terran 0 Posted September 2 (edited) Memory leak on TParallel.For it happens on empty TParallel.For TParallel.For(0, 10, procedure(yy:integer) begin for var xx:=0 to 10 do begin end; end); Quote This application has leaked memory. The leaks ordered by size are: 8: 54 x System.TObject 24: 27 x System.SyncObjs.TLightweightEvent 32: 27 x System.Threading.TWorkStealingQueue<System.Threading.TThreadPool.IThreadPoolWorkItem> 52: 1 x System.Threading.TThreadPool.TThreadPoolMonitor 68: 27 x System.Threading.TThreadPool.TQueueWorkerThread 74: 1 x UnicodeString 136: 27 x Unknown 176: 1 x UnicodeString No my code in stack. No "minimal (non)-reproducible example" can be done. It's a DLL, and it does its job inside a third-party application. MemoryManager_EventLog.txt Edited September 2 by terran Share this post Link to post
Kas Ob. 121 Posted September 2 I don't have an answer, just one to do about thing this 43 minutes ago, terran said: No my code in stack. No "minimal (non)-reproducible example" can be done. It's a DLL, and it does its job inside a third-party application. Add a fake (not used) TMyObject to your code, create it inside that loop you are doubting, then don't free it ! See if the report is consistent and reliable, with 11 leaked TMyObject. This might save time. Share this post Link to post
terran 0 Posted September 3 11 hours ago, Dmitry Arefiev said: What is the Delphi version ? 12 Share this post Link to post
Kas Ob. 121 Posted September 3 @terran i see you updated you post with a log Yes that log does shows memory leaks, and you didn't do what i asked for and suggested, but yet more information is needed to pin point the problem, i do understand you can't share codes, But as curtesy and respect for our time as yours, read what people write you and if you don't understand their reasons and logic, then you can ask, you might learn something or two. So here what i see with the little provided: I put your log in Notepad++ and searched for all the occurrences of "The allocation number is", the result is Line 28: The allocation number is: 3155 Line 60: The allocation number is: 504725 Line 92: The allocation number is: 504689 Line 124: The allocation number is: 504673 Line 156: The allocation number is: 504650 Line 188: The allocation number is: 504623 Line 220: The allocation number is: 504604 Line 252: The allocation number is: 502198 Line 284: The allocation number is: 486818 Line 316: The allocation number is: 486791 Line 348: The allocation number is: 486093 Line 380: The allocation number is: 504750 Line 412: The allocation number is: 504747 Line 444: The allocation number is: 504733 Line 476: The allocation number is: 504727 Line 508: The allocation number is: 504694 Line 540: The allocation number is: 504690 Line 572: The allocation number is: 504678 Line 604: The allocation number is: 504674 Line 636: The allocation number is: 504656 Line 668: The allocation number is: 504652 Line 700: The allocation number is: 504630 Line 732: The allocation number is: 504625 Line 764: The allocation number is: 504608 Line 796: The allocation number is: 504605 Line 828: The allocation number is: 502202 Line 860: The allocation number is: 502199 Line 892: The allocation number is: 486839 Line 924: The allocation number is: 486795 Line 956: The allocation number is: 486792 Line 988: The allocation number is: 486099 Line 1020: The allocation number is: 486094 Line 1052: The allocation number is: 486819 Line 1084: The allocation number is: 484903 Line 1116: The allocation number is: 484900 Line 1148: The allocation number is: 2221 Line 1180: The allocation number is: 2293 Line 1212: The allocation number is: 2127 Line 1244: The allocation number is: 2087 Line 1276: The allocation number is: 2047 Line 1308: The allocation number is: 504746 Line 1340: The allocation number is: 2018 Line 1372: The allocation number is: 1971 Line 1404: The allocation number is: 3168 Line 1436: The allocation number is: 1944 Line 1468: The allocation number is: 1896 Line 1500: The allocation number is: 1873 Line 1532: The allocation number is: 1860 Line 1564: The allocation number is: 1888 Line 1596: The allocation number is: 1850 Line 1628: The allocation number is: 484899 Line 1660: The allocation number is: 1902 Line 1694: The allocation number is: 504748 Line 1728: The allocation number is: 504729 Line 1762: The allocation number is: 504691 Line 1796: The allocation number is: 504675 