Fix concurrency on the client (#183)

* reworked peer connection establishment logic eliminating race conditions and deadlocks while running many peers

client/internal/peer/error.go

@@ -0,0 +1,56 @@
+package peer
+
+import (
+	"fmt"
+	"time"
+)
+
+// ConnectionTimeoutError is an error indicating that a peer Conn has been timed out
+type ConnectionTimeoutError struct {
+	peer    string
+	timeout time.Duration
+}
+
+func (e *ConnectionTimeoutError) Error() string {
+	return fmt.Sprintf("connection to peer %s timed out after %s", e.peer, e.timeout.String())
+}
+
+// NewConnectionTimeoutError creates a new ConnectionTimeoutError error
+func NewConnectionTimeoutError(peer string, timeout time.Duration) error {
+	return &ConnectionTimeoutError{
+		peer:    peer,
+		timeout: timeout,
+	}
+}
+
+// ConnectionClosedError is an error indicating that a peer Conn has been forcefully closed
+type ConnectionClosedError struct {
+	peer string
+}
+
+func (e *ConnectionClosedError) Error() string {
+	return fmt.Sprintf("connection to peer %s has been closed", e.peer)
+}
+
+// NewConnectionClosedError creates a new ConnectionClosedError error
+func NewConnectionClosedError(peer string) error {
+	return &ConnectionClosedError{
+		peer: peer,
+	}
+}
+
+// ConnectionDisconnectedError is an error indicating that a peer Conn has ctx from the remote
+type ConnectionDisconnectedError struct {
+	peer string
+}
+
+func (e *ConnectionDisconnectedError) Error() string {
+	return fmt.Sprintf("disconnected from peer %s", e.peer)
+}
+
+// NewConnectionDisconnectedError creates a new ConnectionDisconnectedError error
+func NewConnectionDisconnectedError(peer string) error {
+	return &ConnectionDisconnectedError{
+		peer: peer,
+	}
+}