Ada POSIX绑定是Ada语言的一个库，它提供了一组函数和类型定义，用于与POSIX标准进行交互。这些绑定包含了一些用于进程间通信（IPC）的POSIX接口集合。

下面是一个示例，演示了如何在Ada程序中使用POSIX消息队列进行进程间通信：

with Ada.Text_IO;
with System;
with Interfaces.C;
with Interfaces.C.Strings;

procedure Message_Queue is
   package IIO renames Ada.Text_IO;
   package SC renames System.Storage_Elements;
   package C renames Interfaces.C;
   package CS renames C.Strings;

   type mqd_t is new SC.Address;
   type mq_attr is record
      mq_flags : C.int;
      mq_maxmsg : C.int;
      mq_msgsize : C.int;
      mq_curmsgs : C.int;
   end record;

   function mq_open (name : CS.chars_ptr; oflag : C.int; mode : C.mode_t; attr : access mq_attr) return mqd_t;
   pragma Import (C, mq_open, "mq_open");

   function mq_close (mqdes : mqd_t) return C.int;
   pragma Import (C, mq_close, "mq_close");

   function mq_send (mqdes : mqd_t; msg_ptr : CS.chars_ptr; msg_len : C.size_t; msg_prio : C.uint) return C.int;
   pragma Import (C, mq_send, "mq_send");

   function mq_receive (mqdes : mqd_t; msg_ptr : CS.chars_ptr; msg_len : C.size_t; msg_prio : access C.uint) return C.ssize_t;
   pragma Import (C, mq_receive, "mq_receive");

   function mq_unlink (name : CS.chars_ptr) return C.int;
   pragma Import (C, mq_unlink, "mq_unlink");

   type mq_message is record
      msg_text : CS.chars_array (1 .. 1024);
   end record;

   procedure Send_Message (Queue_Name : String; Message : String) is
      Queue : mqd_t;
      Msg : mq_message;
      Ret : C.int;
   begin
      Queue := mq_open (CS.New_String (Queue_Name), C.O_RDWR or C.O_CREAT, C.S_IRWXU, null);
      if Queue = mqd_t'null then
         IIO.Put_Line ("Failed to open message queue");
         return;
      end if;

      Msg.msg_text := CS.New_String (Message);
      Ret := mq_send (Queue, Msg.msg_text'Access, CS.Length (Msg.msg_text), 0);
      if Ret = -1 then
         IIO.Put_Line ("Failed to send message");
      end if;

      Ret := mq_close (Queue);
      if Ret = -1 then
         IIO.Put_Line ("Failed to close message queue");
      end if;
   end Send_Message;

   function Receive_Message (Queue_Name : String) return String is
      Queue : mqd_t;
      Msg : mq_message;
      Msg_Prio : C.uint;
      Ret : C.ssize_t;
   begin
      Queue := mq_open (CS.New_String (Queue_Name), C.O_RDONLY, 0, null);
      if Queue = mqd_t'null then
         IIO.Put_Line ("Failed to open message queue");
         return "";
      end if;

      Ret := mq_receive (Queue, Msg.msg_text'Access, CS.Length (Msg.msg_text), Msg_Prio'Access);
      if Ret = -1 then
         IIO.Put_Line ("Failed to receive message");
         return "";
      end if;

      Ret := mq_close (Queue);
      if Ret = -1 then
         IIO.Put_Line ("Failed to close message queue");
         return "";
      end if;

      return CS.Value (Msg.msg_text);
   end Receive_Message;

   procedure Delete_Message_Queue (Queue_Name : String) is
      Ret : C.int;
   begin
      Ret := mq_unlink (CS.New_String (Queue_Name));
      if Ret = -1 then
         IIO.Put_Line ("Failed to delete message queue");
      end if;
   end Delete_Message_Queue;

begin
   -- 示例使用
   Send_Message ("/my_queue", "Hello, World!");

   declare
      Msg : String := Receive_Message ("/my_queue");
   begin
      IIO.Put_Line (Msg);
   end;

   Delete_Message_Queue ("/my_queue");
end Message_Queue;

上面的示例代码定义了一些用于POSIX消息队列的函数和数据类型，包括mq_open、`