--- /dev/null
+/*
+ * 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, bool)
+{
+ 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, bool)
+{
+ 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
projects / apple / javascriptcore.git / blobdiff