DRLVM has a complex system of locks used to synchronize multiple threads operation.

Thread primitives in DRLVM

Low-level primitives for use in C++ code

• Mutex: hymutex_create, hymutex_lock, hymutex_trylock, hymutex_unlock, hymutex_destroy
  Most of the internal DRLVM locks are mutexes
• Conditional variable: hycond_create, hycond_wait, hycond_wait_timed, hycond_wait_interruptable, hycond_notify, hycond_notify_all, hycond_destroy
  Conditional variables are used in pair with mutex. Most of the internal DRLVM events are implemented using conditional variables.

Higher-level synchronization objects

• Java monitors are accessible from C++ code using fucntions

jthread_monitor_init  thread\src\thread_java_monitors.c
jthread_monitor_enter thread\src\thread_java_monitors.c
jthread_monitor_try_enter thread\src\thread_java_monitors.c
jthread_monitor_exit  thread\src\thread_java_monitors.c
jthread_monitor_notify thread\src\thread_java_monitors.c
jthread_monitor_notify_all thread\src\thread_java_monitors.c
jthread_monitor_wait  thread\src\thread_java_monitors.c
jthread_monitor_timed_wait thread\src\thread_java_monitors.c
jthread_monitor_init  thread/src/thread_java_monitors.c
jthread_monitor_enter thread/src/thread_java_monitors.c
jthread_monitor_try_enter thread/src/thread_java_monitors.c
jthread_monitor_exit  thread/src/thread_java_monitors.c
jthread_monitor_notify thread/src/thread_java_monitors.c
jthread_monitor_notify_all thread/src/thread_java_monitors.c
jthread_monitor_wait  thread/src/thread_java_monitors.c
jthread_monitor_timed_wait thread/src/thread_java_monitors.c

Topics to be covered by this page

• What synchronization objects should be used and when during DRLVM development
• The general locking rules ("locking protocol") in DRLVM
  • the list of global locks
  • the order of obtaining locks
  • interaction with suspension
    

Some of the topics are already covered by http://harmony.apache.org/subcomponents/drlvm/TM.html