diff options
Diffstat (limited to 'vendor/golang.org/x/net/http2/gotrack.go')
-rw-r--r-- | vendor/golang.org/x/net/http2/gotrack.go | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/gotrack.go b/vendor/golang.org/x/net/http2/gotrack.go new file mode 100644 index 000000000..9933c9f8c --- /dev/null +++ b/vendor/golang.org/x/net/http2/gotrack.go @@ -0,0 +1,170 @@ +// Copyright 2014 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. + +// Defensive debug-only utility to track that functions run on the +// goroutine that they're supposed to. + +package http2 + +import ( + "bytes" + "errors" + "fmt" + "os" + "runtime" + "strconv" + "sync" +) + +var DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1" + +type goroutineLock uint64 + +func newGoroutineLock() goroutineLock { + if !DebugGoroutines { + return 0 + } + return goroutineLock(curGoroutineID()) +} + +func (g goroutineLock) check() { + if !DebugGoroutines { + return + } + if curGoroutineID() != uint64(g) { + panic("running on the wrong goroutine") + } +} + +func (g goroutineLock) checkNotOn() { + if !DebugGoroutines { + return + } + if curGoroutineID() == uint64(g) { + panic("running on the wrong goroutine") + } +} + +var goroutineSpace = []byte("goroutine ") + +func curGoroutineID() uint64 { + bp := littleBuf.Get().(*[]byte) + defer littleBuf.Put(bp) + b := *bp + b = b[:runtime.Stack(b, false)] + // Parse the 4707 out of "goroutine 4707 [" + b = bytes.TrimPrefix(b, goroutineSpace) + i := bytes.IndexByte(b, ' ') + if i < 0 { + panic(fmt.Sprintf("No space found in %q", b)) + } + b = b[:i] + n, err := parseUintBytes(b, 10, 64) + if err != nil { + panic(fmt.Sprintf("Failed to parse goroutine ID out of %q: %v", b, err)) + } + return n +} + +var littleBuf = sync.Pool{ + New: func() interface{} { + buf := make([]byte, 64) + return &buf + }, +} + +// parseUintBytes is like strconv.ParseUint, but using a []byte. +func parseUintBytes(s []byte, base int, bitSize int) (n uint64, err error) { + var cutoff, maxVal uint64 + + if bitSize == 0 { + bitSize = int(strconv.IntSize) + } + + s0 := s + switch { + case len(s) < 1: + err = strconv.ErrSyntax + goto Error + + case 2 <= base && base <= 36: + // valid base; nothing to do + + case base == 0: + // Look for octal, hex prefix. + switch { + case s[0] == '0' && len(s) > 1 && (s[1] == 'x' || s[1] == 'X'): + base = 16 + s = s[2:] + if len(s) < 1 { + err = strconv.ErrSyntax + goto Error + } + case s[0] == '0': + base = 8 + default: + base = 10 + } + + default: + err = errors.New("invalid base " + strconv.Itoa(base)) + goto Error + } + + n = 0 + cutoff = cutoff64(base) + maxVal = 1<<uint(bitSize) - 1 + + for i := 0; i < len(s); i++ { + var v byte + d := s[i] + switch { + case '0' <= d && d <= '9': + v = d - '0' + case 'a' <= d && d <= 'z': + v = d - 'a' + 10 + case 'A' <= d && d <= 'Z': + v = d - 'A' + 10 + default: + n = 0 + err = strconv.ErrSyntax + goto Error + } + if int(v) >= base { + n = 0 + err = strconv.ErrSyntax + goto Error + } + + if n >= cutoff { + // n*base overflows + n = 1<<64 - 1 + err = strconv.ErrRange + goto Error + } + n *= uint64(base) + + n1 := n + uint64(v) + if n1 < n || n1 > maxVal { + // n+v overflows + n = 1<<64 - 1 + err = strconv.ErrRange + goto Error + } + n = n1 + } + + return n, nil + +Error: + return n, &strconv.NumError{Func: "ParseUint", Num: string(s0), Err: err} +} + +// Return the first number n such that n*base >= 1<<64. +func cutoff64(base int) uint64 { + if base < 2 { + return 0 + } + return (1<<64-1)/uint64(base) + 1 +} |