gh-135953: Reduce memory usage of stack collectors

[lkollar]

The stack collector base class keeps all frames until export() is called, which causes significant unnecessary memory usage. Instead, we can process the frames on the fly in the collect call by dispatching the aggregation logic to the subclass through the process_frames method.

• Issue: Expose internal stack introspection APIs as a statistical runtime analysis tool #135953

[pablogsal]

Amazing! I have pushed a commit adding an initial version of the string table for the flame graph. We can improve that in subsequent PRs

[pablogsal]

Will fix merge conflicts tomorrow

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 CentOS9 NoGIL Refleaks 3.x (tier-1) has failed when building commit 3e06cfc.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/#/builders/1610/builds/2071) and take a look at the build logs.
4. Check if the failure is related to this commit (3e06cfc) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/#/builders/1610/builds/2071

Failed tests:

• test_free_threading

Test leaking resources:

• test_free_threading: file descriptors

Summary of the results of the build (if available):

==

Click to see traceback logs

remote: Enumerating objects: 22, done.        
remote: Counting objects:   4% (1/22)        
remote: Counting objects:   9% (2/22)        
remote: Counting objects:  13% (3/22)        
remote: Counting objects:  18% (4/22)        
remote: Counting objects:  22% (5/22)        
remote: Counting objects:  27% (6/22)        
remote: Counting objects:  31% (7/22)        
remote: Counting objects:  36% (8/22)        
remote: Counting objects:  40% (9/22)        
remote: Counting objects:  45% (10/22)        
remote: Counting objects:  50% (11/22)        
remote: Counting objects:  54% (12/22)        
remote: Counting objects:  59% (13/22)        
remote: Counting objects:  63% (14/22)        
remote: Counting objects:  68% (15/22)        
remote: Counting objects:  72% (16/22)        
remote: Counting objects:  77% (17/22)        
remote: Counting objects:  81% (18/22)        
remote: Counting objects:  86% (19/22)        
remote: Counting objects:  90% (20/22)        
remote: Counting objects:  95% (21/22)        
remote: Counting objects: 100% (22/22)        
remote: Counting objects: 100% (22/22), done.        
remote: Compressing objects:  12% (1/8)        
remote: Compressing objects:  25% (2/8)        
remote: Compressing objects:  37% (3/8)        
remote: Compressing objects:  50% (4/8)        
remote: Compressing objects:  62% (5/8)        
remote: Compressing objects:  75% (6/8)        
remote: Compressing objects:  87% (7/8)        
remote: Compressing objects: 100% (8/8)        
remote: Compressing objects: 100% (8/8), done.        
remote: Total 12 (delta 9), reused 5 (delta 4), pack-reused 0 (from 0)        
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HEAD is now at 3e06cfcaeee gh-135953: Reduce memory usage of stack collectors (#138875)
Switched to and reset branch 'main'

configure: WARNING: no system libmpdec found; falling back to pure-Python version for the decimal module

make: *** [Makefile:2486: buildbottest] Error 2