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Diffstat (limited to 'mojo/edk/system/handle_table.cc')
| -rw-r--r-- | mojo/edk/system/handle_table.cc | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/mojo/edk/system/handle_table.cc b/mojo/edk/system/handle_table.cc deleted file mode 100644 index e054919..0000000 --- a/mojo/edk/system/handle_table.cc +++ /dev/null @@ -1,243 +0,0 @@ -// Copyright 2014 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#include "mojo/edk/system/handle_table.h" - -#include <limits> -#include "base/logging.h" -#include "base/macros.h" -#include "mojo/edk/system/configuration.h" -#include "mojo/edk/system/dispatcher.h" - -namespace mojo { -namespace system { - -HandleTable::Entry::Entry() : busy(false) { -} - -HandleTable::Entry::Entry(const scoped_refptr<Dispatcher>& dispatcher) - : dispatcher(dispatcher), busy(false) { -} - -HandleTable::Entry::~Entry() { - DCHECK(!busy); -} - -HandleTable::HandleTable() : next_handle_(MOJO_HANDLE_INVALID + 1) { -} - -HandleTable::~HandleTable() { - // This should usually not be reached (the only instance should be owned by - // the singleton |Core|, which lives forever), except in tests. -} - -Dispatcher* HandleTable::GetDispatcher(MojoHandle handle) { - DCHECK_NE(handle, MOJO_HANDLE_INVALID); - - HandleToEntryMap::iterator it = handle_to_entry_map_.find(handle); - if (it == handle_to_entry_map_.end()) - return nullptr; - return it->second.dispatcher.get(); -} - -MojoResult HandleTable::GetAndRemoveDispatcher( - MojoHandle handle, - scoped_refptr<Dispatcher>* dispatcher) { - DCHECK_NE(handle, MOJO_HANDLE_INVALID); - DCHECK(dispatcher); - - HandleToEntryMap::iterator it = handle_to_entry_map_.find(handle); - if (it == handle_to_entry_map_.end()) - return MOJO_RESULT_INVALID_ARGUMENT; - if (it->second.busy) - return MOJO_RESULT_BUSY; - *dispatcher = it->second.dispatcher; - handle_to_entry_map_.erase(it); - - return MOJO_RESULT_OK; -} - -MojoHandle HandleTable::AddDispatcher( - const scoped_refptr<Dispatcher>& dispatcher) { - if (handle_to_entry_map_.size() >= GetConfiguration().max_handle_table_size) - return MOJO_HANDLE_INVALID; - return AddDispatcherNoSizeCheck(dispatcher); -} - -std::pair<MojoHandle, MojoHandle> HandleTable::AddDispatcherPair( - const scoped_refptr<Dispatcher>& dispatcher0, - const scoped_refptr<Dispatcher>& dispatcher1) { - if (handle_to_entry_map_.size() + 1 >= - GetConfiguration().max_handle_table_size) - return std::make_pair(MOJO_HANDLE_INVALID, MOJO_HANDLE_INVALID); - return std::make_pair(AddDispatcherNoSizeCheck(dispatcher0), - AddDispatcherNoSizeCheck(dispatcher1)); -} - -bool HandleTable::AddDispatcherVector(const DispatcherVector& dispatchers, - MojoHandle* handles) { - size_t max_message_num_handles = GetConfiguration().max_message_num_handles; - size_t max_handle_table_size = GetConfiguration().max_handle_table_size; - - DCHECK_LE(dispatchers.size(), max_message_num_handles); - DCHECK(handles); - DCHECK_LT( - static_cast<uint64_t>(max_handle_table_size) + max_message_num_handles, - std::numeric_limits<size_t>::max()) - << "Addition may overflow"; - - if (handle_to_entry_map_.size() + dispatchers.size() > max_handle_table_size) - return false; - - for (size_t i = 0; i < dispatchers.size(); i++) { - if (dispatchers[i]) { - handles[i] = AddDispatcherNoSizeCheck(dispatchers[i]); - } else { - LOG(WARNING) << "Invalid dispatcher at index " << i; - handles[i] = MOJO_HANDLE_INVALID; - } - } - return true; -} - -MojoResult HandleTable::MarkBusyAndStartTransport( - MojoHandle disallowed_handle, - const MojoHandle* handles, - uint32_t num_handles, - std::vector<DispatcherTransport>* transports) { - DCHECK_NE(disallowed_handle, MOJO_HANDLE_INVALID); - DCHECK(handles); - DCHECK_LE(num_handles, GetConfiguration().max_message_num_handles); - DCHECK(transports); - DCHECK_EQ(transports->size(), num_handles); - - std::vector<Entry*> entries(num_handles); - - // First