test/mapnan.go: add regression test for non-empty interfaces.

LGTM=rsc, khr
R=rsc, khr, bradfitz
CC=golang-codereviews
https://golang.org/cl/126720043

diff --git a/test/map.go b/test/map.go
index 485e743fe4624371c97ff4db1f02d4067c0b946e..2c1cf8a14038259d1453a57e3d4e7a7d27da7ea6 100644 (file)
--- a/test/map.go
+++ b/test/map.go
@@ -5,7 +5,7 @@
 // license that can be found in the LICENSE file.
 
 // Test maps, almost exhaustively.
-// NaN complexity test is in mapnan.go.
+// Complexity (linearity) test is in maplinear.go.
 
 package main
 

diff --git a/test/maplinear.go b/test/maplinear.go
new file mode 100644 (file)
index 0000000..56e5095
--- /dev/null
+++ b/test/maplinear.go
@@ -0,0 +1,143 @@
+// +build darwin linux
+// run
+
+// Copyright 2013 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.
+
+// Test that maps don't go quadratic for NaNs and other values.
+
+package main
+
+import (
+       "fmt"
+       "math"
+       "time"
+)
+
+// checkLinear asserts that the running time of f(n) is in O(n).
+// tries is the initial number of iterations.
+func checkLinear(typ string, tries int, f func(n int)) {
+       // Depending on the machine and OS, this test might be too fast
+       // to measure with accurate enough granularity. On failure,
+       // make it run longer, hoping that the timing granularity
+       // is eventually sufficient.
+
+       timeF := func(n int) time.Duration {
+               t1 := time.Now()
+               f(n)
+               return time.Since(t1)
+       }
+
+       t0 := time.Now()
+
+       n := tries
+       fails := 0
+       for {
+               t1 := timeF(n)
+               t2 := timeF(2 * n)
+
+               // should be 2x (linear); allow up to 3x
+               if t2 < 3*t1 {
+                       if false {
+                               fmt.Println(typ, "\t", time.Since(t0))
+                       }
+                       return
+               }
+               fails++
+               if fails == 6 {
+                       panic(fmt.Sprintf("%s: too slow: %d inserts: %v; %d inserts: %v\n",
+                               typ, n, t1, 2*n, t2))
+               }
+               if fails < 4 {
+                       n *= 2
+               }
+       }
+}
+
+type I interface {
+       f()
+}
+
+type C int
+
+func (C) f() {}
+
+func main() {
+       // NaNs. ~31ms on a 1.6GHz Zeon.
+       checkLinear("NaN", 30000, func(n int) {
+               m := map[float64]int{}
+               nan := math.NaN()
+               for i := 0; i < n; i++ {
+                       m[nan] = 1
+               }
+               if len(m) != n {
+                       panic("wrong size map after nan insertion")
+               }
+       })
+
+       // ~6ms on a 1.6GHz Zeon.
+       checkLinear("eface", 10000, func(n int) {
+               m := map[interface{}]int{}
+               for i := 0; i < n; i++ {
+                       m[i] = 1
+               }
+       })
+
+       // ~7ms on a 1.6GHz Zeon.
+       // Regression test for CL 119360043.
+       checkLinear("iface", 10000, func(n int) {
+               m := map[I]int{}
+               for i := 0; i < n; i++ {
+                       m[C(i)] = 1
+               }
+       })
+
+       // ~6ms on a 1.6GHz Zeon.
+       checkLinear("int", 10000, func(n int) {
+               m := map[int]int{}
+               for i := 0; i < n; i++ {
+                       m[i] = 1
+               }
+       })
+
+       // ~18ms on a 1.6GHz Zeon.
+       checkLinear("string", 10000, func(n int) {
+               m := map[string]int{}
+               for i := 0; i < n; i++ {
+                       m[fmt.Sprint(i)] = 1
+               }
+       })
+
+       // ~6ms on a 1.6GHz Zeon.
+       checkLinear("float32", 10000, func(n int) {
+               m := map[float32]int{}
+               for i := 0; i < n; i++ {
+                       m[float32(i)] = 1
+               }
+       })
+
+       // ~6ms on a 1.6GHz Zeon.
+       checkLinear("float64", 10000, func(n int) {
+               m := map[float64]int{}
+               for i := 0; i < n; i++ {
+                       m[float64(i)] = 1
+               }
+       })
+
+       // ~22ms on a 1.6GHz Zeon.
+       checkLinear("complex64", 10000, func(n int) {
+               m := map[complex64]int{}
+               for i := 0; i < n; i++ {
+                       m[complex(float32(i), float32(i))] = 1
+               }
+       })
+
+       // ~32ms on a 1.6GHz Zeon.
+       checkLinear("complex128", 10000, func(n int) {
+               m := map[complex128]int{}
+               for i := 0; i < n; i++ {
+                       m[complex(float64(i), float64(i))] = 1
+               }
+       })
+}

diff --git a/test/mapnan.go b/test/mapnan.go
deleted file mode 100644 (file)
index f081cab..0000000
--- a/test/mapnan.go
+++ /dev/null
@@ -1,56 +0,0 @@
-// +build darwin linux
-// run
-
-// Copyright 2013 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.
-
-// Test that NaNs in maps don't go quadratic.
-
-package main
-
-import (
-       "fmt"
-       "math"
-       "time"
-)
-
-func main() {
-
-       // Test that NaNs in maps don't go quadratic.
-       t := func(n int) time.Duration {
-               t1 := time.Now()
-               m := map[float64]int{}
-               nan := math.NaN()
-               for i := 0; i < n; i++ {
-                       m[nan] = 1
-               }
-               if len(m) != n {
-                       panic("wrong size map after nan insertion")
-               }
-               return time.Since(t1)
-       }
-
-       // Depending on the machine and OS, this test might be too fast
-       // to measure with accurate enough granularity. On failure,
-       // make it run longer, hoping that the timing granularity
-       // is eventually sufficient.
-
-       n := 30000 // ~8ms user time on a Mid 2011 MacBook Air (1.8 GHz Core i7)
-       fails := 0
-       for {
-               t1 := t(n)
-               t2 := t(2 * n)
-               // should be 2x (linear); allow up to 3x
-               if t2 < 3*t1 {
-                       return
-               }
-               fails++
-               if fails == 6 {
-                       panic(fmt.Sprintf("too slow: %d inserts: %v; %d inserts: %v\n", n, t1, 2*n, t2))
-               }
-               if fails < 4 {
-                       n *= 2
-               }
-       }
-}