Fix scheduler hang when pending limit is reached

[pollydrag]

What do these changes do?

Do not add job to _jobs list while waiting for a free slot in the pending queue.

Related issue number

#97, #98

Checklist

• [x] I think the code is well written
• [x] Unit tests for the changes exist
• [x] Documentation reflects the changes
• [x] Add a new news fragment into the CHANGES folder

[codecov[bot]]

Codecov Report

Merging #135 (f56e16c) into master (041945f) will not change coverage. The diff coverage is 100.00%.

:exclamation: Current head f56e16c differs from pull request most recent head 91cb325. Consider uploading reports for the commit 91cb325 to get more accurate results

@@            Coverage Diff            @@
##            master      #135   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            4         4           
  Lines          231       246   +15     
=========================================
+ Hits           231       246   +15     

Impacted Files	Coverage Δ
aiojobs/_scheduler.py	100.00% <100.00%> (ø)
aiojobs/_job.py	100.00% <0.00%> (ø)
aiojobs/aiohttp.py	100.00% <0.00%> (ø)

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[Tinche]

We might be hitting this in production.

[oleynikandrey]

Is there any plans to merge this PR?

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
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[NotoriousRebel]

@pollydrag Any updates?

[pollydrag]

@asvetlov Can you review this, please?

[simon-liebehenschel]

Hi guys, does anybody have a maintained fork of this repository? It may be great to have a maintained fork.

[simon-liebehenschel]

@hlecnt and other people:

As long as the package is abandoned, I will maintain a fork to help everyone keep using this package without critical bugs. This fix is available:

pip install aiojobs-fork==1.0.2