From 6645115377bd9699ae6785608753d33067b8e036 Mon Sep 17 00:00:00 2001 From: Marco Costalba Date: Sun, 1 Mar 2015 17:12:09 +0100 Subject: [PATCH] Allow to disable spinlocks And use mutex instead. You may never want to do this. It is a workaround to run c++11 on fishtest where many machiens have HTenabled and this can be a problem when number of cores set is higher than number of physical cores. To disable spinlocks, just compile with -DNO_SPINLOCK flag No functional change. --- src/thread.h | 14 +++++++++++++- src/types.h | 3 +++ 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/src/thread.h b/src/thread.h index b6809f4e..a639cf7e 100644 --- a/src/thread.h +++ b/src/thread.h @@ -39,7 +39,7 @@ const size_t MAX_THREADS = 128; const size_t MAX_SPLITPOINTS_PER_THREAD = 8; const size_t MAX_SLAVES_PER_SPLITPOINT = 4; - +#if !defined(NO_SPINLOCK) /// Spinlock class wraps low level atomic operations to provide a spin lock class Spinlock { @@ -55,6 +55,18 @@ public: void release() { lock.store(1, std::memory_order_release); } }; +#else + +class Spinlock { + + std::mutex mutex; + +public: + void acquire() { mutex.lock(); } + void release() { mutex.unlock(); } +}; + +#endif /// SplitPoint struct stores information shared by the threads searching in /// parallel below the same split point. It is populated at splitting time. diff --git a/src/types.h b/src/types.h index eebd69e5..c8078546 100644 --- a/src/types.h +++ b/src/types.h @@ -31,6 +31,9 @@ /// -DNO_PREFETCH | Disable use of prefetch asm-instruction. You may need this to /// | run on some very old machines. /// +/// -DNO_SPINLOCK | Use mutex instead of spinlocks. This is much slower, so you +/// | really don't want to do this in general case. +/// /// -DUSE_POPCNT | Add runtime support for use of popcnt asm-instruction. Works /// | only in 64-bit mode and requires hardware with popcnt support. /// -- 2.39.2