In this document

Dalvik Debug Monitor Service
Dalvik Debug Monitor Server Ddms
Dalvik Debug Monitor Services

Android Debug bridge(ADB) Android virtual devices (AVDs) TraceView; Dalvik Debug Monitor Service Server; Android designing user interface. Using resources, Adapters, Animations, Using images; View Components; Layouts, Menus, Events and Notifications; Android storage.

The Android Device Monitor is a stand-alone tool with a graphical user interface for serveral Android application debugging and analysis tools, including the Dalvik Debug Monitor Server (DDMS). You can use the Android Device Monitor to analyze memory usage, profile methods, monitor network traffic and simulate incoming calls and messages. In my app I am downloading a kml file from a webserver. I have set the permission for external storage and internet in my android manifest file. I am new to Android, your help is greatly appreciate. Dalvik is the name of Android’s virtual machine. The Dalvik VM is an interpreter-only virtual machine that executes files in the Dalvik Executable (.dex) format. The virtual machine is register-based and can run classes compiled by Java language compiler that have been altered into its native format using the included ‘dx’ tool.

Using DDMS

Android ships with a debugging tool called the Dalvik Debug Monitor Server (DDMS), which provides port-forwarding services, screen capture on the device, thread and heap information on the device, logcat, process, and radio state information, incoming call and SMS spoofing, location data spoofing, and more. This page provides a modest discussion of DDMS features; it is not an exhaustive exploration of all the features and capabilities.

Running DDMS

DDMS is integrated into Eclipse and is also shipped in the tools/ directory of the SDK. DDMS works with both the emulator and a connected device. If both are connected and running simultaneously, DDMS defaults to the emulator.

From Eclipse: Click Window > Open Perspective > Other.. > DDMS.
From the command line: Type ddms (or ./ddms on Mac/Linux) from the tools/ directory.

How DDMS Interacts with a Debugger

On Android, every application runs in its own process, each of which runs in its own virtual machine (VM). Each VM exposes a unique port that a debugger can attach to.

When DDMS starts, it connects to adb. When a device is connected, a VM monitoring service is created between adb and DDMS, which notifies DDMS when a VM on the device is started or terminated. Once a VM is running, DDMS retrieves the the VM's process ID (pid), via adb, and opens a connection to the VM's debugger, through the adb daemon (adbd) on the device. DDMS can now talk to the VM using a custom wire protocol.

Download the latest drivers, firmware, and software for your HP USB SmartCard CCID Keyboard.This is HP’s official website that will help automatically detect and download the correct drivers free of cost for your HP Computing and Printing products for Windows and Mac operating system. Smart card terminal driver.

DDMS assigns a debugging port to each VM on the device. Typically, DDMS assigns port 8600 for the first debuggable VM, the next on 8601, and so on. When a debugger connects to one of these ports, all traffic is forwarded to the debugger from the associated VM. You can only attach a single debugger to a single port, but DDMS can handle multiple, attached debuggers.

By default, DDMS also listens on another debugging port, the DDMS 'base port' (8700, by default). The base port is a port forwarder, which can accept VM traffic from any debugging port and forward it to the debugger on port 8700. This allows you to attach one debugger to port 8700, and debug all the VMs on a device. The traffic that is forwarded is determined by the currently selected process in the DDMS Devices view.

The following screenshot shows a typical DDMS screen in Eclipse. If you are starting DDMS from the command line, the screen is slightly different, but much of the functionality is identical. Notice that the highlighted process, com.android.email, that is running in the emulator has the debugging port 8700 assigned to it as well as 8606. This signifies that DDMS is currently forwarding port 8606 to the static debugging port of 8700.

Figure 1. Screenshot of DDMS

If you are not using Eclipse and ADT, read Configuring your IDE to attach to the debugging port, for more information on attaching your debugger.

Tip: You can set a number of DDMS preferences in File > Preferences. Preferences are saved to $HOME/.android/ddms.cfg.

Known debugging issues with Dalvik
Debugging an application in the Dalvik VM should work the same as it does in other VMs. However, when single-stepping out of synchronized code, the 'current line' cursor may jump to the last line in the method for one step.

Using DDMS

Dalvik Debug Monitor Service

The following sections describe how to use DDMS and the various tabs and panes that are part of the DDMS GUI. The Eclipse version and the command line version have minor UI differences, but the same functionality. For information on running DDMS, see the previous section in this document, Running DDMS.

Viewing heap usage for a process

DDMS allows you to view how much heap memory a process is using. This information is useful in tracking heap usage at a certain point of time during the execution of your application.

To view heap usage for a process:

In the Devices tab, select the process that you want to see the heap information for.
Click the Update Heap button to enable heap information for the process.
In the Heap tab, click Cause GC to invoke garbage collection, which enables the collection of heap data. When the operation completes, you will see a group of object types and the memory that has been allocated for each type. You can click Cause GC again to refresh the data.
Click on an object type in the list to see a bar graph that shows the number of objects allocated for a particular memory size in bytes.

Tracking memory allocation of objects

DDMS provides a feature to track objects that are being allocated to memory and to see which classes and threads are allocating the objects. This allows you to track, in real time, where objects are being allocated when you perform certain actions in your application. This information is valuable for assessing memory usage that can affect application performance.

To track memory allocation of objects:

In the Devices tab, select the process that you want to enable allocation tracking for.
In the Allocation Tracker tab, click the Start Tracking button to begin allocation tracking. At this point, anything you do in your application will be tracked.
Click Get Allocations to see a list of objects that have been allocated since you clicked on the Start Tracking button. You can click on Get Allocations again to append to the list new objects that that have been allocated.
To stop tracking or to clear the data and start over, click the Stop Tracking button.
Click on a specific row in the list to see more detailed information such as the method and line number of the code that allocated the object.

Working with an emulator or device's file system

DDMS provides a File Explorer tab that allows you to view, copy, and delete files on the device. This feature is useful in examining files that are created by your application or if you want to transfer files to and from the device.

To work with an emulator or device's file system:

In the Devices tab, select the emulator that you want to view the file system for.
To copy a file from the device, locate the file in the File Explorer and click the Pull file button.
To copy a file to the device, click the Push file button on the File Explorer tab.

Examining thread information

The Threads tab in DDMS shows you the currently running threads for a selected process.

In the Devices tab, select the process that you want to examine the threads for.
Click the Update Threads button.
In the Threads tab, you can view the thread information for the selected process.