41 lines
973 B
Go
41 lines
973 B
Go
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// +build dragonfly freebsd linux netbsd openbsd plan9 solaris
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package daemon
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import (
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"fmt"
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"syscall"
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)
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func lockFile(fd uintptr) error {
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err := syscall.Flock(int(fd), syscall.LOCK_EX|syscall.LOCK_NB)
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if err == syscall.EWOULDBLOCK {
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err = ErrWouldBlock
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}
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return err
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}
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func unlockFile(fd uintptr) error {
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err := syscall.Flock(int(fd), syscall.LOCK_UN)
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if err == syscall.EWOULDBLOCK {
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err = ErrWouldBlock
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}
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return err
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}
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const pathMax = 0x1000
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func getFdName(fd uintptr) (name string, err error) {
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path := fmt.Sprintf("/proc/self/fd/%d", int(fd))
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// We use predefined pathMax const because /proc directory contains special files
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// so that unable to get correct size of pseudo-symlink through lstat.
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// please see notes and example for readlink syscall:
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// http://man7.org/linux/man-pages/man2/readlink.2.html#NOTES
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buf := make([]byte, pathMax)
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var n int
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if n, err = syscall.Readlink(path, buf); err == nil {
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name = string(buf[:n])
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}
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return
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}
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