fix: read free_memory when the event is captured, not only at SDK startup

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Features
+
+- Read free_memory when the event is captured, not only at SDK startup (#1962)
+
 ### Fixes
 
 - Remove Sentry keys from cached HTTP request headers (#1975)

Sources/Sentry/SentryClient.m

@@ -5,6 +5,7 @@
 #import "SentryCrashDefaultMachineContextWrapper.h"
 #import "SentryCrashIntegration.h"
 #import "SentryCrashStackEntryMapper.h"
+#import "SentryCrashWrapper.h"
 #import "SentryDebugImageProvider.h"
 #import "SentryDefaultCurrentDateProvider.h"
 #import "SentryDependencyContainer.h"
@@ -55,6 +56,7 @@
 @property (nonatomic, strong) SentryThreadInspector *threadInspector;
 @property (nonatomic, strong) id<SentryRandom> random;
 @property (nonatomic, weak) id<SentryClientAttachmentProcessor> attachmentProcessor;
+@property (nonatomic, strong) SentryCrashWrapper *crashWrapper;
 
 @end
 
@@ -101,6 +103,8 @@ - (_Nullable instancetype)initWithOptions:(SentryOptions *)options
                                                                           options:options];
 
         self.random = [SentryDependencyContainer sharedInstance].random;
+
+        self.crashWrapper = [SentryCrashWrapper sharedInstance];
     }
     return self;
 }
@@ -111,13 +115,15 @@ - (instancetype)initWithOptions:(SentryOptions *)options
                     fileManager:(SentryFileManager *)fileManager
                 threadInspector:(SentryThreadInspector *)threadInspector
                          random:(id<SentryRandom>)random
+                   crashWrapper:(SentryCrashWrapper *)crashWrapper
 {
     self = [self initWithOptions:options];
 
     self.transportAdapter = transportAdapter;
     self.fileManager = fileManager;
     self.threadInspector = threadInspector;
     self.random = random;
+    self.crashWrapper = crashWrapper;
 
     return self;
 }
@@ -487,10 +493,13 @@ - (SentryEvent *_Nullable)prepareEvent:(SentryEvent *)event
 
     event = [scope applyToEvent:event maxBreadcrumb:self.options.maxBreadcrumbs];
 
-    // Remove free_memory if OOM as free_memory stems from the current run and not of the time of
-    // the OOM.
     if ([self isOOM:event isCrashEvent:isCrashEvent]) {
+        // Remove free_memory if OOM as free_memory stems from the current run and not of
+        // the time of the OOM.
         [self removeFreeMemoryFromDeviceContext:event];
+    } else {
+        // Store the actual free memory at the time of this event
+        [self storeFreeMemoryToDeviceContext:event];
     }
 
     // With scope applied, before running callbacks run:
@@ -638,7 +647,24 @@ - (BOOL)isOOM:(SentryEvent *)event isCrashEvent:(BOOL)isCrashEvent
         [exception.mechanism.type isEqualToString:SentryOutOfMemoryMechanismType];
 }
 
+- (void)storeFreeMemoryToDeviceContext:(SentryEvent *)event
+{
+    [self modifyDeviceContext:event
+                        block:^(NSMutableDictionary *device) {
+                            device[SentryDeviceContextFreeMemoryKey] =
+                                @(self.crashWrapper.freeMemory);
+                        }];
+}
+
 - (void)removeFreeMemoryFromDeviceContext:(SentryEvent *)event
+{
+    [self modifyDeviceContext:event
+                        block:^(NSMutableDictionary *device) {
+                            [device removeObjectForKey:SentryDeviceContextFreeMemoryKey];
+                        }];
+}
+
+- (void)modifyDeviceContext:(SentryEvent *)event block:(void (^)(NSMutableDictionary *))block
 {
     if (nil == event.context || event.context.count == 0 || nil == event.context[@"device"]) {
         return;
@@ -647,9 +673,8 @@ - (void)removeFreeMemoryFromDeviceContext:(SentryEvent *)event
     NSMutableDictionary *context = [[NSMutableDictionary alloc] initWithDictionary:event.context];
     NSMutableDictionary *device =
         [[NSMutableDictionary alloc] initWithDictionary:context[@"device"]];
-    [device removeObjectForKey:SentryDeviceContextFreeMemoryKey];
+    block(device);
     context[@"device"] = device;
-
     event.context = context;
 }
 

