fix: cpu usage readings for profiling (#3214)

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+### Fixes
+
+- Fix CPU usage collection for upcoming visualization in profiling flamecharts (#3214)
+
 ## 8.9.5
 
 ### Hybrid SDK support

SentryTestUtils/TestSentrySystemWrapper.swift

@@ -6,7 +6,7 @@ public class TestSentrySystemWrapper: SentrySystemWrapper {
         public var memoryFootprintBytes: SentryRAMBytes?
 
         public var cpuUsageError: NSError?
-        public var cpuUsagePerCore: [NSNumber]?
+        public var cpuUsage: NSNumber?
     }
 
     public var overrides = Override()
@@ -19,10 +19,10 @@ public class TestSentrySystemWrapper: SentrySystemWrapper {
         return overrides.memoryFootprintBytes ?? super.memoryFootprintBytes(error)
     }
 
-    public override func cpuUsagePerCore() throws -> [NSNumber] {
+    public override func cpuUsage() throws -> NSNumber {
         if let errorOverride = overrides.cpuUsageError {
             throw errorOverride
         }
-        return try overrides.cpuUsagePerCore ?? super.cpuUsagePerCore()
+        return try overrides.cpuUsage ?? super.cpuUsage()
     }
 }

Sources/Sentry/SentryMetricProfiler.mm

@@ -10,7 +10,6 @@
 #    import "SentryEvent+Private.h"
 #    import "SentryFormatter.h"
 #    import "SentryLog.h"
-#    import "SentryNSProcessInfoWrapper.h"
 #    import "SentryNSTimerFactory.h"
 #    import "SentrySystemWrapper.h"
 #    import "SentryTime.h"
@@ -28,7 +27,7 @@ @implementation SentryMetricReading
 @end
 
 NSString *const kSentryMetricProfilerSerializationKeyMemoryFootprint = @"memory_footprint";
-NSString *const kSentryMetricProfilerSerializationKeyCPUUsageFormat = @"cpu_usage_%d";
+NSString *const kSentryMetricProfilerSerializationKeyCPUUsage = @"cpu_usage";
 
 NSString *const kSentryMetricProfilerSerializationUnitBytes = @"byte";
 NSString *const kSentryMetricProfilerSerializationUnitPercentage = @"percent";
@@ -78,25 +77,14 @@ @implementation SentryMetricReading
 @implementation SentryMetricProfiler {
     SentryDispatchSourceWrapper *_dispatchSource;
 
-    /// arrays of readings keyed on NSNumbers representing the core number for the set of readings
-    NSMutableDictionary<NSNumber *, NSMutableArray<SentryMetricReading *> *> *_cpuUsage;
-
+    NSMutableArray<SentryMetricReading *> *_cpuUsage;
     NSMutableArray<SentryMetricReading *> *_memoryFootprint;
 }
 
 - (instancetype)init
 {
     if (self = [super init]) {
-        _cpuUsage =
-            [NSMutableDictionary<NSNumber *, NSMutableArray<SentryMetricReading *> *> dictionary];
-        const auto processorCount
-            = SentryDependencyContainer.sharedInstance.processInfoWrapper.processorCount;
-        SENTRY_LOG_DEBUG(
-            @"Preparing %lu arrays for CPU core usage readings", (long unsigned)processorCount);
-        for (NSUInteger core = 0; core < processorCount; core++) {
-            _cpuUsage[@(core)] = [NSMutableArray<SentryMetricReading *> array];
-        }
-
+        _cpuUsage = [NSMutableArray<SentryMetricReading *> array];
         _memoryFootprint = [NSMutableArray<SentryMetricReading *> array];
     }
     return self;
@@ -123,11 +111,10 @@ - (void)stop
                                                       and:(uint64_t)endSystemTime;
 {
     NSArray<SentryMetricReading *> *memoryFootprint;
-    NSDictionary<NSNumber *, NSArray<SentryMetricReading *> *> *cpuUsage;
+    NSArray<SentryMetricReading *> *cpuUsage;
     @synchronized(self) {
         memoryFootprint = [NSArray<SentryMetricReading *> arrayWithArray:_memoryFootprint];
-        cpuUsage = [NSDictionary<NSNumber *, NSArray<SentryMetricReading *> *>
-            dictionaryWithDictionary:_cpuUsage];
+        cpuUsage = [NSArray<SentryMetricReading *> arrayWithArray:_cpuUsage];
     }
 
     const auto dict = [NSMutableDictionary<NSString *, id> dictionary];
@@ -137,16 +124,11 @@ - (void)stop
                 kSentryMetricProfilerSerializationUnitBytes, startSystemTime, endSystemTime);
     }
 
