aboutsummaryrefslogtreecommitdiffstats
path: root/emulator/opengl/shared/emugl/common
diff options
context:
space:
mode:
authorDavid 'Digit' Turner <digit@google.com>2014-01-17 16:47:15 +0100
committerDavid 'Digit' Turner <digit@google.com>2014-01-21 03:26:57 +0100
commitbf5b0bc2d53d82bc6ff62ceec2fdaa8b796aa130 (patch)
tree5a144545e29d6894149f673b88e5fcaf647b3137 /emulator/opengl/shared/emugl/common
parent2cab9c9e9b9e8075b27ee466fc01e34392b9380b (diff)
downloadsdk-bf5b0bc2d53d82bc6ff62ceec2fdaa8b796aa130.zip
sdk-bf5b0bc2d53d82bc6ff62ceec2fdaa8b796aa130.tar.gz
sdk-bf5b0bc2d53d82bc6ff62ceec2fdaa8b796aa130.tar.bz2
emulator/opengl: Refactor SmartPtr implementation.
This gets rid of two copies of SmartPtr.h and replaces them with a single implementation under shared/emugl/common/smart_ptr.* Note that this uses a new include path rooted at the shared/ directory for classes that are likely to be built both for the host and the device (in case we back-port this to device/generic/goldfish/opengl/ in the future). + Add a gtest-based set of unittests, after building, just call 'emugl_common_host_unittests' to run it. Note that this probably needs a 64-bit version as well, will come later once I find a way to build GTest for 64-bits without breaking the platform build :-) Also note that this moves the class to the 'emugl' namespace, in order to make the code easier to build out of the platform tree, and embed it in other projects. More classes will be transitioned / refactored in future patches. AOSP_BUG=64806 Change-Id: Ieb326c5f3f002a21537b8a391a82ce2ef9925073
Diffstat (limited to 'emulator/opengl/shared/emugl/common')
-rw-r--r--emulator/opengl/shared/emugl/common/Android.mk34
-rw-r--r--emulator/opengl/shared/emugl/common/smart_ptr.cpp111
-rw-r--r--emulator/opengl/shared/emugl/common/smart_ptr.h150
-rw-r--r--emulator/opengl/shared/emugl/common/smart_ptr_unittest.cpp140
4 files changed, 435 insertions, 0 deletions
diff --git a/emulator/opengl/shared/emugl/common/Android.mk b/emulator/opengl/shared/emugl/common/Android.mk
new file mode 100644
index 0000000..0af670c
--- /dev/null
+++ b/emulator/opengl/shared/emugl/common/Android.mk
@@ -0,0 +1,34 @@
+# This build script corresponds to a library containing many definitions
+# common to both the guest and the host. They relate to
+#
+LOCAL_PATH := $(call my-dir)
+
+### emugl_common host library ###########################################
+
+commonSources := \
+ smart_ptr.cpp \
+
+host_commonSources := $(commonSources)
+
+$(call emugl-begin-host-static-library,libemugl_common)
+LOCAL_SRC_FILES := $(host_commonSources)
+$(call emugl-end-module)
+
+$(call emugl-begin-host-static-library,lib64emugl_common)
+LOCAL_SRC_FILES := $(host_commonSources)
+$(call emugl-export,CFLAGS,-m64)
+$(call emugl-end-module)
+
+
+### emugl_common_unittests ##############################################
+
+host_commonSources := \
+ smart_ptr_unittest.cpp
+
+$(call emugl-begin-host-executable,emugl_common_host_unittests)
+LOCAL_SRC_FILES := $(host_commonSources)
+LOCAL_C_INCLUDES += external/gtest/include
+$(call emugl-export,STATIC_LIBRARIES, libemugl_common libgtest_host libgtest_main_host)
+$(call emugl-end-module)
+
+# TODO(digit): 64-bit version, once we have 64-bit gtest.
diff --git a/emulator/opengl/shared/emugl/common/smart_ptr.cpp b/emulator/opengl/shared/emugl/common/smart_ptr.cpp
new file mode 100644
index 0000000..9ac7339
--- /dev/null
+++ b/emulator/opengl/shared/emugl/common/smart_ptr.cpp
@@ -0,0 +1,111 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "emugl/common/smart_ptr.h"
+
+#ifdef _WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
+namespace emugl {
+
+// Thread-safe atomic reference-counting type.
