Add iomux_wake example

test/iomux_wake.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <assert.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <ucore/iomux.h>
+#include <ucore/iomux_waker.h>
+
+pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+static int counter = 0;
+
+void wake_cb(struct IOMuxWaker *wk)
+{
+    int local_counter;
+    int rc;
+
+    rc = pthread_mutex_lock(&lock);
+    assert(rc == 0);
+    local_counter = counter;
+    printf("counter is %d\n", local_counter);
+
+    rc = pthread_mutex_unlock(&lock);
+    assert(rc == 0);
+
+    if (local_counter == 13) {
+        rc = uc_iomux_waker_destroy(wk);
+        assert(rc == 0);
+    }
+}
+
+void *waker(void *arg)
+{
+    struct IOMuxSignaller *s = arg;
+    int i;
+    int rc;
+
+    rc = pthread_mutex_lock(&lock);
+    assert(rc == 0);
+    for (i = 0; i < 3; i++) {
+
+        counter++;
+        //with the signal in here,
+        //the wake_cb might be woken up
+        //more than once after the loop is done
+        //reading the same counter value more than once.
+        rc = uc_iomux_waker_signal(s);
+        assert(rc == 0);
+    }
+    rc = pthread_mutex_unlock(&lock);
+    assert(rc == 0);
+
+    for (i = 0; i < 10; i++) {
+
+        rc =  pthread_mutex_lock(&lock);
+        assert(rc == 0);
+        counter++;
+        rc = pthread_mutex_unlock(&lock);
+        assert(rc == 0);
+        rc = uc_iomux_waker_signal(s);
+        assert(rc == 0);
+    }
+
+    return NULL;
+}
+
+
+int main(int argc, char *argv[])
+{
+    struct IOMux *mux = iomux_create(IOMUX_TYPE_SELECT);
+    struct IOMuxWaker wk;
+    pthread_t tid;
+
+    uc_iomux_waker_init(mux, &wk, wake_cb);
+
+    pthread_create(&tid,NULL,waker, &wk.signaller);
+    iomux_run(mux);
+
+    printf("reader mux returned\n");
+    pthread_join(tid, NULL);
+    iomux_delete(mux);
+
+    return 0;
+}