src/hotspot/share/oops/methodData.cpp

*** 1,7 ****
  /*
!  * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
--- 1,7 ----
  /*
!  * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.
*** 844,853 ****
--- 844,933 ----
      return false;
    }
    return false;
  }
  
+ #if INCLUDE_JVMCI
+ 
+ void* FailedSpeculation::operator new(size_t size, size_t fs_size) throw() {
+   return CHeapObj<mtCompiler>::operator new(fs_size, std::nothrow);
+ }
+ 
+ FailedSpeculation::FailedSpeculation(address speculation, int speculation_len) : _data_len(speculation_len), _next(NULL) {
+   memcpy(data(), speculation, speculation_len);
+ }
+ 
+ // A heuristic check to detect nmethods that outlive a failed speculations list.
+ static void guarantee_failed_speculations_alive(nmethod* nm, FailedSpeculation** failed_speculations_address) {
+   jlong head = (jlong)(address) *failed_speculations_address;
+   if ((head & 0x1) == 0x1) {
+     stringStream st;
+     if (nm != NULL) {
+       st.print("%d", nm->compile_id());
+       Method* method = nm->method();
+       st.print_raw("{");
+       if (method != NULL) {
+         method->print_name(&st);
+       } else {
+         const char* jvmci_name = nm->jvmci_name();
+         if (jvmci_name != NULL) {
+           st.print_raw(jvmci_name);
+         }
+       }
+       st.print_raw("}");
+     } else {
+       st.print("<unknown>");
+     }
+     fatal("Adding to failed speculations list that appears to have been freed. Source: %s", st.as_string());
+   }
+ }
+ 
+ bool FailedSpeculation::add_failed_speculation(nmethod* nm, FailedSpeculation** failed_speculations_address, address speculation, int speculation_len) {
+   assert(failed_speculations_address != NULL, "must be");
+   size_t fs_size = sizeof(FailedSpeculation) + speculation_len;
+   FailedSpeculation* fs = new (fs_size) FailedSpeculation(speculation, speculation_len);
+   if (fs == NULL) {
+     // no memory -> ignore failed speculation
+     return false;
+   }
+ 
+   guarantee(is_aligned(fs, sizeof(FailedSpeculation*)), "FailedSpeculation objects must be pointer aligned");
+   guarantee_failed_speculations_alive(nm, failed_speculations_address);
+ 
+   FailedSpeculation** cursor = failed_speculations_address;
+   do {
+     if (*cursor == NULL) {
+       FailedSpeculation* old_fs = Atomic::cmpxchg(fs, cursor, (FailedSpeculation*) NULL);
+       if (old_fs == NULL) {
+         // Successfully appended fs to end of the list
+         return true;
+       }
+       cursor = old_fs->next_adr();
+     } else {
+       cursor = (*cursor)->next_adr();
+     }
+   } while (true);
+ }
+ 
+ void FailedSpeculation::free_failed_speculations(FailedSpeculation** failed_speculations_address) {
+   assert(failed_speculations_address != NULL, "must be");
+   FailedSpeculation* fs = *failed_speculations_address;
+   while (fs != NULL) {
+     FailedSpeculation* next = fs->next();
+     delete fs;
+     fs = next;
+   }
+ 
+   // Write an unaligned value to failed_speculations_address to denote
+   // that it is no longer a valid pointer. This is allows for the check
+   // in add_failed_speculation against adding to a freed failed
+   // speculations list.
+   long* head = (long*) failed_speculations_address;
+   (*head) = (*head) | 0x1;
+ }
+ #endif // INCLUDE_JVMCI
+ 
  int MethodData::compute_extra_data_count(int data_size, int empty_bc_count, bool needs_speculative_traps) {
  #if INCLUDE_JVMCI
    if (ProfileTraps) {
      // Assume that up to 30% of the possibly trapping BCIs with no MDP will need to allocate one.
      int extra_data_count = MIN2(empty_bc_count, MAX2(4, (empty_bc_count * 30) / 100));
*** 1225,1234 ****
--- 1305,1315 ----
    _num_blocks = 0;
    _would_profile = unknown;
  
  #if INCLUDE_JVMCI
    _jvmci_ir_size = 0;
+   _failed_speculations = NULL;
  #endif
  
  #if INCLUDE_RTM_OPT
    _rtm_state = NoRTM; // No RTM lock eliding by default
    if (UseRTMLocking &&