mobile/bind/objc/seq_darwin.go

119 lines
2.6 KiB
Go

// Copyright 2015 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.
package objc
/*
#cgo CFLAGS: -x objective-c -fobjc-arc
#cgo LDFLAGS: -framework Foundation
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
void init_seq();
*/
import "C"
import (
"fmt"
"sync"
"unsafe"
"golang.org/x/mobile/bind/seq"
)
const debug = true
const maxSliceLen = 1<<31 - 1
// Send is called by Objective-C to send a request to run a Go function.
//export Send
func Send(descriptor string, code int, req *C.uint8_t, reqlen C.size_t, res **C.uint8_t, reslen *C.size_t) {
fn := seq.Registry[descriptor][code]
if fn == nil {
panic(fmt.Sprintf("invalid descriptor(%s) and code(0x%x)", descriptor, code))
}
var in, out *seq.Buffer
if reqlen > 0 {
in = &seq.Buffer{Data: (*[maxSliceLen]byte)(unsafe.Pointer(req))[:reqlen]}
}
if reslen != nil {
out = new(seq.Buffer)
}
fn(out, in)
if out != nil {
// sender does not expect any results.
seqToBuf(res, reslen, out)
}
}
// DestroyRef is called by Objective-C to inform Go it is done with a reference.
//export DestroyRef
func DestroyRef(refnum C.int32_t) {
seq.Delete(int32(refnum))
}
type request struct {
ref *seq.Ref
handle int32
code int
in *seq.Buffer
}
var recv struct {
sync.Mutex
cond sync.Cond // signals req is not empty
req []request
next int32 // next handle value
}
var res struct {
sync.Mutex
cond sync.Cond // signals a response is filled in
out map[int32]*seq.Buffer // handle -> output
}
func init() {
recv.cond.L = &recv.Mutex
recv.next = 411 // arbitrary starting point distrinct from Go and Objective-C object ref nums.
res.cond.L = &res.Mutex
res.out = make(map[int32]*seq.Buffer)
}
func seqToBuf(bufptr **C.uint8_t, lenptr *C.size_t, buf *seq.Buffer) {
if debug {
fmt.Printf("seqToBuf tag 1, len(buf.Data)=%d, *lenptr=%d\n", len(buf.Data), *lenptr)
}
if len(buf.Data) == 0 {
*lenptr = 0
return
}
if len(buf.Data) > int(*lenptr) {
// TODO(crawshaw): realloc
C.free(unsafe.Pointer(*bufptr))
m := C.malloc(C.size_t(len(buf.Data)))
if uintptr(m) == 0 {
panic(fmt.Sprintf("malloc failed, size=%d", len(buf.Data)))
}
*bufptr = (*C.uint8_t)(m)
*lenptr = C.size_t(len(buf.Data))
}
C.memcpy(unsafe.Pointer(*bufptr), unsafe.Pointer(&buf.Data[0]), C.size_t(len(buf.Data)))
}
func init() {
// TODO: seq.FinalizeRef, seq.Transact.
seq.EncString = func(out *seq.Buffer, v string) {
out.WriteUTF8(v)
}
seq.DecString = func(in *seq.Buffer) string {
return in.ReadUTF8()
}
C.init_seq()
}