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src/hotspot/share/runtime/globals.hpp

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rev 56635 : v2.00 -> v2.05 (CR5/v2.05/8-for-jdk13) patches combined into one; merge with 8229212.patch; merge with jdk-14+11; merge with 8230184.patch; merge with 8230876.patch; merge with jdk-14+15; merge with jdk-14+18.
rev 56638 : Merge the remainder of the lock-free monitor list changes from v2.06 with v2.06a and v2.06b after running the changes through the edit scripts; merge pieces from dcubed.monitor_deflate_conc.v2.06d in dcubed.monitor_deflate_conc.v2.06[ac]; merge pieces from dcubed.monitor_deflate_conc.v2.06e into dcubed.monitor_deflate_conc.v2.06c; merge with jdk-14+11; test work around for test/jdk/tools/jlink/multireleasejar/JLinkMultiReleaseJarTest.java should not been needed anymore; merge with jdk-14+18.
rev 56639 : loosen a couple more counter checks due to races observed in testing; simplify om_release() extraction of mid since list head or cur_mid_in_use is marked; simplify deflate_monitor_list() extraction of mid since there are no parallel deleters due to the safepoint; simplify deflate_monitor_list_using_JT() extraction of mid since list head or cur_mid_in_use is marked; prepend_block_to_lists() - simplify based on David H's comments; does not need load_acquire() or release_store() because of the cmpxchg(); prepend_to_common() - simplify to use mark_next_loop() for m and use mark_list_head() and release_store() for the non-empty list case; add more debugging for "Non-balanced monitor enter/exit" failure mode; fix race in inflate() in the "CASE: neutral" code path; install_displaced_markword_in_object() does not need to clear the header field since that is handled when the ObjectMonitor is moved from the global free list; LSuccess should clear boxReg to set ICC.ZF=1 to avoid depending on existing boxReg contents; update fast_unlock() to detect when object no longer refers to the same ObjectMonitor and take fast path exit instead; clarify fast_lock() code where we detect when object no longer refers to the same ObjectMonitor; add/update comments for movptr() calls where we move a literal into an Address; remove set_owner(); refactor setting of owner field into set_owner_from(2 versions), set_owner_from_BasicLock(), and try_set_owner_from(); the new functions include monitorinflation+owner logging; extract debug code from v2.06 and v2.07 and move to v2.07.debug; change 'jccb' -> 'jcc' and 'jmpb' -> 'jmp' as needed; checkpoint initial version of MacroAssembler::inc_om_ref_count(); update LP64 MacroAssembler::fast_lock() and fast_unlock() to use inc_om_ref_count(); fast_lock() return flag setting logic can use 'testptr(tmpReg, tmpReg)' instead of 'cmpptr(tmpReg, 0)' since that's more efficient; fast_unlock() LSuccess return flag setting logic can use 'testl (boxReg, 0)' instead of 'xorptr(boxReg, boxReg)' since that's more efficient; cleanup "fast-path" vs "fast path" and "slow-path" vs "slow path"; update MacroAssembler::rtm_inflated_locking() to use inc_om_ref_count(); update MacroAssembler::fast_lock() to preserve the flags before decrementing ref_count and restore the flags afterwards; this is more clean than depending on the contents of rax/tmpReg; coleenp CR - refactor async monitor deflation work from ServiceThread::service_thread_entry() to ObjectSynchronizer::deflate_idle_monitors_using_JT(); rehn,eosterlund CR - add support for HandshakeAfterDeflateIdleMonitors for platforms that don't have ObjectMonitor ref_count support implemented in C2 fast_lock() and fast_unlock().


