46 lines
1.1 KiB
Go
46 lines
1.1 KiB
Go
// Copyright 2019 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build debuglog
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package runtime
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const dlogEnabled = true
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// dlogPerM is the per-M debug log data. This is embedded in the m
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// struct.
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type dlogPerM struct {
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dlogCache *dlogger
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}
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// getCachedDlogger returns a cached dlogger if it can do so
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// efficiently, or nil otherwise. The returned dlogger will be owned.
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func getCachedDlogger() *dlogger {
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mp := acquirem()
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// We don't return a cached dlogger if we're running on the
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// signal stack in case the signal arrived while in
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// get/putCachedDlogger. (Too bad we don't have non-atomic
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// exchange!)
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var l *dlogger
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if getg() != mp.gsignal {
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l = mp.dlogCache
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mp.dlogCache = nil
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}
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releasem(mp)
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return l
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}
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// putCachedDlogger attempts to return l to the local cache. It
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// returns false if this fails.
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func putCachedDlogger(l *dlogger) bool {
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mp := acquirem()
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if getg() != mp.gsignal && mp.dlogCache == nil {
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mp.dlogCache = l
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releasem(mp)
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return true
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}
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releasem(mp)
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return false
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}
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