log: SyncLogger: defer mutex unlocks for panic safety (#974)
Peter Bourgon authored 4 years ago
GitHub committed 4 years ago
| 64 | 64 |
// progress, the calling goroutine blocks until the syncWriter is available.
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| 65 | 65 |
func (w *syncWriter) Write(p []byte) (n int, err error) {
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| 66 | 66 |
w.Lock()
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| 67 | |
n, err = w.Writer.Write(p)
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| 68 | |
w.Unlock()
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| 69 | |
return n, err
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defer w.Unlock()
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return w.Writer.Write(p)
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| 70 | 69 |
}
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| 71 | 70 |
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| 72 | 71 |
// fdWriter is an io.Writer that also has an Fd method. The most common
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| 86 | 85 |
// progress, the calling goroutine blocks until the fdSyncWriter is available.
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| 87 | 86 |
func (w *fdSyncWriter) Write(p []byte) (n int, err error) {
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| 88 | 87 |
w.Lock()
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| 89 | |
n, err = w.fdWriter.Write(p)
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| 90 | |
w.Unlock()
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| 91 | |
return n, err
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defer w.Unlock()
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return w.fdWriter.Write(p)
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| 92 | 90 |
}
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| 93 | 91 |
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| 94 | 92 |
// syncLogger provides concurrent safe logging for another Logger.
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| 109 | 107 |
// progress, the calling goroutine blocks until the syncLogger is available.
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| 110 | 108 |
func (l *syncLogger) Log(keyvals ...interface{}) error {
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| 111 | 109 |
l.mu.Lock()
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| 112 | |
err := l.logger.Log(keyvals...)
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| 113 | |
l.mu.Unlock()
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| 114 | |
return err
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defer l.mu.Unlock()
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return l.logger.Log(keyvals...)
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| 115 | 112 |
}
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| 80 | 80 |
t.Error("NewSyncWriter does not pass through Fd method")
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| 81 | 81 |
}
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| 82 | 82 |
}
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func TestSyncLoggerPanic(t *testing.T) {
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|
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var logger log.Logger
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|
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logger = log.LoggerFunc(func(...interface{}) error { panic("!") })
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|
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logger = log.NewSyncLogger(logger)
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f := func() {
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|
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defer func() {
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|
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if x := recover(); x != nil {
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|
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t.Log(x)
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}
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}()
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logger.Log("hello", "world")
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}
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f()
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f() // without defer Unlock, this one can deadlock
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}
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