Dual JVM - Revision history

JaroslavTulach at 12:30, 29 May 2026

2026-05-29T12:30:51Z

←Older revision		Revision as of 12:30, 29 May 2026
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	The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.		The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.

-	See [https://github.com/jtulach/graalvm-native-libs github project] with the essential libraries.	+	See my new [https://github.com/jtulach/graalvm-native-libs github project] with the essential libraries.

	The essential part of the [[Dual JVM]] system design includes an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.		The essential part of the [[Dual JVM]] system design includes an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.

JaroslavTulach at 12:30, 29 May 2026

2026-05-29T12:30:24Z

←Older revision		Revision as of 12:30, 29 May 2026
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	The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.		The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.
		+
		+	See [https://github.com/jtulach/graalvm-native-libs github project] with the essential libraries.

	The essential part of the [[Dual JVM]] system design includes an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.		The essential part of the [[Dual JVM]] system design includes an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.

JaroslavTulach at 05:48, 2 May 2026

2026-05-02T05:48:30Z

←Older revision		Revision as of 05:48, 2 May 2026
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	The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.		The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.

-	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.	+	The essential part of the [[Dual JVM]] system design includes an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.

JaroslavTulach at 05:48, 2 May 2026

2026-05-02T05:48:04Z

←Older revision		Revision as of 05:48, 2 May 2026
Line 2:		Line 2:

	The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.		The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.
-
-
-	~~=== Zero Copy Data Exchange ===~~

	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.		The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.

JaroslavTulach at 05:47, 2 May 2026

2026-05-02T05:47:33Z

←Older revision		Revision as of 05:47, 2 May 2026
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-	A heroic effort was needed to marry the fast start of the [[Enso]] engine (to be attributed to AOT compilation) with the need to dynamically load JVM classes. The effort is being called a ''"dual JVM"'' (see [https://docs.google.com/presentation/d/1f0ygesiiUbMe3rEXVonDPzLI0TyKIWkMeLyhh4okkKE slides]) because there are two [[Java]] virtual machines running in the single [[Enso]] process communicating effectively with each other.	+	A heroic effort was needed to marry the fast start of the [[Enso]] engine (to be attributed to [[AOT]] compilation) with the need to dynamically load [[JVM]] classes. The effort is being called a ''"dual JVM"'' (see [https://docs.google.com/presentation/d/1f0ygesiiUbMe3rEXVonDPzLI0TyKIWkMeLyhh4okkKE slides]) because there are two [[Java]] virtual machines running in the single [[Enso]] process communicating effectively with each other.

	The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.		The initial part of [[Java]] application is [[AOT]] compiled and as such it ''starts blazingly'' fast. At any time it can launch [[HotSpot]] [[JVM]] in the same process and run the remaining parts of the [[Java]] application ''more dynamically'' and [[JIT]] compile them.

JaroslavTulach: /* Zero Copy Data Exchange */

2026-05-02T05:46:49Z

Zero Copy Data Exchange

←Older revision		Revision as of 05:46, 2 May 2026
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	=== Zero Copy Data Exchange ===		=== Zero Copy Data Exchange ===

-	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio\|Buffer}}'' ~~data (typically) in the Apache Arrow format~~ between those two [[JVM]]s.	+	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of data allocated as direct NIO {{JDK\|java/nio\|Buffer}}''s between those two [[JVM]]s.

JaroslavTulach: /* Zero Copy Data Exchange */

2026-05-02T05:45:40Z

Zero Copy Data Exchange

←Older revision		Revision as of 05:45, 2 May 2026
Line 6:		Line 6:
	=== Zero Copy Data Exchange ===		=== Zero Copy Data Exchange ===

-	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio/\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.	+	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.

JaroslavTulach: /* Zero Copy Data Exchange */

2026-05-02T05:45:19Z

Zero Copy Data Exchange

←Older revision		Revision as of 05:45, 2 May 2026
Line 6:		Line 6:
	=== Zero Copy Data Exchange ===		=== Zero Copy Data Exchange ===

-	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio/~~buffer~~\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.	+	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio/\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.

JaroslavTulach: /* Zero Copy Data Exchange */

2026-05-02T05:44:43Z

Zero Copy Data Exchange

←Older revision		Revision as of 05:44, 2 May 2026
Line 6:		Line 6:
	=== Zero Copy Data Exchange ===		=== Zero Copy Data Exchange ===

-	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java.nio.buffer\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.	+	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java/nio/buffer\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.

JaroslavTulach: /* Apache Arrow */

2026-05-02T05:43:52Z

Apache Arrow

←Older revision		Revision as of 05:43, 2 May 2026
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-	=== ~~[[Apache]] Arrow~~ ===	+	=== Zero Copy Data Exchange ===

	The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java.nio.buffer\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.		The essential part of the [[Dual JVM]] system is an ''effective exchange'' of data between those two [[JVM]]s. The system allows '''zero copy''' exchange of {{JDK\|java.nio.buffer\|Buffer}}'' data (typically) in the Apache Arrow format between those two [[JVM]]s.