[WIP] Integrate manage_prime_cores logic into apply_config function

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

Original prompt

Integrate manage_prime_cores logic into apply_config function in src/main.rs.

1. Struct Definitions: Move ThreadStats and PrimeCoreScheduler definitions outside of main function (or where they were in the previous snippet) to the top level of the file, so they are accessible.
   • Ensure ThreadStats and PrimeCoreScheduler are defined.
   • Define Candidate struct used in the logic.
2. Scheduler Instance: In main, create an instance of PrimeCoreScheduler (scheduler) and pass it to apply_config.
   • Update apply_config signature to accept &mut PrimeCoreScheduler.
   • Update apply_config call site in main.
3. Reuse Process Affinity: In apply_config:
   • Define current_mask and system_mask variables before the affinity check block.
   • If config.affinity_mask != 0 OR config.prime_cpu_mask != 0, call GetProcessAffinityMask if it hasn't been called yet.
   • Use this current_mask for the S calculation logic (intersect prime_cpu_mask with current_mask or system_mask as discussed previously: S = PrimeMask & (ProcessAffinity if set else SystemAffinity)).
4. Integrate Logic: Append the manage_prime_cores logic at the end of apply_config (after the cpu set mask block).
   • The logic should use the pid and scheduler passed to apply_config.
   • The logic involves:
     • Calculating S mask and prime_cpuset_ids.
     • Taking a thread snapshot (CreateToolhelp32Snapshot with TH32CS_SNAPTHREAD).
     • Iterating threads for the current pid.
     • Managing handles (open new, reuse existing VIP handle).
     • Querying cycle time (QueryThreadCycleTime).
     • Calculating delta and updating history.
     • Sorting candidates.
     • Applying CPU sets (SetThreadSelectedCpuSets) for VIPs.
     • Resetting CPU sets for demoted threads.
     • Closing handles for non-VIPs.
     • GC-ing dead threads from the scheduler.
5. Struct Updates: Ensure ProcessConfig has the prime_cpu_mask field and read_config parses it (as per previous discussion).

Refinement on apply_config logic flow:

• Open Process Handle h_prc.
• ... (Priority setting) ...
• Affinity Handling:
  • Initialize current_affinity_mask = 0, system_affinity_mask = 0.
  • Check if we need affinity: need_affinity = config.affinity_mask != 0 || config.prime_cpu_mask != 0.
  • If need_affinity:
    • Call GetProcessAffinityMask(h_prc, ...).
    • If successful, store results.
  • If config.affinity_mask != 0 and diff from current, SetProcessAffinityMask.
• ... (Process Default CPU Set setting) ...
• ... (IO Priority) ...
• ... (Memory Priority) ...
• Prime Core Management:
  • If config.prime_cpu_mask != 0:
    • Calculate effective S mask. (User mentioned calculating disjoint sets or intersection. The previous consensus was PrimeMask & (CurrentAffinity if valid else SystemAffinity)).
    • Execute the thread scanning, sorting, and setting logic using scheduler.
• Close h_prc.

Note on Handle Reuse: The user mentioned "write in apply_config might directly utilize some existing HANDLE".

• apply_config holds the Process Handle (h_prc).
• manage_prime_cores needs Thread Handles.
• h_prc is useful for GetProcessAffinityMask.
• h_prc is not directly useful for opening threads (we still need OpenThread or Thread32First), but QueryThreadCycleTime takes a Thread Handle.
• So the reuse is mainly about the affinity mask data.

Code Structure Plan:

• Add ThreadStats, PrimeCoreScheduler structs at module level.
• Add prime_cpu_mask to ProcessConfig.
• Update read_config to parse the 7th column.
• Modify apply_config to take scheduler.
• Inside apply_config, implement the merged logic.
• Modify main to init scheduler and call updated apply_config.

This pull request was created as a result of the following prompt from Copilot chat.

Integrate manage_prime_cores logic into apply_config function in src/main.rs.

1. Struct Definitions: Move ThreadStats and PrimeCoreScheduler definitions outside of main function (or where they were in the previous snippet) to the top level of the file, so they are accessible.
   • Ensure ThreadStats and PrimeCoreScheduler are defined.
   • Define Candidate struct used in the logic.
2. Scheduler Instance: In main, create an instance of PrimeCoreScheduler (scheduler) and pass it to apply_config.
   • Update apply_config signature to accept &mut PrimeCoreScheduler.
   • Update apply_config call site in main.
3. Reuse Process Affinity: In apply_config:
   • Define current_mask and system_mask variables before the affinity check block.
   • If config.affinity_mask != 0 OR config.prime_cpu_mask != 0, call GetProcessAffinityMask if it hasn't been called yet.
   • Use this current_mask for the S calculation logic (intersect prime_cpu_mask with current_mask or system_mask as discussed previously: S = PrimeMask & (ProcessAffinity if set else SystemAffinity)).
4. Integrate Logic: Append the manage_prime_cores logic at the end of apply_config (after the cpu set mask block).
   • The logic should use the pid and scheduler passed to apply_config.
   • The logic involves:
     • Calculating S mask and prime_cpuset_ids.
     • Taking a thread snapshot (CreateToolhelp32Snapshot with TH32CS_SNAPTHREAD).
     • Iterating threads for the current pid.
     • Managing handles (open new, reuse existing VIP handle).
     • Querying cycle time (QueryThreadCycleTime).
     • Calculating delta and updating history.
     • Sorting candidates.
     • Applying CPU sets (SetThreadSelectedCpuSets) for VIPs.
     • Resetting CPU sets for demoted threads.
     • Closing handles for non-VIPs.
     • GC-ing dead threads from the scheduler.
5. Struct Updates: Ensure ProcessConfig has the prime_cpu_mask field and read_config parses it (as per previous discussion).

Refinement on apply_config logic flow:

• Open Process Handle h_prc.
• ... (Priority setting) ...
• Affinity Handling:
  • Initialize current_affinity_mask = 0, system_affinity_mask = 0.
  • Check if we need affinity: need_affinity = config.affinity_mask != 0 || config.prime_cpu_mask != 0.
  • If need_affinity:
    • Call GetProcessAffinityMask(h_prc, ...).
    • If successful, store results.
  • If config.affinity_mask != 0 and diff from current, SetProcessAffinityMask.
• ... (Process Default CPU Set setting) ...
• ... (IO Priority) ...
• ... (Memory Priority) ...
• Prime Core Management:
  • If config.prime_cpu_mask != 0:
    • Calculate effective S mask. (User mentioned calculating disjoint sets or intersection. The previous consensus was PrimeMask & (CurrentAffinity if valid else SystemAffinity)).
    • Execute the thread scanning, sorting, and setting logic using scheduler.
• Close h_prc.

Note on Handle Reuse: The user mentioned "write in apply_config might directly utilize some existing HANDLE".

• apply_config holds the Process Handle (h_prc).
• manage_prime_cores needs Thread Handles.
• h_prc is useful for GetProcessAffinityMask.
• h_prc is not directly useful for opening threads (we still need OpenThread or Thread32First), but QueryThreadCycleTime takes a Thread Handle.
• So the reuse is mainly about the affinity mask data.

Code Structure Plan:

• Add ThreadStats, PrimeCoreScheduler structs at module level.
• Add prime_cpu_mask to ProcessConfig.
• Update read_config to parse the 7th column.
• Modify apply_config to take scheduler.
• Inside apply_config, implement the merged logic.
• Modify main to init scheduler and call updated apply_config.

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