100644
index 7f65409..0000000
--- a/src/syscall/js/callback.go
+++ /dev/null
@@ -1,92 +0,0 @@
-// Copyright 2018 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build js,wasm
-
-package js
-
-import "sync"
-
-var (
- callbacksMu sync.Mutex
- callbacks = make(map[uint32]func(Value, []Value) interface{})
- nextCallbackID uint32 = 1
-)
-
-var _ Wrapper = Callback{} // Callback must implement Wrapper
-
-// Callback is a Go function that got wrapped for use as a JavaScript callback.
-type Callback struct {
- Value // the JavaScript function that invokes the Go function
- id uint32
-}
-
-// NewCallback returns a wrapped callback function.
-//
-// Invoking the callback in JavaScript will synchronously call the Go function fn with the value of JavaScript's
-// "this" keyword and the arguments of the invocation.
-// The return value of the invocation is the result of the Go function mapped back to JavaScript according to ValueOf.
-//
-// A callback triggered during a call from Go to JavaScript gets executed on the same goroutine.
-// A callback triggered by JavaScript's event loop gets executed on an extra goroutine.
-// Blocking operations in the callback will block the event loop.
-// As a consequence, if one callback blocks, other callbacks will not be processed.
-// A blocking callback should therefore explicitly start a new goroutine.
-//
-// Callback.Release must be called to free up resources when the callback will not be used any more.
-func NewCallback(fn func(this Value, args []Value) interface{}) Callback {
- callbacksMu.Lock()
- id := nextCallbackID
- nextCallbackID++
- callbacks[id] = fn
- callbacksMu.Unlock()
- return Callback{
- id: id,
- Value: jsGo.Call("_makeCallbackHelper", id),
- }
-}
-
-// Release frees up resources allocated for the callback.
-// The callback must not be invoked after calling Release.
-func (c Callback) Release() {
- callbacksMu.Lock()
- delete(callbacks, c.id)
- callbacksMu.Unlock()
-}
-
-// setCallbackHandler is defined in the runtime package.
-func setCallbackHandler(fn func())
-
-func init() {
- setCallbackHandler(handleCallback)
-}
-
-func handleCallback() {
- cb := jsGo.Get("_pendingCallback")
- if cb == Null() {
- return
- }
- jsGo.Set("_pendingCallback", Null())
-
- id := uint32(cb.Get("id").Int())
- if id == 0 { // zero indicates deadlock
- select {}
- }
- callbacksMu.Lock()
- f, ok := callbacks[id]
- callbacksMu.Unlock()
- if !ok {
- Global().Get("console").Call("error", "call to closed callback")
- return
- }
-
- this := cb.Get("this")
- argsObj := cb.Get("args")
- args := make([]Value, argsObj.Length())
- for i := range args {
- args[i] = argsObj.Index(i)
- }
- result := f(this, args)
- cb.Set("result", result)
-}
diff --git a/src/syscall/js/func.go b/src/syscall/js/func.go
new file mode 100644
index 0000000..6b7f39b
--- /dev/null
+++ b/src/syscall/js/func.go
@@ -0,0 +1,92 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build js,wasm
+
+package js
+
+import "sync"
+
+var (
+ funcsMu sync.Mutex
+ funcs = make(map[uint32]func(Value, []Value) interface{})
+ nextFuncID uint32 = 1
+)
+
+var _ Wrapper = Func{} // Func must implement Wrapper
+
+// Func is a wrapped Go function to be called by JavaScript.
+type Func struct {
+ Value // the JavaScript function that invokes the Go function
+ id uint32
+}
+
+// FuncOf returns a wrapped function.
+//
+// Invoking the JavaScript function will synchronously call the Go function fn with the value of JavaScript's
+// "this" keyword and the arguments of the invocation.
+// The return value of the invocation is the result of the Go function mapped back to JavaScript according to ValueOf.
+//
+// A wrapped function triggered during a call from Go to JavaScript gets executed on the same goroutine.