-    [cpuUsage enumerateKeysAndObjectsUsingBlock:^(NSNumber *_Nonnull core,
-        NSArray<SentryMetricReading *> *_Nonnull readings, BOOL *_Nonnull stop) {
-        if (readings.count > 0) {
-            dict[[NSString stringWithFormat:kSentryMetricProfilerSerializationKeyCPUUsageFormat,
-                           core.intValue]]
-                = serializeValuesWithNormalizedTime(readings,
-                    kSentryMetricProfilerSerializationUnitPercentage, startSystemTime,
-                    endSystemTime);
-        }
-    }];
+    if (cpuUsage.count > 0) {
+        dict[kSentryMetricProfilerSerializationKeyCPUUsage]
+            = serializeValuesWithNormalizedTime(cpuUsage,
+                kSentryMetricProfilerSerializationUnitPercentage, startSystemTime, endSystemTime);
+    }
 
     return dict;
 }
@@ -165,7 +147,7 @@ - (void)registerSampler
                 attributes:dispatch_queue_attr_make_with_qos_class(
                                DISPATCH_QUEUE_CONCURRENT, QOS_CLASS_UTILITY, 0)
               eventHandler:^{
-                  [weakSelf recordCPUPercentagePerCore];
+                  [weakSelf recordCPUsage];
                   [weakSelf recordMemoryFootprint];
               }];
 }
@@ -186,22 +168,23 @@ - (void)recordMemoryFootprint
     }
 }
 
-- (void)recordCPUPercentagePerCore
+- (void)recordCPUsage
 {
     NSError *error;
     const auto result =
-        [SentryDependencyContainer.sharedInstance.systemWrapper cpuUsagePerCore:&error];
+        [SentryDependencyContainer.sharedInstance.systemWrapper cpuUsageWithError:&error];
 
     if (error) {
         SENTRY_LOG_ERROR(@"Failed to read CPU usages: %@", error);
         return;
     }
 
+    if (result == nil) {
+        return;
+    }
+
     @synchronized(self) {
-        [result enumerateObjectsUsingBlock:^(
-            NSNumber *_Nonnull usage, NSUInteger core, BOOL *_Nonnull stop) {
-            [_cpuUsage[@(core)] addObject:[self metricReadingForValue:usage]];
-        }];
+        [_cpuUsage addObject:[self metricReadingForValue:result]];
     }
 }
 

Sources/Sentry/SentrySystemWrapper.mm

@@ -1,8 +1,22 @@
 #import "SentrySystemWrapper.h"
+#import "SentryDependencyContainer.h"
 #import "SentryError.h"
+#import "SentryNSProcessInfoWrapper.h"
 #import <mach/mach.h>
+#include <thread>
 
-@implementation SentrySystemWrapper
+@implementation SentrySystemWrapper {
+    float processorCount;
+}
+
+- (instancetype)init
+{
+    if ((self = [super init])) {
+        processorCount
+            = (float)SentryDependencyContainer.sharedInstance.processInfoWrapper.processorCount;
+    }
+    return self;
+}
 
 - (SentryRAMBytes)memoryFootprintBytes:(NSError *__autoreleasing _Nullable *)error
 {
@@ -28,35 +42,48 @@ - (SentryRAMBytes)memoryFootprintBytes:(NSError *__autoreleasing _Nullable *)err
     return footprintBytes;
 }
 
-- (NSArray<NSNumber *> *)cpuUsagePerCore:(NSError **)error
+- (NSNumber *)cpuUsageWithError:(NSError **)error
 {
-    natural_t numCPUs = 0U;
-    processor_info_array_t cpuInfo;
-    mach_msg_type_number_t numCPUInfo;
-    const auto status = host_processor_info(
-        mach_host_self(), PROCESSOR_CPU_LOAD_INFO, &numCPUs, &cpuInfo, &numCPUInfo);
-    if (status != KERN_SUCCESS) {
+    mach_msg_type_number_t count;
+    thread_act_array_t list;
+
+    const auto taskThreadsStatus = task_threads(mach_task_self(), &list, &count);
+    if (taskThreadsStatus != KERN_SUCCESS) {
         if (error) {
             *error = NSErrorFromSentryErrorWithKernelError(
-                kSentryErrorKernel, @"host_processor_info reported an error.", status);
+                kSentryErrorKernel, @"task_threads reported an error.", taskThreadsStatus);
         }
+        vm_deallocate(
+            mach_task_self(), reinterpret_cast<vm_address_t>(list), sizeof(*list) * count);
         return nil;
     }
 
