1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_RUNTIME_COMMANDLINEFLAGCONSTRAINTLIST_HPP
  26 #define SHARE_VM_RUNTIME_COMMANDLINEFLAGCONSTRAINTLIST_HPP
  27 
  28 #include "runtime/globals.hpp"
  29 #include "utilities/growableArray.hpp"
  30 
  31 /*
  32  * Here we have a mechanism for extracting constraints (as custom functions) for flags,
  33  * which otherwise can not be expressed via simple range check, specified in flag macro tables.
  34  *
  35  * An example of a constraint is "flag1 < flag2" where both flag1 and flag2 can change.
  36  *
  37  * See runtime "runtime/commandLineFlagConstraintsCompiler.hpp",
  38  * "runtime/commandLineFlagConstraintsGC.hpp" and
  39  * "runtime/commandLineFlagConstraintsRuntime.hpp" for the functions themselves.
  40  */
  41 
  42 typedef Flag::Error (*CommandLineFlagConstraintFunc_bool)(bool value, bool verbose);
  43 typedef Flag::Error (*CommandLineFlagConstraintFunc_int)(int value, bool verbose);
  44 typedef Flag::Error (*CommandLineFlagConstraintFunc_intx)(intx value, bool verbose);
  45 typedef Flag::Error (*CommandLineFlagConstraintFunc_uint)(uint value, bool verbose);
  46 typedef Flag::Error (*CommandLineFlagConstraintFunc_uintx)(uintx value, bool verbose);
  47 typedef Flag::Error (*CommandLineFlagConstraintFunc_uint64_t)(uint64_t value, bool verbose);
  48 typedef Flag::Error (*CommandLineFlagConstraintFunc_size_t)(size_t value, bool verbose);
  49 typedef Flag::Error (*CommandLineFlagConstraintFunc_double)(double value, bool verbose);
  50 
  51 class CommandLineFlagConstraint : public CHeapObj<mtInternal> {
  52 public:
  53   // During VM initialization, constraint validation will be done order of ConstraintType.
  54   enum ConstraintType {
  55     // Will be validated during argument processing (Arguments::parse_argument).
  56     AtParse         = 0,
  57     // Will be validated by CommandLineFlagConstraintList::check_constraints(AfterErgo).
  58     AfterErgo       = 1,
  59     // Will be validated by CommandLineFlagConstraintList::check_constraints(AfterMemoryInit).
  60     AfterMemoryInit = 2
  61   };
  62 
  63 private:
  64   const char* _name;
  65   ConstraintType _validate_type;
  66 
  67 public:
  68   // the "name" argument must be a string literal
  69   CommandLineFlagConstraint(const char* name, ConstraintType type) { _name=name; _validate_type=type; };
  70   ~CommandLineFlagConstraint() {};
  71   const char* name() const { return _name; }
  72   ConstraintType type() const { return _validate_type; }
  73   virtual Flag::Error apply_bool(bool value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  74   virtual Flag::Error apply_int(int value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  75   virtual Flag::Error apply_intx(intx value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  76   virtual Flag::Error apply_uint(uint value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  77   virtual Flag::Error apply_uintx(uintx value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  78   virtual Flag::Error apply_uint64_t(uint64_t value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  79   virtual Flag::Error apply_size_t(size_t value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  80   virtual Flag::Error apply_double(double value, bool verbose = true) { ShouldNotReachHere(); return Flag::ERR_OTHER; };
  81 };
  82 
  83 class CommandLineFlagConstraintList : public AllStatic {
  84 private:
  85   static GrowableArray<CommandLineFlagConstraint*>* _constraints;
  86   // Latest constraint validation type.
  87   static CommandLineFlagConstraint::ConstraintType _validating_type;
  88 public:
  89   static void init();
  90   static int length() { return (_constraints != NULL) ? _constraints->length() : 0; }
  91   static CommandLineFlagConstraint* at(int i) { return (_constraints != NULL) ? _constraints->at(i) : NULL; }
  92   static CommandLineFlagConstraint* find_if_needs_check(const char* name);
  93   static void add(CommandLineFlagConstraint* constraint) { _constraints->append(constraint); }
  94   // True if 'AfterErgo' or later constraint functions are validated.
  95   static bool validated_after_ergo() { return _validating_type >= CommandLineFlagConstraint::AfterErgo; };
  96   static bool check_constraints(CommandLineFlagConstraint::ConstraintType type);
  97 };
  98 
  99 #endif /* SHARE_VM_RUNTIME_COMMANDLINEFLAGCONSTRAINTLIST_HPP */