RFR 8145635 : Add TCP_QUICKACK socket option

[Roger Riggs]

Hi Vyom,

Comments:

  - update copyright
  - use @since 18.3 instead of @since 10

- ExtendedSocketOptions.java: 265,269  include the "TCP_QUICKACK" in the 
exception messages.

     Line 144: if you are going to keep the assert, add a explanation 
about how it could happen.
     I'd remove the assert.

  - The first sentence should be a complete sentence:  "TCP_QUICKACK 
socket option enables sending TCP/IP acks immediately" or similar.

  - A reference to the appropriate TCP/IP spec for quickack would be a 
good addition. At least the RFC # and section.
  - 85: space after "."  The phrasing is a bit odd in places in the javadoc.
  - line 81/82 the value is true to enable and false to disable.
  - This phrase is confusing: "it only enables a switch to or from 
TCP_QUICKACK mode";
    Since it is set on a socket, it should remain set on that socket 
until it is changed.

  - 203: be consistent in using enable/disable in parameters, etc even 
for private methods.
     "on" -> "enable"

PlainDatagramSocketImpl: 89:
   Why create a new set with zero or one items just to throw it away?
   Use the iterator to add only the non-TCP_QUICKACK options to the 
supported options.
  Also, you can use ExtendedSocketOptions.TCP_QUICKACK to check for the 
option to omit without
  embedding the name.


Sockets.java:
   - The initialization of isQuickAckAvailable might be cleaner as an 
nested static class
     that initializes the value in its static initializer. That would 
delay the init til needed
     and avoid extra flags.

LinuxSocketOptions.java:
    - the native methods should be static; since the instance is unused.

  - line 41: the return type should be Boolean

  - line 46: the return type of getQuickAck0 should be Boolean like the 
argument to set.

  - line 34:  using JNU_ThrowByNameWithLastError directly is sufficient; 
if the errno does not have a string unix supplies "unknown error nnn".


Regards, Roger

On 10/10/2017 2:58 PM, Chris Hegarty wrote:
> Vyom,
>
> What about suggestion 1) below, the name of the socket option?
>
> -Chris.
>
>> On 27 Sep 2017, at 09:56, vyom tewari <vyom.tewari at oracle.com> wrote:
>>
>> Hi Chris,
>>
>> Thanks for review, please find the latest webrev(http://cr.openjdk.java.net/~vtewari/8145635/webrev0.2/index.html). I incorporated review comments from you and re-base the patch to our consolidated repo(jdk10/master).
>>
>> Thanks,
>>
>> Vyom
>>
>>
>> On Monday 25 September 2017 01:57 AM, Chris Hegarty wrote:
>>> Vyom,
>>>
>>>> On 11 Sep 2017, at 16:38, vyom tewari <vyom.tewari at oracle.com> wrote:
>>>>
>>>> Hi All,
>>>>
>>>> As jdk.net API already moved out of java.base, Please review the below code change for jdk10.
>>>>
>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8145635
>>>> Webrev: http://cr.openjdk.java.net/~vtewari/8145635/webrev0.1/index.html
>>>>
>>> This looks quite good. Some comments:
>>>
>>> 1) I wonder if we should just call the option TCP_QUICKACK, rather than SO_QUICKACK? Similar to TCP_NODELAY.
>>>
>>> 2) I think LinuxSocketOptions.h is largely unnecessary, if we do 1) above.
>>>
>>> 3) Java_jdk_net_LinuxSocketOptions_getQuickAck could return jint, rather than jobject, thus avoiding the need for createBoolean. The conversation can happen in the Java layer.  Can you please reduce the lint length in this file, by wrapping similar to the style of the Solaris version.
>>>
>>> 4) ExtendedSocketOptions.java
>>>    - drop the <p>, they are unnecessary.
>>>    - I think, similar to TCP_NODELAY, the spec should say that the options is TCP specific. From TCP_NODELAY: "The socket option is specific to stream-oriented sockets using the TCP/IP protocol.”
>>>    - "In TCP_QUICKACK mode”, maybe “When the option is enabled…”
>>>
>>> -Chris.
>>>
>>>