util/conn: reconnect when initial Dial fails
Peter Bourgon
7 years ago
| 66 | 66 |
func (m *Manager) loop() {
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| 67 | 67 |
var (
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| 68 | 68 |
conn = dial(m.dialer, m.network, m.address, m.logger) // may block slightly
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| 69 | |
connc = make(chan net.Conn)
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69 |
connc = make(chan net.Conn, 1)
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| 70 | 70 |
reconnectc <-chan time.Time // initially nil
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| 71 | 71 |
backoff = time.Second
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| 72 | 72 |
)
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73 |
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74 |
// If the initial dial fails, we need to trigger a reconnect via the loop
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75 |
// body, below. If we did this in a goroutine, we would race on the conn
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|
76 |
// variable. So we use a buffered chan instead.
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|
77 |
connc <- conn
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| 73 | 78 |
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| 74 | 79 |
for {
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| 75 | 80 |
select {
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| 90 | 90 |
}
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| 91 | 91 |
}
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| 92 | 92 |
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93 |
func TestIssue292(t *testing.T) {
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94 |
// The util/conn.Manager won't attempt to reconnect to the provided endpoint
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|
95 |
// if the endpoint is initially unavailable (e.g. dial tcp :8080:
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|
96 |
// getsockopt: connection refused). If the endpoint is up when
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|
97 |
// conn.NewManager is called and then goes down/up, it reconnects just fine.
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98 |
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99 |
var (
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100 |
tickc = make(chan time.Time)
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|
101 |
after = func(time.Duration) <-chan time.Time { return tickc }
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102 |
dialconn = net.Conn(nil)
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103 |
dialerr = errors.New("fail")
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104 |
dialer = func(string, string) (net.Conn, error) { return dialconn, dialerr }
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105 |
mgr = NewManager(dialer, "netw", "addr", after, log.NewNopLogger())
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106 |
)
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107 |
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|
108 |
if conn := mgr.Take(); conn != nil {
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|
109 |
t.Fatal("first Take should have yielded nil conn, but didn't")
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|
110 |
}
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|
111 |
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112 |
dialconn, dialerr = &mockConn{}, nil
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|
113 |
select {
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|
114 |
case tickc <- time.Now():
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|
115 |
case <-time.After(time.Second):
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|
116 |
t.Fatal("manager isn't listening for a tick, despite a failed dial")
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117 |
}
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|
118 |
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119 |
if !within(time.Second, func() bool {
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|
120 |
return mgr.Take() != nil
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|
121 |
}) {
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|
122 |
t.Fatal("second Take should have yielded good conn, but didn't")
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123 |
}
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}
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| 93 | 126 |
type mockConn struct {
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| 94 | 127 |
rd, wr uint64
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| 95 | 128 |
}
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