verify all the handles and get their dispatchers. - uint32_t i; - MojoResult error_result = MOJO_RESULT_INTERNAL; - for (i = 0; i < num_handles; i++) { - // Sending your own handle is not allowed (and, for consistency, returns - // "busy"). - if (handles[i] == disallowed_handle) { - error_result = MOJO_RESULT_BUSY; - break; - } - - HandleToEntryMap::iterator it = handle_to_entry_map_.find(handles[i]); - if (it == handle_to_entry_map_.end()) { - error_result = MOJO_RESULT_INVALID_ARGUMENT; - break; - } - - entries[i] = &it->second; - if (entries[i]->busy) { - error_result = MOJO_RESULT_BUSY; - break; - } - // Note: By marking the handle as busy here, we're also preventing the - // same handle from being sent multiple times in the same message. - entries[i]->busy = true; - - // Try to start the transport. - DispatcherTransport transport = - Dispatcher::HandleTableAccess::TryStartTransport( - entries[i]->dispatcher.get()); - if (!transport.is_valid()) { - // Only log for Debug builds, since this is not a problem with the system - // code, but with user code. - DLOG(WARNING) << "Likely race condition in user code detected: attempt " - "to transfer handle " << handles[i] - << " while it is in use on a different thread"; - - // Unset the busy flag (since it won't be unset below). - entries[i]->busy = false; - error_result = MOJO_RESULT_BUSY; - break; - } - - // Check if the dispatcher is busy (e.g., in a two-phase read/write). - // (Note that this must be done after the dispatcher's lock is acquired.) - if (transport.IsBusy()) { - // Unset the busy flag and end the transport (since it won't be done - // below). - entries[i]->busy = false; - transport.End(); - error_result = MOJO_RESULT_BUSY; - break; - } - - // Hang on to the transport (which we'll need to end the transport). - (*transports)[i] = transport; - } - if (i < num_handles) { - DCHECK_NE(error_result, MOJO_RESULT_INTERNAL); - - // Unset the busy flags and release the locks. - for (uint32_t j = 0; j < i; j++) { - DCHECK(entries[j]->busy); - entries[j]->busy = false; - (*transports)[j].End(); - } - return error_result; - } - - return MOJO_RESULT_OK; -} - -MojoHandle HandleTable::AddDispatcherNoSizeCheck( - const scoped_refptr<Dispatcher>& dispatcher) { - DCHECK(dispatcher); - DCHECK_LT(handle_to_entry_map_.size(), - GetConfiguration().max_handle_table_size); - DCHECK_NE(next_handle_, MOJO_HANDLE_INVALID); - - // TODO(vtl): Maybe we want to do something different/smarter. (Or maybe try - // assigning randomly?) - while (handle_to_entry_map_.find(next_handle_) != - handle_to_entry_map_.end()) { - next_handle_++; - if (next_handle_ == MOJO_HANDLE_INVALID) - next_handle_++; - } - - MojoHandle new_handle = next_handle_; - handle_to_entry_map_[new_handle] = Entry(dispatcher); - - next_handle_++; - if (next_handle_ == MOJO_HANDLE_INVALID) - next_handle_++; - - return new_handle; -} - -void HandleTable::RemoveBusyHandles(const MojoHandle* handles, - uint32_t num_handles) { - DCHECK(handles); - DCHECK_LE(num_handles, GetConfiguration().max_message_num_handles); - - for (uint32_t i = 0; i < num_handles; i++) { - HandleToEntryMap::iterator it = handle_to_entry_map_.find(handles[i]); - DCHECK(it != handle_to_entry_map_.end()); - DCHECK(it->second.busy); - it->second.busy = false; // For the sake of a |DCHECK()|. - handle_to_entry_map_.erase(it); - } -} - -void HandleTable::RestoreBusyHandles(const MojoHandle* handles, - uint32_t num_handles) { - DCHECK(handles); - DCHECK_LE(num_handles, GetConfiguration().max_message_num_handles); - - for (uint32_t i = 0; i < num_handles; i++) { - HandleToEntryMap::iterator it = handle_to_entry_map_.find(handles[i]); - DCHECK(it != handle_to_entry_map_.end()); - DCHECK(it->second.busy); - it->second.busy = false; - } -} - -} // namespace system -} // namespace mojo |