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       1             : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* This Source Code Form is subject to the terms of the Mozilla Public
       3             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       4             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       5             : 
       6             : #include "GMPSharedMemManager.h"
       7             : #include "GMPMessageUtils.h"
       8             : #include "mozilla/ipc/SharedMemory.h"
       9             : #include "mozilla/StaticPtr.h"
      10             : #include "mozilla/ClearOnShutdown.h"
      11             : 
      12             : namespace mozilla {
      13             : namespace gmp {
      14             : 
      15             : // Really one set of pools on each side of the plugin API.
      16             : 
      17             : // YUV buffers go from Encoder parent to child; pool there, and then return
      18             : // with Decoded() frames to the Decoder parent and goes into the parent pool.
      19             : // Compressed (encoded) data goes from the Decoder parent to the child;
      20             : // pool there, and then return with Encoded() frames and goes into the parent
      21             : // pool.
      22             : bool
      23           0 : GMPSharedMemManager::MgrAllocShmem(GMPSharedMem::GMPMemoryClasses aClass, size_t aSize,
      24             :                                    ipc::Shmem::SharedMemory::SharedMemoryType aType,
      25             :                                    ipc::Shmem* aMem)
      26             : {
      27           0 :   mData->CheckThread();
      28             : 
      29             :   // first look to see if we have a free buffer large enough
      30           0 :   for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
      31           0 :     MOZ_ASSERT(GetGmpFreelist(aClass)[i].IsWritable());
      32           0 :     if (aSize <= GetGmpFreelist(aClass)[i].Size<uint8_t>()) {
      33           0 :       *aMem = GetGmpFreelist(aClass)[i];
      34           0 :       GetGmpFreelist(aClass).RemoveElementAt(i);
      35           0 :       return true;
      36             :     }
      37             :   }
      38             : 
      39             :   // Didn't find a buffer free with enough space; allocate one
      40           0 :   size_t pagesize = ipc::SharedMemory::SystemPageSize();
      41           0 :   aSize = (aSize + (pagesize-1)) & ~(pagesize-1); // round up to page size
      42           0 :   bool retval = Alloc(aSize, aType, aMem);
      43           0 :   if (retval) {
      44             :     // The allocator (or NeedsShmem call) should never return less than we ask for...
      45           0 :     MOZ_ASSERT(aMem->Size<uint8_t>() >= aSize);
      46           0 :     mData->mGmpAllocated[aClass]++;
      47             :   }
      48           0 :   return retval;
      49             : }
      50             : 
      51             : bool
      52           0 : GMPSharedMemManager::MgrDeallocShmem(GMPSharedMem::GMPMemoryClasses aClass, ipc::Shmem& aMem)
      53             : {
      54           0 :   mData->CheckThread();
      55             : 
      56           0 :   size_t size = aMem.Size<uint8_t>();
      57           0 :   size_t total = 0;
      58             : 
      59             :   // XXX Bug NNNNNNN Until we put better guards on ipc::shmem, verify we
      60             :   // weren't fed an shmem we already had.
      61           0 :   for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
      62           0 :     if (NS_WARN_IF(aMem == GetGmpFreelist(aClass)[i])) {
      63             :       // Safest to crash in this case; should never happen in normal
      64             :       // operation.
      65           0 :       MOZ_CRASH("Deallocating Shmem we already have in our cache!");
      66             :       //return true;
      67             :     }
      68             :   }
      69             : 
      70             :   // XXX This works; there are better pool algorithms.  We need to avoid
      71             :   // "falling off a cliff" with too low a number
      72           0 :   if (GetGmpFreelist(aClass).Length() > 10) {
      73           0 :     Dealloc(GetGmpFreelist(aClass)[0]);
      74           0 :     GetGmpFreelist(aClass).RemoveElementAt(0);
      75             :     // The allocation numbers will be fubar on the Child!
      76           0 :     mData->mGmpAllocated[aClass]--;
      77             :   }
      78           0 :   for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
      79           0 :     MOZ_ASSERT(GetGmpFreelist(aClass)[i].IsWritable());
      80           0 :     total += GetGmpFreelist(aClass)[i].Size<uint8_t>();
      81           0 :     if (size < GetGmpFreelist(aClass)[i].Size<uint8_t>()) {
      82           0 :       GetGmpFreelist(aClass).InsertElementAt(i, aMem);
      83           0 :       return true;
      84             :     }
      85             :   }
      86           0 :   GetGmpFreelist(aClass).AppendElement(aMem);
      87             : 
      88           0 :   return true;
      89             : }
      90             : 
      91             : uint32_t
      92           0 : GMPSharedMemManager::NumInUse(GMPSharedMem::GMPMemoryClasses aClass)
      93             : {
      94           0 :   return mData->mGmpAllocated[aClass] - GetGmpFreelist(aClass).Length();
      95             : }
      96             : 
      97             : } // namespace gmp
      98             : } // namespace mozilla