Bug 605362, part 5: Centralize more of the accounting. r=joe

ipc/glue/SharedMemory.cpp

@@ -63,6 +63,8 @@ NS_MEMORY_REPORTER_IMPLEMENT(ShmemMapped,
                              nsnull)
 
 SharedMemory::SharedMemory()
+  : mAllocSize(0)
+  , mMappedSize(0)
 {
   // NB: SharedMemory is main-thread-only at the moment, but that may
   // change soon
@@ -82,32 +84,36 @@ SharedMemory::PageAlignedSize(size_t aSize)
   return pageSize * nPagesNeeded;
 }
 
-/*static*/ void
+void
 SharedMemory::Created(size_t aNBytes)
 {
-  gShmemAllocated += aNBytes;
+  mAllocSize = aNBytes;
+  gShmemAllocated += mAllocSize;
 }
 
-/*static*/ void
+void
 SharedMemory::Mapped(size_t aNBytes)
 {
-  gShmemMapped += aNBytes;
+  mMappedSize = aNBytes;
+  gShmemMapped += mMappedSize;
 }
 
-/*static*/ void
-SharedMemory::Unmapped(size_t aNBytes)
+void
+SharedMemory::Unmapped()
 {
-  NS_ABORT_IF_FALSE(gShmemMapped >= PRInt64(aNBytes),
+  NS_ABORT_IF_FALSE(gShmemMapped >= PRInt64(mMappedSize),
                     "Can't unmap more than mapped");
-  gShmemMapped -= aNBytes;
+  gShmemMapped -= mMappedSize;
+  mMappedSize = 0;
 }
 
 /*static*/ void
-SharedMemory::Destroyed(size_t aNBytes)
+SharedMemory::Destroyed()
 {
-  NS_ABORT_IF_FALSE(gShmemAllocated >= PRInt64(aNBytes),
+  NS_ABORT_IF_FALSE(gShmemAllocated >= PRInt64(mAllocSize),
                     "Can't destroy more than allocated");
-  gShmemAllocated -= aNBytes;
+  gShmemAllocated -= mAllocSize;
+  mAllocSize = 0;
 }
 
 } // namespace ipc

ipc/glue/SharedMemory.h

@@ -67,9 +67,9 @@ public:
     TYPE_UNKNOWN
   };
 
-  virtual ~SharedMemory() { }
+  virtual ~SharedMemory() { Unmapped(); Destroyed(); }
 
-  virtual size_t Size() const = 0;
+  size_t Size() const { return mMappedSize; }
 
   virtual void* memory() const = 0;
 
@@ -115,10 +115,19 @@ protected:
   //   Created (Mapped Unmapped)* Destroy
   //
   // but this isn't checked.
-  static void Created(size_t aNBytes);
-  static void Mapped(size_t aNBytes);
-  static void Unmapped(size_t aNBytes);
-  static void Destroyed(size_t aNBytes);
+  void Created(size_t aNBytes);
+  void Mapped(size_t aNBytes);
+  void Unmapped();
+  void Destroyed();
+
+  // The size of the shmem region requested in Create(), if
+  // successful.  SharedMemorys that are opened from a foreign handle
+  // have an alloc size of 0, even though they have access to the
+  // alloc-size information.
+  size_t mAllocSize;
+  // The size of the region mapped in Map(), if successful.  All
+  // SharedMemorys that are mapped have a non-zero mapped size.
+  size_t mMappedSize;
 };
 
 } // namespace ipc

ipc/glue/SharedMemoryBasic_android.cpp

@@ -70,15 +70,11 @@ LogError(const char* what)
 
 SharedMemoryBasic::SharedMemoryBasic()
   : mShmFd(-1)
-  , mAllocSize(0)
-  , mSize(0)
   , mMemory(nsnull)
 { }
 
 SharedMemoryBasic::SharedMemoryBasic(const Handle& aHandle)
   : mShmFd(aHandle.fd)
-  , mAllocSize(0)
-  , mSize(0)
   , mMemory(nsnull)
 { }
 
@@ -107,7 +103,6 @@ SharedMemoryBasic::Create(size_t aNbytes)
   }
 
   mShmFd = shmfd;
-  mAllocSize = aNbytes;
   Created(aNbytes);
   return true;
 }
@@ -128,7 +123,6 @@ SharedMemoryBasic::Map(size_t nBytes)
     return false;
   }
 
-  mSize = nBytes;
   Mapped(nBytes);
   return true;
 }
@@ -157,12 +151,10 @@ SharedMemoryBasic::Unmap()
     return;
   }
 
