absolutely amazingly, basically working skip list

src/arch/x86/kmain.cpp

@@ -10,6 +10,7 @@
 #include "memman.hpp"
 #include "misc.hpp"
 #include "mutex.hpp"
+#include "rand.h"
 #include "serial.hpp"
 #include "task.hpp"
 #include "timer.hpp"
@@ -165,6 +166,9 @@ void kmain() {
         (*ctor)();
 
     init_timer();
+    
+    srand(micros);// NOLINT
+
     new_ktask(ktask_main, "ktask_main");
     new_ktask(dummy_task, "dummy");
     init_tasks();

src/kernel/CMakeLists.txt

@@ -1,5 +1,5 @@
 target_include_directories(kernel.elf PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 
-target_sources(kernel.elf PRIVATE mutex.cpp cv.cpp cppsupport.cpp Spinlock.cpp LockGuard.cpp)
+target_sources(kernel.elf PRIVATE mutex.cpp cv.cpp cppsupport.cpp Spinlock.cpp LockGuard.cpp rand.c)
 
 add_subdirectory(templates)

src/kernel/rand.c

@@ -0,0 +1,19 @@
+//
+// Created by Stepan Usatiuk on 21.10.2023.
+//
+
+#include "rand.h"
+
+// The following functions define a portable implementation of rand and srand.
+
+static unsigned long int next = 1;// NB: "unsigned long int" is assumed to be 32 bits wide
+
+int rand(void)// RAND_MAX assumed to be 32767
+{
+    next = next * 1103515245 + 12345;
+    return (unsigned int) (next / 65536ULL) % 32768;
+}
+
+void srand(unsigned int seed) {
+    next = seed;
+}

src/kernel/rand.h

@@ -0,0 +1,21 @@
+//
+// Created by Stepan Usatiuk on 21.10.2023.
+//
+
+#ifndef OS2_RAND_H
+#define OS2_RAND_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// The following functions define a portable implementation of rand and srand.
+#define RAND_MAX 32767
+int rand(void);
+void srand(unsigned int seed);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif//OS2_RAND_H

src/kernel/string.h

@@ -5,8 +5,12 @@
 #ifndef OS2_STRING_H
 #define OS2_STRING_H
 
-#include <cstddef>
-#include <cstdint>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stddef.h>
+#include <stdint.h>
 
 inline void *memcpy(void *dest, const void *src, size_t n) {
     uint8_t *pdest = (uint8_t *) dest;
@@ -98,4 +102,8 @@ inline void strcpy(const char *src, char *dst) {
     dst[i] = '\0';
 }
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif//OS2_STRING_H

src/kernel/templates/SkipList.hpp

@@ -1,24 +1,17 @@
 #ifndef SKIPLIST_H
 #define SKIPLIST_H
-static bool seedSet = false;
 
-class SeedSetter {
-public:
-    SeedSetter() noexcept {
-        if (!seedSet) {
-            std::cout << "seed set!" << std::endl;
-            srand(time(nullptr));// NOLINT
-            seedSet = true;
-        }
-    }
-};
+#include <cstddef>
+#include <cstdint>
+#include <type_traits>
+#include <utility>
 
-[[maybe_unused]] static SeedSetter seedSetter;
+#include "rand.h"
+#include "serial.hpp"
 
 template<typename K, typename V>
 class SkipList {
     static constexpr size_t maxL{31};
-    friend SkipListTester;
 
 public:
     struct Node {
@@ -41,13 +34,14 @@ private:
 
         ~NodeAllocator() noexcept {
             for (int i = top; i >= 0; i--) {
-                delete nodes[i];
+                //                delete nodes[i];
             }
         }
 
         void push(Node *&e) {
             if (top >= size - 1) {
-                delete e;
+                // TODO: ????
+                //                delete e;
                 return;
             }
             nodes[++top] = e;
@@ -72,10 +66,13 @@ private:
     };
 
     static int randomL() {
-        return ffs(rand()) - 1;// NOLINT
+        int ret = __builtin_ffs(rand());
+        assert(ret >= 0);
+        return ret;// NOLINT
     }
 
