SDL  2.0
SDL_threadprio.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #ifdef __LINUX__
24 
25 #include "SDL_stdinc.h"
26 
27 #if !SDL_THREADS_DISABLED
28 #include <sys/time.h>
29 #include <sys/resource.h>
30 #include <pthread.h>
31 #include "SDL_system.h"
32 
33 #if SDL_USE_LIBDBUS
34 #include "SDL_dbus.h"
35 /* d-bus queries to org.freedesktop.RealtimeKit1. */
36 #define RTKIT_DBUS_NODE "org.freedesktop.RealtimeKit1"
37 #define RTKIT_DBUS_PATH "/org/freedesktop/RealtimeKit1"
38 #define RTKIT_DBUS_INTERFACE "org.freedesktop.RealtimeKit1"
39 
40 static pthread_once_t rtkit_initialize_once = PTHREAD_ONCE_INIT;
41 static Sint32 rtkit_min_nice_level = -20;
42 
43 static void
44 rtkit_initialize()
45 {
46  SDL_DBusContext *dbus = SDL_DBus_GetContext();
47 
48  /* Try getting minimum nice level: this is often greater than PRIO_MIN (-20). */
49  if (!dbus || !SDL_DBus_QueryPropertyOnConnection(dbus->system_conn, RTKIT_DBUS_NODE, RTKIT_DBUS_PATH, RTKIT_DBUS_INTERFACE, "MinNiceLevel",
50  DBUS_TYPE_INT32, &rtkit_min_nice_level)) {
51  rtkit_min_nice_level = -20;
52  }
53 }
54 
55 static SDL_bool
56 rtkit_setpriority(pid_t thread, int nice_level)
57 {
58  Uint64 ui64 = (Uint64)thread;
59  Sint32 si32 = (Sint32)nice_level;
60  SDL_DBusContext *dbus = SDL_DBus_GetContext();
61 
62  pthread_once(&rtkit_initialize_once, rtkit_initialize);
63 
64  if (si32 < rtkit_min_nice_level)
65  si32 = rtkit_min_nice_level;
66 
67  if (!dbus || !SDL_DBus_CallMethodOnConnection(dbus->system_conn,
68  RTKIT_DBUS_NODE, RTKIT_DBUS_PATH, RTKIT_DBUS_INTERFACE, "MakeThreadHighPriority",
69  DBUS_TYPE_UINT64, &ui64, DBUS_TYPE_INT32, &si32, DBUS_TYPE_INVALID,
70  DBUS_TYPE_INVALID)) {
71  return SDL_FALSE;
72  }
73  return SDL_TRUE;
74 }
75 #endif /* dbus */
76 #endif /* threads */
77 
78 
79 /* this is a public symbol, so it has to exist even if threads are disabled. */
80 int
81 SDL_LinuxSetThreadPriority(Sint64 threadID, int priority)
82 {
83 #if SDL_THREADS_DISABLED
84  return SDL_Unsupported();
85 #else
86  if (setpriority(PRIO_PROCESS, (id_t)threadID, priority) == 0) {
87  return 0;
88  }
89 
90 #if SDL_USE_LIBDBUS
91  /* Note that this fails if you're trying to set high priority
92  and you don't have root permission. BUT DON'T RUN AS ROOT!
93 
94  You can grant the ability to increase thread priority by
95  running the following command on your application binary:
96  sudo setcap 'cap_sys_nice=eip' <application>
97 
98  Let's try setting priority with RealtimeKit...
99 
100  README and sample code at: http://git.0pointer.net/rtkit.git
101  */
102  if (rtkit_setpriority((pid_t)threadID, priority)) {
103  return 0;
104  }
105 #endif
106 
107  return SDL_SetError("setpriority() failed");
108 #endif
109 }
110 
111 #endif /* __LINUX__ */
112 
113 /* vi: set ts=4 sw=4 expandtab: */
Sint32
int32_t Sint32
Definition: SDL_stdinc.h:197
SDL_LinuxSetThreadPriority
#define SDL_LinuxSetThreadPriority
Definition: SDL_dynapi_overrides.h:673
SDL_dbus.h
SDL_FALSE
Definition: SDL_stdinc.h:163
SDL_bool
SDL_bool
Definition: SDL_stdinc.h:161
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:30
Uint64
uint64_t Uint64
Definition: SDL_stdinc.h:216
SDL_TRUE
Definition: SDL_stdinc.h:164
SDL_system.h
SDL_stdinc.h
SDL_Unsupported
#define SDL_Unsupported()
Definition: SDL_error.h:53
Sint64
int64_t Sint64
Definition: SDL_stdinc.h:210