diff options
-rw-r--r-- | Makefile | 5 | ||||
-rw-r--r-- | bin/base_task.c | 133 |
2 files changed, 137 insertions, 1 deletions
@@ -6,7 +6,7 @@ LIBS= ./liblitmus.a | |||
6 | LIB_OBJ= litmus.o syscalls.o sched_trace.o adaptive.o edf-hsb.o task.o kernel_iface.o | 6 | LIB_OBJ= litmus.o syscalls.o sched_trace.o adaptive.o edf-hsb.o task.o kernel_iface.o |
7 | 7 | ||
8 | TARGETS = showsched iotest set_rt_mode run timeout rt_launch edfhsb liblitmus.a \ | 8 | TARGETS = showsched iotest set_rt_mode run timeout rt_launch edfhsb liblitmus.a \ |
9 | wait_test np_test stdump mode_test | 9 | wait_test np_test stdump mode_test base_task |
10 | 10 | ||
11 | vpath %.h include/ | 11 | vpath %.h include/ |
12 | vpath %.c src/ bin/ | 12 | vpath %.c src/ bin/ |
@@ -15,6 +15,9 @@ all: ${TARGETS} | |||
15 | clean: | 15 | clean: |
16 | rm -f *.o *~ ${TARGETS} | 16 | rm -f *.o *~ ${TARGETS} |
17 | 17 | ||
18 | base_task: base_task.o liblitmus.a | ||
19 | cc -static -o base_task base_task.o ${LIBS} | ||
20 | |||
18 | wait_test: wait_test.o litmus.h liblitmus.a | 21 | wait_test: wait_test.o litmus.h liblitmus.a |
19 | cc -static -o wait_test wait_test.o ${LIBS} | 22 | cc -static -o wait_test wait_test.o ${LIBS} |
20 | 23 | ||
diff --git a/bin/base_task.c b/bin/base_task.c new file mode 100644 index 0000000..e5f50b1 --- /dev/null +++ b/bin/base_task.c | |||
@@ -0,0 +1,133 @@ | |||
1 | /* based_task.c -- A basic real-time task skeleton. | ||
2 | * | ||
3 | * This (by itself useless) task demos how to setup LITMUS^RT real-time task. | ||
4 | * | ||
5 | * Compile: | ||
6 | * | ||
7 | */ | ||
8 | |||
9 | |||
10 | /* First, we include standard headers. | ||
11 | * Generally speaking, a LITMUS^RT real-time task can perform any | ||
12 | * system call, etc., but no real-time guarantees can be made if a | ||
13 | * system call blocks. To be on the safe side, only use I/O for debugging | ||
14 | * purposes and from non-real-time sections. | ||
15 | */ | ||
16 | #include <stdio.h> | ||
17 | #include <stdlib.h> | ||
18 | |||
19 | /* Second, we include the LITMUS^RT user space library header. | ||
20 | * This header, part of liblitmus, provides the user space API of | ||
21 | * LITMUS^RT. | ||
22 | */ | ||
23 | #include "litmus.h" | ||
24 | |||
25 | /* Next, we define period and execution cost to be constant. | ||
26 | * These are only constants for convenience in this example, they can be | ||
27 | * determined at run time, e.g., from command line parameters. | ||
28 | */ | ||
29 | #define PERIOD 100 | ||
30 | #define EXEC_COST 10 | ||
31 | |||
32 | /* Declare the periodically invoked job. | ||
33 | * Returns 1 -> task should exit. | ||
34 | * 0 -> task should continue. | ||
35 | */ | ||
36 | int job(void); | ||
37 | |||
38 | /* typically, main() does a couple of things: | ||
39 | * 1) parse command line parameters, etc. | ||
40 | * 2) Setup work environment. | ||
41 | * 3) Setup real-time parameters. | ||
42 | * 4) Transition to real-time mode. | ||
43 | * 5) Invoke periodic or sporadic jobs. | ||
44 | * 6) Transition to background mode. | ||
45 | * 7) Clean up and exit. | ||
46 | * | ||
47 | * The following main() function provides the basic skeleton of a single-threaded | ||
48 | * LITMUS^RT real-time task. In a real program, all the return values should be | ||
49 | * checked for errors. | ||
50 | */ | ||
51 | int main(int argc, char** argv) | ||
52 | { | ||
53 | int do_exit; | ||
54 | |||
55 | /* The task is in background mode upon startup. */ | ||
56 | |||
57 | |||
58 | /***** | ||
59 | * 1) Command line paramter parsing would be done here. | ||
60 | */ | ||
61 | |||
62 | |||
63 | |||
64 | /***** | ||
65 | * 2) Work environment (e.g., global data structures, file data, etc.) would | ||
66 | * be setup here. | ||
67 | */ | ||
68 | |||
69 | |||
70 | |||
71 | /***** | ||
72 | * 3) Setup real-time parameters. | ||
73 | * In this example, we create a sporadic task that does not specify a | ||
74 | * target partition (and thus is intended to run under global scheduling). | ||
75 | * If this were to execute under a partitioned scheduler, it would be assigned | ||
76 | * to the first partition (since partitioning is performed offline). | ||
77 | */ | ||
78 | init_litmus(); | ||
79 | sporadic_global(EXEC_COST, PERIOD); | ||
80 | |||
81 | /* To specify a partition, use sporadic_partitioned(). | ||
82 | * Example: | ||
83 | * | ||
84 | * sporadic_partitioned(EXEC_COST, PERIOD, CPU); | ||
85 | * | ||
86 | * where CPU ranges from 0 to "Number of CPUs" - 1. | ||
87 | */ | ||
88 | |||
89 | |||
90 | |||
91 | /***** | ||
92 | * 4) Transition to real-time mode. | ||
93 | */ | ||
94 | task_mode(LITMUS_RT_TASK); | ||
95 | |||
96 | /* The task is now executing as a real-time task if the call didn't fail. | ||
97 | */ | ||
98 | |||
99 | |||
100 | |||
101 | /***** | ||
102 | * 5) Invoke real-time jobs. | ||
103 | */ | ||
104 | do { | ||
105 | /* Wait until the next job is released. */ | ||
106 | sleep_next_period(); | ||
107 | /* Invoke job. */ | ||
108 | do_exit = job(); | ||
109 | } while (!do_exit); | ||
110 | |||
111 | |||
112 | |||
113 | /***** | ||
114 | * 6) Transition to background mode. | ||
115 | */ | ||
116 | task_mode(BACKGROUND_TASK); | ||
117 | |||
118 | |||
119 | |||
120 | /***** | ||
121 | * 7) Clean up and exit. | ||
122 | */ | ||
123 | return 0; | ||
124 | } | ||
125 | |||
126 | |||
127 | int job(void) | ||
128 | { | ||
129 | /* Do real-time calculation. */ | ||
130 | |||
131 | /* Don't exit. */ | ||
132 | return 0; | ||
133 | } | ||