binutils-gdb/gdb/python/py-event.h
Simon Farre 28ab59607e gdb/Python: Added ThreadExitedEvent
v6:
Fix comments.
Fix copyright
Remove unnecessary test suite stuff. save_var had to stay, as it mutates
some test suite state that otherwise fails.

v5:
Did what Tom Tromey requested in v4; which can be found here: https://pi.simark.ca/gdb-patches/87pmjm0xar.fsf@tromey.com/

v4:
Doc formatting fixed.

v3:
Eli:
Updated docs & NEWS to reflect new changes. Added
a reference from the .ptid attribute of the ThreadExitedEvent
to the ptid attribute of InferiorThread. To do this,
I've added an anchor to that attribute.

Tom:
Tom requested that I should probably just emit the thread object;
I ran into two issues for this, which I could not resolve in this patch;

1 - The Thread Object (the python type) checks it's own validity
by doing a comparison of it's `thread_info* thread` to nullptr. This
means that any access of it's attributes may (probably, since we are
in "async" land) throw Python exceptions because the thread has been
removed from the thread object. Therefore I've decided in v3 of this
patch to just emit most of the same fields that gdb.InferiorThread has, namely
global_num, name, num and ptid (the 3-attribute tuple provided by
gdb.InferiorThread.ptid).

2 - A python user can hold a global reference to an exiting thread. Thus
in order to have a ThreadExit event that can provide attribute access
reliably (both as a global reference, but also inside the thread exit
handler, as we can never guarantee that it's executed _before_ the
thread_info pointer is removed from the gdbpy thread object),
the `thread_info *` thread pointer must not be null. However, this
comes at the cost of gdb.InferiorThread believing it is "valid" - which means,
that if a user holds takes a global reference to that
exiting event thread object, they can some time later do `t.switch()` at which
point GDB will 'explode' so to speak.

v2:
Fixed white space issues and NULL/nullptr stuff,
as requested by Tom Tromey.

v1:
Currently no event is emitted for a thread exit.

This adds this functionality by emitting a new gdb.ThreadExitedEvent.

It currently provides four attributes:
- global_num: The GDB assigned global thread number
- num: the per-inferior thread number
- name: name of the thread or none if not set
- ptid: the PTID of the thread, a 3-attribute tuple, identical to
InferiorThread.ptid attribute

Added info to docs & the NEWS file as well.

Added test to test suite.

Fixed formatting.

Feedback wanted and appreciated.
2023-06-19 16:17:21 +02:00

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3.0 KiB
C

/* Python interface to inferior events.
Copyright (C) 2009-2023 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef PYTHON_PY_EVENT_H
#define PYTHON_PY_EVENT_H
#include "py-events.h"
#include "command.h"
#include "python-internal.h"
#include "inferior.h"
/* Declare all event types. */
#define GDB_PY_DEFINE_EVENT_TYPE(name, py_name, doc, base) \
extern PyTypeObject name##_event_object_type \
CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("event_object");
#include "py-event-types.def"
#undef GDB_PY_DEFINE_EVENT_TYPE
struct event_object
{
PyObject_HEAD
PyObject *dict;
};
extern int emit_continue_event (ptid_t ptid);
extern int emit_exited_event (const LONGEST *exit_code, struct inferior *inf);
/* For inferior function call events, discriminate whether event is
before or after the call. */
enum inferior_call_kind
{
/* Before the call */
INFERIOR_CALL_PRE,
/* after the call */
INFERIOR_CALL_POST,
};
extern int emit_inferior_call_event (inferior_call_kind kind,
ptid_t thread, CORE_ADDR addr);
extern int emit_register_changed_event (frame_info_ptr frame,
int regnum);
extern int emit_memory_changed_event (CORE_ADDR addr, ssize_t len);
extern int evpy_emit_event (PyObject *event,
eventregistry_object *registry);
/* Emits a thread exit event for THREAD */
extern int emit_thread_exit_event (thread_info * thread);
extern gdbpy_ref<> create_event_object (PyTypeObject *py_type);
/* thread events can either be thread specific or process wide. If gdb is
running in non-stop mode then the event is thread specific, otherwise
it is process wide.
This function returns the currently stopped thread in non-stop mode and
Py_None otherwise. */
extern gdbpy_ref<> py_get_event_thread (ptid_t ptid);
extern gdbpy_ref<> create_thread_event_object (PyTypeObject *py_type,
PyObject *thread);
extern int emit_new_objfile_event (struct objfile *objfile);
extern int emit_free_objfile_event (struct objfile *objfile);
extern int emit_clear_objfiles_event (void);
extern void evpy_dealloc (PyObject *self);
extern int evpy_add_attribute (PyObject *event,
const char *name, PyObject *attr)
CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
int gdbpy_initialize_event_generic (PyTypeObject *type, const char *name)
CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
#endif /* PYTHON_PY_EVENT_H */