Add example for iomux signals

test/iomux_signal_test.c

@@ -0,0 +1,41 @@
+#include "ucore/iomux_signal.h"
+#include <stdio.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+#include <assert.h>
+
+void sig_handler(struct IOMux *mux, int signo, void *cookie)
+{
+    char sig_str[64];
+    snprintf(sig_str, sizeof sig_str, "Got signal %d\n", signo);
+
+    write(STDOUT_FILENO, sig_str, strlen(sig_str));
+}
+
+int main(int argc, char *argv[])
+{
+    
+    struct IOMux *mux = iomux_create(IOMUX_TYPE_EPOLL);
+    int rc;
+
+    rc = iomux_register_unixsignal(mux, SIGKILL, sig_handler, NULL);
+    assert(rc != 0);
+    rc = iomux_register_unixsignal(mux, SIGUSR1, sig_handler, NULL);
+    assert(rc == 0);
+    rc = iomux_unregister_unixsignal(mux, SIGINT);
+    assert(rc == 0);
+    rc = iomux_unregister_unixsignal(mux, SIGUSR1);
+    assert(rc == 0);
+    rc = iomux_register_unixsignal(mux, SIGINT, sig_handler, NULL);
+    assert(rc == 0);
+    rc = iomux_register_unixsignal(mux, SIGUSR1, sig_handler, NULL);
+    assert(rc == 0);
+    rc = iomux_register_unixsignal(mux, SIGUSR1, sig_handler, NULL);
+    assert(rc != 0);
+    
+    iomux_run(mux);
+    iomux_delete(mux);
+
+    return 0;
+}