src/share/vm/interpreter/invocationCounter.cpp

rev 7045 : 7115356: assert(!m->was_never_executed()) failed
Summary: Race when asserting on invocation counters
Reviewed-by:

*** 30,150 ****
  
  // Implementation of InvocationCounter
  
  void InvocationCounter::init() {
    _counter = 0;  // reset all the bits, including the sticky carry
-   reset();
  }
  
  void InvocationCounter::reset() {
!   // Only reset the state and don't make the method look like it's never
!   // been executed
!   set_state(wait_for_compile);
  }
  
! void InvocationCounter::set_carry() {
!   set_carry_flag();
!   // The carry bit now indicates that this counter had achieved a very
!   // large value.  Now reduce the value, so that the method can be
!   // executed many more times before re-entering the VM.
!   int old_count = count();
    int new_count = MIN2(old_count, (int) (CompileThreshold / 2));
    // prevent from going to zero, to distinguish from never-executed methods
!   if (new_count == 0)  new_count = 1;
!   if (old_count != new_count)  set(state(), new_count);
! }
  
! void InvocationCounter::set_state(State state) {
!   assert(0 <= state && state < number_of_states, "illegal state");
!   int init = _init[state];
!   // prevent from going to zero, to distinguish from never-executed methods
!   if (init == 0 && count() > 0)  init = 1;
!   int carry = (_counter & carry_mask);    // the carry bit is sticky
!   _counter = (init << number_of_noncount_bits) | carry | state;
  }
  
  
  void InvocationCounter::print() {
!   tty->print_cr("invocation count: up = %d, limit = %d, carry = %s, state = %s",
!                                    count(), limit(),
!                                    carry() ? "true" : "false",
!                                    state_as_string(state()));
  }
  
  void InvocationCounter::print_short() {
!   tty->print(" [%d%s;%s]", count(), carry()?"+carry":"", state_as_short_string(state()));
  }
  
  // Initialization
- 
- int                       InvocationCounter::_init  [InvocationCounter::number_of_states];
- InvocationCounter::Action InvocationCounter::_action[InvocationCounter::number_of_states];
  int                       InvocationCounter::InterpreterInvocationLimit;
  int                       InvocationCounter::InterpreterBackwardBranchLimit;
  int                       InvocationCounter::InterpreterProfileLimit;
  
- 
- const char* InvocationCounter::state_as_string(State state) {
-   switch (state) {
-     case wait_for_nothing            : return "wait_for_nothing";
-     case wait_for_compile            : return "wait_for_compile";
-   }
-   ShouldNotReachHere();
-   return NULL;
- }
- 
- const char* InvocationCounter::state_as_short_string(State state) {
-   switch (state) {
-     case wait_for_nothing            : return "not comp.";
-     case wait_for_compile            : return "compileable";
-   }
-   ShouldNotReachHere();
-   return NULL;
- }
- 
- 
- static address do_nothing(methodHandle method, TRAPS) {
-   // dummy action for inactive invocation counters
-   MethodCounters* mcs = method->method_counters();
-   assert(mcs != NULL, "");
-   mcs->invocation_counter()->set_carry();
-   mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing);
-   return NULL;
- }
- 
- 
- static address do_decay(methodHandle method, TRAPS) {
-   // decay invocation counters so compilation gets delayed
-   MethodCounters* mcs = method->method_counters();
-   assert(mcs != NULL, "");
-   mcs->invocation_counter()->decay();
-   return NULL;
- }
- 
- 
- void InvocationCounter::def(State state, int init, Action action) {
-   assert(0 <= state && state < number_of_states, "illegal state");
-   assert(0 <= init  && init  < count_limit, "initial value out of range");
-   _init  [state] = init;
-   _action[state] = action;
- }
- 
- address dummy_invocation_counter_overflow(methodHandle m, TRAPS) {
-   ShouldNotReachHere();
-   return NULL;
- }
- 
  void InvocationCounter::reinitialize(bool delay_overflow) {
-   // define states
-   guarantee((int)number_of_states <= (int)state_limit, "adjust number_of_state_bits");
-   def(wait_for_nothing, 0, do_nothing);
-   if (delay_overflow) {
-     def(wait_for_compile, 0, do_decay);
-   } else {
-     def(wait_for_compile, 0, dummy_invocation_counter_overflow);
-   }
- 
    InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits;
    InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits;
  
    // When methodData is collected, the backward branch limit is compared against a
    // methodData counter, rather than an InvocationCounter.  In the former case, we
--- 30,98 ----
  
  // Implementation of InvocationCounter
  
  void InvocationCounter::init() {
    _counter = 0;  // reset all the bits, including the sticky carry
  }
  
  void InvocationCounter::reset() {
!   uint counter = raw_counter();
!   int init = 0;
!   // prevent from going to zero, to distinguish from never-executed methods
!   if (count(counter) > 0) {
!     init = 1;
!   }
!   counter = (init << number_of_noncount_bits) | (counter & carry_mask);
!   set_raw(counter);
  }
  
! void InvocationCounter::set_carry_and_reduce() {
!   // single read
!   uint counter = raw_counter();
! 
!   //update
!   set_carry_flag(&counter);
!   int old_count = count(counter);
    int new_count = MIN2(old_count, (int) (CompileThreshold / 2));
    // prevent from going to zero, to distinguish from never-executed methods
!   if (new_count == 0) {
!     new_count = 1;
!   }
!   if (old_count != new_count) {
!     set_count(&counter, new_count);
!   }
  
!   // single write
!   set_raw(counter);
  }
  
+ void InvocationCounter::set_carry_if_necessary() {
+   // single read
+   uint counter = raw_counter();
+ 
+   //update
+   if (!carry(counter) && count(counter) > count_limit / 2) {
+     set_carry_flag(&counter);
+     set_raw(counter);
+   }
+ }
  
  void InvocationCounter::print() {
!   tty->print_cr("invocation count: up = %d, carry = %s",
!                                    count(), carry() ? "true" : "false");
  }
  
  void InvocationCounter::print_short() {
!   tty->print(" [%d%s]", count(), carry()?"+carry":"");
  }
  
  // Initialization
  int                       InvocationCounter::InterpreterInvocationLimit;
  int                       InvocationCounter::InterpreterBackwardBranchLimit;
  int                       InvocationCounter::InterpreterProfileLimit;
  
  void InvocationCounter::reinitialize(bool delay_overflow) {
    InterpreterInvocationLimit = CompileThreshold << number_of_noncount_bits;
    InterpreterProfileLimit = ((CompileThreshold * InterpreterProfilePercentage) / 100)<< number_of_noncount_bits;
  
    // When methodData is collected, the backward branch limit is compared against a
    // methodData counter, rather than an InvocationCounter.  In the former case, we