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Diffstat (limited to 'src/runtime/example_test.go')
-rw-r--r-- | src/runtime/example_test.go | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/runtime/example_test.go b/src/runtime/example_test.go new file mode 100644 index 0000000..dcb8f77 --- /dev/null +++ b/src/runtime/example_test.go @@ -0,0 +1,62 @@ +// Copyright 2017 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. + +package runtime_test + +import ( + "fmt" + "runtime" + "strings" +) + +func ExampleFrames() { + c := func() { + // Ask runtime.Callers for up to 10 PCs, including runtime.Callers itself. + pc := make([]uintptr, 10) + n := runtime.Callers(0, pc) + if n == 0 { + // No PCs available. This can happen if the first argument to + // runtime.Callers is large. + // + // Return now to avoid processing the zero Frame that would + // otherwise be returned by frames.Next below. + return + } + + pc = pc[:n] // pass only valid pcs to runtime.CallersFrames + frames := runtime.CallersFrames(pc) + + // Loop to get frames. + // A fixed number of PCs can expand to an indefinite number of Frames. + for { + frame, more := frames.Next() + + // Process this frame. + // + // To keep this example's output stable + // even if there are changes in the testing package, + // stop unwinding when we leave package runtime. + if !strings.Contains(frame.File, "runtime/") { + break + } + fmt.Printf("- more:%v | %s\n", more, frame.Function) + + // Check whether there are more frames to process after this one. + if !more { + break + } + } + } + + b := func() { c() } + a := func() { b() } + + a() + // Output: + // - more:true | runtime.Callers + // - more:true | runtime_test.ExampleFrames.func1 + // - more:true | runtime_test.ExampleFrames.func2 + // - more:true | runtime_test.ExampleFrames.func3 + // - more:true | runtime_test.ExampleFrames +} |