1/*
2    SDL - Simple DirectMedia Layer
3    Copyright (C) 1997-2012 Sam Lantinga
4
5    This library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9
10    This library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14
15    You should have received a copy of the GNU Lesser General Public
16    License along with this library; if not, write to the Free Software
17    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18
19    Sam Lantinga
20    slouken@libsdl.org
21*/
22#include "SDL_config.h"
23
24#ifdef SDL_TIMER_RISCOS
25
26#include <stdio.h>
27#include <time.h>
28#include <sys/time.h>
29#include <unistd.h>
30#include <string.h>
31#include <errno.h>
32
33#include "SDL_timer.h"
34#include "../SDL_timer_c.h"
35
36#if SDL_THREADS_DISABLED
37/* Timer  SDL_arraysize(Timer ),start/reset time */
38static Uint32 timerStart;
39/* Timer running function */
40void RISCOS_CheckTimer();
41#else
42#include <pthread.h>
43extern Uint32 riscos_main_thread;
44extern int riscos_using_threads;
45extern Uint32 SDL_ThreadID();
46extern Uint32 SDL_EventThreadID(void);
47#endif
48
49
50extern void RISCOS_BackgroundTasks(void);
51
52/* The first ticks value of the application */
53clock_t start;
54
55void SDL_StartTicks(void)
56{
57	/* Set first ticks value */
58	start = clock();
59}
60
61Uint32 SDL_GetTicks (void)
62{
63	clock_t ticks;
64
65	ticks=clock()-start;
66
67
68#if CLOCKS_PER_SEC == 1000
69
70	return(ticks);
71
72#elif CLOCKS_PER_SEC == 100
73
74	return (ticks * 10);
75
76#else
77
78	return ticks*(1000/CLOCKS_PER_SEC);
79
80#endif
81
82}
83
84void SDL_Delay (Uint32 ms)
85{
86    Uint32 now,then,elapsed;
87#if !SDL_THREADS_DISABLED
88    int is_event_thread;
89    if (riscos_using_threads)
90    {
91       is_event_thread = 0;
92       if (SDL_EventThreadID())
93       {
94          if (SDL_EventThreadID() == SDL_ThreadID()) is_event_thread = 1;
95       } else if (SDL_ThreadID() == riscos_main_thread) is_event_thread = 1;
96    } else is_event_thread = 1;
97#endif
98
99        /*TODO: Next version of Unixlib may allow us to use usleep here */
100        /*      for non event threads */
101
102	/* Set the timeout interval - Linux only needs to do this once */
103	then = SDL_GetTicks();
104
105	do {
106		/* Do background tasks required while sleeping as we are not multithreaded */
107#if SDL_THREADS_DISABLED
108		RISCOS_BackgroundTasks();
109#else
110		/* For threaded build only run background tasks in event thread */
111		if (is_event_thread) RISCOS_BackgroundTasks();
112#endif
113
114		/* Calculate the time interval left (in case of interrupt) */
115		now = SDL_GetTicks();
116		elapsed = (now-then);
117		then = now;
118		if ( elapsed >= ms ) {
119			break;
120		}
121		ms -= elapsed;
122#if !SDL_THREADS_DISABLED
123            /* Need to yield to let other threads have a go */
124            if (riscos_using_threads) pthread_yield();
125#endif
126
127	} while ( 1 );
128}
129
130#if SDL_THREADS_DISABLED
131
132/* Non-threaded version of timer */
133
134int SDL_SYS_TimerInit(void)
135{
136	return(0);
137}
138
139void SDL_SYS_TimerQuit(void)
140{
141	SDL_SetTimer(0, NULL);
142}
143
144int SDL_SYS_StartTimer(void)
145{
146	timerStart = SDL_GetTicks();
147
148	return(0);
149}
150
151void SDL_SYS_StopTimer(void)
152{
153	/* Don't need to do anything as we use SDL_timer_running
154	   to detect if we need to check the timer */
155}
156
157
158void RISCOS_CheckTimer()
159{
160	if (SDL_timer_running && SDL_GetTicks() - timerStart >= SDL_alarm_interval)
161	{
162		Uint32 ms;
163
164		ms = SDL_alarm_callback(SDL_alarm_interval);
165		if ( ms != SDL_alarm_interval )
166		{
167			if ( ms )
168			{
169				SDL_alarm_interval = ROUND_RESOLUTION(ms);
170			} else
171			{
172				SDL_alarm_interval = 0;
173				SDL_timer_running = 0;
174			}
175		}
176		if (SDL_alarm_interval) timerStart = SDL_GetTicks();
177	}
178}
179
180#else
181
182/* Threaded version of timer - based on code for linux */
183
184#include "SDL_thread.h"
185
186/* Data to handle a single periodic alarm */
187static int timer_alive = 0;
188static SDL_Thread *timer = NULL;
189
190static int RunTimer(void *unused)
191{
192	while ( timer_alive ) {
193		if ( SDL_timer_running ) {
194			SDL_ThreadedTimerCheck();
195		}
196		SDL_Delay(1);
197	}
198	return(0);
199}
200
201/* This is only called if the event thread is not running */
202int SDL_SYS_TimerInit(void)
203{
204	timer_alive = 1;
205	timer = SDL_CreateThread(RunTimer, NULL);
206	if ( timer == NULL )
207		return(-1);
208	return(SDL_SetTimerThreaded(1));
209}
210
211void SDL_SYS_TimerQuit(void)
212{
213	timer_alive = 0;
214	if ( timer ) {
215		SDL_WaitThread(timer, NULL);
216		timer = NULL;
217	}
218}
219
220int SDL_SYS_StartTimer(void)
221{
222	SDL_SetError("Internal logic error: RISC OS uses threaded timer");
223	return(-1);
224}
225
226void SDL_SYS_StopTimer(void)
227{
228	return;
229}
230
231#endif /* SDL_THREADS_DISABLED */
232
233#endif /* SDL_TIMER_RISCOS */
234