@ -14,64 +14,30 @@ import (
"github.com/google/go-cmp/cmp"
)
type ResourceCheck struct {
startNumRoutines int
startDump string
}
func NewResourceCheck ( ) * ResourceCheck {
// NOTE(apenwarr): I'd rather not pre-generate a goroutine dump here.
// However, it turns out to be tricky to debug when eg. the initial
// goroutine count > the ending goroutine count, because of course
// the missing ones are not in the final dump. Also, we have to
// render the profile as a string right away, because the
// pprof.Profile object doesn't stay stable over time. Every time
// you render the string, you might get a different answer.
r := & ResourceCheck { }
r . startNumRoutines , r . startDump = goroutineDump ( )
return r
}
func goroutineDump ( ) ( int , string ) {
p := pprof . Lookup ( "goroutine" )
b := & bytes . Buffer { }
p . WriteTo ( b , 1 )
return p . Count ( ) , b . String ( )
}
func ( r * ResourceCheck ) Assert ( t testing . TB ) {
if t . Failed ( ) {
func ResourceCheck ( tb testing . TB ) {
startN , startStacks := goroutines ( )
tb . Cleanup ( func ( ) {
if tb . Failed ( ) {
// Something else went wrong.
// Assume that that is responsible for the leak
// and don't pile on a bunch of extra of output.
return
}
t . Helper ( )
want := r . startNumRoutines
// Some goroutines might be still exiting, so give them a chance
got := runtime . NumGoroutine ( )
if want != got {
_ , dump := goroutineDump ( )
tb . Helper ( )
// Goroutines might be still exiting.
for i := 0 ; i < 100 ; i ++ {
got = runtime . NumGoroutine ( )
if want == got {
break
if runtime . NumGoroutine ( ) <= startN {
return
}
time . Sleep ( 1 * time . Millisecond )
}
endN , endStacks := goroutines ( )
tb . Logf ( "goroutine diff:\n%v\n" , cmp . Diff ( startStacks , endStacks ) )
tb . Fatalf ( "goroutine count: expected %d, got %d\n" , startN , endN )
} )
}
// If the count is *still* wrong, that's a failure.
if want != got {
t . Logf ( "goroutine diff:\n%v\n" , cmp . Diff ( r . startDump , dump ) )
t . Logf ( "goroutine count: expected %d, got %d\n" , want , got )
// Don't fail if there are *fewer* goroutines than
// expected. That just might be some leftover ones
// from the previous test, which are pretty hard to
// eliminate.
if want < got {
t . Fatalf ( "ResourceCheck: goroutine count: expected %d, got %d\n" , want , got )
}
}
}
func goroutines ( ) ( int , [ ] byte ) {
p := pprof . Lookup ( "goroutine" )
b := new ( bytes . Buffer )
p . WriteTo ( b , 1 )
return p . Count ( ) , b . Bytes ( )
}
Josh Bleecher Snyder
4 years ago
committed by