-  if (munmap(mMemory, mSize)) {
+  if (munmap(mMemory, Size())) {
     LogError("ShmemAndroid::Unmap()");
   }
   mMemory = nsnull;
-  mSize = 0;
-  Unmapped(mSize);
 }
 
 void
@@ -170,9 +162,6 @@ SharedMemoryBasic::Destroy()
 {
   if (mShmFd > 0) {
     close(mShmFd);
-    if (mAllocSize) {
-      Destroyed(mAllocSize);
-    }
   }
 }
 

ipc/glue/SharedMemoryBasic_android.h

@@ -70,12 +70,6 @@ public:
   NS_OVERRIDE
   virtual bool Map(size_t nBytes);
 
-  NS_OVERRIDE
-  virtual size_t Size() const
-  {
-    return mSize;
-  }
-
   NS_OVERRIDE
   virtual void* memory() const
   {
@@ -107,10 +101,6 @@ private:
 
   // The /dev/ashmem fd we allocate.
   int mShmFd;
-  // Allocated size, 0 if unallocated
-  size_t mAllocSize;
-  // Mapped size, 0 if unmapped.
-  size_t mSize;
   // Pointer to mapped region, null if unmapped.
   void *mMemory;
 };

ipc/glue/SharedMemoryBasic_chromium.h

@@ -59,33 +59,19 @@ public:
   typedef base::SharedMemoryHandle Handle;
 
   SharedMemoryBasic()
-    : mAllocSize(0)
-    , mSize(0)
   {
   }
 
   SharedMemoryBasic(const Handle& aHandle)
     : mSharedMemory(aHandle, false)
-    , mAllocSize(0)
-    , mSize(0)
   {
   }
 
-  virtual ~SharedMemoryBasic() {
-    if (memory()) {
-      Unmapped(mSize);
-    }
-    if (mAllocSize) {
-      Destroyed(mAllocSize);
-    }
-  }
-
   NS_OVERRIDE
   virtual bool Create(size_t aNbytes)
   {
     bool ok = mSharedMemory.Create("", false, false, aNbytes);
     if (ok) {
-      mAllocSize = aNbytes;
       Created(aNbytes);
     }
     return ok;
@@ -96,18 +82,11 @@ public:
   {
     bool ok = mSharedMemory.Map(nBytes);
     if (ok) {
-      mSize = nBytes;
       Mapped(nBytes);
     }
     return ok;
   }
 
-  NS_OVERRIDE
-  virtual size_t Size() const
-  {
-    return mSize;
-  }
-
   NS_OVERRIDE
   virtual void* memory() const
   {
@@ -142,9 +121,6 @@ public:
 
 private:
   base::SharedMemory mSharedMemory;
-  size_t mAllocSize;
-  // NB: we have to track this because shared_memory_win.cc doesn't
-  size_t mSize;
 };
 
 } // namespace ipc

ipc/glue/SharedMemorySysV.h

@@ -74,33 +74,21 @@ public:
 
   SharedMemorySysV() :
     mHandle(-1),
-    mData(nsnull),
-    mAllocSize(0),
-    mSize(0)
+    mData(nsnull)
   {
   }
 
   SharedMemorySysV(Handle aHandle) :
     mHandle(aHandle),
-    mData(nsnull),
-    mAllocSize(0),
-    mSize(0)
+    mData(nsnull)
   {
   }
 
   virtual ~SharedMemorySysV()
   {
-    if (memory()) {
-      Unmapped(mSize);
-    }
-    if (mAllocSize) {
-      Destroyed(mAllocSize);
-    }
-
     shmdt(mData);
     mHandle = -1;
     mData = nsnull;
-    mSize = 0;
   }
 
   NS_OVERRIDE
@@ -143,7 +131,6 @@ public:
     shmctl(mHandle, IPC_RMID, 0);
 
     mData = mem;
-    mSize = nBytes;
 
 #ifdef NS_DEBUG
     struct shmid_ds info;
@@ -158,12 +145,6 @@ public:
     return true;
   }
 
-  NS_OVERRIDE
-  virtual size_t Size() const
-  {
-    return mSize;
-  }
-
   NS_OVERRIDE
   virtual void* memory() const
   {
@@ -195,8 +176,6 @@ public:
 private:
   Handle mHandle;
   void* mData;
-  size_t mAllocSize;
-  size_t mSize;
 };
 
 } // namespace ipc