| 1 | /* $Id: AutoStateDep.h 69500 2017-10-28 15:14:05Z vboxsync $ */
|
|---|
| 2 | #ifndef ____H_AUTOSTATEDEP
|
|---|
| 3 | #define ____H_AUTOSTATEDEP
|
|---|
| 4 |
|
|---|
| 5 | /** @file
|
|---|
| 6 | *
|
|---|
| 7 | * AutoStateDep template classes, formerly in MachineImpl.h. Use these if
|
|---|
| 8 | * you need to ensure that the machine state does not change over a certain
|
|---|
| 9 | * period of time.
|
|---|
| 10 | */
|
|---|
| 11 |
|
|---|
| 12 | /*
|
|---|
| 13 | * Copyright (C) 2006-2017 Oracle Corporation
|
|---|
| 14 | *
|
|---|
| 15 | * This file is part of VirtualBox Open Source Edition (OSE), as
|
|---|
| 16 | * available from http://www.virtualbox.org. This file is free software;
|
|---|
| 17 | * you can redistribute it and/or modify it under the terms of the GNU
|
|---|
| 18 | * General Public License (GPL) as published by the Free Software
|
|---|
| 19 | * Foundation, in version 2 as it comes in the "COPYING" file of the
|
|---|
| 20 | * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
|
|---|
| 21 | * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
|
|---|
| 22 | */
|
|---|
| 23 |
|
|---|
| 24 | /**
|
|---|
| 25 | * Helper class that safely manages the machine state dependency by
|
|---|
| 26 | * calling Machine::addStateDependency() on construction and
|
|---|
| 27 | * Machine::releaseStateDependency() on destruction. Intended for Machine
|
|---|
| 28 | * children. The usage pattern is:
|
|---|
| 29 | *
|
|---|
| 30 | * @code
|
|---|
| 31 | * AutoCaller autoCaller(this);
|
|---|
| 32 | * if (FAILED(autoCaller.rc())) return autoCaller.rc();
|
|---|
| 33 | *
|
|---|
| 34 | * Machine::AutoStateDependency<MutableStateDep> adep(mParent);
|
|---|
| 35 | * if (FAILED(stateDep.rc())) return stateDep.rc();
|
|---|
| 36 | * ...
|
|---|
| 37 | * // code that depends on the particular machine state
|
|---|
| 38 | * ...
|
|---|
| 39 | * @endcode
|
|---|
| 40 | *
|
|---|
| 41 | * Note that it is more convenient to use the following individual
|
|---|
| 42 | * shortcut classes instead of using this template directly:
|
|---|
| 43 | * AutoAnyStateDependency, AutoMutableStateDependency,
|
|---|
| 44 | * AutoMutableOrSavedStateDependency, AutoMutableOrRunningStateDependency
|
|---|
| 45 | * or AutoMutableOrSavedOrRunningStateDependency. The usage pattern is
|
|---|
| 46 | * exactly the same as above except that there is no need to specify the
|
|---|
| 47 | * template argument because it is already done by the shortcut class.
|
|---|
| 48 | *
|
|---|
| 49 | * @param taDepType Dependency type to manage.
