Add option for specifying maximum concurrent unpack operations

For tracing issues with the multithreaded extraction and limiting the
processor load from the installer.

Task-number: QTIFW-2586
Change-Id: I5df0bf6be30b4ee5ef8470c407281e2a4318ed0c
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Katja Marttila <katja.marttila@qt.io>

1 files changed, 19 insertions, 3 deletions

diff --git a/src/libs/installer/concurrentoperationrunner.cpp b/src/libs/installer/concurrentoperationrunner.cpp
index 03012c593..c1a87ded2 100644
--- a/src/libs/installer/concurrentoperationrunner.cpp
+++ b/src/libs/installer/concurrentoperationrunner.cpp
@@ -42,8 +42,9 @@ using namespace QInstaller;
 
     The class accepts an operation list of any registered operation type. It can be
     used to execute the \c Backup, \c Perform, or \c Undo steps of the operations. The
-    operations are run in the global thread pool, which by default limits the maximum
-    number of threads to the ideal number of logical processor cores in the system.
+    operations are run in a separate thread pool of this class, which by default limits
+    the maximum number of threads to the ideal number of logical processor cores in the
+    system.
 */
 
 /*!
@@ -67,6 +68,7 @@ ConcurrentOperationRunner::ConcurrentOperationRunner(QObject *parent)
     , m_totalOperations(0)
     , m_operations(nullptr)
     , m_type(Operation::OperationType::Perform)
+    , m_threadPool(new QThreadPool(this))
 {
 }
 
@@ -81,6 +83,7 @@ ConcurrentOperationRunner::ConcurrentOperationRunner(OperationList *operations,
     , m_totalOperations(0)
     , m_operations(operations)
     , m_type(type)
+    , m_threadPool(new QThreadPool(this))
 {
     m_totalOperations = m_operations->size();
 }
@@ -112,6 +115,19 @@ void ConcurrentOperationRunner::setType(const Operation::OperationType type)
 }
 
 /*!
+    Sets the maximum \a count of threads used by the thread pool of this class.
+    A value of \c 0 sets the count automatically to ideal number of threads.
+*/
+void ConcurrentOperationRunner::setMaxThreadCount(int count)
+{
+    if (count == 0) {
+        m_threadPool->setMaxThreadCount(QThread::idealThreadCount());
+        return;
+    }
+    m_threadPool->setMaxThreadCount(count);
+}
+
+/*!
     \internal
 
     Runs \a operation in mode of \a type. Returns \c true on success, \c false otherwise.
@@ -148,7 +164,7 @@ QHash<Operation *, bool> ConcurrentOperationRunner::run()
         connect(futureWatcher, &QFutureWatcher<bool>::finished,
             this, &ConcurrentOperationRunner::onOperationfinished);
 
-        futureWatcher->setFuture(QtConcurrent::run(&runOperation, operation, m_type));
+        futureWatcher->setFuture(QtConcurrent::run(m_threadPool, &runOperation, operation, m_type));
     }
 
     if (!m_operationWatchers.isEmpty()) {