It is common to close network connection while another goroutine is
blocked reading on another goroutine. This sequence corresponds to
windows calls to WSARecv to start io, followed by GetQueuedCompletionStatus
that blocks until io completes, and, finally, closesocket called from
another thread. We were expecting that closesocket would unblock
GetQueuedCompletionStatus, and it does, but not always
(http://code.google.com/p/go/issues/detail?id=4170#c5). Also that sequence
results in connection is being reset.
This CL inserts CancelIo between GetQueuedCompletionStatus and closesocket,
and waits for both WSARecv and GetQueuedCompletionStatus to complete before
proceeding to closesocket. This seems to fix both connection resets and
issue 4170. It also makes windows code behave similar to unix version.
Unfortunately, CancelIo needs to be called on the same thread as WSARecv.
So we have to employ strategy we use for connections with deadlines to
every connection now. It means, there are 2 unavoidable thread switches
for every io. Some newer versions of windows have new CancelIoEx api that
doesn't have these drawbacks, and this CL uses this capability when available.
As time goes by, we should have less of CancelIo and more of CancelIoEx
systems. Computers with CancelIoEx are also not affected by issue 4195 anymore.
Fixes#3710Fixes#3746Fixes#4170
Partial fix for issue 4195
R=golang-dev, mikioh.mikioh, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/6604072
The set of errors forwarded by the os package varied with system and
was therefore non-portable.
Three helpers added for portable error checking: IsExist, IsNotExist, and IsPermission.
One or two more may need to come, but let's keep the set very small to discourage
thinking about errors that way.
R=mikioh.mikioh, gustavo, r, rsc
CC=golang-dev
https://golang.org/cl/5672047
Once we've evicted all the blocked I/O, the ref count
should go to zero quickly, so it should be safe to
postpone the close(2) until then.
Fixes#1898.
Fixes#2116.
Fixes#2122.
R=golang-dev, mikioh.mikioh, bradfitz, fullung, iant
CC=golang-dev
https://golang.org/cl/5649076
Both are unused and undocumented.
InvalidConnError is also non-idiomatic: a FooError type can
typically describe something, else it would be an ErrFoo
variable.
R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/5609045
It works with NewTicker too, but is potentially a bit less efficient,
and reads wrong.
This is what happens when you TBR Windows changes, I guess.
R=golang-dev, gri, iant
CC=golang-dev
https://golang.org/cl/5536060
Previously, a timeout (in int64 nanoseconds) applied to a granularity
even smaller than one operation: a 100 byte read with a 1 second timeout
could take 100 seconds, if the bytes all arrived on the network 1 second
apart. This was confusing.
Rather than making the timeout granularity be per-Read/Write,
this CL makes callers set an absolute deadline (in time.Time)
after which operations will fail. This makes it possible to
set deadlines at higher levels, without knowing exactly how
many read/write operations will happen in e.g. reading an HTTP
request.
Fixes#2723
R=r, rsc, dave
CC=golang-dev
https://golang.org/cl/5555048
- syscall (not os) now defines the Errno type.
- the low-level assembly functions Syscall, Syscall6, and so on
return Errno, not uintptr
- syscall wrappers all return error, not uintptr.
R=golang-dev, mikioh.mikioh, r, alex.brainman
CC=golang-dev
https://golang.org/cl/5372080
I don't know the protocol regarding the zsyscall files which appear to
be hand-generated, so I've re-done them and added them to the change.
R=rsc, alex.brainman, nigeltao
CC=golang-dev
https://golang.org/cl/4975060
We must keep memory used by syscall.WSARecvFrom away from
garbage collector until after overlapped call is completed.
Fixes#2094.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4817050
It was left in netFD.connect() by an oversight (as the name
implies, bind has no business being in connect). As a result
of this change and by only calling netFD.connect() when ra
isn't nil it becomes simpler with less code duplication.
Additionally, if netFD.connect() fails, set sysfd to -1 to
avoid finalizers (e.g. on windows) calling shutdown on a
closed and possibly reopened socket that just happened to
share the same descriptor.
R=golang-dev, rsc1, rsc
CC=golang-dev
https://golang.org/cl/4328043
Refactored bind/connect from sock.go into netFD.connect(), as
a consequence newFD() doesn't accept laddr/raddr anymore, and
expects an (optional) call to netFD.connect() followed by a
call to netFD.setAddr().
Windows code is updated, but still uses blocking connect,
since otherwise it needs support for ConnectEx syscall.
R=brainman, rsc
CC=golang-dev
https://golang.org/cl/4303060
