Struct gio::MemoryMonitor

pub struct MemoryMonitor { /* private fields */ }

Available on crate feature v2_64 only.

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
• Call malloc_trim(3) to return cached heap pages to the kernel (if supported by your libc)

Note that some actions may not always improve system performance, and so should be profiled for your application. malloc_trim(), for example, may make future heap allocations slower (due to releasing cached heap pages back to the kernel).

See MemoryMonitorWarningLevel for details on the various warning levels.

⚠️ The following code is in C ⚠️

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 low-memory-warning signal, and unref the MemoryMonitor itself when exiting.

Signals

low-memory-warning

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.

Implements

MemoryMonitorExt, InitableExt

Implementations

impl MemoryMonitor

pub const NONE: Option<&'static MemoryMonitor> = None

pub fn dup_default() -> MemoryMonitor

Gets a reference to the default MemoryMonitor for the system.

Returns

a new reference to the default MemoryMonitor

Trait Implementations

impl Clone for MemoryMonitor

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for MemoryMonitor

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for MemoryMonitor

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl HasParamSpec for MemoryMonitor

type ParamSpec = ParamSpecObject

type SetValue = MemoryMonitor

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, MemoryMonitor>

fn param_spec_builder() -> Self::BuilderFn

impl Hash for MemoryMonitor

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for MemoryMonitor

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<OT: ObjectType> PartialEq<OT> for MemoryMonitor

fn eq(&self, other: &OT) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<OT: ObjectType> PartialOrd<OT> for MemoryMonitor

fn partial_cmp(&self, other: &OT) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for MemoryMonitor

fn static_type() -> Type

Returns the type identifier of Self.

impl Eq for MemoryMonitor

impl IsA<Initable> for MemoryMonitor