Timer: Generic BLI_timer with Python wrapper

There is a new `bpy.app.timers` api.
For more details, look in the Python API documentation.

Reviewers: campbellbarton

Differential Revision: https://developer.blender.org/D3994

9 files changed, 487 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_timer.h b/source/blender/blenlib/BLI_timer.h
new file mode 100644
index 00000000000..6dfb13fd738
--- /dev/null
+++ b/source/blender/blenlib/BLI_timer.h
@@ -0,0 +1,58 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2008 Blender Foundation.
+ * All rights reserved.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __BLI_TIMER_H__
+#define __BLI_TIMER_H__
+
+#include "BLI_utildefines.h"
+
+/** \file BLI_timer.h
+ *  \ingroup BLI
+ */
+
+/* ret < 0: the timer will be removed.
+ * ret >= 0: the timer will be called again in ret seconds */
+typedef double (*BLI_timer_func)(uintptr_t uuid, void *user_data);
+typedef void (*BLI_timer_data_free)(uintptr_t uuid, void *user_data);
+
+/* `func(...) < 0`: The timer will be removed.
+ * `func(...) >= 0`: The function will be called again in that many seconds. */
+void BLI_timer_register(
+        uintptr_t uuid,
+        BLI_timer_func func,
+        void *user_data,
+        BLI_timer_data_free user_data_free,
+        double first_interval,
+        bool persistent);
+
+bool BLI_timer_is_registered(uintptr_t uuid);
+
+/* Returns False when the timer does not exist (anymore). */
+bool BLI_timer_unregister(uintptr_t uuid);
+
+/* Execute all registered functions that are due. */
+void BLI_timer_execute(void);
+
+void BLI_timer_free(void);
+
+#endif  /* __BLI_TIMER_H__ */
diff --git a/source/blender/blenlib/CMakeLists.txt b/source/blender/blenlib/CMakeLists.txt
index 5e6764a5c0e..91887c1ef5e 100644
--- a/source/blender/blenlib/CMakeLists.txt
+++ b/source/blender/blenlib/CMakeLists.txt
@@ -55,6 +55,7 @@ set(SRC
 	intern/BLI_memarena.c
 	intern/BLI_memiter.c
 	intern/BLI_mempool.c
+	intern/BLI_timer.c
 	intern/DLRB_tree.c
 	intern/array_store.c
 	intern/array_store_utils.c
@@ -214,6 +215,7 @@ set(SRC
 	BLI_task.h
 	BLI_threads.h
 	BLI_timecode.h
+	BLI_timer.h
 	BLI_utildefines.h
 	BLI_utildefines_iter.h
 	BLI_utildefines_stack.h
diff --git a/source/blender/blenlib/intern/BLI_timer.c b/source/blender/blenlib/intern/BLI_timer.c
new file mode 100644
index 00000000000..875b667de46
--- /dev/null
+++ b/source/blender/blenlib/intern/BLI_timer.c
@@ -0,0 +1,186 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file, with exception of below:
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blenlib/intern/BLI_timer.c
+ *  \ingroup bli
+ */
+
+#include "BLI_timer.h"
+#include "BLI_listbase.h"
+#include "BLI_callbacks.h"
+
+#include "MEM_guardedalloc.h"
+#include "PIL_time.h"
+
+#define GET_TIME() PIL_check_seconds_timer()
+
+typedef struct TimedFunction {
+	struct TimedFunction *next, *prev;
+	BLI_timer_func func;
+	BLI_timer_data_free user_data_free;
+	void *user_data;
+	double next_time;
+	uintptr_t uuid;
+	bool tag_removal;
+	bool persistent;
+} TimedFunction;
+
+typedef struct TimerContainer {
+	ListBase funcs;
+	bool file_load_cb_registered;
+} TimerContainer;
+
+static TimerContainer GlobalTimer = { 0 };
+
+static void ensure_callback_is_registered(void);
+
+void BLI_timer_register(
+        uintptr_t uuid,
+        BLI_timer_func func,
+        void *user_data,
+        BLI_timer_data_free user_data_free,
+        double first_interval,
+        bool persistent)
+{
+	ensure_callback_is_registered();
+
+	TimedFunction *timed_func = MEM_callocN(sizeof(TimedFunction), __func__);
+	timed_func->func = func;
