From d57c82f4969bfc7c523375bcedfd83139284fcb9 Mon Sep 17 00:00:00 2001
From: augustin64 <me.git@augustin64.fr>
Date: Sun, 31 Mar 2024 18:27:05 +0200
Subject: [PATCH] TP1: VMap: Initial commit

---
 TP/TP1/rendu/vmap.c | 132 ++++++++++++++++++++++++++++++++++++++++++++
 TP/TP1/rendu/vmap.h |  32 ++++++++++-
 2 files changed, 161 insertions(+), 3 deletions(-)
 create mode 100644 TP/TP1/rendu/vmap.c

diff --git a/TP/TP1/rendu/vmap.c b/TP/TP1/rendu/vmap.c
new file mode 100644
index 0000000..70ad2e3
--- /dev/null
+++ b/TP/TP1/rendu/vmap.c
@@ -0,0 +1,132 @@
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#include "vmap.h"
+
+VMap* vmap_init() {
+    VMap* vmap = (VMap*)malloc(sizeof(VMap));
+    vmap->mmap = mmap_init();
+    vmap->pages = createLinkedList();
+    vmap->index = 0;
+
+    return vmap;
+}
+
+PageMapInfo* vmap_new_page(VMap* vmap) {
+    PageMapInfo* page = (PageMapInfo*)malloc(sizeof(PageMapInfo));
+    
+    bool moved;
+    page->key = page_create(vmap->mmap, &moved)->key;
+    page->start = vmap->index;
+    page->cursor = 0;
+    page->nb_allocs = 0;
+    page->swapped = moved;
+
+    vmap->index += 4096;
+
+    insertFirst(vmap->pages, page->start, page);
+
+    return page;
+}
+
+int page_map_available_size(PageMapInfo* page) {
+    int avail = page->start + 4096 - page->cursor;
+    assert(avail >= 0);
+    return avail;
+}
+
+
+void vmap_free_page(VMap* vmap, PageMapInfo* page) {
+    deleteElement(vmap->pages, page->key);
+    page_remove(vmap->mmap, page->key);
+    free(page);
+}
+
+PageMapInfo* vmap_get_page(VMap* vmap, void* ptr) {
+    node* current = vmap->pages->head;
+    while (current) {
+        PageMapInfo* page = current->data;
+        if (page->start <= (int64_t)ptr && page->start+4096 > (int64_t)ptr) {
+            return page;
+        }
+        current = current->next;
+    }
+    return NULL;
+}
+
+void vmap_unswap(VMap* vmap, PageMapInfo* page) {
+    if (!page->swapped)
+        return;
+
+    read_from_swap(vmap->mmap, page_lookup(vmap->mmap, page->key));
+    page->swapped = false;
+}
+
+
+void* my_malloc(VMap* vmap, int size) {
+    // Parcours de la liste pour trouver un candidat. Sinon, nouvelle page
+    node* current = vmap->pages->head;
+    while (current) {
+        PageMapInfo* page = current->data;
+        if (page_map_available_size(page) >= size) {
+            void* ptr = (void*)((uint64_t)page->start+page->cursor);
+            page->cursor += size;
+            page->nb_allocs++;
+
+            return ptr;
+        }
+        current = current->next;
+    }
+
+    PageMapInfo* page = vmap_new_page(vmap);
+
+    void* ptr = (void*)((uint64_t)page->start+page->cursor);
+    page->cursor += size;
+    page->nb_allocs++;
+
+    return ptr;
+}
+
+void my_free(VMap* vmap, void* ptr) {
+    PageMapInfo* page = vmap_get_page(vmap, ptr);
+
+    if (!page) {
+        fprintf(stderr, "my_free: Double free or memory corrupted\n");
+        exit(1);
+    }
+
+    page->nb_allocs--;       
+    if (page->nb_allocs == 0) {
+        vmap_free_page(vmap, page);
+    }
+}
+
+void my_copy(VMap* vmap, void* src, void* dst, int size) {
+    PageMapInfo* page_map_src =  vmap_get_page(vmap, src);
+    PageMapInfo* page_map_dst =  vmap_get_page(vmap, dst);
+
+    if (((int64_t)src % 4096) + size >= 4096) {
+        fprintf(stderr, "my_copy: size not available in this src page\n");
+        exit(1);
+    }
+
+    if (((int64_t)dst % 4096) + size >= 4096) {
+        fprintf(stderr, "my_copy: size not available in this dst page\n");
+        exit(1);
+    }
+
+    if (page_map_src->swapped) {
+        vmap_unswap(vmap, page_map_src);
+    }
+    if (page_map_dst->swapped) {
+        vmap_unswap(vmap, page_map_dst);
+    }
+
+    PageInfo* page_src = page_lookup(vmap->mmap, page_map_src->key);
+    PageInfo* page_dst = page_lookup(vmap->mmap, page_map_dst->key);
+
+    memcpy(page_dst->data, page_src->data, size);
+}
\ No newline at end of file
diff --git a/TP/TP1/rendu/vmap.h b/TP/TP1/rendu/vmap.h
index fb30ca8..30a29c0 100644
--- a/TP/TP1/rendu/vmap.h
+++ b/TP/TP1/rendu/vmap.h
@@ -1,3 +1,29 @@
-void *my_malloc(int size);
-void my_free(void *data);
-void my_copy(void *mem, void *data, int size);
\ No newline at end of file
+#ifndef DEF_VMAP_H
+#define DEF_VMAP_H
+
+#include "mmap.h"
+
+typedef struct VMap {
+    MMap* mmap;
+    linkedList* pages;
+    int index; // index of virt memory
+} VMap;
+
+typedef struct PageMapInfo {
+    int start;
+    int key; // key for mmap
+    int cursor; // Last allocation end
+    int nb_allocs; // Free page if 0
+    bool swapped;
+} PageMapInfo;
+
+/**
+ * Get page hosting a certain pointer
+*/
+PageMapInfo* vmap_get_page(VMap* vmap, void* ptr);
+
+void* my_malloc(VMap* vmap, int size);
+void my_free(VMap* vmap, void* ptr);
+void my_copy(VMap* vmap, void* src, void* dst, int size);
+
+#endif
\ No newline at end of file