luc14n0/glib
1
0
Fork 0
mirror of https://gitlab.gnome.org/GNOME/glib.git synced 2025-02-23 18:52:09 +01:00
Code Issues Packages Projects Releases Wiki Activity

Add some support code to GTask and a gtask-bt gdb command

Browse Source 
Whenever we invoke the GTask callback we push the current
task to a thread-local variable, and during construction we
pick this up as the "parent" of the task which lets us
construct call chains for GTask invocations.

Additionally, g_task_new is #defined to g_task_new_with_caller
with an additional __builtin_return_address(0) argument, which
gives the caller of the function that created the GTask, which
is typically the interesting user-level code.

We then read this back in a gtask-bt gdb command that prints a
backtrace like:

Thread 5 "gdbus" hit Breakpoint 1, g_task_new_with_caller (source_object=source_object@entry=0x1003e0130, cancellable=cancellable@entry=0x1003bbf00,
    callback=callback@entry=0x7fa8d0efa890 <_g_dbus_worker_do_read_cb>, callback_data=callback_data@entry=0x1003e3800, caller=0x7fa8d0ef8a81 <_g_dbus_worker_do_read_unlocked+161>) at gtask.c:743
743	{
(gdb) gtask-bt
 #1 GTask 0x7fa8b4004cc0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #2 GTask 0x7fa8b8012200 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #3 GTask 0x7fa8b80122f0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #4 GTask 0x7fa8b80123e0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #5 GTask 0x7fa8b80124d0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #6 GTask 0x7fa8b8012020 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #7 GTask 0x100c5c690 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #8 GTask 0x100988030 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #9 GTask 0x1009886c0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
      _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #10 GTask 0x1009883f0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #11 GTask 0x1009d1a00 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #12 GTask 0x100766930 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
 #13 GTask 0x10072dae0 - _g_dbus_worker_do_read_unlocked (gdbusprivate.c:854)
     _g_socket_read_with_control_messages -> _g_dbus_worker_do_read_cb
This commit is contained in:
Alexander Larsson 2017-08-29 12:54:09 +02:00
parent 728857e261
commit 6fb5b6d0f2
3 changed files with 154 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

