Deeper test coverage for support tree generation.

Restructuring for testability.

src/libslic3r/SLA/SLAConcurrency.hpp

@@ -0,0 +1,56 @@
+#ifndef SLACONCURRENCY_H
+#define SLACONCURRENCY_H
+
+#include <tbb/spin_mutex.h>
+#include <tbb/mutex.h>
+#include <tbb/parallel_for.h>
+
+namespace Slic3r {
+namespace sla {
+
+// Set this to true to enable full parallelism in this module.
+// Only the well tested parts will be concurrent if this is set to false.
+const constexpr bool USE_FULL_CONCURRENCY = false;
+
+template<bool> struct _ccr {};
+
+template<> struct _ccr<true>
+{
+    using SpinningMutex = tbb::spin_mutex;
+    using BlockingMutex  = tbb::mutex;
+    
+    template<class It, class Fn>
+    static inline void enumerate(It from, It to, Fn fn)
+    {
+        auto   iN = to - from;
+        size_t N  = iN < 0 ? 0 : size_t(iN);
+        
+        tbb::parallel_for(size_t(0), N, [from, fn](size_t n) {
+            fn(*(from + decltype(iN)(n)), n);
+        });
+    }
+};
+
+template<> struct _ccr<false>
+{
+private:
+    struct _Mtx { inline void lock() {} inline void unlock() {} };
+    
+public:
+    using SpinningMutex = _Mtx;
+    using BlockingMutex = _Mtx;
+    
+    template<class It, class Fn>
+    static inline void enumerate(It from, It to, Fn fn)
+    {
+        for (auto it = from; it != to; ++it) fn(*it, size_t(it - from));
+    }
+};
+
+using ccr = _ccr<USE_FULL_CONCURRENCY>;
+using ccr_seq = _ccr<false>;
+using ccr_par = _ccr<true>;
+
+}} // namespace Slic3r::sla
+
+#endif // SLACONCURRENCY_H