Source code

Revision control

Other Tools

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "GMPSharedMemManager.h"
#include "GMPMessageUtils.h"
#include "mozilla/ipc/SharedMemory.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/ClearOnShutdown.h"
namespace mozilla::gmp {
// Really one set of pools on each side of the plugin API.
// YUV buffers go from Encoder parent to child; pool there, and then return
// with Decoded() frames to the Decoder parent and goes into the parent pool.
// Compressed (encoded) data goes from the Decoder parent to the child;
// pool there, and then return with Encoded() frames and goes into the parent
// pool.
bool GMPSharedMemManager::MgrAllocShmem(
GMPSharedMem::GMPMemoryClasses aClass, size_t aSize,
ipc::Shmem::SharedMemory::SharedMemoryType aType, ipc::Shmem* aMem) {
mData->CheckThread();
// first look to see if we have a free buffer large enough
for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
MOZ_ASSERT(GetGmpFreelist(aClass)[i].IsWritable());
if (aSize <= GetGmpFreelist(aClass)[i].Size<uint8_t>()) {
*aMem = GetGmpFreelist(aClass)[i];
GetGmpFreelist(aClass).RemoveElementAt(i);
return true;
}
}
// Didn't find a buffer free with enough space; allocate one
size_t pagesize = ipc::SharedMemory::SystemPageSize();
aSize = (aSize + (pagesize - 1)) & ~(pagesize - 1); // round up to page size
bool retval = Alloc(aSize, aType, aMem);
if (retval) {
// The allocator (or NeedsShmem call) should never return less than we ask
// for...
MOZ_ASSERT(aMem->Size<uint8_t>() >= aSize);
mData->mGmpAllocated[aClass]++;
}
return retval;
}
bool GMPSharedMemManager::MgrDeallocShmem(GMPSharedMem::GMPMemoryClasses aClass,
ipc::Shmem& aMem) {
mData->CheckThread();
size_t size = aMem.Size<uint8_t>();
// XXX Bug NNNNNNN Until we put better guards on ipc::shmem, verify we
// weren't fed an shmem we already had.
for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
if (NS_WARN_IF(aMem == GetGmpFreelist(aClass)[i])) {
// Safest to crash in this case; should never happen in normal
// operation.
MOZ_CRASH("Deallocating Shmem we already have in our cache!");
// return true;
}
}
// XXX This works; there are better pool algorithms. We need to avoid
// "falling off a cliff" with too low a number
if (GetGmpFreelist(aClass).Length() > 10) {
Dealloc(std::move(GetGmpFreelist(aClass)[0]));
GetGmpFreelist(aClass).RemoveElementAt(0);
// The allocation numbers will be fubar on the Child!
mData->mGmpAllocated[aClass]--;
}
for (uint32_t i = 0; i < GetGmpFreelist(aClass).Length(); i++) {
MOZ_ASSERT(GetGmpFreelist(aClass)[i].IsWritable());
if (size < GetGmpFreelist(aClass)[i].Size<uint8_t>()) {
GetGmpFreelist(aClass).InsertElementAt(i, aMem);
return true;
}
}
GetGmpFreelist(aClass).AppendElement(aMem);
return true;
}
uint32_t GMPSharedMemManager::NumInUse(GMPSharedMem::GMPMemoryClasses aClass) {
return mData->mGmpAllocated[aClass] - GetGmpFreelist(aClass).Length();
}
} // namespace mozilla::gmp