net: sockets: move select() implementation to zvfs

Move the implementation of zsock_select() to zvfs_select(). This
allows other types of file descriptors to also make use of
select() functionality even when the network subsystem is not
enabled.

Additionally, it partially removes a dependency cycle between
posix and networking by moving functionality into a mutual
dependency.

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>

include/zephyr/net/socket_select.h

@@ -19,17 +19,18 @@
  * @{
  */
 
+#include <time.h>
+
 #include <zephyr/toolchain.h>
 #include <zephyr/net/socket_types.h>
+#include <zephyr/sys/fdtable.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /** Socket file descriptor set. */
-typedef struct zsock_fd_set {
-	uint32_t bitset[(CONFIG_ZVFS_OPEN_MAX + 31) / 32];
-} zsock_fd_set;
+typedef struct zvfs_fd_set zsock_fd_set;
 
 /**
  * @brief Legacy function to poll multiple sockets for events
@@ -47,13 +48,16 @@ typedef struct zsock_fd_set {
  * it may conflict with generic POSIX ``select()`` function).
  * @endrst
  */
-__syscall int zsock_select(int nfds, zsock_fd_set *readfds,
-			   zsock_fd_set *writefds,
-			   zsock_fd_set *exceptfds,
-			   struct zsock_timeval *timeout);
+static inline int zsock_select(int nfds, zsock_fd_set *readfds, zsock_fd_set *writefds,
+			       zsock_fd_set *exceptfds, struct zsock_timeval *timeout)
+{
+	struct timeval;
+
+	return zvfs_select(nfds, readfds, writefds, exceptfds, (struct timeval *)timeout);
+}
 
 /** Number of file descriptors which can be added to zsock_fd_set */
-#define ZSOCK_FD_SETSIZE (sizeof(((zsock_fd_set *)0)->bitset) * 8)
+#define ZSOCK_FD_SETSIZE ZVFS_FD_SETSIZE
 
 /**
  * @brief Initialize (clear) fd_set
@@ -67,7 +71,10 @@ __syscall int zsock_select(int nfds, zsock_fd_set *readfds,
  * if :kconfig:option:`CONFIG_POSIX_API` is defined.
  * @endrst
  */
-void ZSOCK_FD_ZERO(zsock_fd_set *set);
+static inline void ZSOCK_FD_ZERO(zsock_fd_set *set)
+{
+	ZVFS_FD_ZERO(set);
+}
 
 /**
  * @brief Check whether socket is a member of fd_set
@@ -81,7 +88,10 @@ void ZSOCK_FD_ZERO(zsock_fd_set *set);
  * if :kconfig:option:`CONFIG_POSIX_API` is defined.
  * @endrst
  */
-int ZSOCK_FD_ISSET(int fd, zsock_fd_set *set);
+static inline int ZSOCK_FD_ISSET(int fd, zsock_fd_set *set)
+{
+	return ZVFS_FD_ISSET(fd, set);
+}
 
 /**
  * @brief Remove socket from fd_set
@@ -95,7 +105,10 @@ int ZSOCK_FD_ISSET(int fd, zsock_fd_set *set);
  * if :kconfig:option:`CONFIG_POSIX_API` is defined.
  * @endrst
  */
-void ZSOCK_FD_CLR(int fd, zsock_fd_set *set);
+static inline void ZSOCK_FD_CLR(int fd, zsock_fd_set *set)
+{
+	ZVFS_FD_CLR(fd, set);
+}
 
 /**
  * @brief Add socket to fd_set
@@ -109,7 +122,10 @@ void ZSOCK_FD_CLR(int fd, zsock_fd_set *set);
  * if :kconfig:option:`CONFIG_POSIX_API` is defined.
  * @endrst
  */
-void ZSOCK_FD_SET(int fd, zsock_fd_set *set);
+static inline void ZSOCK_FD_SET(int fd, zsock_fd_set *set)
+{
+	ZVFS_FD_SET(fd, set);
+}
 
