Add signalfd support (#5322)

* add signalfd_siginfo to linux bits

* Cast sigaddset's shift value to u5

* linux: add signalfd4

* os: add signalfd

1 files changed, 14 insertions, 0 deletions

diff --git a/lib/std/os.zig b/lib/std/os.zig
index 3e05ac41e5..1665a2efa6 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -5133,3 +5133,17 @@ pub fn ioctl_SIOCGIFINDEX(fd: fd_t, ifr: *ifreq) IoCtl_SIOCGIFINDEX_Error!void {
         }
     }
 }
+
+pub fn signalfd(fd: fd_t, mask: *const sigset_t, flags: i32) !fd_t {
+    const rc = system.signalfd4(fd, mask, flags);
+    switch (errno(rc)) {
+        0 => return @intCast(fd_t, rc),
+        EBADF, EINVAL => unreachable,
+        ENFILE => return error.SystemFdQuotaExceeded,
+        ENOMEM => return error.SystemResources,
+        EMFILE => return error.ProcessResources,
+        ENODEV => return error.InodeMountFail,
+        ENOSYS => return error.SystemOutdated,
+        else => |err| return std.os.unexpectedErrno(err),
+    }
+}