diff --git a/src/main/java/com/loomcom/symon/Bus.java b/src/main/java/com/loomcom/symon/Bus.java index 9b9e91d..5ec836e 100644 --- a/src/main/java/com/loomcom/symon/Bus.java +++ b/src/main/java/com/loomcom/symon/Bus.java @@ -26,6 +26,11 @@ package com.loomcom.symon; import com.loomcom.symon.devices.Device; import com.loomcom.symon.exceptions.MemoryAccessException; import com.loomcom.symon.exceptions.MemoryRangeException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.List; +import java.util.HashMap; +import java.util.Map; import java.util.SortedSet; import java.util.TreeSet; @@ -45,11 +50,8 @@ public class Bus { // The CPU private Cpu cpu; - // Ordered list of IO devices. - private SortedSet devices; - - // Ordered list of IO devices that have overlapping memory locations - private SortedSet overlapDevices; + // Ordered sets of IO devices, associated with their priority + private Map> deviceMap; // an array for quick lookup of adresses, brute-force style private Device[] deviceAddressArray; @@ -60,8 +62,7 @@ public class Bus { } public Bus(int startAddress, int endAddress) { - this.devices = new TreeSet(); - this.overlapDevices = new TreeSet(); + this.deviceMap = new HashMap>(); this.startAddress = startAddress; this.endAddress = endAddress; } @@ -78,48 +79,37 @@ public class Bus { // TODO: Find out why +2 and not +1 is needed here int size = (this.endAddress - this.startAddress) + 2; deviceAddressArray = new Device[size]; - for(Device device : devices) { - MemoryRange range = device.getMemoryRange(); - for(int address = range.startAddress; address <= range.endAddress; ++address) { - deviceAddressArray[address] = device; - } - } - for(Device device : overlapDevices) { - MemoryRange range = device.getMemoryRange(); - for(int address = range.startAddress; address <= range.endAddress; ++address) { - deviceAddressArray[address] = device; - } - } - } - - /** - * Add a device to the bus. Throws a MemoryRangeException if the device overlaps with any others, unless the overlap parameter is true. - * - * @param device - * @param overlap - * @throws MemoryRangeException - */ - public void addDevice(Device device, boolean overlap) throws MemoryRangeException { - // Make sure there's no memory overlap. - MemoryRange memRange = device.getMemoryRange(); - if(!overlap) { - for (Device d : devices) { - if (d.getMemoryRange().overlaps(memRange)) { - throw new MemoryRangeException("The device being added at " + - String.format("$%04X", memRange.startAddress()) + - " overlaps with an existing " + - "device, '" + d + "'"); + + List priorities = new ArrayList(deviceMap.keySet()); + Collections.sort(priorities); + + for(int priority : priorities) { + SortedSet deviceSet = deviceMap.get(priority); + for(Device device : deviceSet) { + MemoryRange range = device.getMemoryRange(); + for(int address = range.startAddress; address <= range.endAddress; ++address) { + deviceAddressArray[address] = device; } } } + + } - // Add the device - device.setBus(this); - if(overlap) { - overlapDevices.add(device); - } else { - devices.add(device); + /** + * Add a device to the bus. + * + * @param device + * @param priority + */ + public void addDevice(Device device, int priority) { + + SortedSet deviceSet = deviceMap.get(priority); + if(deviceSet == null) { + deviceSet = new TreeSet(); + deviceMap.put(priority, deviceSet); } + + deviceSet.add(device); buildDeviceAddressArray(); } @@ -130,7 +120,7 @@ public class Bus { * @throws MemoryRangeException */ public void addDevice(Device device) throws MemoryRangeException { - addDevice(device, false); + addDevice(device, 0); } @@ -140,14 +130,10 @@ public class Bus { * @param device */ public void removeDevice(Device device) { - if (devices.contains(device)) { - devices.remove(device); - buildDeviceAddressArray(); - } - if (overlapDevices.contains(device)) { - overlapDevices.remove(device); - buildDeviceAddressArray(); + for(SortedSet deviceSet : deviceMap.values()) { + deviceSet.remove(device); } + buildDeviceAddressArray(); } public void addCpu(Cpu cpu) { @@ -161,19 +147,17 @@ public class Bus { * device. */ public boolean isComplete() { - // Empty maps cannot be complete. - if (devices.isEmpty()) { - return false; + if(deviceAddressArray == null) { + buildDeviceAddressArray(); } - - // Loop over devices and add their size - int filledMemory = 0; - for (Device d : devices) { - filledMemory += d.getSize(); + + for(int address = startAddress; address <= endAddress; ++address) { + if(deviceAddressArray[address] == null) { + return false; + } } - - // Returns if the total size of the devices fill the bus' memory space - return filledMemory == endAddress - startAddress + 1; + + return true; } public int read(int address) throws MemoryAccessException { @@ -225,7 +209,19 @@ public class Bus { public SortedSet getDevices() { // Expose a copy of the device list, not the original - return new TreeSet(devices); + SortedSet devices = new TreeSet(); + + List priorities = new ArrayList(deviceMap.keySet()); + Collections.sort(priorities); + + for(int priority : priorities) { + SortedSet deviceSet = deviceMap.get(priority); + for(Device device : deviceSet) { + devices.add(device); + } + } + + return devices; } public Cpu getCpu() { diff --git a/src/main/java/com/loomcom/symon/machines/MulticompMachine.java b/src/main/java/com/loomcom/symon/machines/MulticompMachine.java index 5b252b0..f5ec3cc 100644 --- a/src/main/java/com/loomcom/symon/machines/MulticompMachine.java +++ b/src/main/java/com/loomcom/symon/machines/MulticompMachine.java @@ -73,7 +73,7 @@ public class MulticompMachine implements Machine { bus.addCpu(cpu); bus.addDevice(ram); - bus.addDevice(acia, true); + bus.addDevice(acia, 1); // TODO: Make this configurable, of course. File romImage = new File("rom.bin"); diff --git a/src/test/java/com/loomcom/symon/BusTest.java b/src/test/java/com/loomcom/symon/BusTest.java index b4a8a9a..26a4eb4 100644 --- a/src/test/java/com/loomcom/symon/BusTest.java +++ b/src/test/java/com/loomcom/symon/BusTest.java @@ -59,22 +59,6 @@ public class BusTest extends TestCase { assertEquals(2, b.getDevices().size()); } - public void testOverlappingDevicesShouldFail() throws MemoryRangeException { - Device memory = new Memory(0x0000, 0x0100, true); - Device rom = new Memory(0x00ff, 0x0200, false); - - Bus b = new Bus(0x0000, 0xffff); - - b.addDevice(memory); - - try { - b.addDevice(rom); - fail("Should have thrown a MemoryRangeException."); - } catch (MemoryRangeException ex) { - // expected - } - } - public void testIsCompleteWithFirstDeviceNotStartingAtStartAddress() throws MemoryRangeException { Device memory = new Memory(0x00ff, 0xff00, true);