+	timed_func->user_data_free = user_data_free;
+	timed_func->user_data = user_data;
+	timed_func->next_time = GET_TIME() + first_interval;
+	timed_func->tag_removal = false;
+	timed_func->persistent = persistent;
+	timed_func->uuid = uuid;
+
+	BLI_addtail(&GlobalTimer.funcs, timed_func);
+}
+
+static void clear_user_data(TimedFunction *timed_func)
+{
+	if (timed_func->user_data_free) {
+		timed_func->user_data_free(timed_func->uuid, timed_func->user_data);
+		timed_func->user_data_free = NULL;
+	}
+}
+
+bool BLI_timer_unregister(uintptr_t uuid)
+{
+	LISTBASE_FOREACH(TimedFunction *, timed_func, &GlobalTimer.funcs) {
+		if (timed_func->uuid == uuid) {
+			if (timed_func->tag_removal) {
+				return false;
+			}
+			else {
+				timed_func->tag_removal = true;
+				clear_user_data(timed_func);
+				return true;
+			}
+		}
+	}
+	return false;
+}
+
+bool BLI_timer_is_registered(uintptr_t uuid)
+{
+	LISTBASE_FOREACH(TimedFunction *, timed_func, &GlobalTimer.funcs) {
+		if (timed_func->uuid == uuid && !timed_func->tag_removal) {
+			return true;
+		}
+	}
+	return false;
+}
+
+static void execute_functions_if_necessary(void)
+{
+	double current_time = GET_TIME();
+
+	LISTBASE_FOREACH(TimedFunction *, timed_func, &GlobalTimer.funcs) {
+		if (timed_func->tag_removal) continue;
+		if (timed_func->next_time > current_time) continue;
+
+		double ret = timed_func->func(timed_func->uuid, timed_func->user_data);
+
+		if (ret < 0) {
+			timed_func->tag_removal = true;
+		}
+		else {
+			timed_func->next_time = current_time + ret;
+		}
+	}
+}
+
+static void remove_tagged_functions(void)
+{
+	for (TimedFunction *timed_func = GlobalTimer.funcs.first; timed_func; ) {
+		TimedFunction *next = timed_func->next;
+		if (timed_func->tag_removal) {
+			clear_user_data(timed_func);
+			BLI_freelinkN(&GlobalTimer.funcs, timed_func);
+		}
+		timed_func = next;
+	}
+}
+
+void BLI_timer_execute()
+{
+	execute_functions_if_necessary();
+	remove_tagged_functions();
+}
+
+void BLI_timer_free()
+{
+	LISTBASE_FOREACH(TimedFunction *, timed_func, &GlobalTimer.funcs) {
+		timed_func->tag_removal = true;
+	}
+
+	remove_tagged_functions();
+}
+
+struct Main;
+struct ID;
+static void remove_non_persistent_functions(struct Main *UNUSED(_1), struct ID *UNUSED(_2), void *UNUSED(_3))
+{
+	LISTBASE_FOREACH(TimedFunction *, timed_func, &GlobalTimer.funcs) {
+		if (!timed_func->persistent) {
+			timed_func->tag_removal = true;
+		}
+	}
+}
+
+static bCallbackFuncStore load_post_callback = {
+	NULL, NULL, /* next, prev */
+	remove_non_persistent_functions, /* func */
+	NULL, /* arg */
+	0 /* alloc */
+};
+
+static void ensure_callback_is_registered()
+{
+	if (!GlobalTimer.file_load_cb_registered) {
+		BLI_callback_add(&load_post_callback, BLI_CB_EVT_LOAD_POST);
+		GlobalTimer.file_load_cb_registered = true;
+	}
+}
diff --git a/source/blender/python/intern/CMakeLists.txt b/source/blender/python/intern/CMakeLists.txt
index b561504505b..bd7306cddf2 100644
--- a/source/blender/python/intern/CMakeLists.txt
+++ b/source/blender/python/intern/CMakeLists.txt
@@ -58,6 +58,7 @@ set(SRC
 	bpy_app_opensubdiv.c
 	bpy_app_openvdb.c
 	bpy_app_sdl.c
+	bpy_app_timers.c
 	bpy_app_translations.c
 	bpy_capi_utils.c
 	bpy_driver.c
@@ -96,6 +97,7 @@ set(SRC
 	bpy_app_opensubdiv.h
 	bpy_app_openvdb.h
 	bpy_app_sdl.h
+	bpy_app_timers.h
 	bpy_app_translations.h
 	bpy_capi_utils.h
 	bpy_driver.h
diff --git a/source/blender/python/intern/bpy_app.c b/source/blender/python/intern/bpy_app.c
index d8c74bdf565..bba9eee0316 100644
--- a/source/blender/python/intern/bpy_app.c
+++ b/source/blender/python/intern/bpy_app.c
@@ -49,6 +49,7 @@
 
