Documentation/concurrency.md - third_party/github.com/grpc/grpc-go - Git at Google

 # Concurrency

 In general, gRPC-go provides a concurrency-friendly API. What follows are some
 guidelines.

 ## Clients

 A [ClientConn][client-conn] can safely be accessed concurrently. Using
 [helloworld][helloworld] as an example, one could share the `ClientConn` across
 multiple goroutines to create multiple `GreeterClient` types. In this case,
 RPCs would be sent in parallel.  `GreeterClient`, generated from the proto
 definitions and wrapping `ClientConn`, is also concurrency safe, and may be
 directly shared in the same way.  Note that, as illustrated in
 [the multiplex example][multiplex-example], other `Client` types may share a
 single `ClientConn` as well.

 ## Streams

 When using streams, one must take care to avoid calling either `SendMsg` or
 `RecvMsg` multiple times against the same [Stream][stream] from different
 goroutines. In other words, it's safe to have a goroutine calling `SendMsg` and
 another goroutine calling `RecvMsg` on the same stream at the same time. But it
 is not safe to call `SendMsg` on the same stream in different goroutines, or to
 call `RecvMsg` on the same stream in different goroutines.

 ## Servers

 Each RPC handler attached to a registered server will be invoked in its own
 goroutine. For example, [SayHello][say-hello] will be invoked in its own
 goroutine. The same is true for service handlers for streaming RPCs, as seen
 in the route guide example [here][route-guide-stream].  Similar to clients,
 multiple services can be registered to the same server.

 [helloworld]: https://github.com/grpc/grpc-go/blob/master/examples/helloworld/greeter_client/main.go#L43
 [client-conn]: https://godoc.org/google.golang.org/grpc#ClientConn
 [stream]: https://godoc.org/google.golang.org/grpc#Stream
 [say-hello]: https://github.com/grpc/grpc-go/blob/master/examples/helloworld/greeter_server/main.go#L41
 [route-guide-stream]: https://github.com/grpc/grpc-go/blob/master/examples/route_guide/server/server.go#L126
 [multiplex-example]: https://github.com/grpc/grpc-go/tree/master/examples/features/multiplex
	# Concurrency

	In general, gRPC-go provides a concurrency-friendly API. What follows are some
	guidelines.

	## Clients

	A [ClientConn][client-conn] can safely be accessed concurrently. Using
	[helloworld][helloworld] as an example, one could share the `ClientConn` across
	multiple goroutines to create multiple `GreeterClient` types. In this case,
	RPCs would be sent in parallel. `GreeterClient`, generated from the proto
	definitions and wrapping `ClientConn`, is also concurrency safe, and may be
	directly shared in the same way. Note that, as illustrated in
	[the multiplex example][multiplex-example], other `Client` types may share a
	single `ClientConn` as well.

	## Streams

	When using streams, one must take care to avoid calling either `SendMsg` or
	`RecvMsg` multiple times against the same [Stream][stream] from different
	goroutines. In other words, it's safe to have a goroutine calling `SendMsg` and
	another goroutine calling `RecvMsg` on the same stream at the same time. But it
	is not safe to call `SendMsg` on the same stream in different goroutines, or to
	call `RecvMsg` on the same stream in different goroutines.

	## Servers

	Each RPC handler attached to a registered server will be invoked in its own
	goroutine. For example, [SayHello][say-hello] will be invoked in its own
	goroutine. The same is true for service handlers for streaming RPCs, as seen
	in the route guide example [here][route-guide-stream]. Similar to clients,
	multiple services can be registered to the same server.

	[helloworld]: https://github.com/grpc/grpc-go/blob/master/examples/helloworld/greeter_client/main.go#L43
	[client-conn]: https://godoc.org/google.golang.org/grpc#ClientConn
	[stream]: https://godoc.org/google.golang.org/grpc#Stream
	[say-hello]: https://github.com/grpc/grpc-go/blob/master/examples/helloworld/greeter_server/main.go#L41
	[route-guide-stream]: https://github.com/grpc/grpc-go/blob/master/examples/route_guide/server/server.go#L126
	[multiplex-example]: https://github.com/grpc/grpc-go/tree/master/examples/features/multiplex