Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(500)

Unified Diff: mojo/public/cpp/system/handle.h

Issue 814543006: Move //mojo/{public, edk} underneath //third_party (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Rebase Created 5 years, 11 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « mojo/public/cpp/system/functions.h ('k') | mojo/public/cpp/system/macros.h » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: mojo/public/cpp/system/handle.h
diff --git a/mojo/public/cpp/system/handle.h b/mojo/public/cpp/system/handle.h
deleted file mode 100644
index 0c5adc77aa1f02825ace5845274597130b1387a0..0000000000000000000000000000000000000000
--- a/mojo/public/cpp/system/handle.h
+++ /dev/null
@@ -1,305 +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.
-
-#ifndef MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
-#define MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
-
-#include <assert.h>
-#include <limits>
-
-#include "mojo/public/c/system/functions.h"
-#include "mojo/public/c/system/types.h"
-#include "mojo/public/cpp/system/macros.h"
-
-namespace mojo {
-
-// OVERVIEW
-//
-// |Handle| and |...Handle|:
-//
-// |Handle| is a simple, copyable wrapper for the C type |MojoHandle| (which is
-// just an integer). Its purpose is to increase type-safety, not provide
-// lifetime management. For the same purpose, we have trivial *subclasses* of
-// |Handle|, e.g., |MessagePipeHandle| and |DataPipeProducerHandle|. |Handle|
-// and its subclasses impose *no* extra overhead over using |MojoHandle|s
-// directly.
-//
-// Note that though we provide constructors for |Handle|/|...Handle| from a
-// |MojoHandle|, we do not provide, e.g., a constructor for |MessagePipeHandle|
-// from a |Handle|. This is for type safety: If we did, you'd then be able to
-// construct a |MessagePipeHandle| from, e.g., a |DataPipeProducerHandle| (since
-// it's a |Handle|).
-//
-// |ScopedHandleBase| and |Scoped...Handle|:
-//
-// |ScopedHandleBase<HandleType>| is a templated scoped wrapper, for the handle
-// types above (in the same sense that a C++11 |unique_ptr<T>| is a scoped
-// wrapper for a |T*|). It provides lifetime management, closing its owned
-// handle on destruction. It also provides (emulated) move semantics, again
-// along the lines of C++11's |unique_ptr| (and exactly like Chromium's
-// |scoped_ptr|).
-//
-// |ScopedHandle| is just (a typedef of) a |ScopedHandleBase<Handle>|.
-// Similarly, |ScopedMessagePipeHandle| is just a
-// |ScopedHandleBase<MessagePipeHandle>|. Etc. Note that a
-// |ScopedMessagePipeHandle| is *not* a (subclass of) |ScopedHandle|.
-//
-// Wrapper functions:
-//
-// We provide simple wrappers for the |Mojo...()| functions (in
-// mojo/public/c/system/core.h -- see that file for details on individual
-// functions).
-//
-// The general guideline is functions that imply ownership transfer of a handle
-// should take (or produce) an appropriate |Scoped...Handle|, while those that
-// don't take a |...Handle|. For example, |CreateMessagePipe()| has two
-// |ScopedMessagePipe| "out" parameters, whereas |Wait()| and |WaitMany()| take
-// |Handle| parameters. Some, have both: e.g., |DuplicatedBuffer()| takes a
-// suitable (unscoped) handle (e.g., |SharedBufferHandle|) "in" parameter and
-// produces a suitable scoped handle (e.g., |ScopedSharedBufferHandle| a.k.a.
-// |ScopedHandleBase<SharedBufferHandle>|) as an "out" parameter.
-//
-// An exception are some of the |...Raw()| functions. E.g., |CloseRaw()| takes a
-// |Handle|, leaving the user to discard the handle.
-//
-// More significantly, |WriteMessageRaw()| exposes the full API complexity of
-// |MojoWriteMessage()| (but doesn't require any extra overhead). It takes a raw
-// array of |Handle|s as input, and takes ownership of them (i.e., invalidates
-// them) on *success* (but not on failure). There are a number of reasons for
-// this. First, C++03 |std::vector|s cannot contain the move-only
-// |Scoped...Handle|s. Second, |std::vector|s impose extra overhead
-// (necessitating heap-allocation of the buffer). Third, |std::vector|s wouldn't
-// provide the desired level of flexibility/safety: a vector of handles would
-// have to be all of the same type (probably |Handle|/|ScopedHandle|). Fourth,
-// it's expected to not be used directly, but instead be used by generated
-// bindings.
-//
-// Other |...Raw()| functions expose similar rough edges, e.g., dealing with raw
-// pointers (and lengths) instead of taking |std::vector|s or similar.
