thread_local _custom_scheduler

Resolves ONCPUML-1331

This patch adds an option to make _custom_scheduler thread_local to
support usage of multiple schedulers handled outside of ACL.
It also adds num_threads() function to Scheduler which reverts to
querying CPUInfo if no scheduler has been set.

Change-Id: Iff706165d8d091895331a5bb3a76f6cabe048912
Signed-off-by: David Svantesson-Yeung <david.svantesson-yeung@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/10748
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: SiCong Li <sicong.li@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 30 insertions, 2 deletions

diff --git a/src/runtime/Scheduler.cpp b/src/runtime/Scheduler.cpp
index e52fb59940..6d961f29a5 100644
--- a/src/runtime/Scheduler.cpp
+++ b/src/runtime/Scheduler.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2020 Arm Limited.
+* Copyright (c) 2017-2020, 2023 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -40,14 +40,18 @@ using namespace arm_compute;
 #if !ARM_COMPUTE_CPP_SCHEDULER && ARM_COMPUTE_OPENMP_SCHEDULER
 Scheduler::Type Scheduler::_scheduler_type = Scheduler::Type::OMP;
 #elif ARM_COMPUTE_CPP_SCHEDULER && !ARM_COMPUTE_OPENMP_SCHEDULER
-Scheduler::Type Scheduler::_scheduler_type = Scheduler::Type::CPP;
+Scheduler::Type Scheduler::_scheduler_type                            = Scheduler::Type::CPP;
 #elif ARM_COMPUTE_CPP_SCHEDULER && ARM_COMPUTE_OPENMP_SCHEDULER
 Scheduler::Type Scheduler::_scheduler_type = Scheduler::Type::CPP;
 #else  /* ARM_COMPUTE_*_SCHEDULER */
 Scheduler::Type Scheduler::_scheduler_type = Scheduler::Type::ST;
 #endif /* ARM_COMPUTE_*_SCHEDULER */
 
+#ifndef ARM_COMPUTE_THREAD_LOCAL_SCHEDULER
 std::shared_ptr<IScheduler> Scheduler::_custom_scheduler = nullptr;
+#else  // ARM_COMPUTE_THREAD_LOCAL_SCHEDULER
+std::shared_ptr<IScheduler> thread_local Scheduler::_custom_scheduler = nullptr;
+#endif // ARM_COMPUTE_THREAD_LOCAL_SCHEDULER
 
 namespace
 {
@@ -74,6 +78,30 @@ void Scheduler::set(Type t)
     _scheduler_type = t;
 }
 
+bool Scheduler::is_set()
+{
+    if (_scheduler_type == Type::CUSTOM)
+    {
+        return _custom_scheduler != nullptr;
+    }
+    else
+    {
+        return !_schedulers.empty();
+    }
+}
+
+unsigned int Scheduler::num_threads()
+{
+    if (Scheduler::is_set())
+    {
+        return Scheduler::get().num_threads();
+    }
+    else
+    {
+        return CPUInfo::get().get_cpu_num();
+    }
+}
+
 bool Scheduler::is_available(Type t)
 {
     if (t == Type::CUSTOM)