1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/plugins/ipc/hangui/MiniShmBase.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,334 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* vim: set ts=2 et sw=2 tw=80: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef mozilla_plugins_MiniShmBase_h
1.11 +#define mozilla_plugins_MiniShmBase_h
1.12 +
1.13 +#include "base/basictypes.h"
1.14 +
1.15 +#include "nsDebug.h"
1.16 +
1.17 +#include <windows.h>
1.18 +
1.19 +namespace mozilla {
1.20 +namespace plugins {
1.21 +
1.22 +/**
1.23 + * This class is used to provide RAII semantics for mapped views.
1.24 + * @see ScopedHandle
1.25 + */
1.26 +class ScopedMappedFileView
1.27 +{
1.28 +public:
1.29 + explicit
1.30 + ScopedMappedFileView(LPVOID aView)
1.31 + : mView(aView)
1.32 + {
1.33 + }
1.34 +
1.35 + ~ScopedMappedFileView()
1.36 + {
1.37 + Close();
1.38 + }
1.39 +
1.40 + void
1.41 + Close()
1.42 + {
1.43 + if (mView) {
1.44 + ::UnmapViewOfFile(mView);
1.45 + mView = nullptr;
1.46 + }
1.47 + }
1.48 +
1.49 + void
1.50 + Set(LPVOID aView)
1.51 + {
1.52 + Close();
1.53 + mView = aView;
1.54 + }
1.55 +
1.56 + LPVOID
1.57 + Get() const
1.58 + {
1.59 + return mView;
1.60 + }
1.61 +
1.62 + LPVOID
1.63 + Take()
1.64 + {
1.65 + LPVOID result = mView;
1.66 + mView = nullptr;
1.67 + return result;
1.68 + }
1.69 +
1.70 + operator LPVOID()
1.71 + {
1.72 + return mView;
1.73 + }
1.74 +
1.75 + bool
1.76 + IsValid() const
1.77 + {
1.78 + return (mView);
1.79 + }
1.80 +
1.81 +private:
1.82 + DISALLOW_COPY_AND_ASSIGN(ScopedMappedFileView);
1.83 +
1.84 + LPVOID mView;
1.85 +};
1.86 +
1.87 +class MiniShmBase;
1.88 +
1.89 +class MiniShmObserver
1.90 +{
1.91 +public:
1.92 + /**
1.93 + * This function is called whenever there is a new shared memory request.
1.94 + * @param aMiniShmObj MiniShmBase object that may be used to read and
1.95 + * write from shared memory.
1.96 + */
1.97 + virtual void OnMiniShmEvent(MiniShmBase *aMiniShmObj) = 0;
1.98 + /**
1.99 + * This function is called once when a MiniShmParent and a MiniShmChild
1.100 + * object have successfully negotiated a connection.
1.101 + *
1.102 + * @param aMiniShmObj MiniShmBase object that may be used to read and
1.103 + * write from shared memory.
1.104 + */
1.105 + virtual void OnMiniShmConnect(MiniShmBase *aMiniShmObj) { }
1.106 +};
1.107 +
1.108 +/**
1.109 + * Base class for MiniShm connections. This class defines the common
1.110 + * interfaces and code between parent and child.
1.111 + */
1.112 +class MiniShmBase
1.113 +{
1.114 +public:
1.115 + /**
1.116 + * Obtains a writable pointer into shared memory of type T.
1.117 + * typename T must be plain-old-data and contain an unsigned integral
1.118 + * member T::identifier that uniquely identifies T with respect to
1.119 + * other types used by the protocol being implemented.
1.120 + *
1.121 + * @param aPtr Pointer to receive the shared memory address.
1.122 + * This value is set if and only if the function
1.123 + * succeeded.
1.124 + * @return NS_OK if and only if aPtr was successfully obtained.
1.125 + * NS_ERROR_ILLEGAL_VALUE if type T is not valid for MiniShm.
1.126 + * NS_ERROR_NOT_INITIALIZED if there is no valid MiniShm connection.
1.127 + * NS_ERROR_NOT_AVAILABLE if the memory is not safe to write.
