Fix Mac Memory leak issue

[shachau]

https://github.com/microsoft/cpp_client_telemetry_modules/issues/176

Multiple users are reporting high memory usage, especially on M1 Macs. We've made some significant gains in the last few months, but we are still running into users seeing 12+GB of usage. I've been in a thread with one such user who has provided leak traces

The "with aria" traces were collected first, in OneDrive's default configuration. The user enabled malloc_history and let the product run until it reached around 1GB usage, at which point it is my understanding that we crashed (this has to do with malloc tracing and not another bug). After that, I had the user disable Aria, and run the same trace again (the "without aria" trace). No crash this time.

From a comparison of the traces, it is obvious that Aria is responsible for significant memory consumption. What seems to be happening here (and this is consistent with when Apple looked at it) is that Aria is allocating objects inside an autoreleasepool that is never released.

What changes:
Just added autorelease pool to functions that were not releasing memory.

[shachau]

@sid-dahiya @lalitb for reference, this is the fix for memory leak issue on Mac that we saw in OneDrive. This fix worked for OneDrive so merging it to the common code.

[shachau]

Getting error.
/Users/runner/work/cpp_client_telemetry/cpp_client_telemetry/lib/pal/WorkerThread.cpp:186:17: error: expected expression
@autoreleasepool

@lalitb what compiler do we use? GCC or Clang compiler
https://stackoverflow.com/questions/13708601/autoreleasepool-expected-expression-before-token

All examples of using autoreleasepool is in mm file.
Do we need to change the macro?

[lalitb]

@lalitb what compiler do we use? GCC or Clang compiler

Clang is used for both mac and iOS compilation. But looking into the PR now, it doesn't make sense to add @autoreleasepool in the C++ code. It is not a C++ construct and will fail with any C++ compiler. Why do we need to add it in the worker thread?

[eduardo-camacho]

@lalitb what compiler do we use? GCC or Clang compiler

Clang is used for both mac and iOS compilation. But looking into the PR now, it doesn't make sense to add @autoreleasepool in the C++ code. It is not a C++ construct and will fail with any C++ compiler. Why do we need to add it in the worker thread?

Agree with your statement, this block do not contain Obj-C object references, hence @autoreleasepool doesn't apply here

[shachau]

Thanks removed the autorelease pool from WorkerThread.cpp

[lalitb]

Thanks. LGTM

[lalitb]

On lighter front, @autoreleasepool user can ignore all these discussions, he is unknowingly getting added here. :)