golang标准库database连接池实现-木庄网络博客

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DB 结构体

type DB struct {
    // Atomic access only. At top of struct to prevent mis-alignment
    // on 32-bit platforms. Of type time.Duration.
    waitDuration int64 // Total time waited for new connections.

    connector driver.Connector
    // numClosed is an atomic counter which represents a total number of
    // closed connections. Stmt.openStmt checks it before cleaning closed
    // connections in Stmt.css.
    numClosed uint64

    mu           sync.Mutex // protects following fields
    freeConn     []*driverConn
    connRequests map[uint64]chan connRequest
    nextRequest  uint64 // Next key to use in connRequests.
    numOpen      int    // number of opened and pending open connections
    // Used to signal the need for new connections
    // a goroutine running connectionOpener() reads on this chan and
    // maybeOpenNewConnections sends on the chan (one send per needed connection)
    // It is closed during db.Close(). The close tells the connectionOpener
    // goroutine to exit.
    openerCh          chan struct{}
    resetterCh        chan *driverConn
    closed            bool
    dep               map[finalCloser]depSet
    lastPut           map[*driverConn]string // stacktrace of last conn's put; debug only
    maxIdle           int                    // zero means defaultMaxIdleConns; negative means 0
    maxOpen           int                    // <= 0 means unlimited
    maxLifetime       time.Duration          // maximum amount of time a connection may be reused
    cleanerCh         chan struct{}
    waitCount         int64 // Total number of connections waited for.
    maxIdleClosed     int64 // Total number of connections closed due to idle.
    maxLifetimeClosed int64 // Total number of connections closed due to max free limit.

    stop func() // stop cancels the connection opener and the session resetter.
}

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感谢作者：香菜__

查看原文：golang标准库database连接池实现