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2 Commits

Author SHA1 Message Date
c8a3a6d4e3 Add MT merger 2023-11-03 11:32:02 +01:00
cd742751ed mobile optimization 2023-11-03 09:03:36 +01:00
4 changed files with 65 additions and 15 deletions

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@ -19,7 +19,8 @@ add_custom_target(task1_7_dataset
${CMAKE_CURRENT_BINARY_DIR}/dataset.dat)
add_executable(task1_7 main.cpp
mergesort.h)
mergesort.h
mergesort_mt.h)
target_link_libraries(task1_7
fmt::fmt

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@ -54,24 +54,25 @@ auto main(int argc, char *argv[]) -> int {
auto dataset_seq = dataset;
auto t1 = std::chrono::high_resolution_clock::now();
algo::MergeSort_v1::sort(dataset_seq.begin(), dataset_seq.end(), [](int32_t a, int32_t b) {
algo::MergeSort_mt::sort(dataset_seq, [](int32_t a, int32_t b) {
return (a > b);
});
}, 0);
auto t2 = std::chrono::high_resolution_clock::now();
auto delay_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t2 - t1);
fmt::print("Sorted {} entries within {} ms in sequential\n", dataset_seq.size(), delay_ms.count());
const int nthreads = std::thread::hardware_concurrency();
//const int max_depth = std::thread::hardware_concurrency();
const int max_depth = 4;
t1 = std::chrono::high_resolution_clock::now();
algo::MergeSort_mt::sort(dataset_par, [](int32_t a, int32_t b) {
return (a > b);
}, nthreads);
}, max_depth);
t2 = std::chrono::high_resolution_clock::now();
delay_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t2 - t1);
fmt::print("Sorted {} entries within {} ms in parallel using {} threads\n", dataset_seq.size(), delay_ms.count(), nthreads);
fmt::print("Sorted {} entries within {} ms in parallel using {} threads\n", dataset_seq.size(), delay_ms.count(), max_depth);
auto eq = (dataset_seq == dataset_par);
fmt::print("Equality: {}\n", eq);

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@ -305,7 +305,7 @@ namespace algo {
while (l < left.end() && r < right.end()) {
if (cmp(*l, *r)) {
output.insert(o, *l);
outpbufut.insert(o, *l);
l++;
} else {
output.insert(o, *r);
@ -327,7 +327,7 @@ namespace algo {
}
template<typename T, typename Comparator>
static auto split(std::vector<T> data, Comparator cmp, int depth, int &num_threads,
static auto split(std::vector<T> data, Comparator cmp, int depth, int &max_depth,
std::mutex &mut) -> std::vector<T>{
if (data.size() <= 1) {
@ -350,15 +350,15 @@ namespace algo {
std::vector<T> left(data.begin(), mid);
std::vector<T> right(mid, data.end());
if (depth < num_threads) {
std::thread left_thread([&]() { left = split(left, cmp, depth + 1, num_threads, mut); });
std::thread right_thread([&]() { right = split(right, cmp, depth + 1, num_threads, mut); });
if (depth < max_depth) {
std::thread left_thread([&]() { left = split(left, cmp, depth + 1, max_depth, mut); });
std::thread right_thread([&]() { right = split(right, cmp, depth + 1, max_depth, mut); });
left_thread.join();
right_thread.join();
} else {
left = split(left, cmp, depth + 1, num_threads, mut);
right = split(right, cmp, depth + 1, num_threads, mut);
left = split(left, cmp, depth + 1, max_depth, mut);
right = split(right, cmp, depth + 1, max_depth, mut);
}
return merge(left, right, cmp, mut);
@ -367,12 +367,12 @@ namespace algo {
public:
template<typename T, typename Comparator>
static auto
sort(std::vector<T> &data, Comparator cmp, int num_threads = std::thread::hardware_concurrency()) -> void {
sort(std::vector<T> &data, Comparator cmp, int max_depth = 0) -> void {
std::mutex local_result_lock;
std::vector<T> output;
output.reserve(data.size());
output = split(data, cmp, 0, num_threads, local_result_lock);
output = split(data, cmp, 0, max_depth, local_result_lock);
data.assign(output.begin(), output.end());
}
};

48
task1/mergesort_mt.h Normal file
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@ -0,0 +1,48 @@
#include <vector>
#include <span>
#include <thread>
#include <mutex>
template<typename T, typename C>
class MergeSorterMT {
C comp;
std::recursive_mutex mut;
auto merge(std::span<T> &output, std::span<T> left, std::span<T> right) -> void {
std::vector<T> buf;
buf.reserver(left.size() + right.size());
auto l = left.begin();
auto r = right.begin();
auto o = buf.begin();
hile (l < left.end() && r < right.end()) {
if (cmp(*l, *r)) {
buf.insert(o, *l);
l++;
} else {
buf.insert(o, *r);
r++;
}
o++;
}
while (l < left.end()) {
buf.insert(o, *l);
o++;
l++;
}
while (r < right.end()) {
buf.insert(o, *r);
o++;
r++;
}
{
std::lock_guard<std::recursive_mutex> lock(mut);
std::move(buf.begin(), buf.end(), output.begin());
}
}
};