-    static inline NodeAllocator nodeAllocator;
+    //    static inline NodeAllocator nodeAllocator;
+    NodeAllocator nodeAllocator;
 
     Node *root;
     Node *endnode;
@@ -355,7 +352,7 @@ public:
 
 
     struct SkipListIterator {
-        using iterator_category = std::forward_iterator_tag;
+        //        using iterator_category = std::forward_iterator_tag;
         using difference_type = std::ptrdiff_t;
         using value_type = const V;
         using pointer = value_type *;
@@ -400,20 +397,20 @@ public:
 
     const_iterator end() const { return SkipListIterator(endnode); }
 
-    void print() const {
-        std::cout << "LIST STATUS" << std::endl;
-
-        for (size_t i = 0; i <= curL; i++) {
-            Node *n = root->next[i];
-            std::cout << "L " << i << ": ";
-            while (n != nullptr && n->next[0]) {
-                std::cout << "GUARD: " << n->end << " KEY: " << n->key << " RANGE: " << n->data
-                          << " <<<<<";
-                n = n->next[i];
-            }
-            std::cout << std::endl;
-        }
-    };
+    //    void print() const {
+    //        std::cout << "LIST STATUS" << std::endl;
+    //
+    //        for (size_t i = 0; i <= curL; i++) {
+    //            Node *n = root->next[i];
+    //            std::cout << "L " << i << ": ";
+    //            while (n != nullptr && n->next[0]) {
+    //                std::cout << "GUARD: " << n->end << " KEY: " << n->key << " RANGE: " << n->data
+    //                          << " <<<<<";
+    //                n = n->next[i];
+    //            }
+    //            std::cout << std::endl;
+    //        }
+    //    };
 };
 
 

src/kernel/templates/TestTemplates.cpp

@@ -5,6 +5,7 @@
 #include "TestTemplates.hpp"
 
 
+#include "SkipList.hpp"
 #include "String.hpp"
 #include "Vector.hpp"
 #include "serial.hpp"
@@ -144,41 +145,39 @@ public:
     }
 };
 
-//class SkipListTester {
-//public:
-//    bool test() {
-//        SkipList<int, std::string> test1;
-//
-//        test1.add(5, "test5", false);
-//        test1.add(999, "test999", false);
-//        test1.add(5, "test5", false);
-//        test1.add(1, "test1", false);
-//        test1.add(999, "test999", false);
-//
-//        assert(test1.find(5)->data == "test5");
-//        assert(test1.find(1)->data == "test1");
-//        assert(test1.find(999)->data == "test999");
-//
-//        test1.erase(1);
-//        assert(test1.find(1)->data != "test1");
-//        test1.add(87, "test87", false);
-//        assert(test1.find(87)->data == "test87");
-//
-//        auto p2 = test1.lower_bound_update(78);
-//        assert(p2->data == "test87");
-//        test1.add(78, "test78", true);
-//        assert(test1.find(78)->data == "test78");
-//
-//        assert(IT::test());
-//
-//        return true;
-//    }
-//};
-//
+class SkipListTester {
+public:
+    bool test() {
+        SkipList<int, String> test1;
+
+        test1.add(5, "test5", false);
+        test1.add(999, "test999", false);
+        test1.add(5, "test5", false);
+        test1.add(1, "test1", false);
+        test1.add(999, "test999", false);
+
+        assert(test1.find(5)->data == "test5");
+        assert(test1.find(1)->data == "test1");
+        assert(test1.find(999)->data == "test999");
+
+        test1.erase(1);
+        assert(test1.find(1)->data != "test1");
+        test1.add(87, "test87", false);
+        assert(test1.find(87)->data == "test87");
+
+        auto p2 = test1.lower_bound_update(78);
+        assert(p2->data == "test87");
+        test1.add(78, "test78", true);
+        assert(test1.find(78)->data == "test78");
+
+        return true;
+    }
+};
+
 int test_templates() {
 
-    //    SkipListTester SLTester;
-    //    SLTester.test();
+    SkipListTester SLTester;
+    SLTester.test();
     StringTester stringTester;
     stringTester.test();
     VectorTester vectorTester;