Sources/Sentry/SentryCrashWrapper.m

@@ -1,6 +1,7 @@
 #import "SentryCrashWrapper.h"
 #import "SentryCrash.h"
 #import "SentryCrashMonitor_AppState.h"
+#import "SentryCrashMonitor_System.h"
 #import "SentryHook.h"
 #import <Foundation/Foundation.h>
 #import <SentryCrashCachedData.h>
@@ -69,6 +70,11 @@ - (NSDictionary *)systemInfo
     return sharedInfo;
 }
 
+- (NSInteger)freeMemory
+{
+    return sentrycrashcm_system_freememory();
+}
+
 @end
 
 NS_ASSUME_NONNULL_END

Sources/Sentry/include/SentryCrashWrapper.h

@@ -30,6 +30,8 @@ SENTRY_NO_INIT
 
 - (NSDictionary *)systemInfo;
 
+- (NSInteger)freeMemory;
+
 @end
 
 NS_ASSUME_NONNULL_END

Sources/SentryCrash/Recording/Monitors/SentryCrashMonitor_System.h

@@ -39,6 +39,8 @@ SentryCrashMonitorAPI *sentrycrashcm_system_getAPI(void);
 
 bool sentrycrash_isSimulatorBuild(void);
 
+uint64_t sentrycrashcm_system_freememory(void);
+
 #ifdef __cplusplus
 }
 #endif

Sources/SentryCrash/Recording/Monitors/SentryCrashMonitor_System.m

@@ -199,6 +199,12 @@
     return 0;
 }
 
+uint64_t
+sentrycrashcm_system_freememory(void)
+{
+    return freeMemory();
+}
+
 static uint64_t
 usableMemory(void)
 {

Tests/SentryTests/SentryClient+TestInit.h

@@ -14,7 +14,8 @@ SentryClient (TestInit)
                transportAdapter:(SentryTransportAdapter *)transportAdapter
                     fileManager:(SentryFileManager *)fileManager
                 threadInspector:(SentryThreadInspector *)threadInspector
-                         random:(id<SentryRandom>)random;
+                         random:(id<SentryRandom>)random
+                   crashWrapper:(SentryCrashWrapper *)crashWrapper;
 
 @end
 

Tests/SentryTests/SentryClientTests.swift

@@ -27,6 +27,7 @@ class SentryClientTest: XCTestCase {
 
         let trace = SentryTracer(transactionContext: TransactionContext(name: "SomeTransaction", operation: "SomeOperation"), hub: nil)
         let transaction: Transaction
+        let crashWrapper = TestSentryCrashWrapper.sharedInstance()
 
         init() {
             session = SentrySession(releaseName: "release")
@@ -59,7 +60,7 @@ class SentryClientTest: XCTestCase {
                 ])
                 configureOptions(options)
 
-                client = Client(options: options, transportAdapter: transportAdapter, fileManager: fileManager, threadInspector: threadInspector, random: random)
+                client = Client(options: options, transportAdapter: transportAdapter, fileManager: fileManager, threadInspector: threadInspector, random: random, crashWrapper: crashWrapper)
             } catch {
                 XCTFail("Options could not be created")
             }
@@ -497,6 +498,20 @@ class SentryClientTest: XCTestCase {
         }
     }
 
+    func testCaptureCrash_FreeMemory() {
+        let event = TestData.event
+        event.threads = nil
+        event.debugMeta = nil
+
+        fixture.crashWrapper.internalFreeMemory = 123_456
+        fixture.getSut().captureCrash(event, with: fixture.scope)
+
+        assertLastSentEventWithAttachment { actual in
+            let eventFreeMemory = actual.context?["device"]?["free_memory"] as? Int
+            XCTAssertEqual(eventFreeMemory, 123_456)
+        }
+    }
+
     func testCaptureErrorWithUserInfo() {
         let expectedValue = "val"
         let error = NSError(domain: "domain", code: 0, userInfo: ["key": expectedValue])

Tests/SentryTests/SentryCrash/TestSentryCrashWrapper.h

@@ -25,6 +25,8 @@ SENTRY_NO_INIT
 
 @property (nonatomic, assign) BOOL closeCalled;
 
+@property (nonatomic, assign) NSInteger internalFreeMemory;
+
 @end
 
 NS_ASSUME_NONNULL_END

Tests/SentryTests/SentryCrash/TestSentryCrashWrapper.m

@@ -14,6 +14,7 @@ + (instancetype)sharedInstance
     instance.internalIsApplicationInForeground = YES;
     instance.installAsyncHooksCalled = NO;
     instance.closeCalled = NO;
+    instance.internalFreeMemory = 0;
     return instance;
 }
 
@@ -57,4 +58,9 @@ - (NSDictionary *)systemInfo
     return @{};
 }
 
+- (NSInteger)freeMemory
+{
+    return self.internalFreeMemory;
+}
+
 @end