1 -----------------------------------------------------------------------------
3 -- Module : System.CPUTime
4 -- Copyright : (c) The University of Glasgow 2001
5 -- License : BSD-style (see the file libraries/core/LICENSE)
7 -- Maintainer : libraries@haskell.org
8 -- Stability : provisional
9 -- Portability : portable
11 -- The standard CPUTime library.
13 -----------------------------------------------------------------------------
17 getCPUTime, -- :: IO Integer
18 cpuTimePrecision -- :: Integer
30 -- -----------------------------------------------------------------------------
31 -- Computation `getCPUTime' returns the number of picoseconds CPU time
32 -- used by the current program. The precision of this result is
33 -- implementation-dependent.
35 -- The `cpuTimePrecision' constant is the smallest measurable difference
36 -- in CPU time that the implementation can record, and is given as an
37 -- integral number of picoseconds.
39 getCPUTime :: IO Integer
42 #if !defined(mingw32_TARGET_OS) && !defined(cygwin32_TARGET_OS)
43 -- getrusage() is right royal pain to deal with when targetting multiple
44 -- versions of Solaris, since some versions supply it in libc (2.3 and 2.5),
45 -- while 2.4 has got it in libucb (I wouldn't be too surprised if it was back
46 -- again in libucb in 2.6..)
48 -- Avoid the problem by resorting to times() instead.
50 #if defined(HAVE_GETRUSAGE) && ! irix_TARGET_OS && ! solaris2_TARGET_OS
51 allocaBytes (#const sizeof(struct rusage)) $ \ p_rusage -> do
52 getrusage (#const RUSAGE_SELF) p_rusage
54 let ru_utime = (#ptr struct rusage, ru_utime) p_rusage
55 let ru_stime = (#ptr struct rusage, ru_stime) p_rusage
56 u_sec <- (#peek struct timeval,tv_sec) ru_utime :: IO CTime
57 u_usec <- (#peek struct timeval,tv_usec) ru_utime :: IO CTime
58 s_sec <- (#peek struct timeval,tv_sec) ru_stime :: IO CTime
59 s_usec <- (#peek struct timeval,tv_usec) ru_stime :: IO CTime
61 return ((fromIntegral u_sec * 1000000 + fromIntegral u_usec +
62 fromIntegral s_sec * 1000000 + fromIntegral s_usec)
66 foreign import ccall unsafe getrusage :: CInt -> Ptr CRUsage -> IO CInt
68 # if defined(HAVE_TIMES)
69 allocaBytes (#const sizeof(struct tms)) $ \ p_tms -> do
71 u_ticks <- (#peek struct tms,tms_utime) p_tms :: IO CClock
72 s_ticks <- (#peek struct tms,tms_stime) p_tms :: IO CClock
73 return (( (fromIntegral u_ticks + fromIntegral s_ticks) * 1000000000000)
74 `div` fromIntegral clockTicks)
77 foreign import ccall unsafe times :: Ptr CTms -> IO CClock
79 ioException (IOError Nothing UnsupportedOperation
87 allocaBytes (#const sizeof(FILETIME)) $ \ p_creationTime -> do
88 allocaBytes (#const sizeof(FILETIME)) $ \ p_exitTime -> do
89 allocaBytes (#const sizeof(FILETIME)) $ \ p_kernelTime -> do
90 allocaBytes (#const sizeof(FILETIME)) $ \ p_userTime -> do
91 pid <- getCurrentProcess
92 ok <- getProcessTimes pid p_creationTime p_exitTime p_kernelTime p_userTime
94 ut <- ft2psecs p_userTime
95 kt <- ft2psecs p_kernelTime
96 return (fromIntegral (ut + kt))
98 where ft2psecs ft = do
99 high <- (#peek FILETIME,dwHighDateTime) ft :: IO CLong
100 low <- (#peek FILETIME,dwLowDateTime) ft :: IO CLong
101 return (((fromIntegral high) * (2^32) + (fromIntegral low)) * 100000)
103 -- ToDo: pin down elapsed times to just the OS thread(s) that
104 -- are evaluating/managing Haskell code.
108 -- need proper Haskell names (initial lower-case character)
109 foreign import ccall unsafe "GetCurrentProcess" getCurrentProcess :: IO (Ptr HANDLE)
110 foreign import ccall unsafe "GetProcessTimes" getProcessTimes :: Ptr HANDLE -> Ptr FILETIME -> Ptr FILETIME -> Ptr FILETIME -> Ptr FILETIME -> IO CInt
112 #endif /* not _WIN32 */
114 cpuTimePrecision :: Integer
115 cpuTimePrecision = round ((1000000000000::Integer) % fromIntegral (clockTicks))
122 unsafePerformIO (sysconf (#const _SC_CLK_TCK) >>= return . fromIntegral)
123 foreign import ccall unsafe sysconf :: CInt -> IO CLong