51 lines
910 B
Go
51 lines
910 B
Go
package tracer
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import (
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cryptorand "crypto/rand"
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"log"
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"math"
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"math/big"
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"math/rand"
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"sync"
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"time"
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)
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// random holds a thread-safe source of random numbers.
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var random *rand.Rand
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func init() {
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var seed int64
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n, err := cryptorand.Int(cryptorand.Reader, big.NewInt(math.MaxInt64))
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if err == nil {
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seed = n.Int64()
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} else {
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log.Printf("%scannot generate random seed: %v; using current time\n", errorPrefix, err)
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seed = time.Now().UnixNano()
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}
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random = rand.New(&safeSource{
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source: rand.NewSource(seed),
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})
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}
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// safeSource holds a thread-safe implementation of rand.Source64.
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type safeSource struct {
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source rand.Source
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sync.Mutex
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}
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func (rs *safeSource) Int63() int64 {
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rs.Lock()
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n := rs.source.Int63()
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rs.Unlock()
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return n
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}
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func (rs *safeSource) Uint64() uint64 { return uint64(rs.Int63()) }
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func (rs *safeSource) Seed(seed int64) {
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rs.Lock()
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rs.Seed(seed)
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rs.Unlock()
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}
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