This page has notes for using some of the CODES components in your own simulations.
Using CODES mapping API
- Step 1: Specifying the LP types in the config file. Here is an example of a config file that specifies the codes LP mapping
——————————-example-test.conf—————————–
LPGROUPS{
MODELNET_GRP{
repetitions=”16″;
server=”1″;
example_net=”1″;
}
}
——————————————————————————
In this config file, there are multiple LP types defined in a single LP group (As we will see in a later example, there can be multiple LP groups in a config file too). There is 1 server LP and 1 example_net LP type in a LP group and this combination is repeated 16 time (repetitions=”16″). ROSS will assign the LPs to the PEs (PEs is an abstraction for MPI rank in ROSS) by placing 1 server LP then 1 example_net LP for a total of 16 times.
The number of server and example_net LPs can be more than 1. Lets assume if we have two example_net LPs for each server then the config file will have the following format:
——————————-example-test2.conf—————————–
LPGROUPS{
MODELNET_GRP{
repetitions=”16″;
server=”1″;
example_net=”2″;
}
}
————————————————————————————-
- Step 2: Loading the config file in the model.
After the initialization function calls of ROSS (tw_init), the configuration file can be loaded in the example program using:
configuration_load(example-test.conf, MPI_COMM_WORLD, &config);
- Step 3: Registering LP types.
Each LP type must register itself with the lp_type_register before setting up the codes-mapping. Following is an example function that registers ‘server’ LP type.
static void svr_add_lp_type(){
lp_type_register(“server”, svr_get_lp_type());
}
- Step 4: setting up CODES mapping.Call to codes_mapping_setup that sets up the LPs of each registered LP type as specified in the config file.
codes_mapping_setup();
- Step 5: Querying number of LPs in each repetition.
int codes_mapping_get_lp_count(group_name, lp_type_name);
For example, to query the number of server LPs in example-test2.conf file, calling
num_servers = codes_mapping_get_lp_count(“MODELNET_GRP”, “server”);
will return 2.
- Step 6: Querying number of repetitions in a particular group.
int codes_mapping_get_group_reps(group_name);
For example, to query the number of repetitions in example-test2.conf file, calling
num_repetitions = codes_mapping_get_group_reps(“MODELNET_GRP”);
will return 16.