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/*
* WaitUtils.cpp
*
* Copyright (C) 2009-12 by RStudio, Inc.
*
* This program is licensed to you under the terms of version 3 of the
* GNU Affero General Public License. This program is distributed WITHOUT
* ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
* AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
*
*/
#include
#include
#include
namespace core {
Error waitWithTimeout(const boost::function& waitFunction,
int initialWaitMs,
int incrementWaitMs,
int maxWaitSec)
{
// wait for the session to be available
using boost::system_time;
using namespace boost::posix_time;
using namespace boost::system;
// wait 30ms (this value is somewhat arbitrary -- ideally it would
// be as close as possible to the expected total launch time of
// rsession (observed to be ~35ms on a 3ghz MacPro w/ SSD disk)
boost::this_thread::sleep(milliseconds(initialWaitMs));
// try the connection again and if we don't get it try to reconnect
// every 10ms until a timeout occurs -- we use a low granularity
// here because expect our initial guess of 30ms to be pretty close
// to the total launch time
boost::system_time timeoutTime = boost::get_system_time() + seconds(maxWaitSec);
while(boost::get_system_time() < timeoutTime)
{
WaitResult result = waitFunction();
if (result.type == WaitSuccess)
return Success();
if (result.type == WaitContinue)
{
// try again after waiting a short while
boost::this_thread::sleep(milliseconds(incrementWaitMs));
continue;
}
else /* if (result.type == WaitError) */
{
// unrecoverable error (return connectError below)
return result.error;
}
}
return systemError(boost::system::errc::timed_out, ERROR_LOCATION);
}
} // namespace core