+class RefCount {
+public:
+ RefCount() : mCount(1) {}
+ ~RefCount() {}
+
+ // Technically not thread-safe, use only for testing.
+ int count() const { return (int)mCount; }
+
+ void increment() {
+#ifdef _WIN32
+ InterlockedIncrement(&mCount);
+#else
+ __sync_fetch_and_add(&mCount, 1);
+#endif
+ }
+
+ bool decrement() {
+#ifdef _WIN32
+ return InterlockedDecrement(&mCount) == 0;
+#else
+ return __sync_add_and_fetch(&mCount, -1) == 0;
+#endif
+ }
+
+private:
+#ifdef _WIN32
+ LONG mCount;
+#else
+ int mCount;
+#endif
+};
+
+
+// SmartPtrBase implementation.
+
+SmartPtrBase::SmartPtrBase(void* ptr) : mPtr(ptr), mRefCount(NULL) {
+ if (mPtr)
+ mRefCount = new RefCount();
+}
+
+
+SmartPtrBase::SmartPtrBase(const SmartPtrBase& other)
+ : mPtr(other.mPtr), mRefCount(other.mRefCount) {
+ if (mRefCount)
+ mRefCount->increment();
+}
+
+
+int SmartPtrBase::getRefCount() const {
+ return mRefCount ? mRefCount->count() : 0;
+}
+
+
+void SmartPtrBase::addRef() {
+ if (mRefCount)
+ mRefCount->increment();
+}
+
+
+void* SmartPtrBase::copyFrom(const SmartPtrBase& other) {
+ void* old_ptr = release();
+
+ mPtr = other.mPtr;
+ mRefCount = other.mRefCount;
+ if (mRefCount)
+ mRefCount->increment();
+
+ return old_ptr;
+}
+
+
+void* SmartPtrBase::release() {
+ void* old_ptr = mPtr;
+ RefCount* old_refcount = mRefCount;
+
+ if (old_refcount) {
+ mPtr = NULL;
+ mRefCount = NULL;
+
+ if (old_refcount->decrement())
+ return old_ptr;
+ }
+
+ return NULL;
+}
+
+} // namespace emugl
diff --git a/emulator/opengl/shared/emugl/common/smart_ptr.h b/emulator/opengl/shared/emugl/common/smart_ptr.h
new file mode 100644
index 0000000..2d7db5b
--- /dev/null
+++ b/emulator/opengl/shared/emugl/common/smart_ptr.h
@@ -0,0 +1,150 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#ifndef EMUGL_SMART_PTR_H
+#define EMUGL_SMART_PTR_H
+
+#include <stddef.h>
+
+namespace emugl {
+
+// Hidden atomic ref-counting implementation.
+class RefCount;
+
+// Base class for all templated SmartPtr<> instances. Reduces
+// template expansion and code. Consider this to be an implementation
+// detail of SmartPtr<>, so don't rely on anything here.
+class SmartPtrBase {
+public:
+ // Defrault constructor.
+ SmartPtrBase() : mPtr(NULL), mRefCount(NULL) {}
+
+ // Normal constructor. This takes ownership of |ptr|, though only
+ // template instances are capable of destroying the object.
+ explicit SmartPtrBase(void* ptr);
+
+ // Copy-constructor, this increments the reference count.
+ SmartPtrBase(const SmartPtrBase& other);
+
+ // Assignment operator, also increments the reference count.
+ SmartPtrBase& operator=(const SmartPtrBase& other);
+
+ // Nothing happens in this constructor, the real work must be performed
+ // in subclasses.
+ ~SmartPtrBase() {}
+
+
+ // Used to enable 'if (smart_ptr) { ... }' properly.
