Block::BlockPtr SialOpsParallel::wait_and_check(Block::BlockPtr b, int line) {
if (b->state().pending()) {
if (sialx_timers_){
sialx_timers_->start_timer(line, SialxTimer::BLOCKWAITTIME);
b->state().wait(b->size());
sialx_timers_->pause_timer(line, SialxTimer::BLOCKWAITTIME);
}
else b->state().wait(b->size());
}
return b;
}
//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;
}