 /* modules */
 #include "bpy_app_icons.h"
+#include "bpy_app_timers.h"
 
 #include "BLI_utildefines.h"
 
@@ -124,6 +125,7 @@ static PyStructSequence_Field app_info_fields[] = {
 
 	/* Modules (not struct sequence). */
 	{(char *)"icons", (char *)"Manage custom icons"},
+	{(char *)"timers", (char *)"Manage timers"},
 	{NULL},
 };
 
@@ -137,6 +139,7 @@ PyDoc_STRVAR(bpy_app_doc,
 "\n"
 "   bpy.app.handlers.rst\n"
 "   bpy.app.icons.rst\n"
+"   bpy.app.timers.rst\n"
 "   bpy.app.translations.rst\n"
 );
 
@@ -220,6 +223,7 @@ static PyObject *make_app_info(void)
 
 	/* modules */
 	SetObjItem(BPY_app_icons_module());
+	SetObjItem(BPY_app_timers_module());
 
 #undef SetIntItem
 #undef SetStrItem
diff --git a/source/blender/python/intern/bpy_app_timers.c b/source/blender/python/intern/bpy_app_timers.c
new file mode 100644
index 00000000000..cd0e57200ec
--- /dev/null
+++ b/source/blender/python/intern/bpy_app_timers.c
@@ -0,0 +1,199 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/python/intern/bpy_app_timers.c
+ *  \ingroup pythonintern
+ */
+
+#include <Python.h>
+#include "BLI_utildefines.h"
+#include "BLI_timer.h"
+#include "PIL_time.h"
+
+#include "BPY_extern.h"
+#include "bpy_app_timers.h"
+
+#include "../generic/py_capi_utils.h"
+#include "../generic/python_utildefines.h"
+
+
+static double handle_returned_value(PyObject *function, PyObject *ret)
+{
+	if (ret == NULL) {
+		PyErr_PrintEx(0);
+		PyErr_Clear();
+		return -1;
+	}
+
+	if (ret == Py_None) {
+		return -1;
+	}
+
+	double value = PyFloat_AsDouble(ret);
+	if (value == -1.0f && PyErr_Occurred()) {
+		PyErr_Clear();
+		printf("Error: 'bpy.app.timers' callback ");
+		PyObject_Print(function, stdout, Py_PRINT_RAW);
+		printf(" did not return None or float.\n");
+		return -1;
+	}
+
+	if (value < 0.0) {
+		value = 0.0;
+	}
+
+	return value;
+}
+
+static double py_timer_execute(uintptr_t UNUSED(uuid), void *user_data)
+{
+	PyObject *function = user_data;
+
+	PyGILState_STATE gilstate;
+	gilstate = PyGILState_Ensure();
+
+	PyObject *py_ret = PyObject_CallObject(function, NULL);
+	double ret = handle_returned_value(function, py_ret);
+
+	PyGILState_Release(gilstate);
+
+	return ret;
+}
+
+static void py_timer_free(uintptr_t UNUSED(uuid), void *user_data)
+{
+	PyObject *function = user_data;
+
+	PyGILState_STATE gilstate;
+	gilstate = PyGILState_Ensure();
+
+	Py_DECREF(function);
+
+	PyGILState_Release(gilstate);
+}
+
+
+PyDoc_STRVAR(bpy_app_timers_register_doc,
+".. function:: register(function, first_interval=0, persistent=False)\n"
+"\n"
+"   Add a new function that will be called after the specified amount of seconds.\n"
+"   The function gets no arguments and is expected to return either None or a float.\n"
+"   If ``None`` is returned, the timer will be unregistered.\n"
+"   A returned number specifies the delay until the function is called again.\n"
+"   ``functools.partial`` can be used to assign some parameters.\n"
+"\n"
+"   :arg function: The function that should called.\n"
+"   :type function: Callable[[], Union[float, None]]\n"
+"   :arg first_interval: Seconds until the callback should be called the first time.\n"
+"   :type first_interval: float\n"
+"   :arg persistent: Don't remove timer when a new file is loaded.\n"
+"   :type persistent: bool\n"
+);
+static PyObject *bpy_app_timers_register(PyObject *UNUSED(self), PyObject *args, PyObject *kw)
+{
+	PyObject *function;
+	double first_interval = 0;
+	int persistent = false;
+
+	static const char *_keywords[] = {"function", "first_interval", "persistent", NULL};
+	static _PyArg_Parser _parser = {"O|$dp:register", _keywords, 0};
+	if (!_PyArg_ParseTupleAndKeywordsFast(
+	            args, kw, &_parser,
+	            &function, &first_interval, &persistent))
+	{
+		return NULL;
+	}
+
+	if (!PyCallable_Check(function)) {
+		PyErr_SetString(PyExc_TypeError, "function is not callable");
+		return NULL;
+	}
+
+	Py_INCREF(function);
