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package main
import (
"runtime"
"sync"
)
var wg sync.WaitGroup
func main() {
println("# simple recover")
recoverSimple()
println("\n# recover with result")
result := recoverWithResult()
println("result:", result)
println("\n# nested defer frame")
nestedDefer()
println("\n# nested panic: panic inside recover")
nestedPanic()
println("\n# panic inside defer")
panicInsideDefer()
println("\n# panic replace")
panicReplace()
println("\n# defer panic")
deferPanic()
println("\n# runtime.Goexit")
runtimeGoexit()
}
func recoverSimple() {
defer func() {
println("recovering...")
printitf("recovered:", recover())
}()
println("running panic...")
panic("panic")
}
func recoverWithResult() (result int) {
defer func() {
printitf("recovered:", recover())
}()
result = 3
println("running panic...")
panic("panic")
}
func nestedDefer() {
defer func() {
printitf("recovered:", recover())
}()
func() {
// The defer here doesn't catch the panic using recover(), so the outer
// panic should do that.
defer func() {
println("deferred nested function")
}()
panic("panic")
}()
println("unreachable")
}
func nestedPanic() {
defer func() {
printitf("recovered 1:", recover())
defer func() {
printitf("recovered 2:", recover())
}()
panic("foo")
}()
panic("panic")
}
func panicInsideDefer() {
defer func() {
printitf("recovered:", recover())
}()
defer func() {
panic("panic")
}()
}
func panicReplace() {
defer func() {
printitf("recovered:", recover())
}()
defer func() {
println("panic 2")
panic("panic 2")
}()
println("panic 1")
panic("panic 1")
}
func deferPanic() {
defer func() {
printitf("recovered from deferred call:", recover())
}()
// This recover should not do anything.
defer recover()
defer panic("deferred panic")
println("defer panic")
}
func runtimeGoexit() {
wg.Add(1)
go func() {
defer func() {
println("Goexit deferred function, recover is nil:", recover() == nil)
wg.Done()
}()
runtime.Goexit()
}()
wg.Wait()
}
func printitf(msg string, itf interface{}) {
switch itf := itf.(type) {
case string:
println(msg, itf)
default:
println(msg, itf)
}
}
|
