Only call std::string constructor in gl::Error when necessary

std::string's constructor is very expensive in debug builds. In some applications we have seen it use 10% of the CPU. This change makes (e)gl::Error store a pointer to an std::string, and only create a string when necessary. Change-Id: I78bfbda86568944681517fe32df9d1556e4ebee7 Reviewed-on: https://chromium-review.googlesource.com/240495Tested-by: Austin Kinross <aukinros@microsoft.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>

Only call std::string constructor in gl::Error when necessary
3940a453 · Austin Kinross · Geoff Lang · 7700ff65 · 3940a453 · 3940a453
Commit 3940a453 authored Jan 14, 2015 by Austin Kinross Committed by Geoff Lang Jan 20, 2015
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Showing with 90 additions and 14 deletions

Error.cpp src/libANGLE/Error.cpp +80 -10

Error.h src/libANGLE/Error.h +10 -4

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--- a/src/libANGLE/Error.cpp
+++ b/src/libANGLE/Error.cpp
@@ -18,33 +18,68 @@ namespace gl

 Error::Error(GLenum errorCode)
    : mCode(errorCode),
-      mMessage()
+      mMessage(NULL)
 {
 }

 Error::Error(GLenum errorCode, const char *msg, ...)
    : mCode(errorCode),
-      mMessage()
+      mMessage(NULL)
 {
    va_list vararg;
    va_start(vararg, msg);
-    mMessage = FormatString(msg, vararg);
+    createMessageString();
+    *mMessage = FormatString(msg, vararg);
    va_end(vararg);
 }

 Error::Error(const Error &other)
    : mCode(other.mCode),
-      mMessage(other.mMessage)
+      mMessage(NULL)
 {
+    if (other.mMessage != NULL)
+    {
+        createMessageString();
+        *mMessage = *(other.mMessage);
+    }
+}
+
+Error::~Error()
+{
+    SafeDelete(mMessage);
 }

 Error &Error::operator=(const Error &other)
 {
    mCode = other.mCode;
-    mMessage = other.mMessage;
+
+    if (other.mMessage != NULL)
+    {
+        createMessageString();
+        *mMessage = *(other.mMessage);
+    }
+    else
+    {
+        SafeDelete(mMessage);
+    }
+
    return *this;
 }

+void Error::createMessageString() const
+{
+    if (mMessage != NULL)
+    {
+        mMessage = new std::string();
+    }
+}
+
+const std::string &Error::getMessage() const
+{
+    createMessageString();
+    return *mMessage;
+}
+
 }

 namespace egl
@@ -52,31 +87,66 @@ namespace egl

 Error::Error(EGLint errorCode)
    : mCode(errorCode),
-      mMessage()
+      mMessage(NULL)
 {
 }

 Error::Error(EGLint errorCode, const char *msg, ...)
    : mCode(errorCode),
-    mMessage()
+      mMessage(NULL)
 {
    va_list vararg;
    va_start(vararg, msg);
-    mMessage = FormatString(msg, vararg);
+    createMessageString();
+    *mMessage = FormatString(msg, vararg);
    va_end(vararg);
 }

 Error::Error(const Error &other)
    : mCode(other.mCode),
-    mMessage(other.mMessage)
+      mMessage(NULL)
 {
+    if (other.mMessage != NULL)
+    {
+        createMessageString();
+        *mMessage = *(other.mMessage);
+    }
+}
+
+Error::~Error()
+{
+    SafeDelete(mMessage);
 }

 Error &Error::operator=(const Error &other)
 {
    mCode = other.mCode;
-    mMessage = other.mMessage;
+
+    if (other.mMessage != NULL)
+    {
+        createMessageString();
+        *mMessage = *(other.mMessage);
+    }
+    else
+    {
+        SafeDelete(mMessage);
+    }
+
    return *this;
 }

+void Error::createMessageString() const
+{
+    if (mMessage != NULL)
+    {
+        mMessage = new std::string();
+    }
+}
+
+const std::string &Error::getMessage() const
+{
+    createMessageString();
+    return *mMessage;
+}
+
 }
--- a/src/libANGLE/Error.h
+++ b/src/libANGLE/Error.h
@@ -23,16 +23,19 @@ class Error
    explicit Error(GLenum errorCode);
    Error(GLenum errorCode, const char *msg, ...);
    Error(const Error &other);
+    ~Error();
    Error &operator=(const Error &other);

    GLenum getCode() const { return mCode; }
    bool isError() const { return (mCode != GL_NO_ERROR); }

-    const std::string &getMessage() const { return mMessage; }
+    const std::string &getMessage() const;

  private:
+    void createMessageString() const;
+
    GLenum mCode;
-    std::string mMessage;
+    mutable std::string *mMessage;
 };

 }
@@ -46,16 +49,19 @@ class Error
    explicit Error(EGLint errorCode);
    Error(EGLint errorCode, const char *msg, ...);
    Error(const Error &other);
+    ~Error();
    Error &operator=(const Error &other);

    EGLint getCode() const { return mCode; }
    bool isError() const { return (mCode != EGL_SUCCESS); }

-    const std::string &getMessage() const { return mMessage; }
+    const std::string &getMessage() const;

  private:
+    void createMessageString() const;
+
    EGLint mCode;
-    std::string mMessage;
+    mutable std::string *mMessage;
 };

 }