Message queues

C++ API message queues definitions. More...

Classes
class	os::rtos::message_queue::attributes
	Message queue attributes. More...
class	os::rtos::message_queue
	POSIX compliant message queue, using the default RTOS allocator. More...
class	os::rtos::message_queue_allocated< Allocator >
	Template of a POSIX compliant message queue with allocator. More...
class	os::rtos::message_queue_inclusive< T, N >
	Template of a POSIX compliant message queue with message type and local storage. More...
class	os::rtos::message_queue_typed< T, Allocator >
	Template of a POSIX compliant message queue with message type and allocator. More...

Typedefs
using	os::rtos::message_queue::allocator_type = memory::allocator< thread::stack::allocation_element_t >
	Default RTOS allocator.
using	os::rtos::message_queue::index_t = message_queue::size_t
	Type of list index storage.
using	os::rtos::message_queue::msg_size_t = uint16_t
	Type of message size storage.
using	os::rtos::message_queue::priority_t = uint8_t
	Type of message priority storage.
using	os::rtos::message_queue::size_t = uint8_t
	Type of a queue size storage.

Variables
static constexpr priority_t	os::rtos::message_queue::default_priority = 0
	Default message priority.
static const attributes	os::rtos::message_queue::initializer
	Default message queue initialiser.
static constexpr msg_size_t	os::rtos::message_queue::max_msg_size = 0xFFFF
	Maximum message size.
static constexpr priority_t	os::rtos::message_queue::max_priority = 0xFF
	Maximum message priority.
static constexpr message_queue::size_t	os::rtos::message_queue::max_size = 0xFF
	Maximum queue size.
static constexpr index_t	os::rtos::message_queue::no_index = max_size
	Index value to represent an illegal index.

Detailed Description

Examples

typedef struct my_msg_s
{
  int i;
  const char* s;
} my_msg_t;
 
int
os_main (int argc, char* argv[])
{
  my_msg_t msg_out
    { 1, "msg" };
 
  my_msg_t msg_in;
 
  // --------------------------------------------------------------------------
 
  // Classic usage; message size and cast to char* must be supplied manually.
    {
      message_queue cq1
        { 3, sizeof(my_msg_t) };
 
      cq1.send (&msg_out, sizeof(my_msg_t));
 
      message_queue cq2
        { "cq2", 3, sizeof(my_msg_t) };
 
      cq2.send (&msg_out, sizeof(my_msg_t));
    }
 
  // --------------------------------------------------------------------------
 
  // Template usage; message size and cast are supplied automatically.
 
  // Define a custom queue type parametrised with the
  // message type.
  using My_queue = message_queue_typed<my_msg_t>;
 
    {
      My_queue tq1
        { 7 };
 
      tq1.send (&msg_out);
      tq1.receive (&msg_in);
 
      tq1.try_send (&msg_out);
      tq1.try_receive (&msg_in);
 
      tq1.timed_send (&msg_out, 1);
      tq1.timed_receive (&msg_in, 1);
 
      My_queue tq2
        { "tq2", 7 };
 
      tq2.send (&msg_out);
      tq2.receive (&msg_in);
    }
 
  // --------------------------------------------------------------------------
 
  // Allocated template usage; message size and cast are supplied automatically.
 
  // Define a custom queue type parametrised with the
  // message type and the queue size.
  using My_inclusive_queue = message_queue_inclusive<my_msg_t, 4>;
 
    {
      // The space for the queue is allocated inside the queue
      // object, in this case on the stack.
      My_inclusive_queue sq1;
 
      sq1.send (&msg_out);
      sq1.receive (&msg_in);
 
      sq1.try_send (&msg_out);
      sq1.try_receive (&msg_in);
 
      sq1.timed_send (&msg_out, 1);
      sq1.timed_receive (&msg_in, 1);
 
      My_inclusive_queue sq2
        { "sq2" };
 
      sq2.send (&msg_out);
      sq2.receive (&msg_in);
    }
}

Typedef Documentation

allocator_type

using os::rtos::message_queue::allocator_type = memory::allocator<thread::stack::allocation_element_t>

Definition at line 223 of file os-mqueue.h.

index_t

using os::rtos::message_queue::index_t = message_queue::size_t

Definition at line 108 of file os-mqueue.h.

msg_size_t

using os::rtos::message_queue::msg_size_t = uint16_t

Definition at line 96 of file os-mqueue.h.

priority_t

using os::rtos::message_queue::priority_t = uint8_t

A numeric value to hold the message priority, which controls the order in which messages are added to the queue (higher values represent higher priorities).

Definition at line 125 of file os-mqueue.h.

size_t

using os::rtos::message_queue::size_t = uint8_t

A numeric value to hold the message queue size, usually an 8-bits value, possibly a 16-bits value if longer queues are needed.

Definition at line 83 of file os-mqueue.h.

Variable Documentation

default_priority

constexpr priority_t os::rtos::message_queue::default_priority = 0

staticconstexpr

Use this value with send() if no special priorities are required.

Definition at line 134 of file os-mqueue.h.

initializer

const message_queue::attributes os::rtos::message_queue::initializer

static

This variable is used by the default constructor.

Definition at line 217 of file os-mqueue.h.

Referenced by os_mqueue_construct(), and os_mqueue_new().

max_msg_size

constexpr msg_size_t os::rtos::message_queue::max_msg_size = 0xFFFF

staticconstexpr

Definition at line 102 of file os-mqueue.h.

max_priority

constexpr priority_t os::rtos::message_queue::max_priority = 0xFF

staticconstexpr

The maximum value allowed by the type, usually used for validation.

Definition at line 144 of file os-mqueue.h.

max_size

constexpr message_queue::size_t os::rtos::message_queue::max_size = 0xFF

staticconstexpr

Definition at line 90 of file os-mqueue.h.

no_index

constexpr index_t os::rtos::message_queue::no_index = max_size

staticconstexpr

Definition at line 114 of file os-mqueue.h.