 /** @cond INTERNAL_HIDDEN */
 
@@ -153,8 +169,6 @@ static inline void FD_SET(int fd, zsock_fd_set *set)
 }
 #endif
 
-#include <zephyr/syscalls/socket_select.h>
-
 /**
  * @}
  */

include/zephyr/posix/sys/select.h

@@ -13,16 +13,18 @@
 extern "C" {
 #endif
 
+#undef fd_set
 #define fd_set zsock_fd_set
-#define FD_SETSIZE ZSOCK_FD_SETSIZE
-#define FD_ZERO ZSOCK_FD_ZERO
-#define FD_SET ZSOCK_FD_SET
-#define FD_CLR ZSOCK_FD_CLR
-#define FD_ISSET ZSOCK_FD_ISSET
+
+#define FD_SETSIZE ZVFS_FD_SETSIZE
 
 struct timeval;
 
-int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);
+int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout);
+void FD_CLR(int fd, fd_set *fdset);
+int FD_ISSET(int fd, fd_set *fdset);
+void FD_SET(int fd, fd_set *fdset);
+void FD_ZERO(fd_set *fdset);
 
 #ifdef __cplusplus
 }

include/zephyr/sys/fdtable.h

@@ -8,6 +8,7 @@
 
 #include <stdarg.h>
 #include <sys/types.h>
+
 /* FIXME: For native_posix ssize_t, off_t. */
 #include <zephyr/fs/fs.h>
 #include <zephyr/sys/mutex.h>
@@ -207,9 +208,23 @@ struct zvfs_pollfd {
 
 __syscall int zvfs_poll(struct zvfs_pollfd *fds, int nfds, int poll_timeout);
 
-struct zsock_fd_set {
+struct zvfs_fd_set {
 	uint32_t bitset[(CONFIG_ZVFS_OPEN_MAX + 31) / 32];
 };
+
+#define ZVFS_FD_SETSIZE (sizeof(((struct zvfs_fd_set *)0)->bitset) * 8)
+
+void ZVFS_FD_CLR(int fd, struct zvfs_fd_set *fdset);
+int ZVFS_FD_ISSET(int fd, struct zvfs_fd_set *fdset);
+void ZVFS_FD_SET(int fd, struct zvfs_fd_set *fdset);
+void ZVFS_FD_ZERO(struct zvfs_fd_set *fdset);
+
+struct timespec;
+__syscall int zvfs_select(int nfds, struct zvfs_fd_set *ZRESTRICT readfds,
+			  struct zvfs_fd_set *ZRESTRICT writefds,
+			  struct zvfs_fd_set *ZRESTRICT errorfds,
+			  const struct timeval *ZRESTRICT timeout);
+
 /**
  * Request codes for fd_op_vtable.ioctl().
  *
@@ -239,4 +254,6 @@ enum {
 }
 #endif
 
+#include <zephyr/syscalls/fdtable.h>
+
 #endif /* ZEPHYR_INCLUDE_SYS_FDTABLE_H_ */

lib/os/zvfs/CMakeLists.txt

@@ -3,3 +3,4 @@
 zephyr_library()
 zephyr_library_sources_ifdef(CONFIG_ZVFS_EVENTFD zvfs_eventfd.c)
 zephyr_library_sources_ifdef(CONFIG_ZVFS_POLL zvfs_poll.c)
+zephyr_library_sources_ifdef(CONFIG_ZVFS_SELECT zvfs_select.c)

lib/os/zvfs/Kconfig

@@ -49,6 +49,11 @@ config ZVFS_POLL_MAX
 	help
 	  Maximum number of entries supported for poll() call.
 
+config ZVFS_SELECT
+	bool "ZVFS select"
+	help
+	  Enable support for zvfs_select().
+
 endif # ZVFS_POLL
 
 endif # ZVFS