From cde5ce9ec6fe7eb634702578f50d2738bce3ac49 Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Thu, 14 Nov 2024 15:18:37 -0700
Subject: [PATCH] QThreadData: make current() inline with a noexcept likely
 portion

This helps compilers with codegen.

Change-Id: I096db2bc39b21ee7605efffdaa257c6c658f38b4
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
---
 src/corelib/thread/qthread.cpp      | 14 +++++++++-----
 src/corelib/thread/qthread_p.h      | 11 ++++++++++-
 src/corelib/thread/qthread_unix.cpp |  9 ++++++---
 src/corelib/thread/qthread_win.cpp  |  9 ++++++---
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index f804ab8b9d3..64a6645db21 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -1119,12 +1119,16 @@ void QThread::setTerminationEnabled(bool)
 // No threads: so we can just use static variables
 Q_CONSTINIT static QThreadData *data = nullptr;
 
-QThreadData *QThreadData::current()
+QThreadData *QThreadData::currentThreadData() noexcept
 {
-    if (!data) {
-        data = new QThreadData;
-        data->thread = new QAdoptedThread(data);
-    }
+    return data;
+}
+
+QThreadData *QThreadData::createCurrentThreadData()
+{
+    Q_ASSERT(!currentThreadData());
+    data = new QThreadData;
+    data->thread = new QAdoptedThread(data);
     return data;
 }
 
diff --git a/src/corelib/thread/qthread_p.h b/src/corelib/thread/qthread_p.h
index 51299ee53b9..5f64293e467 100644
--- a/src/corelib/thread/qthread_p.h
+++ b/src/corelib/thread/qthread_p.h
@@ -308,7 +308,12 @@ public:
     }
     ~QThreadData();
 
-    static Q_AUTOTEST_EXPORT QThreadData *current();
+    static QThreadData *current()
+    {
+        if (QThreadData *data = currentThreadData()) Q_LIKELY_BRANCH
+            return data;
+        return createCurrentThreadData();
+    }
     static void clearCurrentThreadData();
     static QThreadData *get2(QThread *thread)
     { Q_ASSERT_X(thread != nullptr, "QThread", "internal error"); return thread->d_func()->data; }
@@ -363,6 +368,10 @@ public:
     bool canWait = true;
     bool isAdopted = false;
     bool requiresCoreApplication = true;
+
+private:
+    static Q_AUTOTEST_EXPORT QThreadData *currentThreadData() noexcept Q_DECL_PURE_FUNCTION;
+    static Q_AUTOTEST_EXPORT QThreadData *createCurrentThreadData();
 };
 
 class QScopedScopeLevelCounter
diff --git a/src/corelib/thread/qthread_unix.cpp b/src/corelib/thread/qthread_unix.cpp
index 832a21db48c..926b7aea400 100644
--- a/src/corelib/thread/qthread_unix.cpp
+++ b/src/corelib/thread/qthread_unix.cpp
@@ -225,11 +225,14 @@ void QThreadData::clearCurrentThreadData()
     set_thread_data(nullptr);
 }
 
-QThreadData *QThreadData::current()
+QThreadData *QThreadData::currentThreadData() noexcept
 {
-    if (QThreadData *data = get_thread_data(); Q_LIKELY(data))
-        return data;
+    return get_thread_data();
+}
 
+QThreadData *QThreadData::createCurrentThreadData()
+{
+    Q_ASSERT(!currentThreadData());
     std::unique_ptr data = std::make_unique<QThreadData>();
 
     // This needs to be called prior to new QAdoptedThread() to avoid
diff --git a/src/corelib/thread/qthread_win.cpp b/src/corelib/thread/qthread_win.cpp
index 947c1a4e475..8b902ec2cd6 100644
--- a/src/corelib/thread/qthread_win.cpp
+++ b/src/corelib/thread/qthread_win.cpp
@@ -96,11 +96,14 @@ void QThreadData::clearCurrentThreadData()
     set_thread_data(nullptr);
 }
 
-QThreadData *QThreadData::current()
+QThreadData *QThreadData::currentThreadData() noexcept
 {
-    if (QThreadData *data = get_thread_data(); Q_LIKELY(data))
-        return data;
+    return get_thread_data();
+}
 
+QThreadData *QThreadData::createCurrentThreadData()
+{
+    Q_ASSERT(!currentThreadData());
     std::unique_ptr data = std::make_unique<QThreadData>();
 
     // This needs to be called prior to new QAdoptedThread() to avoid