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path: root/vendor/golang.org/x/net/http2/gotrack.go
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Diffstat (limited to 'vendor/golang.org/x/net/http2/gotrack.go')
-rw-r--r--vendor/golang.org/x/net/http2/gotrack.go170
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 0000000..9933c9f
--- /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
+}