Fix all_subinterpreters handling

Author: sergey-miryanov

Modules/_remote_debugging/gc_stats.h

@@ -13,6 +13,11 @@ extern "C" {
 
 #include "_remote_debugging.h"
 
+typedef struct {
+    PyObject *result;
+    bool all_interpreters;
+} ReadGCStatsContext;
+
 static int
 read_gc_stats(struct gc_stats *stats, unsigned long iid, PyObject *result)
 {
@@ -115,6 +120,11 @@ get_gc_stats_from_interpreter_state(RuntimeOffsets *offsets,
                                     unsigned long iid,
                                     void *context)
 {
+    ReadGCStatsContext *ctx = (ReadGCStatsContext *)context;
+    if (!ctx->all_interpreters && iid > 0) {
+        return 0;
+    }
+
     uintptr_t gc_stats_addr;
     uintptr_t gc_stats_pointer_address = interpreter_state_addr
         + offsets->debug_offsets.interpreter_state.gc
@@ -137,8 +147,7 @@ get_gc_stats_from_interpreter_state(RuntimeOffsets *offsets,
         return -1;
     }
 
-    PyObject *result = context;
-    if (read_gc_stats(&stats, iid, result) < 0) {
+    if (read_gc_stats(&stats, iid, ctx->result) < 0) {
         return -1;
     }
 

Modules/_remote_debugging/interpreters.c

@@ -52,7 +52,6 @@ iterate_interpreters(
     }
 
     while (interpreter_state_addr != 0) {
-
         if (0 > _Py_RemoteDebug_ReadRemoteMemory(
                     &offsets->handle,
                     interpreter_state_addr + interpreter_id_offset,
@@ -62,7 +61,6 @@ iterate_interpreters(
             return -1;
         }
 
-
         // Call the processor function for this interpreter
         if (processor(offsets, interpreter_state_addr, iid, context) < 0) {
             return -1;

Modules/_remote_debugging/module.c

@@ -1904,7 +1904,11 @@ _remote_debugging_get_gc_stats_impl(PyObject *module, int pid,
     if (result == NULL) {
         goto error;
     }
-    if (0 > iterate_interpreters(&offsets, get_gc_stats_from_interpreter_state, result)) {
+    ReadGCStatsContext ctx = {
+        .result = result,
+        .all_interpreters = all_interpreters,
+    };
+    if (0 > iterate_interpreters(&offsets, get_gc_stats_from_interpreter_state, &ctx)) {
         goto error;
     }