33 lines
829 B
Go
33 lines
829 B
Go
package hodu
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import "syscall"
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import "unsafe"
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import "golang.org/x/sys/unix"
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// utilize the builtin runtime.nanotime()
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//go:noescape
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//go:linkname nanotime runtime.nanotime
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func nanotime() int64
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func monotonic_time() uint64 {
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var n int64
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var err error
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var uts unix.Timespec
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n = nanotime() // hopefully it's faster than a system call. say, vdso is utilized.
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if n >= 0 { return uint64(n) }
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err = unix.ClockGettime(unix.CLOCK_MONOTONIC, &uts)
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if err != nil {
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//var errno syscall.Errno
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var r uintptr
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var sts syscall.Timespec
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r, _, _/*errno*/ = syscall.Syscall(syscall.SYS_CLOCK_GETTIME, unix.CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&sts)), 0)
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if r == ^uintptr(0) { return uint64(n) } // may be a negative number cast to unsigned. no other fall-back
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return uint64(sts.Nano())
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}
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return uint64(uts.Nano())
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}
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