diff options
Diffstat (limited to 'vendor/modernc.org/libc/ioutil_freebsd.go')
-rw-r--r-- | vendor/modernc.org/libc/ioutil_freebsd.go | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/vendor/modernc.org/libc/ioutil_freebsd.go b/vendor/modernc.org/libc/ioutil_freebsd.go new file mode 100644 index 00000000..40ca5ed0 --- /dev/null +++ b/vendor/modernc.org/libc/ioutil_freebsd.go @@ -0,0 +1,65 @@ +// Copyright 2010 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-GO file. + +// Modifications Copyright 2020 The Libc 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 libc // import "modernc.org/libc" + +import ( + "fmt" + "os" + "sync" + "time" + "unsafe" + + "golang.org/x/sys/unix" +) + +// Random number state. +// We generate random temporary file names so that there's a good +// chance the file doesn't exist yet - keeps the number of tries in +// TempFile to a minimum. +var randState uint32 +var randStateMu sync.Mutex + +func reseed() uint32 { + return uint32(time.Now().UnixNano() + int64(os.Getpid())) +} + +func nextRandom(x uintptr) { + randStateMu.Lock() + r := randState + if r == 0 { + r = reseed() + } + r = r*1664525 + 1013904223 // constants from Numerical Recipes + randState = r + randStateMu.Unlock() + copy((*RawMem)(unsafe.Pointer(x))[:6:6], fmt.Sprintf("%06d", int(1e9+r%1e9)%1e6)) +} + +func tempFile(s, x uintptr, _ int32) (fd int, err error) { + const maxTry = 10000 + nconflict := 0 + for i := 0; i < maxTry; i++ { + nextRandom(x) + if fd, err = unix.Open(GoString(s), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600); err == nil { + return fd, nil + } + + if !os.IsExist(err) { + return -1, err + } + + if nconflict++; nconflict > 10 { + randStateMu.Lock() + randState = reseed() + nconflict = 0 + randStateMu.Unlock() + } + } + return -1, err +} |