gh-138122: Add thread status statistics to flamegraph profiler (#141900)

Co-authored-by: ivonastojanovic <80911834+ivonastojanovic@users.noreply.github.com>

Lib/profiling/sampling/collector.py

@@ -19,7 +19,6 @@ def export(self, filename):
         """Export collected data to a file."""
 
     def _iter_all_frames(self, stack_frames, skip_idle=False):
-        """Iterate over all frame stacks from all interpreters and threads."""
         for interpreter_info in stack_frames:
             for thread_info in interpreter_info.threads:
                 # skip_idle now means: skip if thread is not actively running
@@ -33,3 +32,83 @@ def _iter_all_frames(self, stack_frames, skip_idle=False):
                 frames = thread_info.frame_info
                 if frames:
                     yield frames, thread_info.thread_id
+
+    def _is_gc_frame(self, frame):
+        if isinstance(frame, tuple):
+            funcname = frame[2] if len(frame) >= 3 else ""
+        else:
+            funcname = getattr(frame, "funcname", "")
+
+        return "<GC>" in funcname or "gc_collect" in funcname
+
+    def _collect_thread_status_stats(self, stack_frames):
+        """Collect aggregate and per-thread status statistics from a sample.
+
+        Returns:
+            tuple: (aggregate_status_counts, has_gc_frame, per_thread_stats)
+                - aggregate_status_counts: dict with has_gil, on_cpu, etc.
+                - has_gc_frame: bool indicating if any thread has GC frames
+                - per_thread_stats: dict mapping thread_id to per-thread counts
+        """
+        status_counts = {
+            "has_gil": 0,
+            "on_cpu": 0,
+            "gil_requested": 0,
+            "unknown": 0,
+            "total": 0,
+        }
+        has_gc_frame = False
+        per_thread_stats = {}
+
+        for interpreter_info in stack_frames:
+            threads = getattr(interpreter_info, "threads", [])
+            for thread_info in threads:
+                status_counts["total"] += 1
+
+                # Track thread status using bit flags
+                status_flags = getattr(thread_info, "status", 0)
+
+                if status_flags & THREAD_STATUS_HAS_GIL:
+                    status_counts["has_gil"] += 1
+                if status_flags & THREAD_STATUS_ON_CPU:
+                    status_counts["on_cpu"] += 1
+                if status_flags & THREAD_STATUS_GIL_REQUESTED:
+                    status_counts["gil_requested"] += 1
+                if status_flags & THREAD_STATUS_UNKNOWN:
+                    status_counts["unknown"] += 1
+
+                # Track per-thread statistics
+                thread_id = getattr(thread_info, "thread_id", None)
+                if thread_id is not None:
+                    if thread_id not in per_thread_stats:
+                        per_thread_stats[thread_id] = {
+                            "has_gil": 0,
+                            "on_cpu": 0,
+                            "gil_requested": 0,
+                            "unknown": 0,
+                            "total": 0,
+                            "gc_samples": 0,
+                        }
+
+                    thread_stats = per_thread_stats[thread_id]
+                    thread_stats["total"] += 1
+
+                    if status_flags & THREAD_STATUS_HAS_GIL:
+                        thread_stats["has_gil"] += 1
+                    if status_flags & THREAD_STATUS_ON_CPU:
+                        thread_stats["on_cpu"] += 1
+                    if status_flags & THREAD_STATUS_GIL_REQUESTED:
+                        thread_stats["gil_requested"] += 1
+                    if status_flags & THREAD_STATUS_UNKNOWN:
+                        thread_stats["unknown"] += 1
+
+                    # Check for GC frames in this thread
+                    frames = getattr(thread_info, "frame_info", None)
+                    if frames:
+                        for frame in frames:
+                            if self._is_gc_frame(frame):
+                                thread_stats["gc_samples"] += 1
+                                has_gc_frame = True
+                                break
+
+        return status_counts, has_gc_frame, per_thread_stats