2 files changed, 338 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 7def948..ba1668a 100644
--- a/Makefile
+++ b/Makefile
@@ -71,7 +71,7 @@ AR  := ${CROSS_COMPILE}${AR}
 
 all     = lib ${rt-apps}
 rt-apps = cycles base_task rt_launch rtspin release_ts measure_syscall \
-          base_mt_task runtests dgl_test
+          base_mt_task runtests dglspin
 
 .PHONY: all lib clean dump-config TAGS tags cscope help
 
@@ -203,7 +203,8 @@ obj-cycles = cycles.o
 
 obj-base_task = base_task.o
 
-obj-dgl_test = dgl_test.o
+obj-dglspin = dglspin.o common.o
+lib-dglspin = -lrt
 
 obj-base_mt_task = base_mt_task.o
 ldf-base_mt_task = -pthread
diff --git a/bin/dglspin.c b/bin/dglspin.c
new file mode 100644
index 0000000..805fd85
--- /dev/null
+++ b/bin/dglspin.c
@@ -0,0 +1,335 @@
+#include <sys/time.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <assert.h>
+#include <fcntl.h>
+
+
+#include "litmus.h"
+#include "common.h"
+
+
+
+static void usage(char *error) {
+        fprintf(stderr, "Error: %s\n", error);
+        fprintf(stderr,
+                "Usage:\n"
+                "       rt_spin [COMMON-OPTS] WCET PERIOD DURATION\n"
+                "       rt_spin [COMMON-OPTS] -f FILE [-o COLUMN] WCET PERIOD\n"
+                "       rt_spin -l\n"
+                "\n"
+                "COMMON-OPTS = [-w] [-p PARTITION] [-c CLASS] [-s SCALE]\n"
+                "\n"
+                "WCET and PERIOD are milliseconds, DURATION is seconds.\n");
+        exit(EXIT_FAILURE);
+}
+
+/*
+ * returns the character that made processing stop, newline or EOF
+ */
+static int skip_to_next_line(FILE *fstream)
+{
+        int ch;
+        for (ch = fgetc(fstream); ch != EOF && ch != '\n'; ch = fgetc(fstream));
+        return ch;
+}
+
+static void skip_comments(FILE *fstream)
+{
+        int ch;
+        for (ch = fgetc(fstream); ch == '#'; ch = fgetc(fstream))
+                skip_to_next_line(fstream);
+        ungetc(ch, fstream);
+}
+
+static void get_exec_times(const char *file, const int column,
+                           int *num_jobs,    double **exec_times)
+{
+        FILE *fstream;
+        int  cur_job, cur_col, ch;
+        *num_jobs = 0;
+
+        fstream = fopen(file, "r");
+        if (!fstream)
+                bail_out("could not open execution time file");
+
+        /* figure out the number of jobs */
+        do {
+                skip_comments(fstream);
+                ch = skip_to_next_line(fstream);
+                if (ch != EOF)
+                        ++(*num_jobs);
+        } while (ch != EOF);
+
+        if (-1 == fseek(fstream, 0L, SEEK_SET))
+                bail_out("rewinding file failed");
+
+        /* allocate space for exec times */
+        *exec_times = calloc(*num_jobs, sizeof(*exec_times));
+        if (!*exec_times)
+                bail_out("couldn't allocate memory");
+
+        for (cur_job = 0; cur_job < *num_jobs && !feof(fstream); ++cur_job) {
+
+                skip_comments(fstream);
+
+                for (cur_col = 1; cur_col < column; ++cur_col) {
+                        /* discard input until we get to the column we want */
+                        fscanf(fstream, "%*s,");
+                }
+
+                /* get the desired exec. time */
+                if (1 != fscanf(fstream, "%lf", (*exec_times)+cur_job)) {
+                        fprintf(stderr, "invalid execution time near line %d\n",
+                                        cur_job);
+                        exit(EXIT_FAILURE);
+                }
+
+                skip_to_next_line(fstream);
+        }
+
+        assert(cur_job == *num_jobs);
+        fclose(fstream);
+}
+
+#define NUMS 4096
+static int num[NUMS];
+static char* progname;
+
+static int loop_once(void)
+{
+        int i, j = 0;
+        for (i = 0; i < NUMS; i++)
+                j += num[i]++;
+        return j;
+}
+
+static int loop_for(double exec_time, double emergency_exit, int mask)
+{
+        double last_loop = 0, loop_start;
+        int tmp = 0;
+
+        double start = cputime();
+        double now = cputime();
+
+        while (now + last_loop < start + exec_time) {
+                loop_start = now;
+        dynamic_group_lock(mask);
+                tmp += loop_once();
+        dynamic_group_unlock(mask);
+                now = cputime();
+                last_loop = now - loop_start;
+                if (emergency_exit && wctime() > emergency_exit) {
+                        /* Oops --- this should only be possible if the execution time tracking
+                         * is broken in the LITMUS^RT kernel. */
+                        fprintf(stderr, "!!! rtspin/%d emergency exit!\n", getpid());
+                        fprintf(stderr, "Something is seriously wrong! Do not ignore this.\n");
+                        break;
+                }
+        }
+
+        return tmp;
+}
+
+
+static void debug_delay_loop(void)
+{
+        double start, end, delay;
+
+        while (1) {
+                for (delay = 0.5; delay > 0.01; delay -= 0.01) {
+                        start = wctime();
+                        loop_for(delay, 0, 1);
+                        end = wctime();
+                        printf("%6.4fs: looped for %10.8fs, delta=%11.8fs, error=%7.4f%%\n",
+                               delay,
+                               end - start,
+                               end - start - delay,
+                               100 * (end - start - delay) / delay);
+                }
+        }
+}
+
+static int job(double exec_time, double program_end, int mask)
+{
+        if (wctime() > program_end)
+                return 0;
+        else {
+                loop_for(exec_time, program_end + 1, mask);