+// A wrapped function triggered by JavaScript's event loop gets executed on an extra goroutine.
+// Blocking operations in the wrapped function will block the event loop.
+// As a consequence, if one wrapped function blocks, other wrapped funcs will not be processed.
+// A blocking function should therefore explicitly start a new goroutine.
+//
+// Func.Release must be called to free up resources when the function will not be used any more.
+func FuncOf(fn func(this Value, args []Value) interface{}) Func {
+ funcsMu.Lock()
+ id := nextFuncID
+ nextFuncID++
+ funcs[id] = fn
+ funcsMu.Unlock()
+ return Func{
+ id: id,
+ Value: jsGo.Call("_makeFuncWrapper", id),
+ }
+}
+
+// Release frees up resources allocated for the function.
+// The function must not be invoked after calling Release.
+func (c Func) Release() {
+ funcsMu.Lock()
+ delete(funcs, c.id)
+ funcsMu.Unlock()
+}
+
+// setEventHandler is defined in the runtime package.
+func setEventHandler(fn func())
+
+func init() {
+ setEventHandler(handleEvent)
+}
+
+func handleEvent() {
+ cb := jsGo.Get("_pendingEvent")
+ if cb == Null() {
+ return
+ }
+ jsGo.Set("_pendingEvent", Null())
+
+ id := uint32(cb.Get("id").Int())
+ if id == 0 { // zero indicates deadlock
+ select {}
+ }
+ funcsMu.Lock()
+ f, ok := funcs[id]
+ funcsMu.Unlock()
+ if !ok {
+ Global().Get("console").Call("error", "call to released function")
+ return
+ }
+
+ this := cb.Get("this")
+ argsObj := cb.Get("args")
+ args := make([]Value, argsObj.Length())
+ for i := range args {
+ args[i] = argsObj.Index(i)
+ }
+ result := f(this, args)
+ cb.Set("result", result)
+}
diff --git a/src/syscall/js/js.go b/src/syscall/js/js.go
index 885723f..0893db0 100644
--- a/src/syscall/js/js.go
+++ b/src/syscall/js/js.go
@@ -107,7 +107,7 @@
// | ---------------------- | ---------------------- |
// | js.Value | [its value] |
// | js.TypedArray | typed array |
-// | js.Callback | function |
+// | js.Func | function |
// | nil | null |
// | bool | boolean |
// | integers and floats | number |
diff --git a/src/syscall/js/js_test.go b/src/syscall/js/js_test.go
index b4d2e66..c14d2cc 100644
--- a/src/syscall/js/js_test.go
+++ b/src/syscall/js/js_test.go
@@ -300,9 +300,9 @@
}
}
-func TestCallback(t *testing.T) {
+func TestFuncOf(t *testing.T) {
c := make(chan struct{})
- cb := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+ cb := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
if got := args[0].Int(); got != 42 {
t.Errorf("got %#v, want %#v", got, 42)
}
@@ -314,10 +314,10 @@
<-c
}
-func TestInvokeCallback(t *testing.T) {
+func TestInvokeFunction(t *testing.T) {
called := false
- cb := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
- cb2 := js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+ cb := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
+ cb2 := js.FuncOf(func(this js.Value, args []js.Value) interface{} {
called = true
return 42
})
@@ -329,15 +329,15 @@
t.Errorf("got %#v, want %#v", got, 42)
}
if !called {
- t.Error("callback not called")
+ t.Error("function not called")
}
}
-func ExampleNewCallback() {
- var cb js.Callback
- cb = js.NewCallback(func(this js.Value, args []js.Value) interface{} {
+func ExampleFuncOf() {
+ var cb js.Func
+ cb = js.FuncOf(func(this js.Value, args []js.Value) interface{} {
fmt.Println("button clicked")
- cb.Release() // release the callback if the button will not be clicked again
+ cb.Release() // release the function if the button will not be clicked again
return nil
})
js.Global().Get("document").Call("getElementById", "myButton").Call("addEventListener", "click", cb)