 709                "Disable the use of stack guard pages if the JVM is loaded " \
 710                "on the primordial process thread")                          \
 711                                                                             \
 712   product(bool, UseLWPSynchronization, true,                                \
 713           "Use LWP-based instead of libthread-based synchronization "       \
 714           "(SPARC only)")                                                   \
 715                                                                             \
 716   product(intx, MonitorBound, 0, "(Deprecated) Bound Monitor population")   \
 717           range(0, max_jint)                                                \
 718                                                                             \
 719   diagnostic(bool, AsyncDeflateIdleMonitors, true,                          \
 720           "Deflate idle monitors using JavaThreads and the ServiceThread.") \
 721                                                                             \
 722   /* notice: the max range value here is max_jint, not max_intx  */         \
 723   /* because of overflow issue                                   */         \
 724   diagnostic(intx, AsyncDeflationInterval, 250,                             \
 725           "Async deflate idle monitors every so many milliseconds when "    \
 726           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
 727           range(0, max_jint)                                                \
 728                                                                             \
 729   diagnostic(bool, CheckMonitorLists, false,                                \
 730           "Sanity check the lock free ObjectMonitor lists.")                \

 731                                                                             \
 732   experimental(intx, MonitorUsedDeflationThreshold, 90,                     \
 733           "Percentage of used monitors before triggering deflation (0 is "  \
 734           "off). The check is performed on GuaranteedSafepointInterval "    \
 735           "or AsyncDeflateInterval.")                                       \
 736           range(0, 100)                                                     \
 737                                                                             \
 738   experimental(intx, hashCode, 5,                                           \
 739                "(Unstable) select hashCode generation algorithm")           \
 740                                                                             \
 741   product(bool, FilterSpuriousWakeups, true,                                \
 742           "When true prevents OS-level spurious, or premature, wakeups "    \
 743           "from Object.wait (Ignored for Windows)")                         \
 744                                                                             \
 745   develop(bool, UsePthreads, false,                                         \
 746           "Use pthread-based instead of libthread-based synchronization "   \
 747           "(SPARC only)")                                                   \
 748                                                                             \
 749   product(bool, ReduceSignalUsage, false,                                   \
 750           "Reduce the use of OS signals in Java and/or the VM")             \




 709                "Disable the use of stack guard pages if the JVM is loaded " \
 710                "on the primordial process thread")                          \
 711                                                                             \
 712   product(bool, UseLWPSynchronization, true,                                \
 713           "Use LWP-based instead of libthread-based synchronization "       \
 714           "(SPARC only)")                                                   \
 715                                                                             \
 716   product(intx, MonitorBound, 0, "(Deprecated) Bound Monitor population")   \
 717           range(0, max_jint)                                                \
 718                                                                             \
 719   diagnostic(bool, AsyncDeflateIdleMonitors, true,                          \
 720           "Deflate idle monitors using JavaThreads and the ServiceThread.") \
 721                                                                             \
 722   /* notice: the max range value here is max_jint, not max_intx  */         \
 723   /* because of overflow issue                                   */         \
 724   diagnostic(intx, AsyncDeflationInterval, 250,                             \
 725           "Async deflate idle monitors every so many milliseconds when "    \
 726           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
 727           range(0, max_jint)                                                \
 728                                                                             \
 729   diagnostic_pd(bool, HandshakeAfterDeflateIdleMonitors,                    \
 730           "Handshake with all JavaThreads after async deflating idle "      \
 731           "monitors to force threads to leave C2 monitor code.")            \
 732                                                                             \
 733   experimental(intx, MonitorUsedDeflationThreshold, 90,                     \
 734           "Percentage of used monitors before triggering deflation (0 is "  \
 735           "off). The check is performed on GuaranteedSafepointInterval "    \
 736           "or AsyncDeflateInterval.")                                       \
 737           range(0, 100)                                                     \
 738                                                                             \
 739   experimental(intx, hashCode, 5,                                           \
 740                "(Unstable) select hashCode generation algorithm")           \
 741                                                                             \
 742   product(bool, FilterSpuriousWakeups, true,                                \
 743           "When true prevents OS-level spurious, or premature, wakeups "    \
 744           "from Object.wait (Ignored for Windows)")                         \
 745                                                                             \
 746   develop(bool, UsePthreads, false,                                         \
 747           "Use pthread-based instead of libthread-based synchronization "   \
 748           "(SPARC only)")                                                   \
 749                                                                             \
 750   product(bool, ReduceSignalUsage, false,                                   \
 751           "Reduce the use of OS signals in Java and/or the VM")             \


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