diff options
Diffstat (limited to 'libgo/go/net/net.go')
| -rw-r--r-- | libgo/go/net/net.go | 75 |
1 files changed, 46 insertions, 29 deletions
diff --git a/libgo/go/net/net.go b/libgo/go/net/net.go index 1d7e5e7f652..2e61a7c02e0 100644 --- a/libgo/go/net/net.go +++ b/libgo/go/net/net.go @@ -81,7 +81,6 @@ package net import ( "context" "errors" - "internal/poll" "io" "os" "sync" @@ -112,13 +111,13 @@ type Addr interface { // Multiple goroutines may invoke methods on a Conn simultaneously. type Conn interface { // Read reads data from the connection. - // Read can be made to time out and return an Error with Timeout() == true - // after a fixed time limit; see SetDeadline and SetReadDeadline. + // Read can be made to time out and return an error after a fixed + // time limit; see SetDeadline and SetReadDeadline. Read(b []byte) (n int, err error) // Write writes data to the connection. - // Write can be made to time out and return an Error with Timeout() == true - // after a fixed time limit; see SetDeadline and SetWriteDeadline. + // Write can be made to time out and return an error after a fixed + // time limit; see SetDeadline and SetWriteDeadline. Write(b []byte) (n int, err error) // Close closes the connection. @@ -136,23 +135,22 @@ type Conn interface { // SetReadDeadline and SetWriteDeadline. // // A deadline is an absolute time after which I/O operations - // fail with a timeout (see type Error) instead of - // blocking. The deadline applies to all future and pending - // I/O, not just the immediately following call to Read or - // Write. After a deadline has been exceeded, the connection - // can be refreshed by setting a deadline in the future. + // fail instead of blocking. The deadline applies to all future + // and pending I/O, not just the immediately following call to + // Read or Write. After a deadline has been exceeded, the + // connection can be refreshed by setting a deadline in the future. + // + // If the deadline is exceeded a call to Read or Write or to other + // I/O methods will return an error that wraps os.ErrDeadlineExceeded. + // This can be tested using errors.Is(err, os.ErrDeadlineExceeded). + // The error's Timeout method will return true, but note that there + // are other possible errors for which the Timeout method will + // return true even if the deadline has not been exceeded. // // An idle timeout can be implemented by repeatedly extending // the deadline after successful Read or Write calls. // // A zero value for t means I/O operations will not time out. - // - // Note that if a TCP connection has keep-alive turned on, - // which is the default unless overridden by Dialer.KeepAlive - // or ListenConfig.KeepAlive, then a keep-alive failure may - // also return a timeout error. On Unix systems a keep-alive - // failure on I/O can be detected using - // errors.Is(err, syscall.ETIMEDOUT). SetDeadline(t time.Time) error // SetReadDeadline sets the deadline for future Read calls @@ -315,15 +313,13 @@ type PacketConn interface { // It returns the number of bytes read (0 <= n <= len(p)) // and any error encountered. Callers should always process // the n > 0 bytes returned before considering the error err. - // ReadFrom can be made to time out and return - // an Error with Timeout() == true after a fixed time limit; - // see SetDeadline and SetReadDeadline. + // ReadFrom can be made to time out and return an error after a + // fixed time limit; see SetDeadline and SetReadDeadline. ReadFrom(p []byte) (n int, addr Addr, err error) // WriteTo writes a packet with payload p to addr. - // WriteTo can be made to time out and return - // an Error with Timeout() == true after a fixed time limit; - // see SetDeadline and SetWriteDeadline. + // WriteTo can be made to time out and return an Error after a + // fixed time limit; see SetDeadline and SetWriteDeadline. // On packet-oriented connections, write timeouts are rare. WriteTo(p []byte, addr Addr) (n int, err error) @@ -339,11 +335,17 @@ type PacketConn interface { // SetReadDeadline and SetWriteDeadline. // // A deadline is an absolute time after which I/O operations - // fail with a timeout (see type Error) instead of - // blocking. The deadline applies to all future and pending - // I/O, not just the immediately following call to ReadFrom or - // WriteTo. After a deadline has been exceeded, the connection - // can be refreshed by setting a deadline in the future. + // fail instead of blocking. The deadline applies to all future + // and pending I/O, not just the immediately following call to + // Read or Write. After a deadline has been exceeded, the + // connection can be refreshed by setting a deadline in the future. + // + // If the deadline is exceeded a call to Read or Write or to other + // I/O methods will return an error that wraps os.ErrDeadlineExceeded. + // This can be tested using errors.Is(err, os.ErrDeadlineExceeded). + // The error's Timeout method will return true, but note that there + // are other possible errors for which the Timeout method will + // return true even if the deadline has not been exceeded. // // An idle timeout can be implemented by repeatedly extending // the deadline after successful ReadFrom or WriteTo calls. @@ -420,7 +422,7 @@ func mapErr(err error) error { case context.Canceled: return errCanceled case context.DeadlineExceeded: - return poll.ErrTimeout + return errTimeout default: return err } @@ -567,6 +569,21 @@ func (e InvalidAddrError) Error() string { return string(e) } func (e InvalidAddrError) Timeout() bool { return false } func (e InvalidAddrError) Temporary() bool { return false } +// errTimeout exists to return the historical "i/o timeout" string +// for context.DeadlineExceeded. See mapErr. +// It is also used when Dialer.Deadline is exceeded. +// +// TODO(iant): We could consider changing this to os.ErrDeadlineExceeded +// in the future, but note that that would conflict with the TODO +// at mapErr that suggests changing it to context.DeadlineExceeded. +var errTimeout error = &timeoutError{} + +type timeoutError struct{} + +func (e *timeoutError) Error() string { return "i/o timeout" } +func (e *timeoutError) Timeout() bool { return true } +func (e *timeoutError) Temporary() bool { return true } + // DNSConfigError represents an error reading the machine's DNS configuration. // (No longer used; kept for compatibility.) type DNSConfigError struct { |