user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/tests/linux/timerfd.c

@@ -0,0 +1,64 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <sys/time.h>
+#include <sys/timerfd.h>
+#include <unistd.h>
+
+int main() {
+	int t = timerfd_create(CLOCK_MONOTONIC, 0);
+	assert(t > 0);
+
+	struct itimerspec its;
+	int ret = timerfd_gettime(t, &its);
+	assert(ret == 0);
+	assert(!its.it_value.tv_sec);
+	assert(!its.it_value.tv_nsec);
+	assert(!its.it_interval.tv_sec);
+	assert(!its.it_interval.tv_nsec);
+
+	struct itimerspec new_its = {
+		.it_interval = {0, 0},
+		.it_value = {0, 100000000},
+	};
+	ret = timerfd_settime(t, 0, &new_its, &its);
+	assert(ret == 0);
+	assert(!its.it_value.tv_sec);
+	assert(!its.it_value.tv_nsec);
+	assert(!its.it_interval.tv_sec);
+	assert(!its.it_interval.tv_nsec);
+
+	ret = timerfd_gettime(t, &its);
+	assert(ret == 0);
+	assert(!its.it_value.tv_sec);
+	assert(its.it_value.tv_nsec);
+	assert(!its.it_interval.tv_sec);
+	assert(!its.it_interval.tv_nsec);
+
+	struct timeval before;
+	gettimeofday(&before, NULL);
+	assert(ret == 0);
+	uint64_t ev = 0;
+	ret = read(t, &ev, sizeof(ev));
+	struct timeval after;
+	gettimeofday(&after, NULL);
+
+	assert(ret == sizeof(ev));
+	assert(ev == 1);
+
+	struct timeval diff = {};
+	timersub(&after, &before, &diff);
+	assert(diff.tv_sec || diff.tv_usec);
+
+	fcntl(t, F_SETFL, fcntl(t, F_GETFL, 0) | O_NONBLOCK);
+
+	ret = timerfd_settime(t, 0, &new_its, &its);
+	assert(ret == 0);
+
+	ret = read(t, &ev, sizeof(ev));
+	assert(ret == -1);
+	assert(errno == EAGAIN);
+
+	return 0;
+}