vsm2

commit efb7a2abce2772b736fa3bc27280b3165dae77c9
parent efe2699622b09eea984ebc4b659b86cfa5fa90fa
Author: prenev <an2qzavok@gmail.com>
Date:   Mon, 11 Jul 2022 15:23:44 +0300

more mem code

Diffstat:
M
bus.h
 | 
5
+++++
M
cell.c
 | 
13
++++++++++++-
M
cell.h
 | 
3
++-
M
main.c
 | 
17
++++++++++-------
M
mem.c
 | 
66
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
M
mem.h
 | 
16
++++++++++++++++

6 files changed, 108 insertions(+), 12 deletions(-)
diff --git a/bus.h b/bus.h
@@ -2,6 +2,11 @@
 
 #define BusBufMax 256
 
+enum {
+	ChDebug,
+	ChMem,
+};
+
 typedef struct Bus Bus;
 typedef struct Msg Msg;
 
diff --git a/cell.c b/cell.c
@@ -1,9 +1,10 @@
 #include <stdlib.h>
+#include <string.h>
 
 #include "cell.h"
 
 Cell *
-createcell(int n, char *p)
+createcell(int n, void *p)
 {
 	Cell *new = malloc(sizeof(Cell));
 	new->n = n;
@@ -11,6 +12,16 @@ createcell(int n, char *p)
 	return new;
 }
 
+Cell *
+celldup(Cell *cell)
+{
+	Cell *dup = malloc(sizeof(Cell));
+	dup->n = cell->n;
+	dup->p = malloc(cell->n);
+	memcpy(dup->p, cell->p, cell->n);
+	return cell;
+}
+
 void
 freecell(Cell *cell)
 {
diff --git a/cell.h b/cell.h
@@ -7,5 +7,6 @@ struct Cell {
 	char *p;
 };
 
-Cell * createcell(int, char *);
+Cell * createcell(int, void *);
+Cell * celldup(Cell *);
 void freecell(Cell *);
diff --git a/main.c b/main.c
@@ -9,14 +9,17 @@ int
 main(void)
 {
 	Bus *bus = createbus();
+	Mem *mem = createmem(bus);
 	Cell *cell = createcell(6, strdup("hello"));
-	Msg *msg = createmsg(1, 0, cell);
-	buspush(bus, msg);
-
-	Mem mem = {bus};
-	memstep((void *)&mem);
-	Msg *ret = buspull(bus, 1);
-	if (ret != NULL) printf("yep\n");
+	printf("cell: %s\n", cell->p);
+	memstore(ChDebug, mem, 1234, cell);
+	memstep(mem);
+	memfetch(ChDebug, mem, 1234);
+	memstep(mem);
+	Msg *ret = buspull(bus, ChDebug);
+	if (ret != NULL) {
+		printf("yes: %s\n", ret->dat->p);
+	}
 	else printf("nope\n");
 	freemsg(ret);
 	return 0;
diff --git a/mem.c b/mem.c
@@ -1,19 +1,79 @@
 #include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
 
 #include "cell.h"
 #include "bus.h"
 #include "mem.h"
 
+Mem *
+createmem(Bus *bus)
+{
+	Mem *new = calloc(sizeof(Mem), 1);
+	new->bus = bus;
+	return new;
+}
+
 int
 memstep(void *v)
 {
 	Mem *mem = (Mem *)v;
+	Msg *ret, *msg = buspull(mem->bus, ChMem);
+	Cell *ram, *cell;
 
-	Msg *msg = buspull(mem->bus, 0);
 	if (msg == NULL) return 1;
-	Msg *ret = createmsg(0, msg->src, createcell(0, NULL));
-	buspush(mem->bus, ret);
+
+	if ((msg->dat == NULL)
+	  || (msg->dat->n < sizeof(MemCmd))) {
+		freemsg(msg);
+		fprintf(stderr, "mem: cmd too short\n");
+		return 0;
+	}
+	MemCmd *cmd = (MemCmd *)msg->dat->p;
+	if ((cmd->addr < 0) || (cmd->addr >= MaxRAM)) {
+		fprintf(stderr, "mem: invalid addr: %x\n",
+		  cmd->addr);
+	} else switch (cmd->op) {
+	case '!': //fetch
+		ram = &mem->ram[cmd->addr];
+		cell = celldup(ram);
+		ret = createmsg(ChMem, msg->src, cell);
+		buspush(mem->bus, ret);
+		break;
+	case '@': //store
+		ram = &mem->ram[cmd->addr];
+		ram->n = msg->dat->n - sizeof(MemCmd);
+		ram->p = realloc(ram->p, ram->n);
+		memcpy(ram->p, msg->dat->p + sizeof(MemCmd),
+		  ram->n);
+		break;
+	default:
+		fprintf(stderr, "mem: invalid op: %c\n", cmd->op);
+	}
 	freemsg(msg);
 	return 0;
 }
 
+void
+memfetch(int src, Mem *mem, int n)
+{
+	MemCmd *f = malloc(sizeof(MemCmd));
+	f->op = '!';
+	f->addr = n;
+	Cell *c = createcell(sizeof(MemCmd), f);
+	Msg *msg = createmsg(src, ChMem, c);
+	buspush(mem->bus, msg);
+}
+
+void
+memstore(int src, Mem *mem, int n, Cell *c)
+{
+	MemCmd *s = malloc(sizeof(MemCmd) + c->n);
+	s->op = '@';
+	s->addr = n;
+	memcpy((char *)s + sizeof(MemCmd), c->p, c->n);
+	Cell *cell = createcell(sizeof(MemCmd) + c->n, s);
+	Msg *msg = createmsg(src, ChMem, cell);
+	buspush(mem->bus, msg);
+}
+
diff --git a/mem.h b/mem.h
@@ -1,9 +1,25 @@
 /* concerning the memory management */
 
+/* currently memory structure is a simple
+   array of Cells. */
+
+#define MaxRAM 4096
+
 typedef struct Mem Mem;
+typedef struct MemCmd MemCmd;
 
 struct Mem {
 	Bus *bus;
+	Cell ram[MaxRAM];
 };
 
+struct MemCmd {
+	char op;
+	int addr;
+};
+
+Mem * createmem(Bus *);
 int memstep(void *);
+
+void memfetch(int, Mem *, int);
+void memstore(int, Mem *, int, Cell *);