user: implement mlibc as the libc, finally.

It's finally done..

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

user/include/mlibc/tests/posix/sigtimedwait.c

@@ -0,0 +1,93 @@
+#include <stdio.h>
+
+#include <assert.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <errno.h>
+
+pid_t parent;
+pid_t child;
+
+int fds[2];
+
+void parent_fn() {
+	int res;
+
+	sigset_t set;
+	sigemptyset(&set);
+	sigaddset(&set, SIGUSR2);
+	sigprocmask(SIG_BLOCK, &set, NULL);
+
+	res = write(fds[1], "!", 1);
+	assert(res == 1);
+
+	siginfo_t info;
+	res = sigwaitinfo(&set, &info);
+	assert(res == SIGUSR2);
+	assert(info.si_signo == SIGUSR2);
+
+	res = write(fds[1], "!", 1);
+	assert(res == 1);
+
+	// XXX: This may not be long enough to get scheduled
+	struct timespec tout = {1, 0};
+	res = sigtimedwait(&set, &info, &tout);
+	assert(res == SIGUSR2);
+	assert(info.si_signo == SIGUSR2);
+
+	res = write(fds[1], "!", 1);
+	assert(res == 1);
+
+	int sig;
+	res = sigwait(&set, &sig);
+	assert(res == 0);
+	assert(sig == SIGUSR2);
+
+	res = write(fds[1], "!", 1);
+	assert(res == 1);
+
+	res = sigtimedwait(&set, &info, &tout);
+	assert(res < 0);
+	assert(errno == EAGAIN);
+
+	int wsts;
+	res = waitpid(child, &wsts, 0);
+	assert(res >= 0);
+}
+
+void child_fn() {
+	int res;
+	char c;
+
+	res = read(fds[0], &c, 1);
+	assert(res == 1);
+	kill(parent, SIGUSR2);
+	res = read(fds[0], &c, 1);
+	assert(res == 1);
+	kill(parent, SIGUSR2);
+	res = read(fds[0], &c, 1);
+	assert(res == 1);
+	kill(parent, SIGUSR2);
+	res = read(fds[0], &c, 1);
+	assert(res == 1);
+}
+
+int main() {
+	int res;
+
+	parent = getpid();
+	assert(parent > 0);
+
+	res = pipe(fds);
+	assert(res == 0);
+
+	child = fork();
+	assert(child >= 0);
+	if (child)
+		parent_fn();
+	else
+		child_fn();
+
+	return 0;
+}