| Index: mojo/public/cpp/system/handle.h
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| diff --git a/mojo/public/cpp/system/handle.h b/mojo/public/cpp/system/handle.h
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| deleted file mode 100644
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| index 0c5adc77aa1f02825ace5845274597130b1387a0..0000000000000000000000000000000000000000
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| --- a/mojo/public/cpp/system/handle.h
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| +++ /dev/null
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| @@ -1,305 +0,0 @@
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| -// Copyright 2014 The Chromium Authors. All rights reserved.
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| -// Use of this source code is governed by a BSD-style license that can be
|
| -// found in the LICENSE file.
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| -
|
| -#ifndef MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
|
| -#define MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
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| -
|
| -#include <assert.h>
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| -#include <limits>
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| -
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| -#include "mojo/public/c/system/functions.h"
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| -#include "mojo/public/c/system/types.h"
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| -#include "mojo/public/cpp/system/macros.h"
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| -
|
| -namespace mojo {
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| -
|
| -// OVERVIEW
|
| -//
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| -// |Handle| and |...Handle|:
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| -//
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| -// |Handle| is a simple, copyable wrapper for the C type |MojoHandle| (which is
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| -// just an integer). Its purpose is to increase type-safety, not provide
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| -// lifetime management. For the same purpose, we have trivial *subclasses* of
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| -// |Handle|, e.g., |MessagePipeHandle| and |DataPipeProducerHandle|. |Handle|
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| -// and its subclasses impose *no* extra overhead over using |MojoHandle|s
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| -// directly.
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| -//
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| -// Note that though we provide constructors for |Handle|/|...Handle| from a
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| -// |MojoHandle|, we do not provide, e.g., a constructor for |MessagePipeHandle|
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| -// from a |Handle|. This is for type safety: If we did, you'd then be able to
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| -// construct a |MessagePipeHandle| from, e.g., a |DataPipeProducerHandle| (since
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| -// it's a |Handle|).
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| -//
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| -// |ScopedHandleBase| and |Scoped...Handle|:
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| -//
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| -// |ScopedHandleBase<HandleType>| is a templated scoped wrapper, for the handle
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| -// types above (in the same sense that a C++11 |unique_ptr<T>| is a scoped
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| -// wrapper for a |T*|). It provides lifetime management, closing its owned
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| -// handle on destruction. It also provides (emulated) move semantics, again
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| -// along the lines of C++11's |unique_ptr| (and exactly like Chromium's
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| -// |scoped_ptr|).
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| -//
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| -// |ScopedHandle| is just (a typedef of) a |ScopedHandleBase<Handle>|.
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| -// Similarly, |ScopedMessagePipeHandle| is just a
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| -// |ScopedHandleBase<MessagePipeHandle>|. Etc. Note that a
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| -// |ScopedMessagePipeHandle| is *not* a (subclass of) |ScopedHandle|.
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| -//
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| -// Wrapper functions:
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| -//
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| -// We provide simple wrappers for the |Mojo...()| functions (in
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| -// mojo/public/c/system/core.h -- see that file for details on individual
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| -// functions).
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| -//
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| -// The general guideline is functions that imply ownership transfer of a handle
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| -// should take (or produce) an appropriate |Scoped...Handle|, while those that
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| -// don't take a |...Handle|. For example, |CreateMessagePipe()| has two
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| -// |ScopedMessagePipe| "out" parameters, whereas |Wait()| and |WaitMany()| take
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| -// |Handle| parameters. Some, have both: e.g., |DuplicatedBuffer()| takes a
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| -// suitable (unscoped) handle (e.g., |SharedBufferHandle|) "in" parameter and
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| -// produces a suitable scoped handle (e.g., |ScopedSharedBufferHandle| a.k.a.
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| -// |ScopedHandleBase<SharedBufferHandle>|) as an "out" parameter.
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| -//
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| -// An exception are some of the |...Raw()| functions. E.g., |CloseRaw()| takes a
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| -// |Handle|, leaving the user to discard the handle.
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| -//
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| -// More significantly, |WriteMessageRaw()| exposes the full API complexity of
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| -// |MojoWriteMessage()| (but doesn't require any extra overhead). It takes a raw
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| -// array of |Handle|s as input, and takes ownership of them (i.e., invalidates
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| -// them) on *success* (but not on failure). There are a number of reasons for
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| -// this. First, C++03 |std::vector|s cannot contain the move-only
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| -// |Scoped...Handle|s. Second, |std::vector|s impose extra overhead
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| -// (necessitating heap-allocation of the buffer). Third, |std::vector|s wouldn't
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| -// provide the desired level of flexibility/safety: a vector of handles would
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| -// have to be all of the same type (probably |Handle|/|ScopedHandle|). Fourth,
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| -// it's expected to not be used directly, but instead be used by generated
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| -// bindings.
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| -//
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| -// Other |...Raw()| functions expose similar rough edges, e.g., dealing with raw
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| -// pointers (and lengths) instead of taking |std::vector|s or similar.