+ operator void*() const {
+ return mPtr;
+ }
+
+ // Return internal reference count value, only use for unit testing.
+ int getRefCount() const;
+
+protected:
+ // Used internally to increment the reference count.
+ void addRef();
+
+ // Copy the |other| into this instance, returns the old pointer value
+ // if it needs to be destroyed by the caller, or NULL otherwise.
+ void* copyFrom(const SmartPtrBase& other);
+
+ // Used internally to decrement the reference count, if it reaches 0,
+ // returns the pointer to be destroyed, NULL otherwise.
+ void* release();
+
+ void* mPtr;
+ RefCount* mRefCount;
+};
+
+
+// The real template class to be used for smart pointers.
+// Typical uses:
+//
+// SmartPtr<Foo> ptr(new Foo()); // takes ownership.
+// SmartPtr<Foo> ptr2; // empty pointer.
+// ptr2 = ptr; // copies pointer + increment reference count.
+// Foo* obj = ptr.Ptr(); // access pointed object.
+// ptr->DoStuff(); // operate directly on pointed object.
+// (*ptr)->DoStuff(); // same here.
+//
+// On scope exit, the internal reference count is decremented and the
+// object is deleted automatically when it reaches 0, indicating that
+// there are no more owners.
+//
+// IMPORTANT: You need to be sure that only one 'chain' of smart pointers
+// own a given object. I.e. the following is incorrect:
+//
+// Foo* foo = new Foo(); // create new instance.
+// SmartPtr<Foo> ptr(foo); // |ptr| takes ownership of |foo|.
+// SmartPtr<Foo> ptr2(foo); // |ptr2| takes also ownership of |foo|.
+//
+// The problem is that |ptr| and |ptr2| don't know anything about each
+// other, and will not share the same reference count. Once a smart pointer
+// owns an object, only use other smart pointers that are copy-constructed
+// or assigned with the initial one to keep everything consistent.
+template <class T>
+class SmartPtr : public emugl::SmartPtrBase {
+public:
+ // Default constructor. The instance holds a NULL pointer.
+ SmartPtr() : SmartPtrBase() {}
+
+ // Regular constructor, takes ownership of |ptr|.
+ explicit SmartPtr(T* ptr) : SmartPtrBase(ptr) {}
+
+ // Copy-constructor, |this| and |other| will share the same internal
+ // reference count, which is incremented by 1.
+ SmartPtr(const SmartPtr& other)
+ : SmartPtrBase(reinterpret_cast<const SmartPtrBase&>(other)) {}
+
+ // Assignment operator, same semantics as copy-constructor.
+ SmartPtr& operator=(const SmartPtr& other) {
+ void* old_ptr = copyFrom(static_cast<const SmartPtrBase&>(other));
+ if (old_ptr)
+ delete reinterpret_cast<T*>(old_ptr);
+ return *this;
+ }
+
+ // Destructor, decrements reference count and destroys the object
+ // if it reaches 0 (indicating this was the last owning smart pointer).
+ ~SmartPtr() {
+ void* ptr = release();
+ if (ptr)
+ delete reinterpret_cast<T*>(ptr);
+ }
+
+ // Return owned object instance, or NULL.
+ T* Ptr() const {
+ return reinterpret_cast<T*>(mPtr);
+ }
+
+ // Return owned object instance, or NULL
+ const T* constPtr() const {
+ return reinterpret_cast<const T*>(mPtr);
+ }
+
+ // Operate directly on owned object.
+ T* operator->() const {
+ return Ptr();
+ }
+
+ // Return reference to owned object.
+ T& operator*() const {
+ return *Ptr();
+ }
+};
+
+} // namespace emugl
+
+#endif // EMUGL_SMART_PTR_H
diff --git a/emulator/opengl/shared/emugl/common/smart_ptr_unittest.cpp b/emulator/opengl/shared/emugl/common/smart_ptr_unittest.cpp
new file mode 100644
index 0000000..db9e5f2
--- /dev/null
+++ b/emulator/opengl/shared/emugl/common/smart_ptr_unittest.cpp
@@ -0,0 +1,140 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "emugl/common/smart_ptr.h"
+
+#include <gtest/gtest.h>
+
+namespace emugl {
+
+// This Test sub-class is used to track allocations and deallocations of
+// the MyTestClass instances that are created through newInstance().
