add comment

Author: kumaraditya303

Python/instrumentation.c

@@ -39,7 +39,8 @@
 #endif
 
 #ifdef Py_GIL_DISABLED
-
+// MODIFY_BYTECODE modifies thread local bytecode of all threads,
+// so it must be called with the world stopped.
 #define MODIFY_BYTECODE(code, func, ...)                       \
     do {                                                       \
         ASSERT_WORLD_STOPPED();                                \
@@ -671,6 +672,7 @@ de_instrument(PyCodeObject *code, _Py_CODEUNIT *bytecode, _PyCoMonitoringData *m
 {
     assert(event != PY_MONITORING_EVENT_INSTRUCTION);
     assert(event != PY_MONITORING_EVENT_LINE);
+    ASSERT_WORLD_STOPPED();
 
     _Py_CODEUNIT *instr = &bytecode[i];
     uint8_t *opcode_ptr = &instr->op.code;
@@ -700,6 +702,7 @@ static void
 de_instrument_line(PyCodeObject *code, _Py_CODEUNIT *bytecode, _PyCoMonitoringData *monitoring,
                    int i)
 {
+    ASSERT_WORLD_STOPPED();
     _Py_CODEUNIT *instr = &bytecode[i];
     int opcode = instr->op.code;
     if (opcode != INSTRUMENTED_LINE) {
@@ -724,6 +727,7 @@ static void
 de_instrument_per_instruction(PyCodeObject *code, _Py_CODEUNIT *bytecode,
                               _PyCoMonitoringData *monitoring, int i)
 {
+    ASSERT_WORLD_STOPPED();
     _Py_CODEUNIT *instr = &bytecode[i];
     uint8_t *opcode_ptr = &instr->op.code;
     int opcode = *opcode_ptr;
@@ -749,6 +753,7 @@ de_instrument_per_instruction(PyCodeObject *code, _Py_CODEUNIT *bytecode,
 static void
 instrument(PyCodeObject *code, _Py_CODEUNIT *bytecode, _PyCoMonitoringData *monitoring, int i)
 {
+    ASSERT_WORLD_STOPPED();
     _Py_CODEUNIT *instr = &bytecode[i];
     uint8_t *opcode_ptr = &instr->op.code;
     int opcode =*opcode_ptr;
@@ -778,6 +783,7 @@ instrument(PyCodeObject *code, _Py_CODEUNIT *bytecode, _PyCoMonitoringData *moni
 static void
 instrument_line(PyCodeObject *code, _Py_CODEUNIT *bytecode, _PyCoMonitoringData *monitoring, int i)
 {
+    ASSERT_WORLD_STOPPED();
     uint8_t *opcode_ptr = &bytecode[i].op.code;
     int opcode = *opcode_ptr;
     if (opcode == INSTRUMENTED_LINE) {
@@ -792,6 +798,7 @@ static void
 instrument_per_instruction(PyCodeObject *code, _Py_CODEUNIT *bytecode,
                            _PyCoMonitoringData *monitoring, int i)
 {
+    ASSERT_WORLD_STOPPED();
     _Py_CODEUNIT *instr = &bytecode[i];
     uint8_t *opcode_ptr = &instr->op.code;
     int opcode = *opcode_ptr;