_asyncmsg_connection_attr

Attributes for a connection used for asynchronous messages

---

Asynchronous messaging is an experimental feature; for information about the use of experimental software, see the Commercial Software License Agreement (CSLA) or Partner Software License Agreement (PSLA) in the Licensing area of our website, http://www.qnx.com/legal/licensing/.

---

Synopsis:

#include <sys/asyncmsg.h>

struct _asyncmsg_connection_attr {
    int (*call_back) (int err, 
                      void* buf, 
                      unsigned handle);
    size_t buffer_size;
    unsigned max_num_buffer;
    unsigned trigger_num_msg;
    struct itimertrigger_timer;
};

Description:

The _asyncmsg_connection_attr structure describes connection attributes for use with asynchronous messaging.

The _asyncmsg_connection_attr structure includes these members:

call_back

Callback function for notification. The arguments are:

• err — the error status of the package.
• buf — a pointer to the package buffer.
• handle — a handle associated with the callback function.

If call_back isn't NULL, this function is called when an error occurs during send (after asyncmsg_put() returns) with an error number in err and the faulted buffer in buf. If you use your own buffer, this function is also called when a buffer is empty, with err set to EOK.

buffer_size

The message buffer size.

max_num_buffer

The maximum number of buffers allowed for this connection.

trigger_num_msg

Uses the number of the pending message as triggering criteria.

trigger_timer

Uses the time passed since the last kernel call as triggering criteria.

Classification:

QNX Neutrino

See also:

asyncmsg_connect_attach(), asyncmsg_connect_attr()

Asynchronous Messaging Technote