GI.Gio.Interfaces.MemoryMonitor

MemoryMonitor will monitor system memory and suggest to the application when to free memory so as to leave more room for other applications. It is implemented on Linux using the Low Memory Monitor (API documentation).

There is also an implementation for use inside Flatpak sandboxes.

Possible actions to take when the signal is received are:

• Free caches
• Save files that haven't been looked at in a while to disk, ready to be reopened when needed
• Run a garbage collection cycle
• Try and compress fragmented allocations
• Exit on idle if the process has no reason to stay around

See MemoryMonitorWarningLevel for details on the various warning levels.

C code

static void
warning_cb (GMemoryMonitor *m, GMemoryMonitorWarningLevel level)
{
  g_debug ("Warning level: %d", level);
  if (warning_level > G_MEMORY_MONITOR_WARNING_LEVEL_LOW)
    drop_caches ();
}

static GMemoryMonitor *
monitor_low_memory (void)
{
  GMemoryMonitor *m;
  m = g_memory_monitor_dup_default ();
  g_signal_connect (G_OBJECT (m), "low-memory-warning",
                    G_CALLBACK (warning_cb), NULL);
  return m;
}

Don't forget to disconnect the lowMemoryWarning signal, and unref the MemoryMonitor itself when exiting.

Since: 2.64

Exported types

newtype MemoryMonitor

Memory-managed wrapper type.

Constructors

MemoryMonitor (ManagedPtr MemoryMonitor)

Instances

Eq MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

Methods

(==) :: MemoryMonitor -> MemoryMonitor -> Bool

(/=) :: MemoryMonitor -> MemoryMonitor -> Bool

IsGValue MemoryMonitor

Convert MemoryMonitor to and from GValue with toGValue and fromGValue.

Defined in GI.Gio.Interfaces.MemoryMonitor

Methods

toGValue :: MemoryMonitor -> IO GValue

fromGValue :: GValue -> IO MemoryMonitor

ManagedPtrNewtype MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

Methods

toManagedPtr :: MemoryMonitor -> ManagedPtr MemoryMonitor

TypedObject MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

Methods

glibType :: IO GType

GObject MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

HasParentTypes MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

type ParentTypes MemoryMonitor

Defined in GI.Gio.Interfaces.MemoryMonitor

type ParentTypes MemoryMonitor = '[Initable, Object]

class (GObject o, IsDescendantOf MemoryMonitor o) => IsMemoryMonitor o

Type class for types which can be safely cast to MemoryMonitor, for instance with toMemoryMonitor.

Instances

(GObject o, IsDescendantOf MemoryMonitor o) => IsMemoryMonitor o

Defined in GI.Gio.Interfaces.MemoryMonitor

toMemoryMonitor :: (MonadIO m, IsMemoryMonitor o) => o -> m MemoryMonitor

Cast to MemoryMonitor, for types for which this is known to be safe. For general casts, use castTo.

Methods

Overloaded methods

dupDefault

memoryMonitorDupDefault

Arguments

:: (HasCallStack, MonadIO m)

=> m MemoryMonitor

Returns: a new reference to the default MemoryMonitor

Gets a reference to the default MemoryMonitor for the system.

Since: 2.64

Signals

lowMemoryWarning

type C_MemoryMonitorLowMemoryWarningCallback = Ptr () -> CUInt -> Ptr () -> IO ()

Type for the callback on the (unwrapped) C side.

type MemoryMonitorLowMemoryWarningCallback

Arguments

 = MemoryMonitorWarningLevel

level: the MemoryMonitorWarningLevel warning level

-> IO ()

Emitted when the system is running low on free memory. The signal handler should then take the appropriate action depending on the warning level. See the MemoryMonitorWarningLevel documentation for details.

Since: 2.64

afterMemoryMonitorLowMemoryWarning :: (IsMemoryMonitor a, MonadIO m) => a -> MemoryMonitorLowMemoryWarningCallback -> m SignalHandlerId

Connect a signal handler for the lowMemoryWarning signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after memoryMonitor #lowMemoryWarning callback

genClosure_MemoryMonitorLowMemoryWarning :: MonadIO m => MemoryMonitorLowMemoryWarningCallback -> m (GClosure C_MemoryMonitorLowMemoryWarningCallback)

Wrap the callback into a GClosure.

mk_MemoryMonitorLowMemoryWarningCallback :: C_MemoryMonitorLowMemoryWarningCallback -> IO (FunPtr C_MemoryMonitorLowMemoryWarningCallback)

Generate a function pointer callable from C code, from a C_MemoryMonitorLowMemoryWarningCallback.

noMemoryMonitorLowMemoryWarningCallback :: Maybe MemoryMonitorLowMemoryWarningCallback

A convenience synonym for Nothing :: Maybe MemoryMonitorLowMemoryWarningCallback.

onMemoryMonitorLowMemoryWarning :: (IsMemoryMonitor a, MonadIO m) => a -> MemoryMonitorLowMemoryWarningCallback -> m SignalHandlerId

Connect a signal handler for the lowMemoryWarning signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on memoryMonitor #lowMemoryWarning callback

wrap_MemoryMonitorLowMemoryWarningCallback :: MemoryMonitorLowMemoryWarningCallback -> C_MemoryMonitorLowMemoryWarningCallback

Wrap a MemoryMonitorLowMemoryWarningCallback into a C_MemoryMonitorLowMemoryWarningCallback.