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author | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
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committer | JoramWilander <jwawilander@gmail.com> | 2018-07-10 15:01:43 -0400 |
commit | 6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005 (patch) | |
tree | 5564a47257bf6e85aaef711980c5b0fcb4d07dcc /vendor/golang.org/x/net/http2/client_conn_pool.go | |
parent | c042ffa460296587579aff54b157a5109e022f7e (diff) | |
parent | 1e1a5e5e85240f25c4faddcb24c5a29a915fe6e4 (diff) | |
download | chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.gz chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.tar.bz2 chat-6c7dc2d29ccac5f9925402f6be1a4c2a3c46c005.zip |
Merge branch 'plugins-2'
Diffstat (limited to 'vendor/golang.org/x/net/http2/client_conn_pool.go')
-rw-r--r-- | vendor/golang.org/x/net/http2/client_conn_pool.go | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/http2/client_conn_pool.go b/vendor/golang.org/x/net/http2/client_conn_pool.go new file mode 100644 index 000000000..bdf5652b0 --- /dev/null +++ b/vendor/golang.org/x/net/http2/client_conn_pool.go @@ -0,0 +1,256 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Transport code's client connection pooling. + +package http2 + +import ( + "crypto/tls" + "net/http" + "sync" +) + +// ClientConnPool manages a pool of HTTP/2 client connections. +type ClientConnPool interface { + GetClientConn(req *http.Request, addr string) (*ClientConn, error) + MarkDead(*ClientConn) +} + +// clientConnPoolIdleCloser is the interface implemented by ClientConnPool +// implementations which can close their idle connections. +type clientConnPoolIdleCloser interface { + ClientConnPool + closeIdleConnections() +} + +var ( + _ clientConnPoolIdleCloser = (*clientConnPool)(nil) + _ clientConnPoolIdleCloser = noDialClientConnPool{} +) + +// TODO: use singleflight for dialing and addConnCalls? +type clientConnPool struct { + t *Transport + + mu sync.Mutex // TODO: maybe switch to RWMutex + // TODO: add support for sharing conns based on cert names + // (e.g. share conn for googleapis.com and appspot.com) + conns map[string][]*ClientConn // key is host:port + dialing map[string]*dialCall // currently in-flight dials + keys map[*ClientConn][]string + addConnCalls map[string]*addConnCall // in-flight addConnIfNeede calls +} + +func (p *clientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) { + return p.getClientConn(req, addr, dialOnMiss) +} + +const ( + dialOnMiss = true + noDialOnMiss = false +) + +func (p *clientConnPool) getClientConn(req *http.Request, addr string, dialOnMiss bool) (*ClientConn, error) { + if isConnectionCloseRequest(req) && dialOnMiss { + // It gets its own connection. + const singleUse = true + cc, err := p.t.dialClientConn(addr, singleUse) + if err != nil { + return nil, err + } + return cc, nil + } + p.mu.Lock() + for _, cc := range p.conns[addr] { + if cc.CanTakeNewRequest() { + p.mu.Unlock() + return cc, nil + } + } + if !dialOnMiss { + p.mu.Unlock() + return nil, ErrNoCachedConn + } + call := p.getStartDialLocked(addr) + p.mu.Unlock() + <-call.done + return call.res, call.err +} + +// dialCall is an in-flight Transport dial call to a host. +type dialCall struct { + p *clientConnPool + done chan struct{} // closed when done + res *ClientConn // valid after done is closed + err error // valid after done is closed +} + +// requires p.mu is held. +func (p *clientConnPool) getStartDialLocked(addr string) *dialCall { + if call, ok := p.dialing[addr]; ok { + // A dial is already in-flight. Don't start another. + return call + } + call := &dialCall{p: p, done: make(chan struct{})} + if p.dialing == nil { + p.dialing = make(map[string]*dialCall) + } + p.dialing[addr] = call + go call.dial(addr) + return call +} + +// run in