Added the working set, broke the program, segfault.

Kernel.cpp

@@ -4,8 +4,10 @@
 
 using std::next;
 
-Kernel::Kernel(const List<PhysicalPage> &free_pages, const List<PhysicalPage> &busy_pages)
+Kernel::Kernel(const unsigned int RunQ_max_length, const List<PhysicalPage> &free_pages,
-: free_pages(free_pages), busy_pages(busy_pages) {}
+               const List<PhysicalPage> &busy_pages) : free_pages(free_pages), busy_pages(busy_pages) {
+    RunQ.reserve(RunQ_max_length);
+}
 
 void Kernel::page_fault(std::vector<PTE> *page_table, const unsigned int idx) {
     std::cout << std::format("[kernel:page_fault] Handling {} started", idx) << std::endl;
@@ -16,20 +18,24 @@ void Kernel::page_fault(std::vector<PTE> *page_table, const unsigned int idx) {
         free_pages.remove(page);
         busy_pages.insert_tail(page);
 
-        std::cout << std::format("[kernel:page_fault:free] Found free page #{}, using it", page->PPN) << std::endl;
+        std::cout << std::format("[kernel:page_fault:free] Found free page #{}, using it",
+            page->PPN) << std::endl;
     } else {
         std::cout << "[kernel:page_fault] No free pages available, trying to swap..." << std::endl;
         for (PhysicalPage *curr = busy_pages.get_head();; curr = curr->next) {
             if ((*curr->PT)[curr->idx].R)
                 (*curr->PT)[curr->idx].R = false;
             else {
-                std::cout << std::format("[kernel:page_fault:random] Selected physical page #{} for replacement", curr->PPN) << std::endl;
+                std::cout << std::format("[kernel:page_fault:random] Selected physical page #{} for replacement",
+                                         curr->PPN) << std::endl;
 
-                curr->PT->erase(next(curr->PT->begin(), curr->idx));
+                // curr->PT->erase(next(curr->PT->begin(), curr->idx));
+                (*curr->PT)[curr->idx].P = false;
                 page = curr;
                 busy_pages.set_head(curr->next);
 
-                std::cout << std::format("[kernel:page_fault:random] Auto-advanced the list of busy pages to ppn {}", busy_pages.get_head()->PPN) << std::endl;
+                std::cout << std::format("[kernel:page_fault:random] Auto-advanced the list of busy pages to ppn {}",
+                                         busy_pages.get_head()->PPN) << std::endl;
                 break;
             }
         }
@@ -52,4 +58,5 @@ void Kernel::stat_update() {
             std::cout << std::format("[kernel:update_job] Updating ppn {} status", curr->PPN) << std::endl;
         }
     }
+    busy_pages.set_head(curr);
 }

Kernel.h

@@ -11,8 +11,8 @@
 class Kernel {
 public:
         List<PhysicalPage> free_pages, busy_pages;
-        List<Process> RunQ;
+        std::vector<Process> RunQ;
-        Kernel(const List<PhysicalPage> &free_pages, const List<PhysicalPage> &busy_pages);
+        Kernel(unsigned int RunQ_max_length, const List<PhysicalPage> &free_pages, const List<PhysicalPage> &busy_pages);
         void page_fault(std::vector<PTE> *page_table, unsigned int idx);
         void stat_update();
 

Process.cpp

@@ -1,19 +1,21 @@
 #include "Process.h"
 
+#include <iostream>
+#include <ostream>
 #include <random>
 #include <utility>
 
-Process::Process(const unsigned int id, std::vector<PTE> page_table, const unsigned int working_set_size,
+Process::Process(const unsigned int id, std::vector<PTE> page_table, const unsigned int execution_time, const unsigned int working_set_size)
-    const unsigned int execution_time) : page_table(std::move(page_table)), execution_time(execution_time), elapsed_time(0),
+: page_table(std::move(page_table)), execution_time(execution_time), id(id) {
-                                         id(id), next(nullptr), prev(nullptr) {
     std::random_device rd;
     std::mt19937 gen(rd());
-    std::uniform_int_distribution<unsigned int> page_table_distribution(0, this->page_table.size() - 1);
+    std::uniform_int_distribution<unsigned int> working_set_distribution(0, this->page_table.size() - 1);
+    std::cout << page_table.size() - 1 << std::endl;
     for (int i = 0; i < working_set_size; ++i) {
-        working_set.push_back(page_table_distribution(gen));
+        working_set.push_back(working_set_distribution(gen));
     }
 }
 
-bool Process::is_finished() const {
+bool Process::is_finished(const unsigned int elapsed_time) const {
     return elapsed_time >= execution_time;
 }

Process.h

@@ -7,13 +7,9 @@ class Process {
 public:
     std::vector<PTE> page_table;
     std::vector<unsigned int> working_set;
-    unsigned int execution_time, elapsed_time, id;
+    unsigned int execution_time, id;
-    Process *next, *prev;
+    Process(unsigned int id, std::vector<PTE> page_table, unsigned int execution_time, unsigned int working_set_size);
-
+    [[nodiscard]] bool is_finished(unsigned int elapsed_time) const;
-    Process(unsigned int id, std::vector<PTE> page_table, unsigned int working_set_size, unsigned int execution_time);
-    [[nodiscard]] bool is_finished() const;
 };
 
