Cross posting to hotspot-compiler-...@openjdk.java.net and serviceability-dev@openjdk.java.net since this review request touches both compiler/runtime code and JVMTI code...
New webrev is at http://cr.openjdk.java.net/~tdeneau/6902182/webrev.04 The compiler/runtime part has not changed too much: * Based on Dan's jvmti-related comments, the name of the JavaThread-specific flag is now should_post_on_exceptions * reduced the number of code lines in the common graphKit::uncommon_trap_if_should_post_on_exceptions * moved the BailoutToInterpreterForThrows logic above the jvmti_can_post_exceptions() check to avoid having two uncommon traps on both paths. The jvmti part has changed/simplified quite a bit based on Dan Daugherty's good comments: * There is still a cached thread-specific flag called should_post_on_exceptions. This flag is recalculated in only in JvmtiEventControllerPrivate::recompute_thread_enabled and is handled in a way similar to the thread-specific interp-only mode which was already in recompute_thread_enabled. * There is also a "global" should_post_on_exceptions flag which reflects whether ANY thread has one of the appropriate event notification bits set. This flag is exposed in the normal JVMTI_SUPPORT_FLAG manner in jvmtiExport.cpp/hpp and updated in jvmtiEventControllerPrivate::recompute_enabled. Unlike the thread-specific flag, this global flag is not yet used anywhere else but since it fits into the existing JVMTI_SUPPORT_FLAG structure, it was felt we should put it there for possible future use. * jvmtiEventController logic now handles all the events that were possible if jvmti_can_post_exceptions() was true. These are Throws, Catches, FramePops, and MethodExits. Note to Dan: * We had talked about changing the name of the existing jvmti_can_post_exceptions() to jvmti_can_post_on_exceptions() to make it match the new should_post_on_exceptions name used above. Since this affected some other files, to keep this webrev simpler, I decided not to do that as part of this webrev. If we still want to do this, I can post this additional change as the final webrev. -- Tom Deneau