Line 1830: The allocation number is: 504653 Line 1864: The allocation number is: 504627 Line 1898: The allocation number is: 504606 Line 1932: The allocation number is: 502200 Line 1966: The allocation number is: 486829 Line 2000: The allocation number is: 486793 Line 2034: The allocation number is: 486096 Line 2068: The allocation number is: 3170 Line 2102: The allocation number is: 484901 Line 2136: The allocation number is: 3157 Line 2170: The allocation number is: 2295 Line 2204: The allocation number is: 2223 Line 2238: The allocation number is: 2131 Line 2272: The allocation number is: 2020 Line 2306: The allocation number is: 2090 Line 2340: The allocation number is: 1946 Line 2374: The allocation number is: 1974 Line 2408: The allocation number is: 1899 Line 2442: The allocation number is: 2049 Line 2476: The allocation number is: 1875 Line 2510: The allocation number is: 1890 Line 2544: The allocation number is: 1862 Line 2578: The allocation number is: 1853 Line 2612: The allocation number is: 1989 Line 2654: The allocation number is: 3169 Line 2686: The allocation number is: 2297 Line 2718: The allocation number is: 2225 Line 2750: The allocation number is: 2294 Line 2782: The allocation number is: 2136 Line 2814: The allocation number is: 2222 Line 2846: The allocation number is: 2092 Line 2878: The allocation number is: 2129 Line 2910: The allocation number is: 2051 Line 2942: The allocation number is: 2088 Line 2974: The allocation number is: 3173 Line 3006: The allocation number is: 2022 Line 3038: The allocation number is: 2019 Line 3070: The allocation number is: 1976 Line 3102: The allocation number is: 2048 Line 3134: The allocation number is: 3159 Line 3166: The allocation number is: 1948 Line 3198: The allocation number is: 1972 Line 3230: The allocation number is: 3156 Line 3262: The allocation number is: 1901 Line 3294: The allocation number is: 1945 Line 3326: The allocation number is: 1892 Line 3358: The allocation number is: 1897 Line 3390: The allocation number is: 1877 Line 3422: The allocation number is: 1889 Line 3454: The allocation number is: 1864 Line 3486: The allocation number is: 1874 Line 3518: The allocation number is: 1855 Line 3550: The allocation number is: 1851 Line 3582: The allocation number is: 1861 Line 3614: The allocation number is: 504739 Line 3650: The allocation number is: 504703 Line 3686: The allocation number is: 504687 Line 3722: The allocation number is: 504661 Line 3758: The allocation number is: 504635 Line 3794: The allocation number is: 502167 Line 3830: The allocation number is: 486073 Line 3866: The allocation number is: 486801 Line 3902: The allocation number is: 486575 Line 3938: The allocation number is: 504614 Line 3974: The allocation number is: 3164 Line 4010: The allocation number is: 2174 Line 4046: The allocation number is: 3113 Line 4082: The allocation number is: 2065 Line 4118: The allocation number is: 2107 Line 4154: The allocation number is: 2236 Line 4190: The allocation number is: 1997 Line 4226: The allocation number is: 2031 Line 4262: The allocation number is: 1960 Line 4298: The allocation number is: 1934 Line 4334: The allocation number is: 1893 Line 4365: The allocation number is: 1978 Line 4401: The allocation number is: 1865 Line 4437: The allocation number is: 1878 Line 4473: The allocation number is: 1857 Line 4509: The allocation number is: 1848 Line 4545: The allocation number is: 484882 Line 4581: The allocation number is: 504587 Line 4617: The allocation number is: 504749 Line 4657: The allocation number is: 504731 Line 4697: The allocation number is: 504692 Line 4737: The allocation number is: 504676 Line 4777: The allocation number is: 504655 Line 4817: The allocation number is: 504629 Line 4857: The allocation number is: 504607 Line 4897: The allocation number is: 502201 Line 4937: The allocation number is: 486836 Line 4977: The allocation number is: 486794 Line 5017: The allocation number is: 484902 Line 5057: The allocation number is: 486098 Line 5097: The allocation number is: 3171 Line 5137: The allocation number is: 3158 Line 5177: The allocation number is: 2296 Line 5217: The allocation number is: 2224 Line 5257: The allocation number is: 2133 Line 5297: The allocation number is: 2091 Line 5337: The allocation number is: 2050 Line 5377: The allocation number is: 2021 Line 5417: The allocation number is: 1975 Line 5457: The allocation number is: 1947 Line 