+// See below for typical usage.
+class SmartPtrTest : public testing::Test {
+public:
+ SmartPtrTest() : mNewCount(0), mDeleteCount(0), mDoCount(0) {}
+
+ ~SmartPtrTest() {
+ mNewCount = 0;
+ mDoCount = 0;
+ mDeleteCount = 0;
+ }
+
+ class MyClass;
+
+ MyClass* newInstance() {
+ return new MyClass(this);
+ }
+
+ class MyClass {
+ public:
+ MyClass(SmartPtrTest* test) : mTest(test) {
+ mTest->mNewCount++;
+ }
+
+ void doStuff() {
+ mTest->mDoCount++;
+ }
+
+ ~MyClass() {
+ mTest->mDeleteCount++;
+ }
+ private:
+ SmartPtrTest* mTest;
+ };
+
+ int mNewCount;
+ int mDeleteCount;
+ int mDoCount;
+};
+
+
+TEST_F(SmartPtrTest, Empty) {
+ SmartPtr<MyClass> ptr;
+ EXPECT_FALSE(ptr.Ptr());
+
+ EXPECT_EQ(0, mNewCount);
+ EXPECT_EQ(0, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+}
+
+
+TEST_F(SmartPtrTest, SingleRef) {
+ MyClass* obj = newInstance();
+ EXPECT_EQ(1, mNewCount);
+
+ {
+ SmartPtr<MyClass> ptr(obj);
+ EXPECT_EQ(obj, ptr.Ptr());
+
+ EXPECT_EQ(1, mNewCount);
+ EXPECT_EQ(0, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+ }
+ // Check that the object was deleted.
+ EXPECT_EQ(1, mDeleteCount);
+}
+
+
+TEST_F(SmartPtrTest, CopyConstructor) {
+ MyClass* obj = newInstance();
+ EXPECT_EQ(1, mNewCount);
+
+ {
+ SmartPtr<MyClass> ptr1(obj);
+ {
+ SmartPtr<MyClass> ptr2(ptr1);
+ EXPECT_EQ(2, ptr1.getRefCount());
+ EXPECT_EQ(2, ptr2.getRefCount());
+ EXPECT_EQ(1, mNewCount);
+ EXPECT_EQ(0, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+ }
+ EXPECT_EQ(1, mNewCount);
+ EXPECT_EQ(0, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+ }
+ EXPECT_EQ(1, mNewCount);
+ EXPECT_EQ(1, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+}
+
+
+TEST_F(SmartPtrTest, AssignmentOperator) {
+ SmartPtr<MyClass> ptr1(newInstance());
+ SmartPtr<MyClass> ptr2(newInstance());
+ EXPECT_EQ(2, mNewCount);
+ EXPECT_EQ(0, mDeleteCount);
+ EXPECT_EQ(0, mDoCount);
+
+ ptr2 = ptr1;
+ EXPECT_EQ(2, mNewCount);
+ EXPECT_EQ(1, mDeleteCount);
+
+ EXPECT_EQ(ptr1.Ptr(), ptr2.Ptr());
+ EXPECT_EQ(2, ptr1.getRefCount());
+ EXPECT_EQ(2, ptr2.getRefCount());
+}
+
+
+TEST_F(SmartPtrTest, ArrowOperator) {
+ SmartPtr<MyClass> ptr(newInstance());
+ ptr->doStuff();
+ EXPECT_EQ(1, mDoCount);
+
+ (*ptr).doStuff();
+ EXPECT_EQ(2, mDoCount);
+}
+
+} // namespace emugl
generated by cgit v1.1 at 2025-03-22 20:05:12 +0000