What does heap check mean on my phone

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Register now. Let's get real. Request Demo. Learn about Heap Illuminate. Helping over 8, companies deliver unparalleled digital experiences. A Complete Set of Behavioral Data. The heap is used as a buffer to temporarily store input information before that information is delivered to a specified output.

The size of information in the heap changes based on which application is running; your cell phone will always monitor to see if your app requests to use too much space or requires a larger buffer than is available. Unfortunately, this check halts most systems and will often temporarily lock your phone. If the buffer is the wrong size or not large enough to hold the image, the heap check mode will initiate and provide you with an error message.

The operating system, and sometimes the app, will try to remedy the problem by adjusting its code when the phone is reset. It shows a realtime graph of your app's memory use and lets you capture a heap dump, force garbage collections, and track memory allocations.

Alternatively, you can inspect your app memory from the command line with dumpsys , and also see GC events in logcat. Android provides a managed memory environment —when it determines that your app is no longer using some objects, the garbage collector releases the unused memory back to the heap.

How Android goes about finding unused memory is constantly being improved, but at some point on all Android versions, the system must briefly pause your code.

Most of the time, the pauses are imperceivable. However, if your app allocates memory faster than the system can collect it, your app might be delayed while the collector frees enough memory to satisfy your allocations. The delay could cause your app to skip frames and cause visible slowness. Even if your app doesn't exhibit slowness, if it leaks memory, it can retain that memory even while it's in the background. This behavior can slow the rest of the system's memory performance by forcing unnecessary garbage collection events.

Eventually, the system is forced to kill your app process to reclaim the memory. Then when the user returns to your app, it must restart completely. For information about programming practices that can reduce your app's memory use, read Manage your app's memory.

When you first open the Memory Profiler, you'll see a detailed timeline of your app's memory use and access tools to force garbage collection, capture a heap dump, and record memory allocations. Figure 1. The Memory Profiler. Note: A button to record memory allocations appears to the right of the heap dump button only when connected to a device running Android 7. However, if you're using a device running Android 7. If you see a message that says, "Advanced profiling is unavailable for the selected process," you need to enable advanced profiling to see the following:.

The numbers you see at the top of the Memory Profiler figure 2 are based on all the private memory pages that your app has committed, according to the Android system. This count does not include pages shared with the system or other apps. Figure 2. The memory count legend at the top of the Memory Profiler. Graphics : Memory used for graphics buffer queues to display pixels to the screen, including GL surfaces, GL textures, and so on. Stack : Memory used by both native and Java stacks in your app.

This usually relates to how many threads your app is running. Code : Memory that your app uses for code and resources, such as dex bytecode, optimized or compiled dex code,. Others : Memory used by your app that the system isn't sure how to categorize. When connected to a device running Android 7. So any objects allocated before you start profiling are not accounted for. However, Android 8. When compared to memory counts from the previous Android Monitor tool, the new Memory Profiler records your memory differently, so it might seem like your memory use is now higher.

The Memory Profiler monitors some extra categories that increase the total, but if you only care about the Java heap memory, then the "Java" number should be similar to the value from the previous tool.

Although the Java number probably doesn't exactly match what you saw in Android Monitor, the new number accounts for all physical memory pages that have been allocated to your app's Java heap since it was forked from Zygote.

So this provides an accurate representation of how much physical memory your app is actually using. Memory allocations show you how each Java object and JNI reference in your memory was allocated. Specifically, the Memory Profiler can show you the following about object allocations:. If your device is running Android 8. There's no need to begin a recording session, because Android 8. Video 1. With Android 8. If your device is running Android 7.

While recording, the Memory Profiler tracks all allocations that occur in your app. When you're done, click Stop recording the same button; see video 2 to view the allocations. Video 2. With Android 7.

After you select a region of the timeline or when you finish a recording session with a device running Android 7. Figure 3. Details about each allocated object appear in the Instance View on the right.

You can use the two menus above the list of allocated objects to choose which heap to inspect and how to organize the data. To improve app performance while profiling, the memory profiler samples memory allocations periodically by default. When testing on devices running API level 26 or higher, you can change this behavior by using the Allocation Tracking dropdown. The options available are as follows:.

JNI references are managed manually by the native code, so it is possible for Java objects used by native code to be kept alive for too long. Some objects on the Java heap may become unreachable if a JNI reference is discarded without first being explicitly deleted. Also, it is possible to exhaust the global JNI reference limit.

With this information, you can find when and where global JNI references are created and deleted. While your app is running, select a portion of the timeline that you want to inspect and select JNI heap from the drop-down menu above the class list. You can then inspect objects in the heap as you normally would and double-click objects in the Allocation Call Stack tab to see where the JNI references are allocated and released in your code, as shown in figure 4.

Figure 4. Viewing global JNI references. The Android Studio Memory Profiler includes a Native Memory Profiler for apps deployed to physical devices running Android 10; support for Android 11 devices is currently available in the Android Studio 4.

To initiate a recording, click Record native allocations at the top of the Memory Profiler window:. By default, the Native Memory Profiler uses a sample size of 32 bytes: Every time 32 bytes of memory are allocated, a snapshot of memory is taken.

A smaller sample size results in more frequent snapshots, yielding more accurate data about memory usage. A larger sample size yields less accurate data, but it will consume fewer resources on your system and improve performance while recording. A heap dump shows which objects in your app are using memory at the time you capture the heap dump.

Especially after an extended user session, a heap dump can help identify memory leaks by showing objects still in memory that you believe should no longer be there. To capture a heap dump, click Dump Java heap in the Memory Profiler toolbar. While dumping the heap, the amount of Java memory might increase temporarily. This is normal because the heap dump occurs in the same process as your app and requires some memory to collect the data.