Approximate time helpers

[Alan-Jowett]

Resolves: #4009

Description

This pull request introduces new eBPF helper functions for retrieving time since boot in milliseconds and updates the codebase to use a new timing function, cxplat_query_time_since_boot_precise. Additionally, it includes updates to related data structures and test cases.

New eBPF Helper Functions:

• Added bpf_ktime_get_boot_ms and bpf_ktime_get_ms helper functions to retrieve time since boot in milliseconds, including and excluding suspended time, respectively. (include/bpf_helper_defs.h, include/ebpf_structs.h, libs/execution_context/ebpf_core.c, libs/execution_context/ebpf_general_helpers.c) [1] [2] [3] [4]

Codebase Updates:

• Replaced ebpf_query_time_since_boot_precise and ebpf_query_time_since_boot_approximate with cxplat_query_time_since_boot_precise and cxplat_query_time_since_boot_approximate across various files for better performance and consistency. (libs/execution_context/ebpf_core.c, libs/execution_context/ebpf_maps.c, libs/execution_context/ebpf_program.c, libs/runtime/ebpf_platform.c, tests/performance/platform.cpp) [1] [2] [3] [4] [5]

Data Structures and Test Cases:

• Updated ebpf_utility_helpers_data_t structure to include new timestamp fields in milliseconds. (tests/sample/sample_test_common.h)
• Modified test cases to validate the new timestamp fields and updated the logic to use the new timing functions. (tests/libs/common/common_tests.cpp, tests/sample/sample_common_routines.h) [1] [2]

Testing

CI/CD

Documentation

Yes, doxygen updated.

Installation

No.