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/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Additional permission under GNU GPL version 3 section 7
*
* If you modify this Program, or any covered work, by linking or combining
* it with OpenSSL (or a modified version of that library), containing parts
* covered by the terms of OpenSSL License and SSLeay License, the licensors
* of this Program grant you additional permission to convey the resulting work.
*
*/
#include "miner_work.hpp"
#include "globalStates.hpp"
#include <assert.h>
#include <cmath>
#include <chrono>
#include <cstring>
namespace xmrstak
{
void globalStates::consume_work( miner_work& threadWork, uint64_t& currentJobId)
{
/* Only the executer thread which updates the job is ever setting iConsumeCnt
* to 1000. In this case each consumer must wait until the job is fully updated.
*/
uint64_t numConsumer = 0;
/* Take care that we not consume a job if the job is updated.
* If we leave the loop we have increased iConsumeCnt so that
* the job will not be updated until we leave the method.
*/
do{
numConsumer = iConsumeCnt.load(std::memory_order_relaxed);
if(numConsumer < 1000)
{
// register that thread try consume job data
numConsumer = ++iConsumeCnt;
if(numConsumer >= 1000)
{
iConsumeCnt--;
// 11 is a arbitrary chosen prime number
std::this_thread::sleep_for(std::chrono::milliseconds(11));
}
}
else
{
// an other thread is preparing a new job, 11 is a arbitrary chosen prime number
std::this_thread::sleep_for(std::chrono::milliseconds(11));
}
}
while(numConsumer >= 1000);
threadWork = oGlobalWork;
currentJobId = iGlobalJobNo.load(std::memory_order_relaxed);
// signal that thread consumed work
iConsumeCnt--;
}
void globalStates::switch_work(miner_work& pWork, pool_data& dat)
{
/* 1000 is used to notify that the the job will be updated as soon
* as all consumer (which currently coping oGlobalWork has copied
* all data)
*/
iConsumeCnt += 1000;
// wait until all threads which entered consume_work are finished
while (iConsumeCnt.load(std::memory_order_relaxed) > 1000)
{
// 7 is a arbitrary chosen prime number which is smaller than the consumer waiting time
std::this_thread::sleep_for(std::chrono::milliseconds(7));
}
// BEGIN CRITICAL SECTION
// this notifies all threads that the job has changed
iGlobalJobNo++;
size_t xid = dat.pool_id;
dat.pool_id = pool_id;
pool_id = xid;
/* Maybe a worker thread is updating the nonce while we read it.
* In that case GPUs check the job ID after a nonce update and in the
* case that it is a CPU thread we have a small chance (max 6 nonces per CPU thread)
* that we recalculate a nonce after we reconnect to the current pool
*/
dat.iSavedNonce = iGlobalNonce.exchange(dat.iSavedNonce, std::memory_order_relaxed);
oGlobalWork = pWork;
// END CRITICAL SECTION: allow job consume
iConsumeCnt -= 1000;
}
} // namespace xmrstak
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