Struct gio::MemoryMonitor

source ·
#[repr(transparent)]
pub struct MemoryMonitor { /* private fields */ }
Available on crate feature v2_64 only.
Expand description

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

Implements

MemoryMonitorExt, InitableExt

Implementations§

Gets a reference to the default MemoryMonitor for the system.

Returns

a new reference to the default MemoryMonitor

Trait Implementations§

Returns a copy of the value. Read more
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This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
Returns the type identifier of Self.

Auto Trait Implementations§

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Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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Disconnect a previously connected signal handler.
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