-- POSIX_Poll_Poorly - Provide a rather simple binding specifically for the dumb poll functionality.
-- Copyright (C) 2023 Prince Trippy <programmer@verisimilitudes.net>.

-- This program is free software: you can redistribute it and/or modify it under the terms of the
-- GNU Affero General Public License version 3 as published by the Free Software Foundation.

-- This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
-- even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-- See the GNU Affero General Public License for more details.

-- You should have received a copy of the GNU Affero General Public License along with this program.
-- If not, see <http://www.gnu.org/licenses/>.

-- This library is designed to adhere to the requirements of Ada 1995, due entirely to Interfaces.C.

with Interfaces.C; use Interfaces.C;

-- Poll is much easier to model than Select, since Select uses many asinine text replacement macros.
package POSIX_Poll_Poorly is
   -- Unlike the other libraries, this package exposes those C language types and whatnot, directly.
   -- While distasteful, converting a long array on every call is no reasonable option, and oh well.
   type Pollfd is record
      Socket : Int;
      Events, Read_Events : Unsigned_Short;
   end record;
   pragma Convention(Convention => C, Entity => Pollfd);

   -- I was going to name these Read, Send, Error, Closed, and Invalid respectively, but I care not.
   POLLIN   : constant Unsigned_Short := 1;
   POLLOUT  : constant Unsigned_Short := 4;
   POLLERR  : constant Unsigned_Short := 8;
   POLLHUP  : constant Unsigned_Short := 16;
   POLLNVAL : constant Unsigned_Short := 32;

   type Fds is array (Long range <>) of Pollfd; -- This array's index type could need to be changed.

   -- This call should only fail in the cases of EAGAIN or EINTR, thus one error generally suffices.
   procedure Poll (File_Descriptors : in out Fds; Milliseconds_Timeout : in Int; Count : out Int);

   Poll_Error : exception;
end POSIX_Poll_Poorly;
.