+	BLI_timer_register(
+	        (intptr_t)function,
+	        py_timer_execute, function, py_timer_free,
+	        first_interval, persistent);
+	Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(bpy_app_timers_unregister_doc,
+".. function:: unregister(function)\n"
+"\n"
+"   Unregister timer.\n"
+"\n"
+"   :arg function: Function to unregister.\n"
+"   :type function: function\n"
+);
+static PyObject *bpy_app_timers_unregister(PyObject *UNUSED(self), PyObject *function)
+{
+	if (!BLI_timer_unregister((intptr_t)function)) {
+		PyErr_SetString(PyExc_ValueError, "Error: function is not registered");
+		return NULL;
+	}
+	Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(bpy_app_timers_is_registered_doc,
+".. function:: is_registered(function)\n"
+"\n"
+"   Check if this function is registered as a timer.\n"
+"\n"
+"   :arg function: Function to check.\n"
+"   :type function: int\n"
+"   :return: True when this function is registered, otherwise False.\n"
+"   :rtype: bool\n"
+);
+static PyObject *bpy_app_timers_is_registered(PyObject *UNUSED(self), PyObject *function)
+{
+	bool ret = BLI_timer_is_registered((intptr_t)function);
+	return PyBool_FromLong(ret);
+}
+
+
+static struct PyMethodDef M_AppTimers_methods[] = {
+	{"register", (PyCFunction)bpy_app_timers_register,
+	 METH_VARARGS | METH_KEYWORDS, bpy_app_timers_register_doc},
+	{"unregister", (PyCFunction)bpy_app_timers_unregister,
+	 METH_O, bpy_app_timers_unregister_doc},
+	{"is_registered", (PyCFunction)bpy_app_timers_is_registered,
+	 METH_O, bpy_app_timers_is_registered_doc},
+	{NULL, NULL, 0, NULL}
+};
+
+static struct PyModuleDef M_AppTimers_module_def = {
+	PyModuleDef_HEAD_INIT,
+	"bpy.app.timers", /* m_name */
+	NULL,  /* m_doc */
+	0,     /* m_size */
+	M_AppTimers_methods,  /* m_methods */
+	NULL,  /* m_reload */
+	NULL,  /* m_traverse */
+	NULL,  /* m_clear */
+	NULL,  /* m_free */
+};
+
+PyObject *BPY_app_timers_module(void)
+{
+	PyObject *sys_modules = PyImport_GetModuleDict();
+	PyObject *mod = PyModule_Create(&M_AppTimers_module_def);
+	PyDict_SetItem(sys_modules, PyModule_GetNameObject(mod), mod);
+	return mod;
+}
diff --git a/source/blender/python/intern/bpy_app_timers.h b/source/blender/python/intern/bpy_app_timers.h
new file mode 100644
index 00000000000..ddf0e258e67
--- /dev/null
+++ b/source/blender/python/intern/bpy_app_timers.h
@@ -0,0 +1,30 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * 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 2
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/python/intern/bpy_app_timers.h
+ *  \ingroup pythonintern
+ */
+
+#ifndef __BPY_APP_TIMERS_H__
+#define __BPY_APP_TIMERS_H__
+
+PyObject *BPY_app_timers_module(void);
+
+#endif /* __BPY_APP_TIMERS_H__ */
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 576f5470069..fc2832ee4cb 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -51,6 +51,7 @@
 #include "BLI_dynstr.h"
 #include "BLI_utildefines.h"
 #include "BLI_math.h"
+#include "BLI_timer.h"
 
 #include "BKE_context.h"
 #include "BKE_idprop.h"
@@ -372,6 +373,8 @@ void wm_event_do_notifiers(bContext *C)
 	if (wm == NULL)
 		return;
 
+	BLI_timer_execute();
+
 	/* disable? - keep for now since its used for window level notifiers. */
 #if 1
 	/* cache & catch WM level notifiers, such as frame change, scene/screen set */
diff --git a/source/blender/windowmanager/intern/wm_init_exit.c b/source/blender/windowmanager/intern/wm_init_exit.c
index e6114b44221..9fca91d2f3f 100644
--- a/source/blender/windowmanager/intern/wm_init_exit.c
+++ b/source/blender/windowmanager/intern/wm_init_exit.c
@@ -54,6 +54,7 @@
 #include "BLI_string.h"
 #include "BLI_threads.h"
 #include "BLI_utildefines.h"
+#include "BLI_timer.h"
 
 #include "BLO_writefile.h"
 #include "BLO_undofile.h"
@@ -460,6 +461,8 @@ void WM_exit_ext(bContext *C, const bool do_python)
 		}
 	}
 
+	BLI_timer_free();
+
 	WM_paneltype_clear();
 
 	BKE_addon_pref_type_free();