+                sleep_next_period();
+                return 1;
+        }
+}
+
+#define OPTSTR "p:c:wlveo:f:s:q:"
+
+int main(int argc, char** argv)
+{
+        int ret;
+        lt_t wcet;
+        lt_t period;
+        double wcet_ms, period_ms;
+        unsigned int priority = LITMUS_LOWEST_PRIORITY;
+        int migrate = 0;
+        int cpu = 0;
+        int opt;
+        int wait = 0;
+        int test_loop = 0;
+        int column = 1;
+        const char *file = NULL;
+        int want_enforcement = 0;
+        double duration = 0, start;
+        double *exec_times = NULL;
+        double scale = 1.0;
+        task_class_t class = RT_CLASS_HARD;
+        int cur_job, num_jobs;
+
+    int fd, od_org, od_new, mask;
+
+        progname = argv[0];
+
+        while ((opt = getopt(argc, argv, OPTSTR)) != -1) {
+                switch (opt) {
+                case 'w':
+                        wait = 1;
+                        break;
+                case 'p':
+                        cpu = atoi(optarg);
+                        migrate = 1;
+                        break;
+                case 'q':
+                        priority = atoi(optarg);
+                        if (!litmus_is_valid_fixed_prio(priority))
+                                usage("Invalid priority.");
+                        break;
+                case 'c':
+                        class = str2class(optarg);
+                        if (class == -1)
+                                usage("Unknown task class.");
+                        break;
+                case 'e':
+                        want_enforcement = 1;
+                        break;
+                case 'l':
+                        test_loop = 1;
+                        break;
+                case 'o':
+                        column = atoi(optarg);
+                        break;
+                case 'f':
+                        file = optarg;
+                        break;
+                case 's':
+                        scale = atof(optarg);
+                        break;
+                case ':':
+                        usage("Argument missing.");
+                        break;
+                case '?':
+                default:
+                        usage("Bad argument.");
+                        break;
+                }
+        }
+
+        if (test_loop) {
+                debug_delay_loop();
+                return 0;
+        }
+
+        if (file) {
+                get_exec_times(file, column, &num_jobs, &exec_times);
+
+                if (argc - optind < 2)
+                        usage("Arguments missing.");
+
+                for (cur_job = 0; cur_job < num_jobs; ++cur_job) {
+                        /* convert the execution time to seconds */
+                        duration += exec_times[cur_job] * 0.001;
+                }
+        } else {
+                /*
+                 * if we're not reading from the CSV file, then we need
+                 * three parameters
+                 */
+                if (argc - optind < 3)
+                        usage("Arguments missing.");
+        }
+
+        wcet_ms   = atof(argv[optind + 0]);
+        period_ms = atof(argv[optind + 1]);
+
+        wcet   = wcet_ms * __NS_PER_MS;
+        period = period_ms * __NS_PER_MS;
+        if (wcet <= 0)
+                usage("The worst-case execution time must be a "
+                                "positive number.");
+        if (period <= 0)
+                usage("The period must be a positive number.");
+        if (!file && wcet > period) {
+                usage("The worst-case execution time must not "
+                                "exceed the period.");
+        }
+
+        if (!file)
+                duration  = atof(argv[optind + 2]);
+        else if (file && num_jobs > 1)
+                duration += period_ms * 0.001 * (num_jobs - 1);
+
+        if (migrate) {
+                ret = be_migrate_to(cpu);
+                if (ret < 0)
+                        bail_out("could not migrate to target partition");
+        }
+
+        ret = sporadic_task_ns(wcet, period, 0, cpu, priority, class,
+                               want_enforcement ? PRECISE_ENFORCEMENT
+                                                : NO_ENFORCEMENT,
+                               migrate);
+        if (ret < 0)
+                bail_out("could not setup rt task params");
+
+    fd = open(".dgl_locks", O_RDONLY | O_CREAT);
+
+        init_litmus();
+
+        ret = task_mode(LITMUS_RT_TASK);
+        if (ret != 0)
+                bail_out("could not become RT task");
+
+        if (wait) {
+                ret = wait_for_ts_release();
+                if (ret != 0)
+                        bail_out("wait_for_ts_release()");
+        }
+
+    od_org = open_new_dgl_sem(fd, 0);
+    od_new = attach_dgl_sem(fd, 1, od_org);
+    mask = (1<<od_org) & (1<<od_new);
+
+        start = wctime();
+
+        if (file) {
+                /* use times read from the CSV file */
+                for (cur_job = 0; cur_job < num_jobs; ++cur_job) {
+                        /* convert job's length to seconds */
+                        job(exec_times[cur_job] * 0.001 * scale,
+                                        start + duration, mask);
+                }
+        } else {
+                /* conver to seconds and scale */
+                while (job(wcet_ms * 0.001 * scale, start + duration, mask));
+        }
+
+        ret = task_mode(BACKGROUND_TASK);
+        if (ret != 0)
+                bail_out("could not become regular task (huh?)");
+
+        if (file)
+                free(exec_times);
+
+        return 0;
+}