<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I found the problem, and it is not specific to the backport per se: there are several places where `==` is used to compare `ClassDesc` instances, particularly in the stack map generator. This usually works on JDK 24 or later, but fails on 23 or earlier. The critical clue was when I accidentally ran the backport version of the test on JDK 24 and it passed - telling me that the problem was a JDK behavioral difference.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Dec 12, 2024 at 1:42 PM David Lloyd <<a href="mailto:david.lloyd@redhat.com" target="_blank">david.lloyd@redhat.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Hmm. I will try to come up with a more concise reproducer. Maybe it's a problem with my class hierarchy resolver, or some other configuration that I have locally.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">BTW the example class is from io.smallrye.reactive:mutiny:2.6.2, sorry I failed to specify that. Thanks for looking into it, I'll see if I can make a minimal reproducer.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Dec 12, 2024 at 1:32 PM Chen Liang <<a href="mailto:chen.l.liang@oracle.com" target="_blank">chen.l.liang@oracle.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div>
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Hmm, couldn't reproduce with a local JDK mainline build (25) and the latest smallrye mutiny 2.7.0. (It also appears from bci that your example is an older version of mutiny). I changed the class java/util/ServiceLoader to Dummy in jshell and cannot reproduce
this issue; cannot reproduce with stack maps recomputation either. Here's the javap output of the transformed results.</div>
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static {};</div>
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descriptor: ()V</div>
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flags: (0x0008) ACC_STATIC</div>
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Code:</div>
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stack=2, locals=3, args_size=0</div>
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0: ldc_w #304 // String mutiny.disableCallBackDecorators</div>
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3: invokestatic #306 // Method java/lang/Boolean.getBoolean:(Ljava/lang/String;)Z</div>
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6: putstatic #203 // Field DISABLE_CALLBACK_DECORATORS:Z</div>
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9: ldc_w #312 // class io/smallrye/mutiny/infrastructure/ExecutorConfiguration</div>
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12: invokestatic #561 // Method Dummy.load:(Ljava/lang/Class;)Ljava/util/ServiceLoader;</div>
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15: astore_0</div>
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16: aload_0</div>
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17: invokevirtual #212 // Method java/util/ServiceLoader.iterator:()Ljava/util/Iterator;</div>
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20: astore_1</div>
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21: aload_1</div>
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22: invokeinterface #216, 1 // InterfaceMethod java/util/Iterator.hasNext:()Z</div>
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27: ifeq 61</div>
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30: aload_1</div>
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31: invokeinterface #221, 1 // InterfaceMethod java/util/Iterator.next:()Ljava/lang/Object;</div>
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36: checkcast #312 // class io/smallrye/mutiny/infrastructure/ExecutorConfiguration</div>
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39: astore_2</div>
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40: aload_2</div>
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41: invokeinterface #314, 1 // InterfaceMethod io/smallrye/mutiny/infrastructure/ExecutorConfiguration.getDefaultWorkerExecutor:()Ljava/util/concurrent/Executor;</div>
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46: ldc_w #318 // String executor</div>
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49: invokestatic #167 // Method io/smallrye/mutiny/helpers/ParameterValidation.nonNull:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;</div>
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52: checkcast #320 // class java/util/concurrent/Executor</div>
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55: invokestatic #32 // Method setDefaultExecutor:(Ljava/util/concurrent/Executor;)V</div>
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58: goto 64</div>
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61: invokestatic #322 // Method setDefaultExecutor:()V</div>
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64: invokestatic #324 // Method reload:()V</div>
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67: invokestatic #327 // Method resetCanCallerThreadBeBlockedSupplier:()V</div>
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70: getstatic #241 // Field io/smallrye/mutiny/infrastructure/Infrastructure$PrintAndDumpThrowableConsumer.INSTANCE:Lio/smallrye/mutiny/infrastructure/Infrastructure$PrintAndDumpThrowableConsumer;</div>
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73: putstatic #155 // Field droppedExceptionHandler:Ljava/util/function/Consumer;</div>
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76: getstatic #271 // Field io/smallrye/mutiny/infrastructure/Infrastructure$PrintOperatorEventOperatorLogger.INSTANCE:Lio/smallrye/mutiny/infrastructure/Infrastructure$PrintOperatorEventOperatorLogger;</div>
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79: putstatic #260 // Field operatorLogger:Lio/smallrye/mutiny/infrastructure/Infrastructure$OperatorLogger;</div>
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82: sipush 128</div>
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85: putstatic #16 // Field multiOverflowDefaultBufferSize:I</div>
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88: bipush 32</div>
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90: putstatic #20 // Field bufferSizeXs:I</div>
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93: sipush 256</div>
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96: putstatic #23 // Field bufferSizeS:I</div>
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99: return</div>
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LocalVariableTable:</div>
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Start Length Slot Name Signature</div>
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40 18 2 next Lio/smallrye/mutiny/infrastructure/ExecutorConfiguration;</div>
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16 54 0 executorLoader Ljava/util/ServiceLoader;</div>
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21 49 1 iterator Ljava/util/Iterator;</div>
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LocalVariableTypeTable:</div>
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Start Length Slot Name Signature</div>
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16 54 0 executorLoader Ljava/util/ServiceLoader<Lio/smallrye/mutiny/infrastructure/ExecutorConfiguration;>;</div>
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21 49 1 iterator Ljava/util/Iterator<Lio/smallrye/mutiny/infrastructure/ExecutorConfiguration;>;</div>
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LineNumberTable:</div>
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line 39: 0</div>
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line 42: 9</div>
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line 43: 16</div>
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line 44: 21</div>
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line 45: 30</div>
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line 46: 40</div>
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line 47: 58</div>
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line 48: 61</div>
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line 51: 64</div>
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line 53: 67</div>
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line 63: 70</div>
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line 65: 76</div>
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line 67: 82</div>
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line 69: 88</div>
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line 70: 93</div>
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StackMapTable: number_of_entries = 2</div>
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frame_type = 253 /* append */</div>
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offset_delta = 61</div>
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locals = [ class java/util/ServiceLoader, class java/util/Iterator ]</div>
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frame_type = 2 /* same */</div>
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Regards, Chen</div>
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</div></blockquote></div><div><br clear="all"></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr">- DML • he/him<br></div></div>
</blockquote></div><div><br clear="all"></div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr">- DML • he/him<br></div></div>