dgram: add dgram send queue info

[theanarkh]

Add getSendQueueSize and getSendQueueCount for dgram.

• [x] make -j4 test (UNIX), or vcbuild test (Windows) passes
• [x] tests and/or benchmarks are included
• [x] documentation is changed or added
• [x] commit message follows commit guidelines

[nodejs-github-bot]

Review requested:

• [ ] @nodejs/net

[theanarkh]

Can you add a test where those are non-zero?

Done ! Thanks !

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/45892/

[theanarkh]

@mcollina Hi, can help review this PR again ? Thanks !

[theanarkh]

It failed on Windows.

node:assert:124
  throw new AssertionError(obj);
  ^

AssertionError [ERR_ASSERTION]: Expected values to be strictly equal:

0 !== 10

It seems windows writes the data into os synchronously.

On other platforms they will insert the request into write queue first and wait POLLOUT event.

I think it's difficult to simulate this, so i just change the code as follows.

assert.ok(client.getSendQueueSize() >= 0);
assert.ok(client.getSendQueueCount() >= 0);

cc @mcollina

[mcollina]

You could make an OS conditional switch. At least this oddity would be transparent for the reader.

[theanarkh]

Done.

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/45907/

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/45911/

[theanarkh]

@mcollina Hi , can help review again ? Thanks .

[theanarkh]

@mcollina Hi , can help review again ?

[nodejs-github-bot]

Landed in 97e8bda5b29561c8c6e30736cd15919403fb7a5b

[juanarbol]

This depends on https://github.com/nodejs/node/pull/44056, which is not landed yet in v16.x