Add synchronized to help prevent race condition with fresco client code #2579
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…nitialized, and when we try to perform .init() which means a race condition can occur (as mentioned in facebook/SoLoader#60). This change uses synchronization on the NativeLoader class, and a secondary check to verify that the initialization needs to take place just before we perform it, in order to reduce the window for a race condition to affect client code. When combined with facebook/SoLoader#69 this will remove the race condition from the code because the initialisation inside SoLoader and inside Fresco will both be synchronized on the NativeLoad.class object.
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@wizh has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.
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Thanks for the PR! |
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No problem. If you can share details from intern phab about what the internal problems are I'd be happy to do a cleanup commit. |
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masterbranchMotivation (required)
There is a period of time between checking if NativeLoader has been initialized, and when we try to perform
.init()which means a race condition can occur (as mentioned in facebook/SoLoader#60). This PR provides a mechanism for client code to avoid that race condition.This change uses synchronization on the
NativeLoaderclass object, and a secondary check to verify that the initialization needs to take place just before we perform it in order to reduce the window in which a race condition can happen.When combined with facebook/SoLoader#69 this will remove the race condition from the code because the initialisation inside SoLoader and inside Fresco will both be synchronized on the
NativeLoader.classobject. Without that PR in SoLoader this change will still allow fresco clients to synchronize onNativeLoader.classin their own code around any areas which may race with this code in fresco.Test Plan (required)
This code doesn't alter the functionality of fresco, and so existing tests should provide verification that there is no operational impact.
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