1.128 + */
1.129 + template<typename T> nsresult
1.130 + GetWritePtr(T*& aPtr)
1.131 + {
1.132 + if (!mWriteHeader || !mGuard) {
1.133 + return NS_ERROR_NOT_INITIALIZED;
1.134 + }
1.135 + if (sizeof(T) > mPayloadMaxLen ||
1.136 + T::identifier <= RESERVED_CODE_LAST) {
1.137 + return NS_ERROR_ILLEGAL_VALUE;
1.138 + }
1.139 + if (::WaitForSingleObject(mGuard, mTimeout) != WAIT_OBJECT_0) {
1.140 + return NS_ERROR_NOT_AVAILABLE;
1.141 + }
1.142 + mWriteHeader->mId = T::identifier;
1.143 + mWriteHeader->mPayloadLen = sizeof(T);
1.144 + aPtr = reinterpret_cast<T*>(mWriteHeader + 1);
1.145 + return NS_OK;
1.146 + }
1.147 +
1.148 + /**
1.149 + * Obtains a readable pointer into shared memory of type T.
1.150 + * typename T must be plain-old-data and contain an unsigned integral
1.151 + * member T::identifier that uniquely identifies T with respect to
1.152 + * other types used by the protocol being implemented.
1.153 + *
1.154 + * @param aPtr Pointer to receive the shared memory address.
1.155 + * This value is set if and only if the function
1.156 + * succeeded.
1.157 + * @return NS_OK if and only if aPtr was successfully obtained.
1.158 + * NS_ERROR_ILLEGAL_VALUE if type T is not valid for MiniShm or if
1.159 + * type T does not match the type of the data
1.160 + * stored in shared memory.
1.161 + * NS_ERROR_NOT_INITIALIZED if there is no valid MiniShm connection.
1.162 + */
1.163 + template<typename T> nsresult
1.164 + GetReadPtr(const T*& aPtr)
1.165 + {
1.166 + if (!mReadHeader) {
1.167 + return NS_ERROR_NOT_INITIALIZED;
1.168 + }
1.169 + if (mReadHeader->mId != T::identifier ||
1.170 + sizeof(T) != mReadHeader->mPayloadLen) {
1.171 + return NS_ERROR_ILLEGAL_VALUE;
1.172 + }
1.173 + aPtr = reinterpret_cast<const T*>(mReadHeader + 1);
1.174 + return NS_OK;
1.175 + }
1.176 +
1.177 + /**
1.178 + * Fires the peer's event causing its request handler to execute.
1.179 + *
1.180 + * @return Should return NS_OK if the send was successful.
1.181 + */
1.182 + virtual nsresult
1.183 + Send() = 0;
1.184 +
1.185 +protected:
1.186 + /**
1.187 + * MiniShm reserves some identifier codes for its own use. Any
1.188 + * identifiers used by MiniShm protocol implementations must be
1.189 + * greater than RESERVED_CODE_LAST.
1.190 + */
1.191 + enum ReservedCodes
1.192 + {
1.193 + RESERVED_CODE_INIT = 0,
1.194 + RESERVED_CODE_INIT_COMPLETE = 1,
1.195 + RESERVED_CODE_LAST = RESERVED_CODE_INIT_COMPLETE
1.196 + };
1.197 +
1.198 + struct MiniShmHeader
1.199 + {
1.200 + unsigned int mId;
1.201 + unsigned int mPayloadLen;
1.202 + };
1.203 +
1.204 + struct MiniShmInit
1.205 + {
1.206 + enum identifier_t
1.207 + {
1.208 + identifier = RESERVED_CODE_INIT
1.209 + };
1.210 + HANDLE mParentEvent;
1.211 + HANDLE mParentGuard;
1.212 + HANDLE mChildEvent;
1.213 + HANDLE mChildGuard;
1.214 + };
1.215 +
1.216 + struct MiniShmInitComplete
1.217 + {
1.218 + enum identifier_t
1.219 + {
1.220 + identifier = RESERVED_CODE_INIT_COMPLETE
1.221 + };
1.222 + bool mSucceeded;
1.223 + };
1.224 +
1.225 + MiniShmBase()
1.226 + : mObserver(nullptr),
1.227 + mWriteHeader(nullptr),
1.228 + mReadHeader(nullptr),
1.229 + mPayloadMaxLen(0),
1.230 + mGuard(nullptr),
1.231 + mTimeout(INFINITE)