-    NSMutableArray *result = [NSMutableArray arrayWithCapacity:numCPUs];
-    for (natural_t core = 0U; core < numCPUs; ++core) {
-        const auto indexBase = CPU_STATE_MAX * core;
-        const float user = cpuInfo[indexBase + CPU_STATE_USER];
-        const float sys = cpuInfo[indexBase + CPU_STATE_SYSTEM];
-        const float nice = cpuInfo[indexBase + CPU_STATE_NICE];
-        const float idle = cpuInfo[indexBase + CPU_STATE_IDLE];
-        const auto inUse = user + sys + nice;
-        const auto total = inUse + idle;
-        const auto usagePercent = inUse / total * 100.f;
-        [result addObject:@(usagePercent)];
+    auto usage = 0.f;
+    for (decltype(count) i = 0; i < count; i++) {
+        const auto thread = list[i];
+
+        mach_msg_type_number_t infoSize = THREAD_BASIC_INFO_COUNT;
+        thread_basic_info_data_t data;
+        const auto threadInfoStatus = thread_info(
+            thread, THREAD_BASIC_INFO, reinterpret_cast<thread_info_t>(&data), &infoSize);
+        if (threadInfoStatus != KERN_SUCCESS) {
+            if (error) {
+                *error = NSErrorFromSentryErrorWithKernelError(
+                    kSentryErrorKernel, @"task_threads reported an error.", taskThreadsStatus);
+            }
+            vm_deallocate(
+                mach_task_self(), reinterpret_cast<vm_address_t>(list), sizeof(*list) * count);
+            return nil;
+        }
+
+        usage += data.cpu_usage / processorCount;
     }
 
-    return result;
+    vm_deallocate(mach_task_self(), reinterpret_cast<vm_address_t>(list), sizeof(*list) * count);
+
+    NSLog(@"CPU usage: %f", usage);
+
+    return @(usage);
 }
 
 @end

Sources/Sentry/include/SentryMetricProfiler.h

@@ -9,7 +9,7 @@
 NS_ASSUME_NONNULL_BEGIN
 
 SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationKeyMemoryFootprint;
-SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationKeyCPUUsageFormat;
+SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationKeyCPUUsage;
 
 SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationUnitBytes;
 SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationUnitPercentage;

Sources/Sentry/include/SentrySystemWrapper.h

@@ -24,7 +24,7 @@ typedef mach_vm_size_t SentryRAMBytes;
  * returned by the underlying system call, e.g. @c @[ @c <core-0-CPU-usage>, @c <core-1-CPU-usage>,
  * @c ...] .
  */
-- (nullable NSArray<NSNumber *> *)cpuUsagePerCore:(NSError **)error;
+- (nullable NSNumber *)cpuUsageWithError:(NSError **)error;
 
 @end
 

Tests/SentryProfilerTests/SentryProfilerSwiftTests.swift

@@ -52,8 +52,7 @@ class SentryProfilerSwiftTests: XCTestCase {
             SentryDependencyContainer.sharedInstance().dispatchFactory = dispatchFactory
             SentryDependencyContainer.sharedInstance().timerFactory = timeoutTimerFactory
 
-            systemWrapper.overrides.cpuUsagePerCore = mockCPUUsages.map { NSNumber(value: $0) }
-            processInfoWrapper.overrides.processorCount = UInt(mockCPUUsages.count)
+            systemWrapper.overrides.cpuUsage = NSNumber(value: mockCPUUsage)
             systemWrapper.overrides.memoryFootprintBytes = mockMemoryFootprint
 
 #if !os(macOS)
@@ -87,7 +86,7 @@ class SentryProfilerSwiftTests: XCTestCase {
 
         // mocking
 
-        let mockCPUUsages = [12.4, 63.5, 1.4, 4.6]
+        let mockCPUUsage = 66.6
         let mockMemoryFootprint: SentryRAMBytes = 123_455
         let mockUsageReadingsPerBatch = 2
 
@@ -597,10 +596,7 @@ private extension SentryProfilerSwiftTests {
 
         let expectedUsageReadings = fixture.mockUsageReadingsPerBatch * metricsBatches
 
-        for (i, expectedUsage) in fixture.mockCPUUsages.enumerated() {
-            let key = NSString(format: kSentryMetricProfilerSerializationKeyCPUUsageFormat as NSString, i) as String
-            try assertMetricValue(measurements: measurements, key: key, numberOfReadings: expectedUsageReadings, expectedValue: expectedUsage, transaction: transaction)
-        }
+        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyCPUUsage, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockCPUUsage, transaction: transaction)
 
         try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyMemoryFootprint, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockMemoryFootprint, transaction: transaction)
 

Tests/SentryProfilerTests/SentrySystemWrapperTests.swift

@@ -8,12 +8,8 @@ class SentrySystemWrapperTests: XCTestCase {
 
     func testCPUUsageReportsData() throws {
         XCTAssertNoThrow({
-            let cpuUsages = try self.fixture.systemWrapper.cpuUsagePerCore()
-            XCTAssertGreaterThan(cpuUsages.count, 0)
-            let range = 0.0 ... 100.0
-            cpuUsages.forEach {
-                XCTAssert(range.contains($0.doubleValue))
-            }
+            let cpuUsage = try XCTUnwrap(self.fixture.systemWrapper.cpuUsage())
+            XCTAssert((0.0 ... 100.0).contains(cpuUsage.doubleValue))
         })
     }