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- 3. What is Compilation? Process of turning human readable text into code understandable by machines
- 6. Types of Compilation Interpretation Static compilation
- 7. Does it means that Java is interpreted or statically compilled ?
- 8. Does it means that Java is interpreted or statically compilled ? Yes, and no
- 11. Just-in-time compilation An attempt to mix pros of both static compilation and interpretation
- 12. Just-in-time compilation An attempt to mix pros of both static compilation and interpretation In most cases, operates on some sort of an intermediate level code
- 18. Compilation in Java Source code javac Tiered compilation bytecode JVM
- 19. How many compilers we have in Java?
- 20. How many compilers we have in Java? 3
- 25. Why we have so many compilers in Java?
- 26. Why we have so many compilers in Java? Well, because history
- 27. C1 & C2 background
- 28. C1 & C2 background Long ago JDK was published in two versions: client and server.
- 29. C1 & C2 background Long ago JDK was published in two versions: client and server. C1 was dedicated for the optimization of application startup time.
- 30. C1 & C2 background Long ago JDK was published in two versions: client and server. C1 was dedicated for the optimization of application startup time. C2 was dedicated for a long-running application with strict performance limits.
- 31. C1
- 32. C1 Starts compilation earlier than C2
- 33. C1 Starts compilation earlier than C2 Does not perform costly performance optimizations.
- 34. C2
- 35. C2 Focused at providing profile based optimizations.
- 36. C2 Focused at providing profile based optimizations. C2 compiled code will be much faster than C1.
- 37. C2 Focused at providing profile based optimizations. C2 compiled code will be much faster than C1. At this point no more major enhancements for C2 compiler are possible.
- 39. Why this differentiation exists ? It does not, not longer
- 42. Tiered Compilation It is a technique which combines both C1 and C2 compilers.
- 43. Tiered Compilation - Pros
- 44. Tiered Compilation - Pros Faster application startup
- 45. Tiered Compilation - Pros Faster application startup Better C2 optimizations
- 46. Tiered Compilation - Pros Faster application startup Better C2 optimizations Reduced memory footprint of JVM
- 47. Tiered Compilation - Pros Faster application startup Better C2 optimizations Reduced memory footprint of JVM Adaptive optimization
- 48. Tier Code compilation level Tiered Compilation - Tiers
- 49. Tier Code compilation level 0 bytecode Tiered Compilation - Tiers
- 50. Tier Code compilation level 0 bytecode 1 Simple C1 code Tiered Compilation - Tiers
- 51. Tier Code compilation level 0 bytecode 1 Simple C1 code 2 Limited C1 code Tiered Compilation - Tiers
- 52. Tier Code compilation level 0 bytecode 1 Simple C1 code 2 Limited C1 code 3 Full C1 code Tiered Compilation - Tiers
- 53. Tier Code compilation level 0 bytecode 1 Simple C1 code 2 Limited C1 code 3 Full C1 code 4 C2 compiled Tiered Compilation - Tiers
- 54. 1 Tiered Compilation - Flow Bytecode execution
- 55. 2 1 Tiered Compilation - Flow Bytecode execution Profiling
- 56. 2 1 3 Tiered Compilation - Flow Bytecode execution Profiling Compilation
- 57. 2 1 4 3 Tiered Compilation - Flow Bytecode execution Profiling Compilation Deoptimization
- 58. When the code will be compiled
- 59. When the code will be compiled When piece of code will reach a certain call threshold.
- 60. When the code will be compiled When piece of code will reach a certain call threshold. When loop Back Branching counter will reach certain threshold.
- 61. When the code will be compiled When piece of code will reach a certain call threshold. When loop Back Branching counter will reach certain threshold. Method execution time is also a factor.
- 62. What the word HotSpot means in JVM context?
- 63. What the word HotSpot means in JVM context? Two things
- 64. HotSpot
- 65. HotSpot It is a full name of JVM - Java HotSpot VM
- 66. HotSpot It is a full name of JVM - Java HotSpot VM The place in the code that is frequently called
- 67. Tiered Compilation - Settings
- 68. TieredStopAtLevel Tiered Compilation - Settings
- 71. TieredStopAtLevel CompileThreshold Tier2CompileThreshold CICompilerCount Tiered Compilation - Settings
- 72. TieredStopAtLevel CompileThreshold Tier2CompileThreshold CICompilerCount Tiered Compilation - Settings Try this at home, not on PRODUCTION
- 75. Tiered Compilation - Threads Cores C1 Threads C2 Threads 1 1 1 2 1 1 4 1 2 8 1 2 16 2 6 32 3 7 64 4 8
- 76. GraalVM
- 80. Graal Compiler
- 81. Graal Compiler Written in Java.
- 82. Graal Compiler Written in Java. New communication interface - JVMCI
- 83. Graal Compiler Written in Java. New communication interface - JVMCI Uses tiered compilation concept.
- 84. Graal Compiler Written in Java. New communication interface - JVMCI Uses tiered compilation concept. Includes 62 different optimizations.
- 85. Graal Compiler Written in Java. New communication interface - JVMCI Uses tiered compilation concept. Includes 62 different optimizations. Better at optimizing "new" code.
- 86. Graal Compiler Written in Java. New communication interface - JVMCI Uses tiered compilation concept. Includes 62 different optimizations. Better at optimizing "new" code. Better profile-guided optimization.
- 88. Recap
- 89. We have three types of compilation. Recap
- 90. We have three types of compilation. Java has three compilers. Recap
- 91. We have three types of compilation. Java has three compilers. JVM uses Tiered Compilation. Recap
- 92. We have three types of compilation. Java has three compilers. JVM uses Tiered Compilation. HotSpot comes from the way how JVM compiles code. Recap
- 93. We have three types of compilation. Java has three compilers. JVM uses Tiered Compilation. HotSpot comes from the way how JVM compiles code. Graal brought us a new version of C2 compiler. Recap