1/**************************************************************************/
2/* thread.h */
3/**************************************************************************/
4/* This file is part of: */
5/* GODOT ENGINE */
6/* https://godotengine.org */
7/**************************************************************************/
8/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
9/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
10/* */
11/* Permission is hereby granted, free of charge, to any person obtaining */
12/* a copy of this software and associated documentation files (the */
13/* "Software"), to deal in the Software without restriction, including */
14/* without limitation the rights to use, copy, modify, merge, publish, */
15/* distribute, sublicense, and/or sell copies of the Software, and to */
16/* permit persons to whom the Software is furnished to do so, subject to */
17/* the following conditions: */
18/* */
19/* The above copyright notice and this permission notice shall be */
20/* included in all copies or substantial portions of the Software. */
21/* */
22/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
23/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
24/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
25/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
26/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
27/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
28/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
29/**************************************************************************/
30
31#include "platform_config.h"
32// Define PLATFORM_THREAD_OVERRIDE in your platform's `platform_config.h`
33// to use a custom Thread implementation defined in `platform/[your_platform]/platform_thread.h`
34// Overriding the platform implementation is required in some proprietary platforms
35#ifdef PLATFORM_THREAD_OVERRIDE
36#include "platform_thread.h"
37#else
38
39#ifndef THREAD_H
40#define THREAD_H
41
42#include "core/templates/safe_refcount.h"
43#include "core/typedefs.h"
44
45#include <thread>
46
47class String;
48
49class Thread {
50public:
51 typedef void (*Callback)(void *p_userdata);
52
53 typedef uint64_t ID;
54
55 enum : ID {
56 UNASSIGNED_ID = 0,
57 MAIN_ID = 1
58 };
59
60 enum Priority {
61 PRIORITY_LOW,
62 PRIORITY_NORMAL,
63 PRIORITY_HIGH
64 };
65
66 struct Settings {
67 Priority priority;
68 Settings() { priority = PRIORITY_NORMAL; }
69 };
70
71 struct PlatformFunctions {
72 Error (*set_name)(const String &) = nullptr;
73 void (*set_priority)(Thread::Priority) = nullptr;
74 void (*init)() = nullptr;
75 void (*wrapper)(Thread::Callback, void *) = nullptr;
76 void (*term)() = nullptr;
77 };
78
79private:
80 friend class Main;
81
82 ID id = UNASSIGNED_ID;
83 static SafeNumeric<uint64_t> id_counter;
84 static thread_local ID caller_id;
85 std::thread thread;
86
87 static void callback(ID p_caller_id, const Settings &p_settings, Thread::Callback p_callback, void *p_userdata);
88
89 static PlatformFunctions platform_functions;
90
91 static void make_main_thread() { caller_id = MAIN_ID; }
92 static void release_main_thread() { caller_id = UNASSIGNED_ID; }
93
94public:
95 static void _set_platform_functions(const PlatformFunctions &p_functions);
96
97 _FORCE_INLINE_ ID get_id() const { return id; }
98 // get the ID of the caller thread
99 _FORCE_INLINE_ static ID get_caller_id() {
100 if (unlikely(caller_id == UNASSIGNED_ID)) {
101 caller_id = id_counter.increment();
102 }
103 return caller_id;
104 }
105 // get the ID of the main thread
106 _FORCE_INLINE_ static ID get_main_id() { return MAIN_ID; }
107
108 _FORCE_INLINE_ static bool is_main_thread() { return caller_id == MAIN_ID; } // Gain a tiny bit of perf here because there is no need to validate caller_id here, because only main thread will be set as 1.
109
110 static Error set_name(const String &p_name);
111
112 ID start(Thread::Callback p_callback, void *p_user, const Settings &p_settings = Settings());
113 bool is_started() const;
114 ///< waits until thread is finished, and deallocates it.
115 void wait_to_finish();
116
117 Thread();
118 ~Thread();
119};
120
121#endif // THREAD_H
122
123#endif // PLATFORM_THREAD_OVERRIDE
124