Fix memory leak in PerfServer DelayWorker initialization failure

[Copilot]

Problem

In PerfServer::Init(), when DelayWorkers[i].Initialize() fails during the initialization loop, the function returns QUIC_STATUS_INTERNAL_ERROR without cleaning up the already allocated DelayWorkers array, causing a memory leak.

The problematic code:

DelayWorkers = new (std::nothrow) DelayWorker[ProcCount];
for (uint16_t i = 0; i < ProcCount; ++i) {
    if (!DelayWorkers[i].Initialize(this, i)) {
        WriteOutput("Failed to init delay workers.\n");
        return QUIC_STATUS_INTERNAL_ERROR;  // Memory leak here!
    }
}

Solution

This PR implements a comprehensive fix that addresses both the reported issue and additional edge cases:

1. Allocation failure handling: Added null check after new (std::nothrow) to handle allocation failure gracefully
2. Memory leak fix: Added proper cleanup in the initialization failure path:
   • Calls Shutdown() on all DelayWorkers (safe for both initialized and uninitialized workers)
   • Deletes the DelayWorkers array with delete[] DelayWorkers
   • Sets DelayWorkers = nullptr
3. Pattern consistency: Cleanup logic exactly matches the existing destructor implementation
4. Appropriate error codes: Returns QUIC_STATUS_OUT_OF_MEMORY for allocation failure, QUIC_STATUS_INTERNAL_ERROR for initialization failure

Changes Made

ProcCount = (uint16_t)CxPlatProcCount();
DelayWorkers = new (std::nothrow) DelayWorker[ProcCount];
+if (!DelayWorkers) {
+    WriteOutput("Failed to allocate delay workers.\n");
+    return QUIC_STATUS_OUT_OF_MEMORY;
+}
for (uint16_t i = 0; i < ProcCount; ++i) {
    if (!DelayWorkers[i].Initialize(this, i)) {
+        for (uint16_t j = 0; j < ProcCount; ++j) {
+            DelayWorkers[j].Shutdown();
+        }
+        delete[] DelayWorkers;
+        DelayWorkers = nullptr;
        WriteOutput("Failed to init delay workers.\n");
        return QUIC_STATUS_INTERNAL_ERROR;
    }
}

Verification

Created and tested a mock implementation that simulates the initialization failure scenario, confirming that:

• Successfully initialized DelayWorkers are properly shut down
• Uninitialized DelayWorkers are safely handled by Shutdown()
• Memory is properly deallocated
• No crashes or undefined behavior occurs

The fix is more comprehensive than the original suggestion as it also handles allocation failure and follows the existing destructor cleanup pattern for consistency.

Fixes #5206.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.64%. Comparing base (2623c07) to head (d519690).
Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5213      +/-   ##
==========================================
- Coverage   86.74%   85.64%   -1.11%     
==========================================
  Files          59       59              
  Lines       18330    18330              
==========================================
- Hits        15901    15698     -203     
- Misses       2429     2632     +203     

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