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element-hq / hydrogen-web

Lightweight matrix client with legacy and mobile browser support
Apache License 2.0
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Olm encryption for more than 44 devices fails because libolm runs out of memory #150

Closed bwindels closed 4 years ago

bwindels commented 4 years ago

After the first sync, we send out any pending room key shares in the operations store. This seems to fail without exception (trying with 3 operations in my store now) with the following olm error:

Cannot enlarge memory arrays. Either (1) compile with  -s TOTAL_MEMORY=X  with X higher than the current value 262144, (2) compile with  -s ALLOW_MEMORY_GROWTH=1  which allows increasing the size at runtime, or (3) if you want malloc to return NULL (0) instead of this abort, compile with  -s ABORTING_MALLOC=0

It is surprising that it would already have hit the memory limit right after loading the session, from a cold session load.

This is hydrogen 0.1.10 on latest Chrome.

bwindels commented 4 years ago

I think this is because my test account has 53 e2ee devices and while encrypting a message, we keep hold of all outbound olm sessions. It fails to allocate the 45th olm outbound session. One outbound session needs 3320 bytes, so 44x3320=146080 bytes seems to make us run out of memory.

bwindels commented 4 years ago

We should either increase the memory limit, or not run encryption in parallel anymore.

bwindels commented 4 years ago

Or likely just decrease MAX_BATCH_SIZE in olm/Encryption.js...