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| -
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| -// ScopedHandleBase ------------------------------------------------------------
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| -
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| -// Scoper for the actual handle types defined further below. It's move-only,
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| -// like the C++11 |unique_ptr|.
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| -template <class HandleType>
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| -class ScopedHandleBase {
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| - MOJO_MOVE_ONLY_TYPE(ScopedHandleBase)
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| -
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| - public:
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| - ScopedHandleBase() {}
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| - explicit ScopedHandleBase(HandleType handle) : handle_(handle) {}
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| - ~ScopedHandleBase() { CloseIfNecessary(); }
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| -
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| - template <class CompatibleHandleType>
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| - explicit ScopedHandleBase(ScopedHandleBase<CompatibleHandleType> other)
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| - : handle_(other.release()) {}
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| -
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| - // Move-only constructor and operator=.
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| - ScopedHandleBase(ScopedHandleBase&& other) : handle_(other.release()) {}
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| - ScopedHandleBase& operator=(ScopedHandleBase&& other) {
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| - if (&other != this) {
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| - CloseIfNecessary();
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| - handle_ = other.release();
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| - }
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| - return *this;
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| - }
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| -
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| - const HandleType& get() const { return handle_; }
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| -
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| - template <typename PassedHandleType>
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| - static ScopedHandleBase<HandleType> From(
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| - ScopedHandleBase<PassedHandleType> other) {
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| - static_assert(
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| - sizeof(static_cast<PassedHandleType*>(static_cast<HandleType*>(0))),
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| - "HandleType is not a subtype of PassedHandleType");
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| - return ScopedHandleBase<HandleType>(
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| - static_cast<HandleType>(other.release().value()));
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| - }
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| -
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| - void swap(ScopedHandleBase& other) { handle_.swap(other.handle_); }
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| -
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| - HandleType release() MOJO_WARN_UNUSED_RESULT {
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| - HandleType rv;
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| - rv.swap(handle_);
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| - return rv;
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| - }
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| -
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| - void reset(HandleType handle = HandleType()) {
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| - CloseIfNecessary();
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| - handle_ = handle;
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| - }
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| -
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| - bool is_valid() const { return handle_.is_valid(); }
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| -
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| - private:
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| - void CloseIfNecessary() {
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| - if (!handle_.is_valid())
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| - return;
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| - MojoResult result = MojoClose(handle_.value());
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| - MOJO_ALLOW_UNUSED_LOCAL(result);
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| - assert(result == MOJO_RESULT_OK);
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| - }
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| -
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| - HandleType handle_;
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| -};
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| -
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| -template <typename HandleType>
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| -inline ScopedHandleBase<HandleType> MakeScopedHandle(HandleType handle) {
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| - return ScopedHandleBase<HandleType>(handle);
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| -}
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| -
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| -// Handle ----------------------------------------------------------------------
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| -
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| -const MojoHandle kInvalidHandleValue = MOJO_HANDLE_INVALID;
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| -
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| -// Wrapper base class for |MojoHandle|.
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| -class Handle {
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| - public:
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| - Handle() : value_(kInvalidHandleValue) {}
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| - explicit Handle(MojoHandle value) : value_(value) {}
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| - ~Handle() {}
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| -
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| - void swap(Handle& other) {
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| - MojoHandle temp = value_;
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| - value_ = other.value_;
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| - other.value_ = temp;
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| - }
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| -
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| - bool is_valid() const { return value_ != kInvalidHandleValue; }
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| -
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| - const MojoHandle& value() const { return value_; }
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| - MojoHandle* mutable_value() { return &value_; }
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| - void set_value(MojoHandle value) { value_ = value; }
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| -
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| - private:
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| - MojoHandle value_;
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| -
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| - // Copying and assignment allowed.
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| -};
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| -
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| -// Should have zero overhead.
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| -static_assert(sizeof(Handle) == sizeof(MojoHandle), "Bad size for C++ Handle");
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| -
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| -// The scoper should also impose no more overhead.
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| -typedef ScopedHandleBase<Handle> ScopedHandle;
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| -static_assert(sizeof(ScopedHandle) == sizeof(Handle),
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| - "Bad size for C++ ScopedHandle");
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| -
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| -inline MojoResult Wait(Handle handle,
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| - MojoHandleSignals signals,
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| - MojoDeadline deadline,
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| - MojoHandleSignalsState* signals_state) {
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| - return MojoWait(handle.value(), signals, deadline, signals_state);
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| -}
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| -
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| -const uint32_t kInvalidWaitManyIndexValue = static_cast<uint32_t>(-1);
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| -
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| -// Simplify the interpretation of the output from |MojoWaitMany()|.
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| -class WaitManyResult {
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| - public:
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| - explicit WaitManyResult(MojoResult mojo_wait_many_result)
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| - : result(mojo_wait_many_result), index(kInvalidWaitManyIndexValue) {}
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| -
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| - WaitManyResult(MojoResult mojo_wait_many_result, uint32_t result_index)
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| - : result(mojo_wait_many_result), index(result_index) {}
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| -
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| - // A valid handle index is always returned if |WaitMany()| succeeds, but may
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| - // or may not be returned if |WaitMany()| returns an error. Use this helper
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| - // function to check if |index| is a valid index into the handle array.
