I’m trying to make a task scheduler that does tasks in the given interval and also can handle an occurring panic. My question is how can I continue executing the function after handling the panic.
func scheduleTask(task func() error, interval time.Duration, timeout time.Duration) {
//add waitgroup and mutex
var wg sync.WaitGroup
var mtx sync.Mutex
var startTime = time.Now()
//add each task to a goroutine and set interval and timeout to the function
wg.Add(1)
go func() {
defer wg.Done()
for {
//check if the time is up
if time.Since(startTime) > timeout {
break
}
defer func() {
if r := recover(); r != nil {
log.Println("Recovering from panic:", r)
}
}()
mtx.Lock()
task()
mtx.Unlock()
}
}()
wg.Wait()
}
func main() {
var a = 0
scheduleTask(func() error {
time.Sleep(50 * time.Millisecond)
if a == 3 {
a++
panic("oops")
}
a++
return nil
}, time.Millisecond*100, time.Millisecond*1000)
log.Println(a)
if a != 10 {
log.Fatal("Expected it to be 10")
}
}
>Solution :
When recovering you will exit the current function. In this case you can easily wrap the task() in a closure.
package main
import (
"log"
"sync"
"time"
)
func scheduleTask(task func() error, interval time.Duration, timeout time.Duration) {
//add waitgroup and mutex
var wg sync.WaitGroup
var mtx sync.Mutex
var startTime = time.Now()
//add each task to a goroutine and set interval and timeout to the function
wg.Add(1)
go func() {
defer wg.Done()
for {
//check if the time is up
if time.Since(startTime) > timeout {
break
}
mtx.Lock()
func() {
defer func() {
if r := recover(); r != nil {
log.Println("Recovering from panic:", r)
}
}()
task()
}()
mtx.Unlock()
}
}()
wg.Wait()
}
func main() {
var a = 0
scheduleTask(func() error {
time.Sleep(50 * time.Millisecond)
if a == 3 {
a++
panic("oops")
}
a++
return nil
}, time.Millisecond*100, time.Millisecond*1000)
log.Println(a)
if a != 10 {
log.Fatal("Expected it to be 10")
}
}