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// Copyright 2008, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * 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.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
// OWNER OR 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 "sandbox/src/shared_handles.h"
namespace sandbox {
// Note once again the the assumption here is that the shared memory is
// initialized with zeros in the process that calls SetHandle and that
// the process that calls GetHandle 'sees' this memory.
SharedHandles::SharedHandles() {
shared_.items = NULL;
shared_.max_items = 0;
}
bool SharedHandles::Init(void* raw_mem, size_t size_bytes) {
if (size_bytes < sizeof(shared_.items[0])) {
// The shared memory is too small!
return false;
}
shared_.items = static_cast<SharedItem*>(raw_mem);
shared_.max_items = size_bytes / sizeof(shared_.items[0]);
return true;
}
// Note that an empty slot is marked with a tag == 0 that is why is
// not a valid imput tag
bool SharedHandles::SetHandle(uint32 tag, HANDLE handle) {
if (0 == tag) {
// Invalid tag
return false;
}
// Find empty slot and put the tag and the handle there
SharedItem* empty_slot = FindByTag(0);
if (NULL == empty_slot) {
return false;
}
empty_slot->tag = tag;
empty_slot->item = handle;
return true;
}
bool SharedHandles::GetHandle(uint32 tag, HANDLE* handle) {
if (0 == tag) {
// Invalid tag
return false;
}
SharedItem* found = FindByTag(tag);
if (NULL == found) {
return false;
}
*handle = found->item;
return true;
}
SharedHandles::SharedItem* SharedHandles::FindByTag(uint32 tag) {
for (size_t ix = 0; ix != shared_.max_items; ++ix) {
if (tag == shared_.items[ix].tag) {
return &shared_.items[ix];
}
}
return NULL;
}
} // namespace sandbox
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