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| - bool IsIndexValid() const { return index != kInvalidWaitManyIndexValue; }
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| -
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| - // The |signals_states| array is always returned by |WaitMany()| on success,
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| - // but may or may not be returned if |WaitMany()| returns an error. Use this
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| - // helper function to check if |signals_states| holds valid data.
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| - bool AreSignalsStatesValid() const {
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| - return result != MOJO_RESULT_INVALID_ARGUMENT &&
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| - result != MOJO_RESULT_RESOURCE_EXHAUSTED;
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| - }
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| -
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| - MojoResult result;
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| - uint32_t index;
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| -};
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| -
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| -// |HandleVectorType| and |FlagsVectorType| should be similar enough to
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| -// |std::vector<Handle>| and |std::vector<MojoHandleSignals>|, respectively:
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| -// - They should have a (const) |size()| method that returns an unsigned type.
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| -// - They must provide contiguous storage, with access via (const) reference to
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| -// that storage provided by a (const) |operator[]()| (by reference).
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| -template <class HandleVectorType,
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| - class FlagsVectorType,
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| - class SignalsStateVectorType>
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| -inline WaitManyResult WaitMany(const HandleVectorType& handles,
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| - const FlagsVectorType& signals,
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| - MojoDeadline deadline,
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| - SignalsStateVectorType* signals_states) {
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| - if (signals.size() != handles.size() ||
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| - (signals_states && signals_states->size() != signals.size()))
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| - return WaitManyResult(MOJO_RESULT_INVALID_ARGUMENT);
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| - if (handles.size() >= kInvalidWaitManyIndexValue)
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| - return WaitManyResult(MOJO_RESULT_RESOURCE_EXHAUSTED);
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| -
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| - if (handles.size() == 0) {
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| - return WaitManyResult(
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| - MojoWaitMany(nullptr, nullptr, 0, deadline, nullptr, nullptr));
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| - }
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| -
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| - uint32_t result_index = kInvalidWaitManyIndexValue;
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| - const Handle& first_handle = handles[0];
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| - const MojoHandleSignals& first_signals = signals[0];
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| - MojoHandleSignalsState* first_state =
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| - signals_states ? &(*signals_states)[0] : nullptr;
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| - MojoResult result =
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| - MojoWaitMany(reinterpret_cast<const MojoHandle*>(&first_handle),
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| - &first_signals, static_cast<uint32_t>(handles.size()),
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| - deadline, &result_index, first_state);
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| - return WaitManyResult(result, result_index);
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| -}
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| -
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| -// C++ 4.10, regarding pointer conversion, says that an integral null pointer
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| -// constant can be converted to |std::nullptr_t| (which is a typedef for
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| -// |decltype(nullptr)|). The opposite direction is not allowed.
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| -template <class HandleVectorType, class FlagsVectorType>
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| -inline WaitManyResult WaitMany(const HandleVectorType& handles,
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| - const FlagsVectorType& signals,
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| - MojoDeadline deadline,
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| - decltype(nullptr) signals_states) {
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| - if (signals.size() != handles.size())
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| - return WaitManyResult(MOJO_RESULT_INVALID_ARGUMENT);
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| - if (handles.size() >= kInvalidWaitManyIndexValue)
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| - return WaitManyResult(MOJO_RESULT_RESOURCE_EXHAUSTED);
|
| -
|
| - if (handles.size() == 0) {
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| - return WaitManyResult(
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| - MojoWaitMany(nullptr, nullptr, 0, deadline, nullptr, nullptr));
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| - }
|
| -
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| - uint32_t result_index = kInvalidWaitManyIndexValue;
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| - const Handle& first_handle = handles[0];
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| - const MojoHandleSignals& first_signals = signals[0];
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| - MojoResult result = MojoWaitMany(
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| - reinterpret_cast<const MojoHandle*>(&first_handle), &first_signals,
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| - static_cast<uint32_t>(handles.size()), deadline, &result_index, nullptr);
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| - return WaitManyResult(result, result_index);
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| -}
|
| -
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| -// |Close()| takes ownership of the handle, since it'll invalidate it.
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| -// Note: There's nothing to do, since the argument will be destroyed when it
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| -// goes out of scope.
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| -template <class HandleType>
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| -inline void Close(ScopedHandleBase<HandleType> /*handle*/) {
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| -}
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| -
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| -// Most users should typically use |Close()| (above) instead.
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| -inline MojoResult CloseRaw(Handle handle) {
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| - return MojoClose(handle.value());
|
| -}
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| -
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| -// Strict weak ordering, so that |Handle|s can be used as keys in |std::map|s,
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| -inline bool operator<(const Handle a, const Handle b) {
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| - return a.value() < b.value();
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| -}
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| -
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| -} // namespace mojo
|
| -
|
| -#endif // MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
|
|
|