|
|---|
| 50 | */
|
|---|
| 51 | template <Machine::StateDependency taDepType = Machine::AnyStateDep>
|
|---|
| 52 | class AutoStateDependency
|
|---|
| 53 | {
|
|---|
| 54 | public:
|
|---|
| 55 |
|
|---|
| 56 | AutoStateDependency(Machine *aThat)
|
|---|
| 57 | : mThat(aThat), mRC(S_OK),
|
|---|
| 58 | mMachineState(MachineState_Null),
|
|---|
| 59 | mRegistered(FALSE)
|
|---|
| 60 | {
|
|---|
| 61 | Assert(aThat);
|
|---|
| 62 | mRC = aThat->i_addStateDependency(taDepType, &mMachineState,
|
|---|
| 63 | &mRegistered);
|
|---|
| 64 | }
|
|---|
| 65 | ~AutoStateDependency()
|
|---|
| 66 | {
|
|---|
| 67 | if (SUCCEEDED(mRC))
|
|---|
| 68 | mThat->i_releaseStateDependency();
|
|---|
| 69 | }
|
|---|
| 70 |
|
|---|
| 71 | /** Decreases the number of dependencies before the instance is
|
|---|
| 72 | * destroyed. Note that will reset #rc() to E_FAIL. */
|
|---|
| 73 | void release()
|
|---|
| 74 | {
|
|---|
| 75 | AssertReturnVoid(SUCCEEDED(mRC));
|
|---|
| 76 | mThat->i_releaseStateDependency();
|
|---|
| 77 | mRC = E_FAIL;
|
|---|
| 78 | }
|
|---|
| 79 |
|
|---|
| 80 | /** Restores the number of callers after by #release(). #rc() will be
|
|---|
| 81 | * reset to the result of calling addStateDependency() and must be
|
|---|
| 82 | * rechecked to ensure the operation succeeded. */
|
|---|
| 83 | void add()
|
|---|
| 84 | {
|
|---|
| 85 | AssertReturnVoid(!SUCCEEDED(mRC));
|
|---|
| 86 | mRC = mThat->i_addStateDependency(taDepType, &mMachineState,
|
|---|
| 87 | &mRegistered);
|
|---|
| 88 | }
|
|---|
| 89 |
|
|---|
| 90 | /** Returns the result of Machine::addStateDependency(). */
|
|---|
| 91 | HRESULT rc() const { return mRC; }
|
|---|
| 92 |
|
|---|
| 93 | /** Shortcut to SUCCEEDED(rc()). */
|
|---|
| 94 | bool isOk() const { return SUCCEEDED(mRC); }
|
|---|
| 95 |
|
|---|
| 96 | /** Returns the machine state value as returned by
|
|---|
| 97 | * Machine::addStateDependency(). */
|
|---|
| 98 | MachineState_T machineState() const { return mMachineState; }
|
|---|
| 99 |
|
|---|
| 100 | /** Returns the machine state value as returned by
|
|---|
| 101 | * Machine::addStateDependency(). */
|
|---|
| 102 | BOOL machineRegistered() const { return mRegistered; }
|
|---|
| 103 |
|
|---|
| 104 | protected:
|
|---|
| 105 |
|
|---|
| 106 | Machine *mThat;
|
|---|
| 107 | HRESULT mRC;
|
|---|
| 108 | MachineState_T mMachineState;
|
|---|
| 109 | BOOL mRegistered;
|
|---|
| 110 |
|
|---|
| 111 | private:
|
|---|
| 112 |
|
|---|
| 113 | DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP(AutoStateDependency);
|
|---|
| 114 | DECLARE_CLS_NEW_DELETE_NOOP(AutoStateDependency);
|
|---|
| 115 | };
|
|---|
| 116 |
|
|---|
| 117 | /**
|
|---|
| 118 | * Shortcut to AutoStateDependency<AnyStateDep>.
|
|---|
| 119 | * See AutoStateDependency to get the usage pattern.
|
|---|
| 120 | *
|
|---|
| 121 | * Accepts any machine state and guarantees the state won't change before
|
|---|
| 122 | * this object is destroyed. If the machine state cannot be protected (as
|
|---|
| 123 | * a result of the state change currently in progress), this instance's
|
|---|
| 124 | * #rc() method will indicate a failure, and the caller is not allowed to
|
|---|
| 125 | * rely on any particular machine state and should return the failed
|
|---|
| 126 | * result code to the upper level.
|
|---|
| 127 | */
|
|---|
| 128 | typedef AutoStateDependency<Machine::AnyStateDep> AutoAnyStateDependency;
|
|---|
| 129 |
|
|---|
| 130 | /**
|
|---|
| 131 | * Shortcut to AutoStateDependency<MutableStateDep>.
|
|---|
| 132 | * See AutoStateDependency to get the usage pattern.
|
|---|
| 133 | *
|
|---|
| 134 | * Succeeds only if the machine state is in one of the mutable states, and
|
|---|
| 135 | * guarantees the given mutable state won't change before this object is
|
|---|
| 136 | * destroyed. If the machine is not mutable, this instance's #rc() method
|
|---|
| 137 | * will indicate a failure, and the caller is not allowed to rely on any
|
|---|
| 138 | * particular machine state and should return the failed result code to
|
|---|
| 139 | * the upper level.
