//TODO optimize this. Can reduce searches in block map.
void SialOpsParallel::get(BlockId& block_id) {
//check for "data race"
check_and_set_mode(block_id, READ);
//if block already exists, or has pending request, just return
Block::BlockPtr block = block_manager_.block(block_id);
if (block != NULL)
return;
//send get message to block's server, and post receive
int server_rank = data_distribution_.get_server_rank(block_id);
int get_tag;
get_tag = barrier_support_.make_mpi_tag_for_GET();
sip::check(server_rank>=0&&server_rank<sip_mpi_attr_.global_size(), "invalid server rank",current_line());
SIP_LOG(std::cout<<"W " << sip_mpi_attr_.global_rank()
<< " : sending GET for block " << block_id
<< " to server "<< server_rank << std::endl);
// Construct int array to send to server.
const int to_send_size = BlockId::MPI_BLOCK_ID_COUNT + 2;
const int line_num_offset = BlockId::MPI_BLOCK_ID_COUNT;
const int section_num_offset = line_num_offset + 1;
int to_send[to_send_size]; // BlockId & line number
int *serialized_block_id = block_id.to_mpi_array();
std::copy(serialized_block_id + 0, serialized_block_id + BlockId::MPI_BLOCK_ID_COUNT, to_send);
to_send[line_num_offset] = current_line();
to_send[section_num_offset] = barrier_support_.section_number();
SIPMPIUtils::check_err(
MPI_Send(to_send, to_send_size, MPI_INT,
server_rank, get_tag, MPI_COMM_WORLD));
//allocate block, and insert in block map, using block data as buffer
block = block_manager_.get_block_for_writing(block_id, true);
//post an asynchronous receive and store the request in the
//block's state
MPI_Request request;
SIPMPIUtils::check_err(
MPI_Irecv(block->get_data(), block->size(), MPI_DOUBLE, server_rank,
get_tag, MPI_COMM_WORLD, &request));
block->state().mpi_request_ = request;
}
/**
* A put appears in a SIAL program as
* put target(i,j,k,l) += source(i,j,k,l)
* So we need the target block id, but the source block data.
* Accumulation is done by the server
*
* The implementation will be more complicated if asynchronous send is
* used
*
* @param target
* @param source_ptr
*/
void SialOpsParallel::put_accumulate(BlockId& target_id,
const Block::BlockPtr source_block) {
//partial check for data races
check_and_set_mode(target_id, WRITE);
//send message with target block's id to server
int my_rank = sip_mpi_attr_.global_rank();
int server_rank = data_distribution_.get_server_rank(target_id);
int put_accumulate_tag, put_accumulate_data_tag;
put_accumulate_tag = barrier_support_.make_mpi_tags_for_PUT_ACCUMULATE(
put_accumulate_data_tag);
sip::check(server_rank>=0&&server_rank<sip_mpi_attr_.global_size(), "invalid server rank",current_line());
SIP_LOG(std::cout<<"W " << sip_mpi_attr_.global_rank()
<< " : sending PUT_ACCUMULATE for block " << target_id
<< " to server "<< server_rank << std::endl);
// Construct int array to send to server.
const int to_send_size = BlockId::MPI_BLOCK_ID_COUNT + 2;
const int line_num_offset = BlockId::MPI_BLOCK_ID_COUNT;
const int section_num_offset = line_num_offset + 1;
int to_send[to_send_size]; // BlockId & line number
int *serialized_block_id = target_id.to_mpi_array();
std::copy(serialized_block_id + 0, serialized_block_id + BlockId::MPI_BLOCK_ID_COUNT, to_send);
to_send[line_num_offset] = current_line();
to_send[section_num_offset] = barrier_support_.section_number();
//send block id
SIPMPIUtils::check_err(
MPI_Send(to_send, to_send_size, MPI_INT,
server_rank, put_accumulate_tag, MPI_COMM_WORLD));
//immediately follow with the data
SIPMPIUtils::check_err(
MPI_Send(source_block->get_data(), source_block->size(), MPI_DOUBLE,
server_rank, put_accumulate_data_tag, MPI_COMM_WORLD));
//ack
ack_handler_.expect_ack_from(server_rank, put_accumulate_data_tag);
SIP_LOG(
std::cout<< "W " << sip_mpi_attr_.global_rank() << " : Done with PUT_ACCUMULATE for block " << target_id << " to server rank " << server_rank << std::endl);
}