forked from premiere/premiere-libtorrent
329 lines
8.5 KiB
C++
329 lines
8.5 KiB
C++
/*
|
|
|
|
Copyright (c) 2003, Magnus Jonsson
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the distribution.
|
|
* Neither the name of the author nor the names of its
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_ALLOCATE_RESOURCES_IMPL_HPP_INCLUDED
|
|
#define TORRENT_ALLOCATE_RESOURCES_IMPL_HPP_INCLUDED
|
|
|
|
#include <map>
|
|
#include <utility>
|
|
|
|
#include <boost/shared_ptr.hpp>
|
|
|
|
#include "libtorrent/resource_request.hpp"
|
|
#include "libtorrent/peer_id.hpp"
|
|
#include "libtorrent/socket.hpp"
|
|
#include "libtorrent/size_type.hpp"
|
|
|
|
#ifdef min
|
|
#undef min
|
|
#endif
|
|
|
|
#ifdef max
|
|
#undef max
|
|
#endif
|
|
|
|
namespace libtorrent
|
|
{
|
|
|
|
int saturated_add(int a, int b);
|
|
|
|
namespace aux
|
|
{
|
|
// give num_resources to r,
|
|
// return how how many were actually accepted.
|
|
inline int give(resource_request& r, int num_resources)
|
|
{
|
|
assert(num_resources >= 0);
|
|
assert(r.given <= r.max);
|
|
|
|
int accepted = (std::min)(num_resources, r.max - r.given);
|
|
assert(accepted >= 0);
|
|
|
|
r.given += accepted;
|
|
assert(r.given <= r.max);
|
|
|
|
return accepted;
|
|
}
|
|
|
|
inline int div_round_up(int numerator, int denominator)
|
|
{
|
|
return (numerator + denominator - 1) / denominator;
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
|
|
template<class It, class T>
|
|
class allocate_resources_contract_check
|
|
{
|
|
int m_resources;
|
|
It m_start;
|
|
It m_end;
|
|
resource_request T::* m_res;
|
|
|
|
public:
|
|
allocate_resources_contract_check(
|
|
int resources
|
|
, It start
|
|
, It end
|
|
, resource_request T::* res)
|
|
: m_resources(resources)
|
|
, m_start(start)
|
|
, m_end(end)
|
|
, m_res(res)
|
|
{
|
|
assert(m_resources >= 0);
|
|
for (It i = m_start, end(m_end); i != end; ++i)
|
|
{
|
|
assert(((*i).*m_res).max >= 0);
|
|
assert(((*i).*m_res).given >= 0);
|
|
}
|
|
}
|
|
|
|
~allocate_resources_contract_check()
|
|
{
|
|
int sum_given = 0;
|
|
int sum_max = 0;
|
|
int sum_min = 0;
|
|
for (It i = m_start, end(m_end); i != end; ++i)
|
|
{
|
|
assert(((*i).*m_res).max >= 0);
|
|
assert(((*i).*m_res).min >= 0);
|
|
assert(((*i).*m_res).max >= ((*i).*m_res).min);
|
|
assert(((*i).*m_res).given >= 0);
|
|
assert(((*i).*m_res).given <= ((*i).*m_res).max);
|
|
|
|
sum_given = saturated_add(sum_given, ((*i).*m_res).given);
|
|
sum_max = saturated_add(sum_max, ((*i).*m_res).max);
|
|
sum_min = saturated_add(sum_min, ((*i).*m_res).min);
|
|
}
|
|
if (sum_given != (std::min)(std::max(m_resources, sum_min), sum_max))
|
|
{
|
|
std::cerr << sum_given << " " << m_resources << " " << sum_min << " " << sum_max << std::endl;
|
|
assert(false);
|
|
}
|
|
}
|
|
};
|
|
|
|
#endif
|
|
|
|
template<class It, class T>
|
|
void allocate_resources_impl(
|
|
int resources
|
|
, It start
|
|
, It end
|
|
, resource_request T::* res)
|
|
{
|
|
assert(resources >= 0);
|
|
#ifndef NDEBUG
|
|
allocate_resources_contract_check<It, T> contract_check(
|
|
resources
|
|
, start
|
|
, end
|
|
, res);
|
|
#endif
|
|
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
resource_request& r = (*i).*res;
|
|
r.leftovers = (std::max)(r.used - r.given, 0);
|
|
}
|
|
|
|
if (resources == resource_request::inf)
|
|
{
|
|
// No competition for resources.
|
|
// Just give everyone what they want.