5497: The allocation number is: 1900 Line 5537: The allocation number is: 1891 Line 5577: The allocation number is: 1876 Line 5617: The allocation number is: 1863 Line 5657: The allocation number is: 1854 This shows two group of leaks, one group happen very early, while the other was very late, both group are condensed, meaning they do happen on specific event. I followed what i think is the first (the oldest reported leak) with number 1848, and here is it --------------------------------2024-09-02 17:00:36-------------------------------- A memory block has been leaked. The size is: 68 This block was allocated by thread 0xA44, and the stack trace (return addresses) at the time was: 0542E4D2 [fastmm5.pas][FastMM5][FastMM_DebugGetMem$qqri][7820] 054170D2 [System.pas][System][@GetMem$qqri][4962] 05418F9B [System.pas][System][TObject.NewInstance][18331] 0541969E [System.pas][System][@ClassCreate$qqrpvzc][19661] 05517233 [System.Threading.pas][System.Threading][Threading.TThreadPool.TQueueWorkerThread.Create][3479] 0541970C [System.pas][System][@AfterConstruction$qqrxp14System.TObject][19710] 05516998 [System.Threading.pas][System.Threading][Threading.TThreadPool.CreateWorkerThread][3223] 05516B19 [System.Threading.pas][System.Threading][Threading.TThreadPool.GrowWorkerPool][3269] 05516E1F [System.Threading.pas][System.Threading][Threading.TThreadPool.QueueWorkItem][3357] 05513D9B [System.Threading.pas][System.Threading][Threading.TTask.QueueEvents][2715] 055145C1 [System.Threading.pas][System.Threading][Threading.TParallel.TReplicableTask.QueueEvents][2972] 0551419B [System.Threading.pas][System.Threading][Threading.TTask.Start][2779] 05510F1A [System.Threading.pas][System.Threading][Threading.TParallel.ForWorker][1483] 056D8CF2 [ImageCompare.dpr][ImageCompare][ResizeCanvas$qqrp33Imagingcanvases.TFastARGB32Canvasp30Imagingcanvases.TImagingCanvasiiii][1069] 05653BA6 [ImagingCanvases.pas][ImagingCanvases][TImagingCanvas.ResetClipRect][954] 056CA19D [Imaging.pas][Imaging][GetImageFormatInfo$qqr25Imagingtypes.TImageFormatr29Imagingtypes.TImageFormatInfo][2812] 05653B76 [ImagingCanvases.pas][ImagingCanvases][TImagingCanvas.UpdateCanvasState][949] 056C432E [Imaging.pas][Imaging][TestImage$qqrrx23Imagingtypes.TImageData][921] 056D97E9 [ImageCompare.dpr][ImageCompare][TProcessFile.GetdHash$qqrr22Imagecompare.TLastInfox20System.UnicodeStringiii][1200] 77911B2C [Unknown function at RtlpNtEnumerateSubKey] The block is currently used for an object of class: System.Threading.TThreadPool.TQueueWorkerThread The allocation number is: 1848 Current memory dump of 76 bytes starting at pointer address 72AE3A0: AC 3C 50 05 A4 9E 00 00 CC 03 00 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 20 FB 2C 07 40 4F 21 07 40 EB 22 07 64 FB 2C 07 68 FB 2C 07 00 CB 27 07 00 00 00 00 D4 2F 2C 8D D2 E4 42 05 . < P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . @ O ! . @ . " . d . , . h . , . . . ' . . . . . . / , . . . B . Now this proof you are wrong about none of your code is involved ! All start in your ImageCompare.dpr, so more information is needed here, Is that ImageCompare.dpr belongs to a DLL or an EXE ? Another thing, is there any thing prohibited you from do what i suggested about deliberately invoked leaks ? Again and for the last time, put TMyObjectX before such loops you pasted above, replace X with a number (1,2,3..) so they can be named and recognized in the log, and put this simple line in the loop "TMyObject.Create;" no variable, no thing, this is enough to cause a leak to report. Depending on the number of reported leaks for these TMyObject1, TMyObject2.... you and we can see a little more, because in your first post there was very interesting numbers 27 and 54, yet the loop is 11 ! This must be addressed also, to get the bigger picture or at least identify a method to catch and categorize the problem, is it a Compiler/RTL bug or some mishandling code. Another thing, Why ImageCompare.dpr does show in the log to begin with ? in case it is a DLL then you must not initialize long process or an even more dangerous process like multithreading, when the thread is Loaded/Attcached, like such process that depend on and identify the calling thread as main one, the calling thread here (in case with DLL) is an OS one that will be created and will be destroyed by the OS, and this will confuse your code with the Process Main Thread, causing all sort of problem. And good luck ! Share this post Link to post
