1635005 - Use uint64_t sizes in profiler

Status: NEW

(Core :: Gecko Profiler, enhancement, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

The profiler currently uses 32-bit values for some parameters, in particular the buffer "capacity". This makes the effective buffer limit 2GiB (2^31, because we only accept powers of 2, and because 2^32 cannot be represented in 32 bits).

We should use uint64_t instead, to allow bigger buffers on 64-bit systems with a lot of memory.

Note: size_t may seem ideal here, as it's only 32 bits on 32-bit systems. However:

• The capacity is not used in lots of places, so it wouldn't save much space or code.
• We may still need 64-bit sizes on a 32-bit system anyway because of remote interactions, e.g.: A 32-bit system controlling a remote 64-bit system.
• We are considering saving profiler data to disk (for long sessions), so the 32-bit memory limitation would not apply anymore.