-
-// ScopedHandleBase ------------------------------------------------------------
-
-// Scoper for the actual handle types defined further below. It's move-only,
-// like the C++11 |unique_ptr|.
-template <class HandleType>
-class ScopedHandleBase {
- MOJO_MOVE_ONLY_TYPE(ScopedHandleBase)
-
- public:
- ScopedHandleBase() {}
- explicit ScopedHandleBase(HandleType handle) : handle_(handle) {}
- ~ScopedHandleBase() { CloseIfNecessary(); }
-
- template <class CompatibleHandleType>
- explicit ScopedHandleBase(ScopedHandleBase<CompatibleHandleType> other)
- : handle_(other.release()) {}
-
- // Move-only constructor and operator=.
- ScopedHandleBase(ScopedHandleBase&& other) : handle_(other.release()) {}
- ScopedHandleBase& operator=(ScopedHandleBase&& other) {
- if (&other != this) {
- CloseIfNecessary();
- handle_ = other.release();
- }
- return *this;
- }
-
- const HandleType& get() const { return handle_; }
-
- template <typename PassedHandleType>
- static ScopedHandleBase<HandleType> From(
- ScopedHandleBase<PassedHandleType> other) {
- static_assert(
- sizeof(static_cast<PassedHandleType*>(static_cast<HandleType*>(0))),
- "HandleType is not a subtype of PassedHandleType");
- return ScopedHandleBase<HandleType>(
- static_cast<HandleType>(other.release().value()));
- }
-
- void swap(ScopedHandleBase& other) { handle_.swap(other.handle_); }
-
- HandleType release() MOJO_WARN_UNUSED_RESULT {
- HandleType rv;
- rv.swap(handle_);
- return rv;
- }
-
- void reset(HandleType handle = HandleType()) {
- CloseIfNecessary();
- handle_ = handle;
- }
-
- bool is_valid() const { return handle_.is_valid(); }
-
- private:
- void CloseIfNecessary() {
- if (!handle_.is_valid())
- return;
- MojoResult result = MojoClose(handle_.value());
- MOJO_ALLOW_UNUSED_LOCAL(result);
- assert(result == MOJO_RESULT_OK);
- }
-
- HandleType handle_;
-};
-
-template <typename HandleType>
-inline ScopedHandleBase<HandleType> MakeScopedHandle(HandleType handle) {
- return ScopedHandleBase<HandleType>(handle);
-}
-
-// Handle ----------------------------------------------------------------------
-
-const MojoHandle kInvalidHandleValue = MOJO_HANDLE_INVALID;
-
-// Wrapper base class for |MojoHandle|.
-class Handle {
- public:
- Handle() : value_(kInvalidHandleValue) {}
- explicit Handle(MojoHandle value) : value_(value) {}
- ~Handle() {}
-
- void swap(Handle& other) {
- MojoHandle temp = value_;
- value_ = other.value_;
- other.value_ = temp;
- }
-
- bool is_valid() const { return value_ != kInvalidHandleValue; }
-
- const MojoHandle& value() const { return value_; }
- MojoHandle* mutable_value() { return &value_; }
- void set_value(MojoHandle value) { value_ = value; }
-
- private:
- MojoHandle value_;
-
- // Copying and assignment allowed.
-};
-
-// Should have zero overhead.
-static_assert(sizeof(Handle) == sizeof(MojoHandle), "Bad size for C++ Handle");
-
-// The scoper should also impose no more overhead.
-typedef ScopedHandleBase<Handle> ScopedHandle;
-static_assert(sizeof(ScopedHandle) == sizeof(Handle),
- "Bad size for C++ ScopedHandle");
-
-inline MojoResult Wait(Handle handle,
- MojoHandleSignals signals,
- MojoDeadline deadline,
- MojoHandleSignalsState* signals_state) {
- return MojoWait(handle.value(), signals, deadline, signals_state);
-}
-
-const uint32_t kInvalidWaitManyIndexValue = static_cast<uint32_t>(-1);
-
-// Simplify the interpretation of the output from |MojoWaitMany()|.
-class WaitManyResult {
- public:
- explicit WaitManyResult(MojoResult mojo_wait_many_result)
- : result(mojo_wait_many_result), index(kInvalidWaitManyIndexValue) {}
-
- WaitManyResult(MojoResult mojo_wait_many_result, uint32_t result_index)
- : result(mojo_wait_many_result), index(result_index) {}
-
- // A valid handle index is always returned if |WaitMany()| succeeds, but may
- // or may not be returned if |WaitMany()| returns an error. Use this helper
- // function to check if |index| is a valid index into the handle array.
