MemoryMonitor

Added in version 2.64.

class MemoryMonitor(*args, **kwargs)

GMemoryMonitor 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) <man: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.

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 GMemoryMonitor itself when exiting.

Methods

class MemoryMonitor

dup_default() → MemoryMonitor: Gets a reference to the default MemoryMonitor for the system.

Added in version 2.64.

Signals

class MemoryMonitor.signals

low_memory_warning(level: MemoryMonitorWarningLevel) → None

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.

Added in version 2.64.

Parameters:: level – the MemoryMonitorWarningLevel warning level

Virtual Methods

class MemoryMonitor

do_low_memory_warning(level: MemoryMonitorWarningLevel) → None

the virtual function pointer for the MemoryMonitor::low-memory-warning signal.

Parameters:: level