Added in [API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

# android.system

*** ** * ** ***

## Classes

|---|---|
| [Int64Ref](https://developer.android.com/reference/android/system/Int64Ref) | A signed 64bit integer reference suitable for passing to lower-level system calls. |
| [Os](https://developer.android.com/reference/android/system/Os) | Access to low-level system functionality. |
| [OsConstants](https://developer.android.com/reference/android/system/OsConstants) | Constants and helper functions for use with `https://developer.android.com/reference/android/system/Os`. |
| [StructCmsghdr](https://developer.android.com/reference/android/system/StructCmsghdr) | Corresponds to C's `struct cmsghdr`. |
| [StructDlInfo](https://developer.android.com/reference/android/system/StructDlInfo) | Corresponds to C's `struct Dl_info`. |
| [StructMsghdr](https://developer.android.com/reference/android/system/StructMsghdr) | Corresponds to C's `struct msghdr` |
| [StructPollfd](https://developer.android.com/reference/android/system/StructPollfd) | Used as an in/out parameter to `https://developer.android.com/reference/android/system/Os#poll(android.system.StructPollfd[],%20int)`. |
| [StructStat](https://developer.android.com/reference/android/system/StructStat) | File information returned by `https://developer.android.com/reference/android/system/Os#fstat(java.io.FileDescriptor)`, `https://developer.android.com/reference/android/system/Os#lstat(java.lang.String)`, and `https://developer.android.com/reference/android/system/Os#stat(java.lang.String)`. |
| [StructStatVfs](https://developer.android.com/reference/android/system/StructStatVfs) | File information returned by `https://developer.android.com/reference/android/system/Os#fstatvfs(java.io.FileDescriptor)` and `https://developer.android.com/reference/android/system/Os#statvfs(java.lang.String)`. |
| [StructTimespec](https://developer.android.com/reference/android/system/StructTimespec) | Corresponds to C's `struct timespec` from `<time.h>`. |
| [StructTimeval](https://developer.android.com/reference/android/system/StructTimeval) | Corresponds to C's `struct timeval` from `sys/time.h`. |
| [StructUtsname](https://developer.android.com/reference/android/system/StructUtsname) | Information returned by `https://developer.android.com/reference/android/system/Os#uname()`. |
| [SystemCleaner](https://developer.android.com/reference/android/system/SystemCleaner) | Java.lang.ref.Cleaner encourages each library to create a Cleaner, with an associated thread, to process Cleaner Runnables for that library's registered cleaning actions. |
| [VmSocketAddress](https://developer.android.com/reference/android/system/VmSocketAddress) | A virtio-vsock address `https://developer.android.com/reference/android/system/VmSocketAddress`. |

## Exceptions

|---|---|
| [ErrnoException](https://developer.android.com/reference/android/system/ErrnoException) | A checked exception thrown when `https://developer.android.com/reference/android/system/Os` methods fail. |

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  ## Classes

  - [Int64Ref](https://developer.android.com/reference/android/system/Int64Ref)
  - [Os](https://developer.android.com/reference/android/system/Os)
  - [OsConstants](https://developer.android.com/reference/android/system/OsConstants)
  - [StructCmsghdr](https://developer.android.com/reference/android/system/StructCmsghdr)
  - [StructDlInfo](https://developer.android.com/reference/android/system/StructDlInfo)
  - [StructMsghdr](https://developer.android.com/reference/android/system/StructMsghdr)
  - [StructPollfd](https://developer.android.com/reference/android/system/StructPollfd)
  - [StructStat](https://developer.android.com/reference/android/system/StructStat)
  - [StructStatVfs](https://developer.android.com/reference/android/system/StructStatVfs)
  - [StructTimespec](https://developer.android.com/reference/android/system/StructTimespec)
  - [StructTimeval](https://developer.android.com/reference/android/system/StructTimeval)
  - [StructUtsname](https://developer.android.com/reference/android/system/StructUtsname)
  - [SystemCleaner](https://developer.android.com/reference/android/system/SystemCleaner)
  - [VmSocketAddress](https://developer.android.com/reference/android/system/VmSocketAddress)
-

  ## Exceptions

  - [ErrnoException](https://developer.android.com/reference/android/system/ErrnoException)