sancar

And upgradable read write lock for go

UpgradableRWMutex is an enhanced version of the standard sync.RWMutex. It has the all methods sync.RWMutex with exact same semantics. It gives more methods to give upgradable-read feature.

The new semantics for upgradable-read are as follows:

• Multiple goroutines can get read-lock together with a single upgradable-read-lock.
• Only one goroutine can have a write-lock and no read-lock/upgradable-read-lock can be acquired in this state.

seibert

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