emu: made netmem aware of busy memory

emu/cmd.c

@@ -184,7 +184,7 @@ static void
 exam(word addr, int fastmem, int format)
 {
 	word *p;
-	p = getmemref(&getapr()->membus, addr, fastmem);
+	p = getmemref(&getapr()->membus, addr, fastmem, nil);
 	if(p == nil){
 		printf("Non existent memory\n");
 		return;
@@ -206,7 +206,7 @@ static void
 dep(word addr, int fastmem, word w)
 {
 	word *p;
-	p = getmemref(&getapr()->membus, addr, fastmem);
+	p = getmemref(&getapr()->membus, addr, fastmem, nil);
 	if(p == nil){
 		printf("Non existent memory\n");
 		return;

emu/dis340.c

@@ -865,7 +865,7 @@ renderthread(void *arg)
 		SDL_RenderClear(renderer);
 
 		render(dis->crt);
-//		SDL_Delay(1);
+//		SDL_Delay(30);
 
 		SDL_UpdateTexture(tex, nil, dis->crt->pixels, 1024*sizeof(u32));
 		SDL_RenderCopy(renderer, tex, nil, nil);

emu/mem.c

@@ -414,17 +414,19 @@ showmem(Membus *bus)
 }
 
 word*
-getmemref(Membus *bus, hword addr, int fastmem)
+getmemref(Membus *bus, hword addr, int fastmem, int *busy)
 {
 	CMem *core;
 	FMem *ff;
 
 	if(fastmem && addr < 020 && bus->fmem){
 		ff = bus->fmem->module;
+		if(busy) *busy = ff->fmc_act;
 		return &ff->ff[addr];
 	}
 	if(bus->cmem[addr>>14]){
 		core = bus->cmem[addr>>14]->module;
+		if(busy) *busy = core->cmc_p_act >= 0;
 		return &core->core[addr & core->mask];
 	}
 	return nil;

emu/netmem.c

@@ -16,72 +16,81 @@ netmemcycle(void *dev)
 {
 	Netmem *nm;
 	nm = (Netmem*)dev;
-	u8 buf[9], len;
+	u8 len;
 	word a, d, *p;
+	int busy;
 
 	if(nm->fd < 0)
 		return;
 
-	if(!hasinput(nm->fd))
-		return;
+	if(!nm->waiting){
+		if(!hasinput(nm->fd))
+			return;
 
-	if(readn(nm->fd, buf, 2)){
-		fprintf(stderr, "netmem fd closed\n");
-		nm->fd = -1;
-		return;
+		if(readn(nm->fd, nm->buf, 2)){
+			fprintf(stderr, "netmem fd closed\n");
+			nm->fd = -1;
+			return;
+		}
+		len = nm->buf[0]<<8 | nm->buf[1];
+		if(len > 9){
+			fprintf(stderr, "netmem botch(%d), closing\n", len);
+			close(nm->fd);
+			nm->fd = -1;
+			return;
+		}
+		memset(nm->buf, 0, sizeof(nm->buf));
+		readn(nm->fd, nm->buf, len);
 	}
-	len = buf[0]<<8 | buf[1];
-	if(len > 9){
-		fprintf(stderr, "netmem botch(%d), closing\n", len);
-		close(nm->fd);
-		nm->fd = -1;
-		return;
-	}
-	memset(buf, 0, sizeof(buf));
-	readn(nm->fd, buf, len);
+	nm->waiting = 0;
 
-	a = buf[1] | buf[2]<<8 | buf[3]<<16;
-	d = buf[4] | buf[5]<<8 | buf[6]<<16 |
-		(word)buf[7]<<24 | (word)buf[8]<<32;
+	a = nm->buf[1] | nm->buf[2]<<8 | nm->buf[3]<<16;
+	d = nm->buf[4] | nm->buf[5]<<8 | nm->buf[6]<<16 |
+		(word)nm->buf[7]<<24 | (word)nm->buf[8]<<32;
 	a &= 0777777;
 	d &= 0777777777777;
 
-	switch(buf[0]){
+	switch(nm->buf[0]){
 	case WRRQ:
-		p = getmemref(&nm->apr->membus, a, 0);
+		p = getmemref(&nm->apr->membus, a, 0, &busy);
 		if(p == nil) goto err;
+		if(busy) goto wait;
 		*p = d;
 		printf("write %06lo %012lo\n", a, d);
-		buf[0] = 0;
-		buf[1] = 1;
-		buf[2] = ACK;
-		writen(nm->fd, buf, buf[1]+2);
+		nm->buf[0] = 0;
+		nm->buf[1] = 1;
+		nm->buf[2] = ACK;
+		writen(nm->fd, nm->buf, nm->buf[1]+2);
 		break;
 	case RDRQ:
-		p = getmemref(&nm->apr->membus, a, 0);
+		p = getmemref(&nm->apr->membus, a, 0, &busy);
 		if(p == nil) goto err;
+		if(busy) goto wait;
 		d = *p;
 		printf("read %06lo %012lo\n", a, d);
-		buf[0] = 0;
-		buf[1] = 6;
-		buf[2] = ACK;
-		buf[3] = d;
-		buf[4] = d>>8;
-		buf[5] = d>>16;
-		buf[6] = d>>24;
-		buf[7] = d>>32;
-		writen(nm->fd, buf, buf[1]+2);
+		nm->buf[0] = 0;
+		nm->buf[1] = 6;
+		nm->buf[2] = ACK;
+		nm->buf[3] = d;
+		nm->buf[4] = d>>8;
+		nm->buf[5] = d>>16;
+		nm->buf[6] = d>>24;
+		nm->buf[7] = d>>32;
+		writen(nm->fd, nm->buf, nm->buf[1]+2);
 		break;
 	default:
-		fprintf(stderr, "unknown netmem message %d\n", buf[0]);
+		fprintf(stderr, "unknown netmem message %d\n", nm->buf[0]);
 		break;
 	}
 	return;
 err:
 	printf("error address %06lo\n", a);
-	buf[0] = 1;
-	buf[1] = ERR;
-	writen(nm->fd, buf, buf[0]+1);
+	nm->buf[0] = 1;
+	nm->buf[1] = ERR;
+	writen(nm->fd, nm->buf, nm->buf[0]+1);
+	return;
+wait:
+	nm->waiting = 1;
 }
 
 Device*

emu/pdp6.h

@@ -230,7 +230,7 @@ Device *make256kmem(int argc, char *argv[]);
 void attachmem(Mem *mem, int p, Membus *bus, int n);
 void readmem(const char *file, word *mem, word size);
 void showmem(Membus *bus);
-word *getmemref(Membus *bus, hword addr, int fastmem);
+word *getmemref(Membus *bus, hword addr, int fastmem, int *busy);
 
 /*
  * IO bus
@@ -665,6 +665,9 @@ struct Netmem
 {
 	Device dev;
 	int fd;
+	u8 buf[9];
+	int waiting;
+
 	// tmp?
 	Apr *apr;
 };