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/*
* Copyright (C) 2010 Apple Inc. All rights reserved.
* Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "OSAllocator.h"
#include "PageAllocatorSymbian.h"
namespace WTF {
// Array to store code chunks used by JIT engine(s)
static RPointerArray<SymbianChunk> codeChunksContainer;
// The singleton data allocator (non code)
static PageAllocatorSymbian dataAllocator;
_LIT(KErrorStringInternalConsistency, "OSAllocator:ConsistencyError");
_LIT(KErrorStringChunkCreation, "OSAllocator:ChunkInitError");
_LIT(KErrorStringPageSize, "OSAllocator:WrongPageSize");
// Makes a new code chunk for a JIT engine with everything in committed state
static void* allocateCodeChunk(size_t bytes)
{
RChunk c;
TInt error = c.CreateLocalCode(bytes, bytes);
__ASSERT_ALWAYS(error == KErrNone, User::Panic(KErrorStringChunkCreation, error));
codeChunksContainer.Append(new SymbianChunk(c.Handle()));
return static_cast<void*>(c.Base());
}
// Frees the _entire_ code chunk in which this address resides.
static bool deallocateCodeChunk(void* address)
{
bool found = false;
for (int i = 0; i < codeChunksContainer.Count(); i++) {
SymbianChunk* p = codeChunksContainer[i];
if (p && p->contains(address)) {
codeChunksContainer.Remove(i);
delete p;
found = true;
}
}
return found;
}
// Return the (singleton) object that manages all non-code VM operations
static PageAllocatorSymbian* dataAllocatorInstance()
{
return &dataAllocator;
}
// Reserve memory and return the base address of the region
void* OSAllocator::reserveUncommitted(size_t reservationSize, Usage usage, bool , bool executable)
{
void* base = 0;
if (executable)
base = allocateCodeChunk(reservationSize);
else
base = dataAllocatorInstance()->reserve(reservationSize);
return base;
}
// Inverse operation of reserveUncommitted()
void OSAllocator::releaseDecommitted(void* parkedBase, size_t bytes)
{
if (dataAllocatorInstance()->contains(parkedBase))
dataAllocatorInstance()->release(parkedBase, bytes);
// NOOP for code chunks (JIT) because we released them in decommit()
}
// Commit what was previously reserved via reserveUncommitted()
void OSAllocator::commit(void* address, size_t bytes, bool, bool executable)
{
// For code chunks, we commit (early) in reserveUncommitted(), so NOOP
// For data regions, do real work
if (!executable)
dataAllocatorInstance()->commit(address, bytes);
}
void OSAllocator::decommit(void* address, size_t bytes)
{
if (dataAllocatorInstance()->contains(address))
dataAllocatorInstance()->decommit(address, bytes);
else
deallocateCodeChunk(address); // for code chunk, decommit AND release
}
void* OSAllocator::reserveAndCommit(size_t bytes, Usage usage, bool writable, bool executable)
{
void* base = reserveUncommitted(bytes, usage, writable, executable);
commit(base, bytes, writable, executable);
return base;
}
// The PageAllocatorSymbian class helps map OSAllocator calls for reserve/commit/decommit
// to a single large Symbian chunk. Only works with multiples of page size, and as a corollary
// all addresses accepted or returned by it are also page-sized aligned.
// Design notes:
// - We initialize a chunk up-front with a large reservation size
// - The entire reservation reserve is logically divided into pageSized blocks (4K on Symbian)
// - The map maintains 1 bit for each of the 4K-sized region in our address space
// - OSAllocator::reserveUncommitted() requests lead to 1 or more bits being set in map
// to indicate internally reserved state. The VM address corresponding to the first bit is returned.
// - OSAllocator::commit() actually calls RChunk.commit() and commits *all or part* of the region
// reserved via reserveUncommitted() previously.
// - OSAllocator::decommit() calls RChunk.decommit()
// - OSAllocator::releaseDecommitted() unparks all the bits in the map, but trusts that a previously
// call to decommit() would have returned the memory to the OS
PageAllocatorSymbian::PageAllocatorSymbian()
{
__ASSERT_ALWAYS(m_pageSize == WTF::pageSize(), User::Panic(KErrorStringPageSize, m_pageSize));
RChunk chunk;
TInt error = chunk.CreateDisconnectedLocal(0, 0, TInt(largeReservationSize));
__ASSERT_ALWAYS(error == KErrNone, User::Panic(KErrorStringChunkCreation, error));
m_chunk = new SymbianChunk(chunk.Handle()); // takes ownership of chunk
}
PageAllocatorSymbian::~PageAllocatorSymbian()
{
delete m_chunk;
}
// Reserves a region internally in the bitmap
void* PageAllocatorSymbian::reserve(size_t bytes)
{
// Find first available region
const size_t nPages = bytes / m_pageSize;
const int64_t startIdx = m_map.findRunOfZeros(nPages);
// Pseudo OOM
if (startIdx < 0)
return 0;
for (size_t i = startIdx; i < startIdx + nPages ; i++)
m_map.set(i);
return static_cast<void*>( m_chunk->m_base + (TUint)(m_pageSize * startIdx) );
}
// Reverses the effects of a reserve() call
void PageAllocatorSymbian::release(void* address, size_t bytes)
{
const size_t startIdx = (static_cast<char*>(address) - m_chunk->m_base) / m_pageSize;
const size_t nPages = bytes / m_pageSize;
for (size_t i = startIdx; i < startIdx + nPages ; i++)
m_map.clear(i);
}
// Actually commit memory from the OS, after a previous call to reserve()
bool PageAllocatorSymbian::commit(void* address, size_t bytes)
{
// sanity check that bits were previously set
const size_t idx = (static_cast<char*>(address) - m_chunk->m_base) / m_pageSize;
const size_t nPages = bytes / m_pageSize;
__ASSERT_ALWAYS(m_map.get(idx), User::Panic(KErrorStringInternalConsistency, idx));
__ASSERT_ALWAYS(m_map.get(idx+nPages-1), User::Panic(KErrorStringInternalConsistency, idx+nPages-1));
TInt error = m_chunk->Commit(static_cast<char*>(address) - m_chunk->m_base, bytes);
return (error == KErrNone);
}
// Inverse operation of commit(), a release() should follow later
bool PageAllocatorSymbian::decommit(void* address, size_t bytes)
{
TInt error = m_chunk->Decommit(static_cast<char*>(address) - m_chunk->m_base, bytes);
return (error == KErrNone);
}
bool PageAllocatorSymbian::contains(const void* address) const
{
return m_chunk->contains(address);
}
} // namespace WTF
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