- bool IsIndexValid() const { return index != kInvalidWaitManyIndexValue; }
-
- // The |signals_states| array is always returned by |WaitMany()| on success,
- // but may or may not be returned if |WaitMany()| returns an error. Use this
- // helper function to check if |signals_states| holds valid data.
- bool AreSignalsStatesValid() const {
- return result != MOJO_RESULT_INVALID_ARGUMENT &&
- result != MOJO_RESULT_RESOURCE_EXHAUSTED;
- }
-
- MojoResult result;
- uint32_t index;
-};
-
-// |HandleVectorType| and |FlagsVectorType| should be similar enough to
-// |std::vector<Handle>| and |std::vector<MojoHandleSignals>|, respectively:
-// - They should have a (const) |size()| method that returns an unsigned type.
-// - They must provide contiguous storage, with access via (const) reference to
-// that storage provided by a (const) |operator[]()| (by reference).
-template <class HandleVectorType,
- class FlagsVectorType,
- class SignalsStateVectorType>
-inline WaitManyResult WaitMany(const HandleVectorType& handles,
- const FlagsVectorType& signals,
- MojoDeadline deadline,
- SignalsStateVectorType* signals_states) {
- if (signals.size() != handles.size() ||
- (signals_states && signals_states->size() != signals.size()))
- return WaitManyResult(MOJO_RESULT_INVALID_ARGUMENT);
- if (handles.size() >= kInvalidWaitManyIndexValue)
- return WaitManyResult(MOJO_RESULT_RESOURCE_EXHAUSTED);
-
- if (handles.size() == 0) {
- return WaitManyResult(
- MojoWaitMany(nullptr, nullptr, 0, deadline, nullptr, nullptr));
- }
-
- uint32_t result_index = kInvalidWaitManyIndexValue;
- const Handle& first_handle = handles[0];
- const MojoHandleSignals& first_signals = signals[0];
- MojoHandleSignalsState* first_state =
- signals_states ? &(*signals_states)[0] : nullptr;
- MojoResult result =
- MojoWaitMany(reinterpret_cast<const MojoHandle*>(&first_handle),
- &first_signals, static_cast<uint32_t>(handles.size()),
- deadline, &result_index, first_state);
- return WaitManyResult(result, result_index);
-}
-
-// C++ 4.10, regarding pointer conversion, says that an integral null pointer
-// constant can be converted to |std::nullptr_t| (which is a typedef for
-// |decltype(nullptr)|). The opposite direction is not allowed.
-template <class HandleVectorType, class FlagsVectorType>
-inline WaitManyResult WaitMany(const HandleVectorType& handles,
- const FlagsVectorType& signals,
- MojoDeadline deadline,
- decltype(nullptr) signals_states) {
- if (signals.size() != handles.size())
- return WaitManyResult(MOJO_RESULT_INVALID_ARGUMENT);
- if (handles.size() >= kInvalidWaitManyIndexValue)
- return WaitManyResult(MOJO_RESULT_RESOURCE_EXHAUSTED);
-
- if (handles.size() == 0) {
- return WaitManyResult(
- MojoWaitMany(nullptr, nullptr, 0, deadline, nullptr, nullptr));
- }
-
- uint32_t result_index = kInvalidWaitManyIndexValue;
- const Handle& first_handle = handles[0];
- const MojoHandleSignals& first_signals = signals[0];
- MojoResult result = MojoWaitMany(
- reinterpret_cast<const MojoHandle*>(&first_handle), &first_signals,
- static_cast<uint32_t>(handles.size()), deadline, &result_index, nullptr);
- return WaitManyResult(result, result_index);
-}
-
-// |Close()| takes ownership of the handle, since it'll invalidate it.
-// Note: There's nothing to do, since the argument will be destroyed when it
-// goes out of scope.
-template <class HandleType>
-inline void Close(ScopedHandleBase<HandleType> /*handle*/) {
-}
-
-// Most users should typically use |Close()| (above) instead.
-inline MojoResult CloseRaw(Handle handle) {
- return MojoClose(handle.value());
-}
-
-// Strict weak ordering, so that |Handle|s can be used as keys in |std::map|s,
-inline bool operator<(const Handle a, const Handle b) {
- return a.value() < b.value();
-}
-
-} // namespace mojo
-
-#endif // MOJO_PUBLIC_CPP_SYSTEM_HANDLE_H_
« no previous file with comments | « mojo/public/cpp/system/functions.h ('k') | mojo/public/cpp/system/macros.h » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698