Unable to print large documents in Electron 4, 5

[justin-elliott]

• Electron Version (output of node_modules/.bin/electron --version):
  • 4.0.4
  • 5.0.0-beta.2
• Operating System (Platform and Version):
  • Windows 10 Pro (1803)
• Last known working Electron version (if applicable):
  • 3.1.3

Expected Behavior

When printing a large document, every page should print successfully.

Actual behavior

When printing a large document, printing fails before completing, or produces a run of blank pages at the end. Given the number of pages involved, 800+, this has only been tested through print-to-file drivers such as Microsoft Print to PDF, and Microsoft XPS Document Writer.

This appears to be memory-related, as memory usage climbs for each additional page spooled. Prior versions of Electron did not exhibit increasing memory usage during page spooling.

To Reproduce

This issue was first observed in a PDF.js-based viewer embedded in our application. I have created a simple application that emulates PDF.js printing behavior, here:

https://github.com/justin-elliott/electron-printing-bug

The README contains details of the testing that I have conducted.

[ablesser]

I've reproduced this with a video showing what happens with windows memory as it creeps up to the 64 gb VMemory limit on my machine and then fails near ~2200 pages out of 2500 using the test app @justin-elliott provided. I also show Resource monitor live monitoring during the process showing electron consuming ungodly amounts of memory (50 + GB) before everything falls over.

Note that the output PDF is 0kb / blank in this case, as the print spooling process (which seems to be running under electron's memory footprint) just seems to fall over.

I also show that windows event viewer triggers a resource exhaustion warning, which may relate to why the process ultimately terminates. Clearly , though this is some sort of memory leak/bloat that didn't exist before.