Function rmw_init_subscription_allocation

Function Documentation

rmw_ret_t rmw_init_subscription_allocation(const rosidl_message_type_support_t *type_support, const rosidl_runtime_c__Sequence__bound *message_bounds, rmw_subscription_allocation_t *allocation)

Initialize a subscription allocation to be used with later takes.

This creates an allocation object that can be used in conjunction with the rmw_take method to perform more carefully control memory allocations.

This will allow the middleware to preallocate the correct amount of memory for a given message type and message bounds. As allocation is performed in this method, it will not be necessary to allocate in the rmw_take method.

Parameters:

  • type_support – [in] Type support of the message to be preallocated.

  • message_bounds – [in] Bounds structure of the message to be preallocated.

  • allocation – [out] Allocation structure to be passed to rmw_take.

Returns:

RMW_RET_OK if successful, or

Returns:

RMW_RET_UNSUPPORTED if it’s unimplemented

Returns:

RMW_RET_INVALID_ARGUMENT if an argument is null, or

Returns:

RMW_RET_ERROR if an unexpected error occurs.