Remy Lebeau 1394 Posted September 3 On 9/2/2024 at 9:18 AM, terran said: Memory leak on TParallel.For ... No "minimal (non)-reproducible example" can be done. It's a DLL, and it does its job inside a third-party application. I wonder if this is a false positive? The log shows a thread pool is involved. Makes me wonder if the pool threads are simply still running when the leak report is generated. You have to make sure everything is shutdown first before the memory manager is cleaned up. Share this post Link to post
terran 0 Posted September 6 (edited) Probably it has exception in System.Threading that is not passed to the program, and the worker threads are waiting in a deadlock. That's all I know. Possible place somewhere here (System.Threading, 3535): Signaled := TMonitor.Wait(ThreadPool.FQueue, WaitTime) and not ThreadPool.FShutdown; Possible stack somewhere here: :7785f8d1 ntdll.ZwWaitForSingleObject + 0x15 :75e51194 kernel32.WaitForSingleObjectEx + 0x43 :75e51148 kernel32.WaitForSingleObject + 0x12 System.SysUtils.WaitForSyncWaitObj(???,???) System.SysUtils.WaitOrSignalObj(???,$9C40,???) System.TMonitor.Wait($73E9040,40000) System.TMonitor.Wait(???,40000) System.Threading.TThreadPool.TQueueWorkerThread.Execute System.Classes.ThreadProc($728E3A0) System.ThreadWrapper($728A850) :75e5343d kernel32.BaseThreadInitThunk + 0x12 :77879812 ntdll.RtlInitializeExceptionChain + 0x63 :778797e5 ntdll.RtlInitializeExceptionChain + 0x36 That's all I know. On 9/3/2024 at 8:59 AM, Kas Ob. said: Is that ImageCompare.dpr belongs to a DLL or an EXE ? DLL It is not used when thread loaded/unloaded. If I didn't answer something, then it did not help, or I didn't understand. That's all I know. On 9/3/2024 at 8:59 AM, Kas Ob. said: Now this proof you are wrong about none of your code is involved ! 1. No my code after start of thread. 2. It happens (even) on empty loop. Edited September 7 by terran Share this post Link to post
Kas Ob. 121 Posted September 7 1) How many loop are there in the code in that DLL ? and many iteration being executed ? and compare that to the reported leaks numbers ? 2) Empty loops does produce leaks ? this means broken logic in TThreadPool, yet doesn't mean it is buggy yet, it could be MM, at least try FastMM4 for both EXE and DLL, make sure you are using the same MM. 3) Not bad idea to use the manually induced leaks, this will consolidate the numbers, like i explained above, you should make sure of consistency of the report, if you have more than one loop. 4) in my opinion, TThreadPoolMonitor is the one behind all these leaks, this easily can happen if it is was locked and corrupted or overwritten, that is your target and the direct cause in this bug hunt, it is reported as leak in your log, and as you pointed to. 8 hours ago, terran said: 1. No my code after start of thread. Yet unless someone can confirm and reproduce it, i am inclined to assume your project environment (setup) is responsible for it. 8 hours ago, terran said: 2. It happens (even) on empty loop. Unfortunately, that is good news, and means replicating or reproducing a smaller and stripped project (the smallest new project) to reproduce this bug is feasible, so please try ! Just one thought, lets imagine one thread belongs to TThreadPool was stuck/frozen/looping, how one thread being would affect the pool exiting and cleaning after the threads, does its position affect the pool behavior, like if it was the first, last or in the middle... I don't have an answer for this, so i suggest to dump pall the threads on exit, also don't know how madshi, but i know eurekalog can do this and triggered by hand or by option and manually induced an exception, in any case try to dump all the threads and their stacks to see if there is a thread is still do something or simply unhinged somewhere. The best way to do this is to introduce any unit to the project that has finalization and here you will trigger the threads dump (to get all threads stacks), make sure this unit is the highest place in the dpr uses clause, right after MM, and of course right after the exception tool you will use. Share this post Link to post
David Heffernan 2345 Posted September 7 I don't know why you don't attempt to debug your code. Share this post Link to post
![Delphi-PRAXiS [en]](https://en.delphipraxis.net/uploads/monthly_2018_12/logo.png.be76d93fcd709295cb24de51900e5888.png){kind=logo}
