Add non-throwing TryGetStartTime and TryGetParentProcessId helpers to avoid first-chance exceptions during enumeration

Co-authored-by: jkotas <[email protected]>

Author: Copilot

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/Process.Win32.cs

@@ -328,13 +328,65 @@ private bool WaitForInputIdleCore(int milliseconds)
         /// </remarks>
         private bool IsParentOf(Process possibleChild)
         {
-            try
+            // Use non-throwing helpers to avoid first-chance exceptions during enumeration.
+            // This is critical for performance when a debugger is attached.
+            if (!TryGetStartTime(out DateTime myStartTime) ||
+                !possibleChild.TryGetStartTime(out DateTime childStartTime) ||
+                !possibleChild.TryGetParentProcessId(out int childParentId))
             {
-                return StartTime < possibleChild.StartTime && Id == possibleChild.ParentProcessId;
+                return false;
             }
-            catch (Exception e) when (IsProcessInvalidException(e))
+
+            return myStartTime < childStartTime && Id == childParentId;
+        }
+
+        /// <summary>
+        /// Try to get the process start time without throwing exceptions.
+        /// </summary>
+        private bool TryGetStartTime(out DateTime startTime)
+        {
+            startTime = default;
+            using (SafeProcessHandle handle = GetProcessHandle(Interop.Advapi32.ProcessOptions.PROCESS_QUERY_LIMITED_INFORMATION, false))
             {
-                return false;
+                if (handle.IsInvalid)
+                {
+                    return false;
+                }
+
+                ProcessThreadTimes processTimes = new ProcessThreadTimes();
+                if (!Interop.Kernel32.GetProcessTimes(handle,
+                    out processTimes._create, out processTimes._exit,
+                    out processTimes._kernel, out processTimes._user))
+                {
+                    return false;
+                }
+
+                startTime = processTimes.StartTime;
+                return true;
+            }
+        }
+
+        /// <summary>
+        /// Try to get the parent process ID without throwing exceptions.
+        /// </summary>
+        private unsafe bool TryGetParentProcessId(out int parentProcessId)
+        {
+            parentProcessId = 0;
+            using (SafeProcessHandle handle = GetProcessHandle(Interop.Advapi32.ProcessOptions.PROCESS_QUERY_LIMITED_INFORMATION, false))
+            {
+                if (handle.IsInvalid)
+                {
+                    return false;
+                }
+
+                Interop.NtDll.PROCESS_BASIC_INFORMATION info;
+                if (Interop.NtDll.NtQueryInformationProcess(handle, Interop.NtDll.ProcessBasicInformation, &info, (uint)sizeof(Interop.NtDll.PROCESS_BASIC_INFORMATION), out _) != 0)
+                {
+                    return false;
+                }
+
+                parentProcessId = (int)info.InheritedFromUniqueProcessId;
+                return true;
             }
         }
 
@@ -359,14 +411,14 @@ private unsafe int ParentProcessId
 
         private bool Equals(Process process)
         {
-            try
-            {
-                return Id == process.Id && StartTime == process.StartTime;
-            }
-            catch (Exception e) when (IsProcessInvalidException(e))
+            // Use non-throwing helper to avoid first-chance exceptions during enumeration.
+            if (!TryGetStartTime(out DateTime myStartTime) ||
+                !process.TryGetStartTime(out DateTime otherStartTime))
             {
                 return false;
             }
+
+            return Id == process.Id && myStartTime == otherStartTime;
         }
 
         private List<Exception>? KillTree()