MemoryBreadcrumbs V2

[philipphofmann]

Description

The SDK reports memory warning breadcrumbs by subscribing to the addObserverForName:UIApplicationDidReceiveMemoryWarningNotification

sentry-cocoa/Sources/Sentry/SentryBreadcrumbTracker.m

Lines 79 to 93 in 6c7ab81

	[NSNotificationCenter.defaultCenter
	addObserverForName:UIApplicationDidReceiveMemoryWarningNotification
	object:nil
	queue:nil
	usingBlock:^(NSNotification *notification) {
	if (nil != [SentrySDK.currentHub getClient]) {
	SentryBreadcrumb *crumb =
	[[SentryBreadcrumb alloc] initWithLevel:kSentryLevelWarning
	category:@"device.event"];
	crumb.type = @"system";
	crumb.data = @ { @"action" : @"LOW_MEMORY" };
	crumb.message = @"Low memory";
	[SentrySDK addBreadcrumb:crumb];
	}
	}];

With #2493 we now use a dispatch queue for a more fine grained approach

sentry-cocoa/Sources/Sentry/SentrySystemWrapper.mm

Lines 73 to 88 in bb77d06

	const auto queueAttributes
	= dispatch_queue_attr_make_with_qos_class(DISPATCH_QUEUE_SERIAL, QOS_CLASS_UTILITY, 0);
	_memoryWarningQueue = dispatch_queue_create("io.sentry.queue.memory-warnings", queueAttributes);
	_memoryWarningSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_MEMORYPRESSURE, 0,
	DISPATCH_MEMORYPRESSURE_NORMAL | DISPATCH_MEMORYPRESSURE_WARN
	| DISPATCH_MEMORYPRESSURE_CRITICAL,
	_memoryWarningQueue);
	__weak auto weakSelf = self;
	dispatch_source_set_event_handler(_memoryWarningSource, ^{
	const auto strongSelf = weakSelf;
	if (!strongSelf) {
	return;
	}
	handler(dispatch_source_get_data(strongSelf->_memoryWarningSource));
	});
	dispatch_resume(_memoryWarningSource);

With that we could also create breadcrumbs for DISPATCH_MEMORYPRESSURE_NORMAL, DISPATCH_MEMORYPRESSURE_WARN, DISPATCH_MEMORYPRESSURE_CRITICA. Furthermore, we could add the currently available memory with

sentry-cocoa/Sources/Sentry/SentrySystemWrapper.mm

Lines 11 to 33 in bb77d06

	- (mach_vm_size_t)memoryFootprintBytes:(NSError *__autoreleasing _Nullable *)error
	{
	task_vm_info_data_t info;
	mach_msg_type_number_t count = TASK_VM_INFO_COUNT;
	const auto status = task_info(mach_task_self(), TASK_VM_INFO, (task_info_t)&info, &count);
	if (status != KERN_SUCCESS) {
	if (error) {
	*error = NSErrorFromSentryErrorWithKernelError(
	kSentryErrorKernel, @"task_info reported an error.", status);
	}
	return 0;
	}
	mach_vm_size_t footprintBytes;
	if (count >= TASK_VM_INFO_REV1_COUNT) {
	footprintBytes = info.phys_footprint;
	} else {
	footprintBytes = info.resident_size;
	}
	return footprintBytes;
	}

Thermal State

sentry-cocoa/Sources/Sentry/SentryMetricProfiler.mm

Lines 171 to 184 in feb2055

	- (void)registerStateChangeNotifications
	{
	// According to Apple docs: "To receive NSProcessInfoThermalStateDidChangeNotification, you must
	// access the thermalState prior to registering for the notification." (from
	// https://developer.apple.com/documentation/foundation/nsprocessinfothermalstatedidchangenotification/)
	[self recordThermalState];
	[_processInfoWrapper monitorForThermalStateChanges:self callback:@selector(recordThermalState)];
	if (@available(macOS 12.0, *)) {
	[_processInfoWrapper monitorForPowerStateChanges:self
	callback:@selector(recordPowerLevelState)];
	}
	}

[brustolin]

We should ensure that this doesn't spam breadcrumbs. Its possible for the system to be in the edge of a warning On and Off.