1.232 + {
1.233 + }
1.234 + virtual ~MiniShmBase()
1.235 + { }
1.236 +
1.237 + virtual void
1.238 + OnEvent()
1.239 + {
1.240 + if (mObserver) {
1.241 + mObserver->OnMiniShmEvent(this);
1.242 + }
1.243 + }
1.244 +
1.245 + virtual void
1.246 + OnConnect()
1.247 + {
1.248 + if (mObserver) {
1.249 + mObserver->OnMiniShmConnect(this);
1.250 + }
1.251 + }
1.252 +
1.253 + nsresult
1.254 + SetView(LPVOID aView, const unsigned int aSize, bool aIsChild)
1.255 + {
1.256 + if (!aView || aSize <= 2 * sizeof(MiniShmHeader)) {
1.257 + return NS_ERROR_ILLEGAL_VALUE;
1.258 + }
1.259 + // Divide the region into halves for parent and child
1.260 + if (aIsChild) {
1.261 + mReadHeader = static_cast<MiniShmHeader*>(aView);
1.262 + mWriteHeader = reinterpret_cast<MiniShmHeader*>(static_cast<char*>(aView)
1.263 + + aSize / 2U);
1.264 + } else {
1.265 + mWriteHeader = static_cast<MiniShmHeader*>(aView);
1.266 + mReadHeader = reinterpret_cast<MiniShmHeader*>(static_cast<char*>(aView)
1.267 + + aSize / 2U);
1.268 + }
1.269 + mPayloadMaxLen = aSize / 2U - sizeof(MiniShmHeader);
1.270 + return NS_OK;
1.271 + }
1.272 +
1.273 + nsresult
1.274 + SetGuard(HANDLE aGuard, DWORD aTimeout)
1.275 + {
1.276 + if (!aGuard || !aTimeout) {
1.277 + return NS_ERROR_ILLEGAL_VALUE;
1.278 + }
1.279 + mGuard = aGuard;
1.280 + mTimeout = aTimeout;
1.281 + return NS_OK;
1.282 + }
1.283 +
1.284 + inline void
1.285 + SetObserver(MiniShmObserver *aObserver) { mObserver = aObserver; }
1.286 +
1.287 + /**
1.288 + * Obtains a writable pointer into shared memory of type T. This version
1.289 + * differs from GetWritePtr in that it allows typename T to be one of
1.290 + * the private data structures declared in MiniShmBase.
1.291 + *
1.292 + * @param aPtr Pointer to receive the shared memory address.
1.293 + * This value is set if and only if the function
1.294 + * succeeded.
1.295 + * @return NS_OK if and only if aPtr was successfully obtained.
1.296 + * NS_ERROR_ILLEGAL_VALUE if type T not an internal MiniShm struct.
1.297 + * NS_ERROR_NOT_INITIALIZED if there is no valid MiniShm connection.
1.298 + */
1.299 + template<typename T> nsresult
1.300 + GetWritePtrInternal(T*& aPtr)
1.301 + {
1.302 + if (!mWriteHeader) {
1.303 + return NS_ERROR_NOT_INITIALIZED;
1.304 + }
1.305 + if (sizeof(T) > mPayloadMaxLen ||
1.306 + T::identifier > RESERVED_CODE_LAST) {
1.307 + return NS_ERROR_ILLEGAL_VALUE;
1.308 + }
1.309 + mWriteHeader->mId = T::identifier;
1.310 + mWriteHeader->mPayloadLen = sizeof(T);
1.311 + aPtr = reinterpret_cast<T*>(mWriteHeader + 1);
1.312 + return NS_OK;
1.313 + }
1.314 +
1.315 + static VOID CALLBACK
1.316 + SOnEvent(PVOID aContext, BOOLEAN aIsTimer)
1.317 + {
1.318 + MiniShmBase* object = static_cast<MiniShmBase*>(aContext);
1.319 + object->OnEvent();
1.320 + }
1.321 +
1.322 +private:
1.323 + MiniShmObserver* mObserver;
1.324 + MiniShmHeader* mWriteHeader;
1.325 + MiniShmHeader* mReadHeader;
1.326 + unsigned int mPayloadMaxLen;
1.327 + HANDLE mGuard;
1.328 + DWORD mTimeout;
1.329 +
1.330 + DISALLOW_COPY_AND_ASSIGN(MiniShmBase);
1.331 +};
1.332 +
1.333 +} // namespace plugins
1.334 +} // namespace mozilla
1.335 +
1.336 +#endif // mozilla_plugins_MiniShmBase_h
1.337 +