135
gio/gtask.c
View File

@ -27,6 +27,8 @@
#include "glibintl.h"
#undef g_task_new
/**
* SECTION:gtask
* @short_description: Cancellable synchronous or asynchronous task
@ -544,6 +546,11 @@ struct _GTask {
gpointer task_data;
GDestroyNotify task_data_destroy;
GTask *invoke_stack_parent;
GTask *parent;
guint n_children;
gpointer caller;
GMainContext *context;
gint64 creation_time;
gint priority;
@ -601,6 +608,32 @@ static GSource *task_pool_manager;
static guint64 task_wait_time;
static gint tasks_running;
__thread GTask *g_task_invoke_stack = NULL;
static void
g_task_push (GTask *task)
{
g_assert (task->invoke_stack_parent == NULL);
task->invoke_stack_parent = g_task_invoke_stack;
g_task_invoke_stack = task;
}
static void
g_task_pop (GTask *task)
{
g_assert (g_task_invoke_stack == task);
g_task_invoke_stack = task->invoke_stack_parent;
task->invoke_stack_parent = NULL;
}
GTask * g_task_peek (void);
GTask *
g_task_peek (void)
{
return g_task_invoke_stack;
}
/* When the task pool fills up and blocks, and the program keeps
* queueing more tasks, we will slowly add more threads to the pool
* (in case the existing tasks are trying to queue subtasks of their
@ -617,10 +650,51 @@ static gint tasks_running;
#define G_TASK_WAIT_TIME_MULTIPLIER 1.03
#define G_TASK_WAIT_TIME_MAX (30 * 60 * 1000000)
static GList *all_tasks = NULL;
G_LOCK_DEFINE_STATIC (all_tasks);
static int
g_task_depth (GTask *task)
{
if (task->parent)
return 1 + g_task_depth (task->parent);
return 1;
}
static void
g_task_init (GTask *task)
{
GTask *parent;
G_LOCK (all_tasks);
all_tasks = g_list_prepend (all_tasks, task);
G_UNLOCK (all_tasks);
task->check_cancellable = TRUE;
parent = g_task_peek ();
if (parent)
{
task->parent = g_object_ref (parent);
parent->n_children++;
g_print ("GTask %p created with parent %p (depth %d)\n", task, parent, g_task_depth (task));
}
}
gpointer * g_tasks_get (void);
gpointer *
g_tasks_get (void)
{
GPtrArray *array = g_ptr_array_new ();
GList *l;
G_LOCK (all_tasks);
for (l = all_tasks; l != NULL; l = l->next)
g_ptr_array_add (array, l->data);
g_ptr_array_add (array, NULL);
G_UNLOCK (all_tasks);
return g_ptr_array_free (array, FALSE);
}
static void
@ -628,6 +702,16 @@ g_task_finalize (GObject *object)
{
GTask *task = G_TASK (object);
G_LOCK (all_tasks);
all_tasks = g_list_remove (all_tasks, task);
G_UNLOCK (all_tasks);
if (task->parent)
{
g_print ("GTask %p freed with parent %p\n", task, task->parent);
task->parent->n_children--;
g_clear_object (&task->parent);
}
g_clear_object (&task->source_object);
g_clear_object (&task->cancellable);
@ -652,6 +736,35 @@ g_task_finalize (GObject *object)
G_OBJECT_CLASS (g_task_parent_class)->finalize (object);
}
GTask *
g_task_new_with_caller (gpointer source_object,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer callback_data,
gpointer caller)
{
GTask *task;
GSource *source;
task = g_object_new (G_TYPE_TASK, NULL);
task->source_object = source_object ? g_object_ref (source_object) : NULL;
task->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
task->caller = caller;
task->callback = callback;
task->callback_data = callback_data;
task->context = g_main_context_ref_thread_default ();
source = g_main_current_source ();
if (source)
task->creation_time = g_source_get_time (source);
TRACE (GIO_TASK_NEW (task, source_object, cancellable,
callback, callback_data));
return task;
}
/**
* g_task_new:
* @source_object: (nullable) (type GObject): the #GObject that owns
@ -687,24 +800,7 @@ g_task_new (gpointer source_object,
GAsyncReadyCallback callback,
gpointer callback_data)
{
GTask *task;
GSource *source;
task = g_object_new (G_TYPE_TASK, NULL);
task->source_object = source_object ? g_object_ref (source_object) : NULL;
task->cancellable = cancellable ? g_object_ref (cancellable) : NULL;
task->callback = callback;
task->callback_data = callback_data;
task->context = g_main_context_ref_thread_default ();
source = g_main_current_source ();
if (source)
task->creation_time = g_source_get_time (source);
TRACE (GIO_TASK_NEW (task, source_object, cancellable,
callback, callback_data));
return task;
return g_task_new_with_caller (source_object, cancellable, callback, callback_data, NULL);
}
/**
@ -1131,7 +1227,6 @@ g_task_get_source_tag (GTask *task)
return task->source_tag;
}
static void
g_task_return_now (GTask *task)
{
@ -1139,6 +1234,7 @@ g_task_return_now (GTask *task)
task->callback_data));
g_main_context_push_thread_default (task->context);
g_task_push (task);
if (task->callback != NULL)
{
@ -1150,6 +1246,7 @@ g_task_return_now (GTask *task)
task->completed = TRUE;
g_object_notify (G_OBJECT (task), "completed");
g_task_pop (task);
g_main_context_pop_thread_default (task->context);
}

9
gio/gtask.h
View File

@ -44,6 +44,12 @@ GTask *g_task_new (gpointer source_object,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer callback_data);
GLIB_AVAILABLE_IN_2_54
GTask *g_task_new_with_caller (gpointer source_object,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer callback_data,
gpointer caller);
GLIB_AVAILABLE_IN_2_36
void g_task_report_error (gpointer source_object,
@ -155,6 +161,9 @@ gboolean g_task_had_error (GTask *task);
GLIB_AVAILABLE_IN_2_44
gboolean g_task_get_completed (GTask *task);
#define g_task_new(_o,_c,_cb,_cbd) g_task_new_with_caller(_o,_c,_cb,_cbd,__builtin_return_address(0))
G_END_DECLS
#endif /* __G_TASK_H__ */

29
glib/glib_gdb.py
View File

@ -259,3 +259,32 @@ class ForeachCommand (gdb.Command):
func(var, container, command)
ForeachCommand ()
class GTaskBacktrace (gdb.Command):
"""GTask backtrace"""
def __init__ (self):
super (GTaskBacktrace, self).__init__ ("gtask-bt", gdb.COMMAND_STACK)
def decode_pc_function(self, value):
block = gdb.block_for_pc(int(value))
return block.function.name
def decode_pc(self, value):
f = self.decode_pc_function(value)
sal = gdb.find_pc_line(int(value))
return "%s (%s:%d)" % (f, sal.symtab.filename, sal.line)
def print_task_frame(self, frame, task):
print ("#%d GTask %s - %s\n %s -> %s" % (
frame,
hex(int(task)),
self.decode_pc(task["caller"]),
self.decode_pc_function(task["source_tag"]),
self.decode_pc_function(task["callback"])))
def invoke (self, arg, from_tty):
task = gdb.lookup_global_symbol("g_task_invoke_stack").value()
frame = 1
while int(task) != 0:
self.print_task_frame(frame, task)
task = task["parent"]
frame = frame + 1
GTaskBacktrace()