vrt: Bind select.

Author: bhelyer

rt/src/core/c/posix/sys/select.volt

@@ -0,0 +1,56 @@
+module core.c.posix.sys.select;
+
+version (Posix):
+extern (C):
+
+import core.c.config : c_long;
+import core.c.posix.sys.time : timeval;
+
+private enum FD_SETSIZE = 1024;
+private enum NFDBITS = 8 * cast(i32)typeid(fd_mask).size;
+
+version (OSX) {
+	alias fd_mask = i32;
+} else {
+	alias fd_mask = c_long;
+}
+
+struct fd_set
+{
+	fds_bits: fd_mask[FD_SETSIZE / NFDBITS];
+}
+
+private fn FD_ELT(d: i32) i32
+{
+	return d / NFDBITS;
+}
+
+private fn FD_MASK(d: i32) fd_mask
+{
+	return cast(fd_mask)(1 << (d % NFDBITS));
+}
+
+fn FD_ZERO(set: fd_set*)
+{
+	for (i: u32 = 0; i < typeid(fd_set).size / typeid(fd_mask).size; ++i) {
+		set.fds_bits[i] = 0;
+	}
+}
+
+fn FD_SET(fd: i32, set: fd_set*)
+{
+	set.fds_bits[FD_ELT(fd)] |= FD_MASK(fd);
+}
+
+fn FD_CLR(fd: i32, set: fd_set*)
+{
+	set.fds_bits[FD_ELT(fd)] &= ~FD_MASK(fd);
+}
+
+fn FD_ISSET(fd: i32, set: fd_set*) i32
+{
+	return (set.fds_bits[FD_ELT(fd)] & FD_MASK(fd)) != 0;
+}
+
+fn select(i32, fd_set*, fd_set*, fd_set*, timeval*) i32;
+