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
((*i).*res).given = ((*i).*res).max;
|
|
}
|
|
return;
|
|
}
|
|
|
|
// Resources are scarce
|
|
|
|
int sum_max = 0;
|
|
int sum_min = 0;
|
|
// the number of consumer that saturated their
|
|
// quota last time slice
|
|
int num_saturated = 0;
|
|
// the total resources those that saturated their
|
|
// quota used. This is used to calculate the mean
|
|
// of the saturating consumers, in order to
|
|
// balance their quotas for the next time slice.
|
|
size_type saturated_sum = 0;
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
resource_request& r = (*i).*res;
|
|
sum_max = saturated_add(sum_max, r.max);
|
|
assert(r.min < resource_request::inf);
|
|
assert(r.min >= 0);
|
|
assert(r.min <= r.max);
|
|
sum_min += r.min;
|
|
|
|
// a consumer that uses 95% or more of its assigned
|
|
// quota is considered saturating
|
|
size_type used = r.used;
|
|
if (r.given == 0) continue;
|
|
if (used * 20 / r.given >= 19)
|
|
{
|
|
++num_saturated;
|
|
saturated_sum += r.given;
|
|
}
|
|
}
|
|
|
|
if (sum_max <= resources)
|
|
{
|
|
// it turns out that there's no competition for resources
|
|
// after all.
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
((*i).*res).given = ((*i).*res).max;
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (sum_min >= resources)
|
|
{
|
|
// the amount of resources is smaller than
|
|
// the minimum resources to distribute, so
|
|
// give everyone the minimum
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
((*i).*res).given = ((*i).*res).min;
|
|
}
|
|
return;
|
|
}
|
|
|
|
// now, the "used" field will be used as a target value.
|
|
// the algorithm following this loop will then scale the
|
|
// used values to fit the available resources and store
|
|
// the scaled values as given. So, the ratios of the
|
|
// used values will be maintained.
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
resource_request& r = (*i).*res;
|
|
|
|
int target;
|
|
size_type used = r.used;
|
|
if (r.given > 0 && used * 20 / r.given >= 19)
|
|
{
|
|
assert(num_saturated > 0);
|
|
target = div_round_up(saturated_sum, num_saturated);
|
|
target += div_round_up(target, 10);
|
|
}
|
|
else
|
|
{
|
|
target = r.used;
|
|
}
|
|
if (target > r.max) target = r.max;
|
|
else if (target < r.min) target = r.min;
|
|
|
|
// move 50% towards the the target value
|
|
r.used = r.given + div_round_up(target - r.given, 2);
|
|
r.given = r.min;
|
|
}
|
|
|
|
|
|
resources = (std::max)(resources, sum_min);
|
|
int resources_to_distribute = (std::min)(resources, sum_max) - sum_min;
|
|
assert(resources_to_distribute >= 0);
|
|
#ifndef NDEBUG
|
|
int prev_resources_to_distribute = resources_to_distribute;
|
|
#endif
|
|
while (resources_to_distribute > 0)
|
|
{
|
|
// in order to scale, we need to calculate the sum of
|
|
// all the used values.
|
|
size_type total_used = 0;
|
|
size_type max_used = 0;
|
|
for (It i = start; i != end; ++i)
|
|
{
|
|
resource_request& r = (*i).*res;
|
|
if (r.given == r.max) continue;
|
|
|
|
assert(r.given < r.max);
|
|
|
|
max_used = (std::max)(max_used, (size_type)r.used + 1);
|
|
total_used += (size_type)r.used + 1;
|
|
}
|
|
|
|
|
|
size_type kNumer = resources_to_distribute;
|
|
size_type kDenom = total_used;
|
|
assert(kNumer >= 0);
|
|
assert(kDenom >= 0);
|
|
assert(kNumer <= (std::numeric_limits<int>::max)());
|
|
|
|
if (kNumer * max_used <= kDenom)
|
|
{
|
|
kNumer = 1;
|
|
kDenom = max_used;
|
|
assert(kDenom >= 0);
|
|
}
|
|
|
|
for (It i = start; i != end && resources_to_distribute > 0; ++i)
|
|
{
|
|
resource_request& r = (*i).*res;
|
|
if (r.given == r.max) continue;
|
|
|
|
assert(r.given < r.max);
|
|
|
|
size_type used = (size_type)r.used + 1;
|
|
if (used < 1) used = 1;
|
|
size_type to_give = used * kNumer / kDenom;
|
|
if (to_give > resources_to_distribute)
|
|
to_give = resources_to_distribute;
|
|
assert(to_give >= 0);
|
|
assert(to_give <= resources_to_distribute);
|
|
#ifndef NDEBUG
|
|
int tmp = resources_to_distribute;
|
|
#endif
|
|
resources_to_distribute -= give(r, (int)to_give);
|
|
assert(resources_to_distribute <= tmp);
|
|
assert(resources_to_distribute >= 0);
|
|
}
|
|
|
|
assert(resources_to_distribute >= 0);
|
|
assert(resources_to_distribute < prev_resources_to_distribute);
|
|
#ifndef NDEBUG
|
|
prev_resources_to_distribute = resources_to_distribute;
|
|
#endif
|
|
}
|
|
assert(resources_to_distribute == 0);
|
|
}
|
|
|
|
} // namespace libtorrent::aux
|
|
}
|
|
|
|
|
|
#endif
|