|
|---|
| 140 | *
|
|---|
| 141 | * Intended to be used within all setter methods of IMachine
|
|---|
| 142 | * children objects (DVDDrive, NetworkAdapter, AudioAdapter, etc.) to
|
|---|
| 143 | * provide data protection and consistency. There must be no VM process,
|
|---|
| 144 | * i.e. use for settings changes which are valid when the VM is shut down.
|
|---|
| 145 | */
|
|---|
| 146 | typedef AutoStateDependency<Machine::MutableStateDep> AutoMutableStateDependency;
|
|---|
| 147 |
|
|---|
| 148 | /**
|
|---|
| 149 | * Shortcut to AutoStateDependency<MutableOrSavedStateDep>.
|
|---|
| 150 | * See AutoStateDependency to get the usage pattern.
|
|---|
| 151 | *
|
|---|
| 152 | * Succeeds only if the machine state is in one of the mutable states, or
|
|---|
| 153 | * if the machine is in the Saved state, and guarantees the given mutable
|
|---|
| 154 | * state won't change before this object is destroyed. If the machine is
|
|---|
| 155 | * not mutable, this instance's #rc() method will indicate a failure, and
|
|---|
| 156 | * the caller is not allowed to rely on any particular machine state and
|
|---|
| 157 | * should return the failed result code to the upper level.
|
|---|
| 158 | *
|
|---|
| 159 | * Intended to be used within setter methods of IMachine
|
|---|
| 160 | * children objects that may operate on shut down or Saved machines.
|
|---|
| 161 | */
|
|---|
| 162 | typedef AutoStateDependency<Machine::MutableOrSavedStateDep> AutoMutableOrSavedStateDependency;
|
|---|
| 163 |
|
|---|
| 164 | /**
|
|---|
| 165 | * Shortcut to AutoStateDependency<MutableOrRunningStateDep>.
|
|---|
| 166 | * See AutoStateDependency to get the usage pattern.
|
|---|
| 167 | *
|
|---|
| 168 | * Succeeds only if the machine state is in one of the mutable states, or
|
|---|
| 169 | * if the machine is in the Running or Paused state, and guarantees the
|
|---|
| 170 | * given mutable state won't change before this object is destroyed. If
|
|---|
| 171 | * the machine is not mutable, this instance's #rc() method will indicate
|
|---|
| 172 | * a failure, and the caller is not allowed to rely on any particular
|
|---|
| 173 | * machine state and should return the failed result code to the upper
|
|---|
| 174 | * level.
|
|---|
| 175 | *
|
|---|
| 176 | * Intended to be used within setter methods of IMachine
|
|---|
| 177 | * children objects that may operate on shut down or running machines.
|
|---|
| 178 | */
|
|---|
| 179 | typedef AutoStateDependency<Machine::MutableOrRunningStateDep> AutoMutableOrRunningStateDependency;
|
|---|
| 180 |
|
|---|
| 181 | /**
|
|---|
| 182 | * Shortcut to AutoStateDependency<MutableOrSavedOrRunningStateDep>.
|
|---|
| 183 | * See AutoStateDependency to get the usage pattern.
|
|---|
| 184 | *
|
|---|
| 185 | * Succeeds only if the machine state is in one of the mutable states, or
|
|---|
| 186 | * if the machine is in the Running, Paused or Saved state, and guarantees
|
|---|
| 187 | * the given mutable state won't change before this object is destroyed.
|
|---|
| 188 | * If the machine is not mutable, this instance's #rc() method will
|
|---|
| 189 | * indicate a failure, and the caller is not allowed to rely on any
|
|---|
| 190 | * particular machine state and should return the failed result code to
|
|---|
| 191 | * the upper level.
|
|---|
| 192 | *
|
|---|
| 193 | * Intended to be used within setter methods of IMachine
|
|---|
| 194 | * children objects that may operate on shut down, running or saved
|
|---|
| 195 | * machines.
|
|---|
| 196 | */
|
|---|
| 197 | typedef AutoStateDependency<Machine::MutableOrSavedOrRunningStateDep> AutoMutableOrSavedOrRunningStateDependency;
|
|---|
| 198 |
|
|---|
| 199 | #endif // ____H_AUTOSTATEDEP
|
|---|
| 200 |
|
|---|
