Event Loop & Socket Type Multi-Support

[xiazhvera]

Issue #, if available:

Description of changes:

• Allow select from different event loop type
• Allow select from different socket implementation
• The CI Job was renamed as we introduced new compile options. I will update the required CI once before merge.
  macos -> macos(-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)
  macos-debug -> macos-debug (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 66.02564% with 53 lines in your changes missing coverage. Please review.

Project coverage is 79.66%. Comparing base (b1d0202) to head (c8e57c5).

Files with missing lines	Patch %	Lines
source/event_loop.c	43.10%	33 Missing ⚠️
source/socket.c	74.68%	20 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #692      +/-   ##
==========================================
- Coverage   80.10%   79.66%   -0.45%     
==========================================
  Files          29       30       +1     
  Lines        6001     6121     +120     
==========================================
+ Hits         4807     4876      +69     
- Misses       1194     1245      +51     

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[bretambrose]

How would we be here if this wasn't defined?

[xiazhvera]

If not defined AWS_ENABLE_KQUEUE, the following function should be defined. (in source/event_loop.c)

#ifndef AWS_ENABLE_KQUEUE
struct aws_event_loop *aws_event_loop_new_with_kqueue(
    struct aws_allocator *alloc,
    const struct aws_event_loop_options *options) {
    (void)alloc;
    (void)options;
    AWS_ASSERT(0);

    AWS_LOGF_DEBUG(AWS_LS_IO_EVENT_LOOP, "Kqueue is not supported on the platform");
    aws_raise_error(AWS_ERROR_PLATFORM_NOT_SUPPORTED);
    return NULL;
}
#endif // AWS_ENABLE_EPOLL

[bretambrose]

Hmm, a rephrasing: "why is this source file being compiled if AWS_ENABLE_KQUEUE is not defined at compile time?"

[xiazhvera]

This is a compromise due to a limit on Swift package.
The Swift package cannot differentiate between Apple platforms when including source files, so the KQUEUE source file gets included for all Apple platforms, as it is required for macOS. While it is possible to define different compile flags for different Apple platforms (e.g., enabling AWS_ENABLE_KQUEUE only for macOS and not for iOS).
Eventually, on iOS, we end up in a scenario where the kqueue source file is included, but AWS_ENABLE_KQUEUE is disabled.

[bretambrose]

Hmm, a rephrasing: "why is this source file being compiled if AWS_ENABLE_KQUEUE is not defined at compile time?"

[xiazhvera]

The CI Job was renamed as we introduced new compile options. I will update the required CI once before merge.
macos -> macos(-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)
macos-debug -> macos-debug (-DAWS_USE_APPLE_NETWORK_FRAMEWORK=OFF)