gdb/gdb-python-gil.patch
2019-12-31 23:48:37 +08:00

109 lines
3.8 KiB
Diff

diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -232,6 +232,14 @@ returned as a string. The default is @code{False}, in which case the
return value is @code{None}. If @var{to_string} is @code{True}, the
@value{GDBN} virtual terminal will be temporarily set to unlimited width
and height, and its pagination will be disabled; @pxref{Screen Size}.
+
+The @var{release_gil} flag specifies whether @value{GDBN} ought to
+release the Python GIL before executing the command. This is useful
+in multi-threaded Python programs where by default the Python
+interpreter will acquire the GIL and lock other threads from
+executing. After the command has completed executing in @value{GDBN}
+the Python GIL is reacquired. This flag must be a boolean value. If
+omitted, it defaults to @code{False}.
@end defun
@findex gdb.breakpoints
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -148,6 +148,8 @@ typedef int Py_ssize_t;
#define PyGILState_Release(ARG) ((void)(ARG))
#define PyEval_InitThreads()
#define PyThreadState_Swap(ARG) ((void)(ARG))
+#define PyEval_SaveThread() ((void)(ARG))
+#define PyEval_RestoreThread(ARG) ((void)(ARG))
#define PyEval_ReleaseLock()
#endif
diff --git a/gdb/python/python.c b/gdb/python/python.c
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -556,12 +556,16 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
{
const char *arg;
PyObject *from_tty_obj = NULL, *to_string_obj = NULL;
- int from_tty, to_string;
- static const char *keywords[] = { "command", "from_tty", "to_string", NULL };
+ int from_tty, to_string, release_gil;
+ static const char *keywords[] = {"command", "from_tty", "to_string", "release_gil", NULL };
+ PyObject *release_gil_obj = NULL;
+ /* Initialize it just to avoid a GCC false warning. */
+ PyThreadState *state = NULL;
- if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!O!", keywords, &arg,
+ if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!O!O!", keywords, &arg,
&PyBool_Type, &from_tty_obj,
- &PyBool_Type, &to_string_obj))
+ &PyBool_Type, &to_string_obj,
+ &PyBool_Type, &release_gil_obj))
return NULL;
from_tty = 0;
@@ -582,6 +586,15 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
to_string = cmp;
}
+ release_gil = 0;
+ if (release_gil_obj)
+ {
+ int cmp = PyObject_IsTrue (release_gil_obj);
+ if (cmp < 0)
+ return NULL;
+ release_gil = cmp;
+ }
+
std::string to_string_res;
TRY
@@ -602,6 +615,13 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
counted_command_line lines = read_command_lines_1 (reader, 1, nullptr);
+ /* In the case of long running GDB commands, allow the user to
+ release the Python GIL acquired by Python. Restore the GIL
+ after the command has completed before handing back to
+ Python. */
+ if (release_gil)
+ state = PyEval_SaveThread();
+
scoped_restore save_async = make_scoped_restore (&current_ui->async, 0);
scoped_restore save_uiout = make_scoped_restore (&current_uiout);
@@ -617,10 +637,22 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw)
from_tty);
else
execute_control_commands (lines.get (), from_tty);
+
+ /* Reacquire the GIL if it was released earlier. */
+ if (release_gil)
+ PyEval_RestoreThread (state);
}
CATCH (except, RETURN_MASK_ALL)
{
- GDB_PY_HANDLE_EXCEPTION (except);
+ if (except.reason < 0)
+ {
+ /* Reacquire the GIL if it was released earlier. */
+ if (release_gil)
+ PyEval_RestoreThread (state);
+
+ gdbpy_convert_exception (except);
+ return NULL;
+ }
}
END_CATCH