4f4a855d82
Reviewed-on: https://go-review.googlesource.com/c/158019 gotools/: * Makefile.am (go_cmd_vet_files): Update for Go1.12beta2 release. (GOTOOLS_TEST_TIMEOUT): Increase to 600. (check-runtime): Export LD_LIBRARY_PATH before computing GOARCH and GOOS. (check-vet): Copy golang.org/x/tools into check-vet-dir. * Makefile.in: Regenerate. gcc/testsuite/: * go.go-torture/execute/names-1.go: Stop using debug/xcoff, which is no longer externally visible. From-SVN: r268084
93 lines
2.5 KiB
Go
93 lines
2.5 KiB
Go
// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build js,wasm
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package js
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import "sync"
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var (
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funcsMu sync.Mutex
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funcs = make(map[uint32]func(Value, []Value) interface{})
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nextFuncID uint32 = 1
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)
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var _ Wrapper = Func{} // Func must implement Wrapper
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// Func is a wrapped Go function to be called by JavaScript.
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type Func struct {
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Value // the JavaScript function that invokes the Go function
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id uint32
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}
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// FuncOf returns a wrapped function.
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//
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// Invoking the JavaScript function will synchronously call the Go function fn with the value of JavaScript's
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// "this" keyword and the arguments of the invocation.
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// The return value of the invocation is the result of the Go function mapped back to JavaScript according to ValueOf.
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//
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// A wrapped function triggered during a call from Go to JavaScript gets executed on the same goroutine.
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// A wrapped function triggered by JavaScript's event loop gets executed on an extra goroutine.
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// Blocking operations in the wrapped function will block the event loop.
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// As a consequence, if one wrapped function blocks, other wrapped funcs will not be processed.
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// A blocking function should therefore explicitly start a new goroutine.
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//
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// Func.Release must be called to free up resources when the function will not be used any more.
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func FuncOf(fn func(this Value, args []Value) interface{}) Func {
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funcsMu.Lock()
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id := nextFuncID
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nextFuncID++
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funcs[id] = fn
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funcsMu.Unlock()
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return Func{
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id: id,
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Value: jsGo.Call("_makeFuncWrapper", id),
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}
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}
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// Release frees up resources allocated for the function.
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// The function must not be invoked after calling Release.
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func (c Func) Release() {
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funcsMu.Lock()
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delete(funcs, c.id)
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funcsMu.Unlock()
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}
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// setEventHandler is defined in the runtime package.
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func setEventHandler(fn func())
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func init() {
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setEventHandler(handleEvent)
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}
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func handleEvent() {
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cb := jsGo.Get("_pendingEvent")
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if cb == Null() {
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return
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}
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jsGo.Set("_pendingEvent", Null())
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id := uint32(cb.Get("id").Int())
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if id == 0 { // zero indicates deadlock
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select {}
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}
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funcsMu.Lock()
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f, ok := funcs[id]
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funcsMu.Unlock()
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if !ok {
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Global().Get("console").Call("error", "call to released function")
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return
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}
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this := cb.Get("this")
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argsObj := cb.Get("args")
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args := make([]Value, argsObj.Length())
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for i := range args {
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args[i] = argsObj.Index(i)
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}
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result := f(this, args)
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cb.Set("result", result)
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}
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