Add WITH_GC_MARK_ALIVE and WITH_GC_TIMING_STATS

python · nascheme · Oct 19, 2024 · Oct 20, 2024 · Oct 20, 2024 · Oct 21, 2024
commit 12ceba2e6ed365b1204141a9121b4adb6232fcd8
diff --git a/Include/internal/pycore_gc.h b/Include/internal/pycore_gc.h
@@ -282,6 +282,43 @@ struct gc_generation_stats {
    Py_ssize_t uncollectable;
 };

+// if true, enable GC timing statistics
+#define WITH_GC_TIMING_STATS 1
+
+#if WITH_GC_TIMING_STATS
+
+#define QUANTILE_COUNT 5
+#define MARKER_COUNT (QUANTILE_COUNT * 3 + 2)
+
+typedef struct {
+    double q[MARKER_COUNT];
+    double dn[MARKER_COUNT];
+    double np[MARKER_COUNT];
+    int n[MARKER_COUNT];
+    int count;
+    double max;
+} p2_engine;
+
+struct gc_timing_state {
+    /* timing statistics computed by P^2 algorithm */
+    p2_engine auto_all; // timing for all automatic collections
+    p2_engine auto_full; // timing for full (gen2) automatic collections
+    /* Total time spent inside cyclic GC */
+    PyTime_t gc_total_time;
+    /* Time spent inside incremental mark part of cyclic GC */
+    PyTime_t gc_mark_time;
+    /* Maximum GC pause time */
+    PyTime_t gc_max_pause;
+    /* Total number of times GC was run */
+    PyTime_t gc_runs;
+};
+#endif // WITH_GC_TIMING_STATS
+
+
+// if true, enable the GC mark alive feature
+#define WITH_GC_MARK_ALIVE 1
+
+#if WITH_GC_MARK_ALIVE
 struct gc_mark_state {
    /* Objects in oldest generation that have be determined to be alive */
    PyGC_Head old_alive;
@@ -297,15 +334,9 @@ struct gc_mark_state {
    int mark_steps;
    /* Number of steps available before full collection */
    int mark_steps_total;
-    /* Total time spent inside cyclic GC */
-    PyTime_t gc_total_time;
-    /* Time spent inside incremental mark part of cyclic GC */
-    PyTime_t gc_mark_time;
-    /* Maximum GC pause time */
-    PyTime_t gc_max_pause;
-    /* Total number of times GC was run */
-    PyTime_t gc_runs;
 };
+#endif // WITH_GC_MARK_ALIVE
+

 struct _gc_runtime_state {
    /* List of objects that still need to be cleaned up, singly linked
@@ -329,8 +360,14 @@ struct _gc_runtime_state {
    PyObject *garbage;
    /* a list of callbacks to be invoked when collection is performed */
    PyObject *callbacks;
+#if WITH_GC_MARK_ALIVE
    /* state for the incremental "mark alive" logic */
    struct gc_mark_state mark_state;
+#endif
+#if WITH_GC_TIMING_STATS
+    /* state for GC timing statistics */
+    struct gc_timing_state timing_state;
+#endif

    /* This is the number of objects that survived the last full
       collection. It approximates the number of long lived objects