| |
| ------------ |
| Benchmarking |
| ------------ |
| There is a set a benchmarking programs in the |
| "tests" directory. These should be runnable using the |
| following command-lines corresponding to each of the possible |
| library builds: |
| |
| MSVC: |
| nmake clean VC-bench |
| nmake clean VCE-bench |
| nmake clean VSE-bench |
| |
| Mingw32: |
| make clean GC-bench |
| make clean GCE-bench |
| |
| UWIN: |
| The benchtests are run as part of the testsuite. |
| |
| |
| Mutex benchtests |
| ---------------- |
| |
| benchtest1 - Lock plus unlock on an unlocked mutex. |
| benchtest2 - Lock plus unlock on a locked mutex. |
| benchtest3 - Trylock on a locked mutex. |
| benchtest4 - Trylock plus unlock on an unlocked mutex. |
| |
| |
| Each test times up to three alternate synchronisation |
| implementations as a reference, and then times each of |
| the four mutex types provided by the library. Each is |
| described below: |
| |
| Simple Critical Section |
| - uses a simple Win32 critical section. There is no |
| additional overhead for this case as there is in the |
| remaining cases. |
| |
| POSIX mutex implemented using a Critical Section |
| - The old implementation which uses runtime adaptation |
| depending on the Windows variant being run on. When |
| the pthreads DLL was run on WinNT or higher then |
| POSIX mutexes would use Win32 Critical Sections. |
| |
| POSIX mutex implemented using a Win32 Mutex |
| - The old implementation which uses runtime adaptation |
| depending on the Windows variant being run on. When |
| the pthreads DLL was run on Win9x then POSIX mutexes |
| would use Win32 Mutexes (because TryEnterCriticalSection |
| is not implemented on Win9x). |
| |
| PTHREAD_MUTEX_DEFAULT |
| PTHREAD_MUTEX_NORMAL |
| PTHREAD_MUTEX_ERRORCHECK |
| PTHREAD_MUTEX_RECURSIVE |
| - The current implementation supports these mutex types. |
| The underlying basis of POSIX mutexes is now the same |
| irrespective of the Windows variant, and should therefore |
| have consistent performance. |
| |
| |
| Semaphore benchtests |
| -------------------- |
| |
| benchtest5 - Timing for various uncontended cases. |
| |
| |
| In all benchtests, the operation is repeated a large |
| number of times and an average is calculated. Loop |
| overhead is measured and subtracted from all test times. |
| |
