diff options
Diffstat (limited to 'liblo/pthreads.2/tests/rwlock8.c')
| -rw-r--r-- | liblo/pthreads.2/tests/rwlock8.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/liblo/pthreads.2/tests/rwlock8.c b/liblo/pthreads.2/tests/rwlock8.c new file mode 100644 index 0000000..3db7287 --- /dev/null +++ b/liblo/pthreads.2/tests/rwlock8.c @@ -0,0 +1,205 @@ +/*
+ * rwlock8.c
+ *
+ * Hammer on a bunch of rwlocks to test robustness and fairness.
+ * Printed stats should be roughly even for each thread.
+ *
+ * Yield during each access to exercise lock contention code paths
+ * more than rwlock7.c does (particularly on uni-processor systems).
+ */
+
+#include "test.h"
+#include <sys/timeb.h>
+
+#ifdef __GNUC__
+#include <stdlib.h>
+#endif
+
+#define THREADS 5
+#define DATASIZE 7
+#define ITERATIONS 100000
+
+/*
+ * Keep statistics for each thread.
+ */
+typedef struct thread_tag {
+ int thread_num;
+ pthread_t thread_id;
+ int updates;
+ int reads;
+ int changed;
+ int seed;
+} thread_t;
+
+/*
+ * Read-write lock and shared data
+ */
+typedef struct data_tag {
+ pthread_rwlock_t lock;
+ int data;
+ int updates;
+} data_t;
+
+static thread_t threads[THREADS];
+static data_t data[DATASIZE];
+
+/*
+ * Thread start routine that uses read-write locks
+ */
+void *thread_routine (void *arg)
+{
+ thread_t *self = (thread_t*)arg;
+ int iteration;
+ int element = 0;
+ int seed = self->seed;
+ int interval = 1 + rand_r (&seed) % 71;
+
+ self->changed = 0;
+
+ for (iteration = 0; iteration < ITERATIONS; iteration++)
+ {
+ if (iteration % (ITERATIONS / 10) == 0)
+ {
+ putchar('.');
+ fflush(stdout);
+ }
+ /*
+ * Each "self->interval" iterations, perform an
+ * update operation (write lock instead of read
+ * lock).
+ */
+ if ((iteration % interval) == 0)
+ {
+ assert(pthread_rwlock_wrlock (&data[element].lock) == 0);
+ data[element].data = self->thread_num;
+ data[element].updates++;
+ self->updates++;
+ interval = 1 + rand_r (&seed) % 71;
+ sched_yield();
+ assert(pthread_rwlock_unlock (&data[element].lock) == 0);
+ } else {
+ /*
+ * Look at the current data element to see whether
+ * the current thread last updated it. Count the
+ * times, to report later.
+ */
+ assert(pthread_rwlock_rdlock (&data[element].lock) == 0);
+
+ self->reads++;
+
+ if (data[element].data != self->thread_num)
+ {
+ self->changed++;
+ interval = 1 + self->changed % 71;
+ }
+
+ sched_yield();
+
+ assert(pthread_rwlock_unlock (&data[element].lock) == 0);
+ }
+
+ element = (element + 1) % DATASIZE;
+
+ }
+
+ return NULL;
+}
+
+int
+main (int argc, char *argv[])
+{
+ int count;
+ int data_count;
+ int thread_updates = 0;
+ int data_updates = 0;
+ int seed = 1;
+
+ struct _timeb currSysTime1;
+ struct _timeb currSysTime2;
+
+ /*
+ * Initialize the shared data.
+ */
+ for (data_count = 0; data_count < DATASIZE; data_count++)
+ {
+ data[data_count].data = 0;
+ data[data_count].updates = 0;
+
+ assert(pthread_rwlock_init (&data[data_count].lock, NULL) == 0);
+ }
+
+ _ftime(&currSysTime1);
+
+ /*
+ * Create THREADS threads to access shared data.
+ */
+ for (count = 0; count < THREADS; count++)
+ {
+ threads[count].thread_num = count;
+ threads[count].updates = 0;
+ threads[count].reads = 0;
+ threads[count].seed = 1 + rand_r (&seed) % 71;
+
+ assert(pthread_create (&threads[count].thread_id,
+ NULL, thread_routine, (void*)&threads[count]) == 0);
+ }
+
+ /*
+ * Wait for all threads to complete, and collect
+ * statistics.
+ */
+ for (count = 0; count < THREADS; count++)
+ {
+ assert(pthread_join (threads[count].thread_id, NULL) == 0);
+ }
+
+ putchar('\n');
+ fflush(stdout);
+
+ for (count = 0; count < THREADS; count++)
+ {
+ if (threads[count].changed > 0)
+ {
+ printf ("Thread %d found changed elements %d times\n",
+ count, threads[count].changed);
+ }
+ }
+
+ putchar('\n');
+ fflush(stdout);
+
+ for (count = 0; count < THREADS; count++)
+ {
+ thread_updates += threads[count].updates;
+ printf ("%02d: seed %d, updates %d, reads %d\n",
+ count, threads[count].seed,
+ threads[count].updates, threads[count].reads);
+ }
+
+ putchar('\n');
+ fflush(stdout);
+
+ /*
+ * Collect statistics for the data.
+ */
+ for (data_count = 0; data_count < DATASIZE; data_count++)
+ {
+ data_updates += data[data_count].updates;
+ printf ("data %02d: value %d, %d updates\n",
+ data_count, data[data_count].data, data[data_count].updates);
+ assert(pthread_rwlock_destroy (&data[data_count].lock) == 0);
+ }
+
+ printf ("%d thread updates, %d data updates\n",
+ thread_updates, data_updates);
+
+ _ftime(&currSysTime2);
+
+ printf( "\nstart: %ld/%d, stop: %ld/%d, duration:%ld\n",
+ currSysTime1.time,currSysTime1.millitm,
+ currSysTime2.time,currSysTime2.millitm,
+ (currSysTime2.time*1000+currSysTime2.millitm) -
+ (currSysTime1.time*1000+currSysTime1.millitm));
+
+ return 0;
+}
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