nswrap/examples/gc/main.go

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package main
import "C"
import (
"fmt"
"runtime"
"time"
"git.wow.st/gmp/nswrap/examples/gc/ns"
)
func releaseX(x int) func (ns.MyClassSupermethods) {
return func(super ns.MyClassSupermethods) {
//fmt.Printf("--release %d\n", x)
super.Release() // comment out for leak
}
}
func memtest1() {
fmt.Println("memtest1 started")
for {
arr := make([]ns.MyClass,1000)
for i := 0; i < 1000; i++ {
// Alloc methods set a finalizer that causes the Go GC to
// Release these objects.
arr[i] = ns.MyClassAlloc()
arr[i].ReleaseCallback(releaseX(i))
// You can still manually retain objects, but that will cause
// them to stick around after their Go pointers are collected.
// This may be necessary if you are adding objects to an
// Objective-C collection?
//arr[i].Retain() // uncomment for leak
}
// Manually run the Go GC at every loop iteration. May not be needed
// in a real program.
runtime.GC()
time.Sleep(time.Second/50)
fmt.Printf("Loop complete\n")
}
}
func memtest2() {
fmt.Println("memtest2 started")
for {
o1 := ns.NSStringAlloc().InitWithGoString("one string")
// NSWrap runs object constructors inside an @autoreleasepool block,
// and then calls "retain" on them before returning to Go. A Go
// finalizer is set allowing the Go GC to call Release().
o2 := ns.NSStringWithGoString("two string") // does not leak
arr := ns.NSArrayWithObjects(o1,o2)
_ = arr
runtime.GC()
time.Sleep(time.Second/50)
}
}
func addStr(arr ns.NSMutableArray) {
s1 := ns.NSStringAlloc().InitWithGoString("a string")
arr.AddObject(s1)
// s1 should be eligible for Go garbage collection here, but is still referenced
// on the Objective-C side. By adding s1 to an array, the array automatically
// calls 'retain' on the underlying Objective-C string.
}
func memtest3() {
fmt.Println("memtest3 started")
arr := ns.NSMutableArrayAlloc().Init() // arr will be garbage collected by Go
addStr(arr)
runtime.GC()
time.Sleep(time.Second)
s1 := arr.ObjectAtIndex(0)
fmt.Println(s1.NSString().UTF8String())
fmt.Println("memtest3 done")
}
func memtest4() {
fmt.Println("memtest4 started")
for {
o1 := ns.NSStringAlloc().InitWithGoString("four string")
c1 := o1.UTF8String()
_ = o1
_ = c1
time.Sleep(time.Second/10)
}
}
func main() {
go memtest1()
go memtest2()
go memtest3()
go memtest4()
select {}
}