facebook/fresco

Occasionally throws FileNotFoundException by reading files after inserting to main disk cache concurrently

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#2,382 opened on 2019年7月23日

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 (3 comments) (0 reactions) (0 assignees)Java (17,072 stars) (3,750 forks)batch import
bughelp wanted

説明

For more details please refer to this repo including a detailed README and a runnable Android app: https://github.com/JuniperPhoton/FrescoFileNotFoundBug

Description

This is an issue on this situation:

Massively and concurrently fetching images from network and insert them into disk cache immediately, and then read the files on the same thread.

By saying Massively and concurrently I mean doing the work on every 50ms, please refer to MainActivity for more details.

The issue is that sometimes it throws java.io.FileNotFoundException on reading saved files by opening a FileInputStream, even if the files do exist. The files can still be found using Android Studio's Device File Explorer can of course be opened.

Furthermore, if you try to open the file exported by content:// by other apps, or do a thread sleeping before accessing them, it will work.

Reproduction

Please refer to this repo: https://github.com/JuniperPhoton/FrescoFileNotFoundBug

Solution

Please refer to this repo: https://github.com/JuniperPhoton/FrescoFileNotFoundBug

Additional Information

  • Fresco version: 2.0.0
  • Platform version: No devices or OS version specified, tested on Android P/Q, Pixel 2 and OnePlus 7 Pro

コントリビューターガイド

技術スタック
javaandroid
領域
mobile
Issue 種別
bug
難度新しい貢献者にとっての実装難度です。1 は非常に小さな変更、5 は専門的な作業です。
4
推定時間経験ある貢献者が調査、実装、テスト、pull request 準備にかけるおおよその時間範囲です。
half day
活動状況Issue が今どれだけ取り組みやすいかを示します。新しい、活発、古い、ブロック中、またはメンテナー入力待ちなどです。
stale
明確さ期待される変更、受け入れ条件、次の手順がどれだけ明確かを示します。
mostly clear
前提条件
Android developmentJavaConcurrent programmingFresco library
初心者向け度初回貢献者にどれだけ取り組みやすいかを 1-100 で推定したスコアです。
35
調査方針
Investigate the reproduction repository at https://github.com/JuniperPhoton/FrescoFileNotFoundBug to understand the concurrent disk cache insertion and reading pattern. Check the Fresco source code for disk cache synchronization, particularly in classes like DiskCache or DefaultDiskStorage. Look for potential race conditions where a file is still being written when read. Consider using thread sleeping as mentioned in the issue to verify timing.
Occasionally throws FileNotFoundException by reading files after inserting to main disk cache concurrently · facebook/fresco#2382 | Good First Issue