-
-
 #endif //PROCESS_H

main.cpp

@@ -14,42 +14,48 @@ int main() {
     std::mt19937 gen(rd());
     std::uniform_int_distribution<unsigned int> page_table_distribution(500, 1000), lifetime_distribution(50, 500), access_type_distr(1, 10);
 
-    Kernel kernel = Kernel(List<PhysicalPage>(), List<PhysicalPage>());
+    Kernel kernel(MAX_PROC, List<PhysicalPage>(), List<PhysicalPage>());
     unsigned int elapsed_time = 0, new_proc_time = 0, new_ppn;
 
     for (new_ppn = 1; new_ppn <= PAGE_N; ++new_ppn) {
         kernel.free_pages.insert_head(new PhysicalPage(new_ppn));
     }
 
-    for (int i = 0; i < MAX_PROC; ++i) {
+    for (int i = 0; i < kernel.RunQ.capacity(); ++i) {
-        kernel.RunQ.insert_head(new Process(i, std::vector(page_table_distribution(gen), PTE()), WORKING_SET_SIZE, lifetime_distribution(gen)));
+        kernel.RunQ.emplace_back(i, std::vector(page_table_distribution(gen), PTE()), lifetime_distribution(gen),
+                                 WORKING_SET_SIZE);
     }
 
     for (int i = 0; i < 10'000; ++i) {
-        Process *current_process = kernel.RunQ.get_head();
+        const int process_index = i % kernel.RunQ.size();
+
+        if (kernel.RunQ.empty()) {
+            break;
+        }
 
         std::uniform_int_distribution<unsigned int> index_distribution;
         for (int j = 0; j < 30; ++j) {
-            const AccessType type = access_type_distr(gen) == 1 ? WRITE : READ;
+            const AccessType access_type = access_type_distr(gen) == 1 ? WRITE : READ;
 
             if (access_type_distr(gen) == 1) {
-                index_distribution = std::uniform_int_distribution<unsigned int>(0, current_process->page_table.size() - 1);
+                index_distribution = std::uniform_int_distribution<unsigned int>(0, kernel.RunQ.at(process_index).page_table.size() - 1);
                 const unsigned int table_index = index_distribution(gen);
-                MMU::access(kernel, &current_process->page_table, table_index, type);
+                MMU::access(kernel, &kernel.RunQ.at(process_index).page_table, table_index, access_type);
-            } else {
+            }
-                index_distribution = std::uniform_int_distribution<unsigned int>(0, current_process->working_set.size() - 1);
+            else {
-                const unsigned int table_index = index_distribution(gen);
+                index_distribution = std::uniform_int_distribution<unsigned int>(0, kernel.RunQ.at(process_index).working_set.size() - 1);
-                MMU::access(kernel, &current_process->page_table, current_process->working_set[table_index], type);
+                const unsigned int table_index = kernel.RunQ.at(process_index).working_set[index_distribution(gen)];
+                MMU::access(kernel, &kernel.RunQ.at(process_index).page_table, table_index, access_type);
             }
         }
 
-        ++current_process->elapsed_time;
+        ++elapsed_time;
         ++new_proc_time;
 
         kernel.stat_update();
 
-        if (current_process->is_finished()) {
+        if (kernel.RunQ.at(process_index).is_finished(elapsed_time)) {
-            std::cout << std::format("[kernel:remove_current_process] Cleaning up process id {}", current_process->id) << std::endl;
+            std::cout << std::format("[kernel:remove_current_process] Cleaning up process id {}", kernel.RunQ.at(process_index).id) << std::endl;
 
             PhysicalPage *curr, *cached_next;
             unsigned int j;
@@ -58,19 +64,20 @@ int main() {
                  curr && j < cached_len;
                  curr = cached_next, ++j) {
                 cached_next = curr->next;
-                if (curr->PT == &current_process->page_table) {
+                if (curr->PT == &kernel.RunQ.at(process_index).page_table) {
                     std::cout << std::format("[kernel:remove_current_process] Found ppn #{}, freeing it", curr->PPN) << std::endl;
 
                     kernel.busy_pages.remove(curr);
+
+                    curr->PT = nullptr;
+
                     kernel.free_pages.insert_tail(curr);
                 }
             }
-
+            kernel.RunQ.erase(kernel.RunQ.begin());
-            kernel.RunQ.set_head(current_process->next);
-            kernel.RunQ.remove(current_process);
 
             if (new_proc_time >= PROC_CREATION_INTERVAL) {
-                kernel.RunQ.insert_tail(new Process(new_ppn, std::vector(page_table_distribution(gen), PTE()), WORKING_SET_SIZE, lifetime_distribution(gen)));
+                kernel.RunQ.emplace_back(new_ppn, std::vector(page_table_distribution(gen), PTE()), lifetime_distribution(gen), WORKING_SET_SIZE);
                 ++new_ppn;
                 new_proc_time = 0;
             }
@@ -81,13 +88,10 @@ int main() {
             std::cout << std::format("[main:metrics] Memory usage stats: busy {}, free {}, total {}", busy_stat, free_stat, free_stat + busy_stat) << std::endl;
         }
 
-        if (kernel.RunQ.is_empty()) {
+        if (kernel.RunQ.empty()) {
             std::cout << "[main:scheduling] No processes left to execute!" << std::endl;
-            break;
         }
     }
 
-    std::cout << "[main:scheduling] Simulation finished." << std::endl;
-
     return 0;
 }