stage 2

inc/kernel.h

@@ -13,7 +13,6 @@ struct RunQ {
 struct RunQ *RunQ(size_t max_procs);
 void RUNQ_add_process(size_t max_page_accesses, size_t total_pages_owned);
 
-static struct RunQ *runq;
 
 
 struct PhysPage {
@@ -21,13 +20,10 @@ struct PhysPage {
 	size_t busy_flag;
 	struct PhysPage *prev;
 	struct PhysPage *next;
-	struct PageTable *pt;
+	struct PageTableEntry *pt;
 	size_t pt_index;
 };
 
-static struct PhysPage *first_free_page;
-static struct PhysPage *first_busy_page;
-
 
 void KERNEL_page_fault(struct PageTableEntry *pt, size_t page_no);
 

src/kernel.c

@@ -1,9 +1,17 @@
 #include <stddef.h>
 #include <stdlib.h>
+#include <stdio.h>
 
 #include "kernel.h"
 #include "process.h"
 
+
+extern struct RunQ *runq;
+
+extern struct PhysPage *first_free_page;
+extern struct PhysPage *first_busy_page;
+
+
 struct RunQ *
 RunQ(size_t max_procs)
 {
@@ -45,8 +53,39 @@ RUNQ_add_process(size_t max_page_accesses,
 void
 KERNEL_page_fault(struct PageTableEntry *pt, size_t page_no)
 {
+	printf("[kernel:page_fault] Handling %d started\n", page_no);
+
 	if (first_free_page) {
+		printf("[kernel:page_fault] Found free page #%d, using it\n", first_free_page->ppn);
 		pt[page_no].ppn = first_free_page->ppn;
 		pt[page_no].p = 1;
+
+		first_free_page->busy_flag = 1;
+		first_free_page->pt = pt;
+		first_free_page->pt_index = page_no;
+
+		// ---- free list -> busy list ----
+		struct PhysPage *this_page = first_free_page;
+
+		if (first_free_page->next != first_free_page) {
+			// reconnect free list items together
+			first_free_page->prev->next = first_free_page->next;
+			first_free_page->next->prev = first_free_page->prev;
+			first_free_page = first_free_page->next;
+		} else {
+			// clear list if it only had this page
+			first_free_page = NULL;
+		}
+
+		if (!first_busy_page) {
+			// initialize the busy list with this page
+			first_busy_page = this_page;
+		} else {
+			// insert this page at the end of the list
+			this_page->next = first_busy_page;
+			this_page->prev = first_busy_page->prev;
+			this_page->prev->next = this_page;
+			this_page->next->prev = this_page;
+		}
 	}
 }

src/main.c

@@ -3,15 +3,22 @@
 #include <stdlib.h>
 
 #include "kernel.h"
+#include "random.h"
 
 #include "config.h"
 
+
+struct RunQ *runq;
+
+struct PhysPage *first_free_page;
+struct PhysPage *first_busy_page;
+
 int
 main(void)
 {
 	first_busy_page = NULL;
 	
-	struct PhysPage *first_free_page = malloc(sizeof(struct PhysPage));
+	first_free_page = malloc(sizeof(struct PhysPage));
 	first_free_page->ppn = 0;
 	first_free_page->busy_flag = 0;
 	first_free_page->prev = first_free_page;
@@ -23,7 +30,7 @@ main(void)
 		pp->busy_flag = 0;
 
 		/*
-		 *        insert into here
+		 *      insert pp into here
 		 *               |
 		 *               v
 		 *           [ ]   [ ]   [ ]
@@ -38,7 +45,13 @@ main(void)
 	}
 
 	runq = RunQ(10);
-	RUNQ_add_process(10000, 50);
-	RUNQ_add_process(10000, 50);
-	RUNQ_add_process(10000, 50);
+
+	for (size_t i = 0; i < 5; i++) {
+		RUNQ_add_process(10000, 10 + randint(70));
+	}
+
+	for (int i = 0; i < 20; i++) {
+		PROCESS_run_for(runq->current_proc, 20);
+		runq->current_proc = runq->current_proc->next;
+	}
 }

src/mmu.c

@@ -1,3 +1,5 @@
+#include <stdio.h>
+
 #include "kernel.h"
 
 void MMU_read(struct PageTableEntry *pt, size_t page_no)
@@ -5,6 +7,7 @@ void MMU_read(struct PageTableEntry *pt, size_t page_no)
 	if (!pt[page_no].p)
 		KERNEL_page_fault(pt, page_no);
 
+	printf("[mmu:read] pt[%d] -> ppn %d\n", page_no, pt[page_no].ppn);
 	pt[page_no].r = 1;
 }
 
@@ -13,6 +16,7 @@ void MMU_write(struct PageTableEntry *pt, size_t page_no)
 	if (!pt[page_no].p)
 		KERNEL_page_fault(pt, page_no);
 
+	printf("[mmu:write] pt[%d] -> ppn %d\n", page_no, pt[page_no].ppn);
 	pt[page_no].r = 1;
 	pt[page_no].m = 1;
 }

src/process.c

@@ -31,10 +31,10 @@ size_t PROCESS_run_for(struct Process *p, size_t time_bits)
 		int accessed_page_no = randint(p->total_pages_owned);
 
 		if (randint(10) > 7) {
-			printf("[process] Writing to page #%d\n", accessed_page_no);
+			printf("[process %d] Writing to page #%d\n", p->id, accessed_page_no);
 			MMU_write(p->pt, accessed_page_no);
 		} else {
-			printf("[process] Reading from page #%d\n", accessed_page_no);
+			printf("[process %d] Reading from page #%d\n", p->id, accessed_page_no);
 			MMU_read(p->pt, accessed_page_no);
 		}
 	}