its own goroutine. +func (c *dialCall) dial(addr string) { + const singleUse = false // shared conn + c.res, c.err = c.p.t.dialClientConn(addr, singleUse) + close(c.done) + + c.p.mu.Lock() + delete(c.p.dialing, addr) + if c.err == nil { + c.p.addConnLocked(addr, c.res) + } + c.p.mu.Unlock() +} + +// addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't +// already exist. It coalesces concurrent calls with the same key. +// This is used by the http1 Transport code when it creates a new connection. Because +// the http1 Transport doesn't de-dup TCP dials to outbound hosts (because it doesn't know +// the protocol), it can get into a situation where it has multiple TLS connections. +// This code decides which ones live or die. +// The return value used is whether c was used. +// c is never closed. +func (p *clientConnPool) addConnIfNeeded(key string, t *Transport, c *tls.Conn) (used bool, err error) { + p.mu.Lock() + for _, cc := range p.conns[key] { + if cc.CanTakeNewRequest() { + p.mu.Unlock() + return false, nil + } + } + call, dup := p.addConnCalls[key] + if !dup { + if p.addConnCalls == nil { + p.addConnCalls = make(map[string]*addConnCall) + } + call = &addConnCall{ + p: p, + done: make(chan struct{}), + } + p.addConnCalls[key] = call + go call.run(t, key, c) + } + p.mu.Unlock() + + <-call.done + if call.err != nil { + return false, call.err + } + return !dup, nil +} + +type addConnCall struct { + p *clientConnPool + done chan struct{} // closed when done + err error +} + +func (c *addConnCall) run(t *Transport, key string, tc *tls.Conn) { + cc, err := t.NewClientConn(tc) + + p := c.p + p.mu.Lock() + if err != nil { + c.err = err + } else { + p.addConnLocked(key, cc) + } + delete(p.addConnCalls, key) + p.mu.Unlock() + close(c.done) +} + +func (p *clientConnPool) addConn(key string, cc *ClientConn) { + p.mu.Lock() + p.addConnLocked(key, cc) + p.mu.Unlock() +} + +// p.mu must be held +func (p *clientConnPool) addConnLocked(key string, cc *ClientConn) { + for _, v := range p.conns[key] { + if v == cc { + return + } + } + if p.conns == nil { + p.conns = make(map[string][]*ClientConn) + } + if p.keys == nil { + p.keys = make(map[*ClientConn][]string) + } + p.conns[key] = append(p.conns[key], cc) + p.keys[cc] = append(p.keys[cc], key) +} + +func (p *clientConnPool) MarkDead(cc *ClientConn) { + p.mu.Lock() + defer p.mu.Unlock() + for _, key := range p.keys[cc] { + vv, ok := p.conns[key] + if !ok { + continue + } + newList := filterOutClientConn(vv, cc) + if len(newList) > 0 { + p.conns[key] = newList + } else { + delete(p.conns, key) + } + } + delete(p.keys, cc) +} + +func (p *clientConnPool) closeIdleConnections() { + p.mu.Lock() + defer p.mu.Unlock() + // TODO: don't close a cc if it was just added to the pool + // milliseconds ago and has never been used. There's currently + // a small race window with the HTTP/1 Transport's integration + // where it can add an idle conn just before using it, and + // somebody else can concurrently call CloseIdleConns and + // break some caller's RoundTrip. + for _, vv := range p.conns { + for _, cc := range vv { + cc.closeIfIdle() + } + } +} + +func filterOutClientConn(in []*ClientConn, exclude *ClientConn) []*ClientConn { + out := in[:0] + for _, v := range in { + if v != exclude { + out = append(out, v) + } + } + // If we filtered it out, zero out the last item to prevent + // the GC from seeing it. + if len(in) != len(out) { + in[len(in)-1] = nil + } + return out +} + +// noDialClientConnPool is an implementation of http2.ClientConnPool +// which never dials. We let the HTTP/1.1 client dial and use its TLS +// connection instead. +type noDialClientConnPool struct{ *clientConnPool } + +func (p noDialClientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) { + return p.getClientConn(req, addr, noDialOnMiss) +} |