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comparison src/timer/nds/SDL_systimer.c @ 5113:481dabb098ef

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Improved timer implementation The new timer model is formalized as using a separate thread to handle timer callbacks. This was the case on almost every platform before, but it's now a requirement, and simplifies the implementation and makes it perform consistently across platforms. Goals: * Minimize timer thread blocking * Dispatch timers as accurately as possible * SDL_AddTimer() and SDL_RemoveTimer() are completely threadsafe * SDL_RemoveTimer() doesn't crash with a timer that's expired or removed
author Sam Lantinga <slouken@libsdl.org>
date Thu, 27 Jan 2011 14:45:06 -0800
parents f7b03b6838cb
children b530ef003506
comparison
equal deleted inserted replaced
5112:0846f18eb625 5113:481dabb098ef
25 25
26 #include <nds.h> 26 #include <nds.h>
27 #include <nds/timers.h> 27 #include <nds/timers.h>
28 28
29 #include "SDL_timer.h" 29 #include "SDL_timer.h"
30 #include "../SDL_timer_c.h"
31 #include "../SDL_systimer.h"
32 30
33 /* Data to handle a single periodic alarm */ 31
34 static int timer_alive = 0; 32 static volatile Uint32 timer_ticks;
35 static Uint32 timer_ticks; 33
34 static void
35 NDS_TimerInterrupt(void)
36 {
37 timer_ticks++;
38 }
36 39
37 void 40 void
38 SDL_StartTicks(void) 41 SDL_StartTicks(void)
39 { 42 {
40 if (!timer_alive) { 43 timer_ticks = 0;
41 SDL_SYS_TimerInit();
42 SDL_SYS_StartTimer();
43 }
44 44
45 timer_ticks = 0; 45 TIMER_CR(3) = TIMER_DIV_1024 | TIMER_IRQ_REQ;
46 TIMER_DATA(3) = TIMER_FREQ_1024(1000);
47 irqSet(IRQ_TIMER3, NDS_TimerInterrupt);
48 irqEnable(IRQ_TIMER3);
46 } 49 }
47 50
48 Uint32 51 Uint32
49 SDL_GetTicks(void) 52 SDL_GetTicks(void)
50 { 53 {
59 if ((SDL_GetTicks() - start) >= ms) 62 if ((SDL_GetTicks() - start) >= ms)
60 break; 63 break;
61 } 64 }
62 } 65 }
63 66
64 static int 67 #endif /* SDL_TIMER_NDS */
65 RunTimer(void *unused)
66 {
67 while (timer_alive) {
68 if (SDL_timer_running) {
69 }
70 SDL_Delay(1);
71 }
72 return (0);
73 }
74 68
75 void
76 NDS_TimerInterrupt(void)
77 {
78 timer_ticks++;
79 }
80
81 /* This is only called if the event thread is not running */
82 int
83 SDL_SYS_TimerInit(void)
84 {
85 timer_alive = 1;
86 timer_ticks = 0;
87 TIMER_CR(3) = TIMER_DIV_1024 | TIMER_IRQ_REQ;
88 TIMER_DATA(3) = TIMER_FREQ_1024(1000);
89 irqSet(IRQ_TIMER3, NDS_TimerInterrupt);
90 irqEnable(IRQ_TIMER3);
91 return 0;
92 }
93
94 void
95 SDL_SYS_TimerQuit(void)
96 {
97 if (timer_alive) {
98 TIMER_CR(3) = 0;
99 }
100 timer_alive = 0;
101 irqDisable(IRQ_TIMER3);
102 }
103
104 int
105 SDL_SYS_StartTimer(void)
106 {
107 TIMER_CR(3) |= TIMER_ENABLE;
108 return 0;
109 }
110
111 void
112 SDL_SYS_StopTimer(void)
113 {
114 TIMER_CR(3) &= ~TIMER_ENABLE;
115 return;
116 }
117
118
119 #endif /* SDL_TIMER_NDS */
120 /* vi: set ts=4 sw=4 expandtab: */ 69 /* vi: set ts=4 sw=4 expandtab: */