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  1. Go Driver
  2. GODRIVER-1540

library stuck in connection.wait()

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      Description

      I've noticed new issues recently.

      I don't know if it's related to the v1.3.0 update, but it never happened before.

      Some MongoDB queries are stuck indefinitely.

      It happens for different types of queries: run command, find.

      Here is the common part of the stack trace:

      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).wait(...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/connection.go:181
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*pool).closeConnection(0xc000410780, 0xc0008dce00, 0x0, 0xd7dd60)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/pool.go:417 +0x1f9
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).close(0xc0008dce00, 0xc000c741c8, 0xc00041d9d0)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/connection.go:302 +0x97
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).readWireMessage(0xc0008dce00, 0xd8aae0, 0xc000099740, 0xc0004d1400, 0x0, 0x200, 0xc0008dce00, 0xd8aae0, 0xc000099740, 0xc0004d1400, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/connection.go:262 +0x4d8
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.initConnection.ReadWireMessage(0xc0008dce00, 0xd8aae0, 0xc000099740, 0xc0004d1400, 0x0, 0x200, 0xc0004d1400, 0x10e, 0x200, 0x0, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/connection.go:351 +0x6a
      go.mongodb.org/mongo-driver/x/mongo/driver.Operation.roundTrip(0xc000d74360, 0xba7b6c, 0x5, 0xd89b60, 0xc000d74370, 0xc000d74380, 0x0, 0x0, 0x0, 0x0, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/operation.go:552 +0x401
      go.mongodb.org/mongo-driver/x/mongo/driver.Operation.Execute(0xc000d74360, 0xba7b6c, 0x5, 0xd89b60, 0xc000d74370, 0xc000d74380, 0x0, 0x0, 0x0, 0x0, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/operation.go:367 +0xc06
      go.mongodb.org/mongo-driver/x/mongo/driver/operation.(*IsMaster).GetDescription(0xc000cda9a0, 0xd8aae0, 0xc000099740, 0xc0004243fa, 0x2b, 0xd8efa0, 0xc0008dce00, 0x0, 0x0, 0x0, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/operation/ismaster.go:418 +0x1ec
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).connect(0xc0008dce00, 0xd8aae0, 0xc000099740)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/connection.go:133 +0x2ac
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*pool).get(0xc000410780, 0xd8aba0, 0xc0009ade90, 0x1, 0x0, 0x0)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/pool.go:380 +0x73c
      go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*Server).Connection(0xc0008bc160, 0xd8aba0, 0xc0009ade90, 0x0, 0x0, 0x0, 0x0)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/topology/server.go:243 +0x1ea
      go.mongodb.org/mongo-driver/x/mongo/driver.Operation.Execute(0xc0012038d0, 0xc000424682, 0xe, 0xd88660, 0xc00028a000, 0xc0012038e0, 0xd7ed80, 0xc000279040, 0xc0000adf80, 0xc00027e220, ...)
      	/home/travis/gopath/pkg/mod/go.mongodb.org/mongo-driver@v1.3.0/x/mongo/driver/operation.go:246 +0x207
      

      I read quickly the source code, and I think there is a deadlock.

      The connection.wait() function call is waiting for a channel to be closed.

      As far as I know, this channel is closed only in another function call: connection.connect(). (defer)

      But this function call is already in the calls stack, so the channel will never be closed.

      That's why I think there is a deadlock.

       

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            Assignee:
            isabella.siu Isabella Siu (Inactive)
            Reporter:
            pierrre Pierre Durand
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              Updated:
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