Kernel/LibC: Implement super basic select

This does not really even block but it works... :D

libc/CMakeLists.txt

@@ -21,6 +21,7 @@ set(LIBC_SOURCES
 	stropts.cpp
 	sys/banan-os.cpp
 	sys/mman.cpp
+	sys/select.cpp
 	sys/socket.cpp
 	sys/stat.cpp
 	sys/wait.cpp

libc/include/bits/types/timeval.h

@@ -0,0 +1,20 @@
+#ifndef _BITS_TIMEVAL_H
+#define _BITS_TIMEVAL_H 1
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define __need_time_t
+#define __need_suseconds_t
+#include <sys/types.h>
+
+struct timeval
+{
+	time_t		tv_sec;		/* Seconds. */
+	suseconds_t	tc_usec;	/* Microseconds. */
+};
+
+__END_DECLS
+
+#endif

libc/include/sys/select.h

@@ -7,9 +7,7 @@
 
 __BEGIN_DECLS
 
-#define __need_time_t
-#define __need_suseconds_t
-#include <sys/types.h>
+#include <bits/types/timeval.h>
 
 #include <signal.h>
 #include <time.h>
@@ -50,6 +48,16 @@ typedef struct {
 			(setp)->__bits[i] = (__fd_mask)0; \
 	} while (0)
 
+struct sys_pselect_t
+{
+	int nfds;
+	fd_set* readfds;
+	fd_set* writefds;
+	fd_set* errorfds;
+	const struct timespec* timeout;
+	const sigset_t* sigmask;
+};
+
 int pselect(int nfds, fd_set* __restrict readfds, fd_set* __restrict writefds, fd_set* __restrict errorfds, const struct timespec* __restrict timeout, const sigset_t* __restrict sigmask);
 int select(int nfds, fd_set* __restrict readfds, fd_set* __restrict writefds, fd_set* __restrict errorfds, struct timeval* __restrict timeout);
 

libc/include/sys/syscall.h

@@ -71,6 +71,7 @@ __BEGIN_DECLS
 #define SYS_ACCEPT 70
 #define SYS_CONNECT 71
 #define SYS_LISTEN 72
+#define SYS_PSELECT 73
 
 __END_DECLS
 

libc/include/sys/time.h

@@ -7,18 +7,10 @@
 
 __BEGIN_DECLS
 
-#define __need_time_t
-#define __need_suseconds_t
-#include <sys/types.h>
-
 // NOTE: select is declared from here
 #include <sys/select.h>
 
-struct timeval
-{
-	time_t		tv_sec;		/* Seconds. */
-	suseconds_t	tc_usec;	/* Microseconds. */
-};
+#include <bits/types/timeval.h>
 
 struct itimerval
 {

libc/sys/select.cpp

@@ -0,0 +1,31 @@
+#include <sys/select.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+int pselect(int nfds, fd_set* __restrict readfds, fd_set* __restrict writefds, fd_set* __restrict errorfds, const struct timespec* __restrict timeout, const sigset_t* __restrict sigmask)
+{
+	sys_pselect_t arguments {
+		.nfds = nfds,
+		.readfds = readfds,
+		.writefds = writefds,
+		.errorfds = errorfds,
+		.timeout = timeout,
+		.sigmask = sigmask
+	};
+	return syscall(SYS_PSELECT, &arguments);
+}
+
+int select(int nfds, fd_set* __restrict readfds, fd_set* __restrict writefds, fd_set* __restrict errorfds, struct timeval* __restrict timeout)
+{
+	timespec* pts = nullptr;
+	timespec ts;
+	if (timeout)
+	{
+		ts.tv_sec = timeout->tv_sec;
+		ts.tv_nsec = timeout->tc_usec * 1000;
+		pts = &ts;
+	}
+
+	// TODO: "select may update timeout", should we?
+	return pselect(nfds, readfds, writefds, errorfds, pts, nullptr);
+}