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 -- $Id: CPUTime.hsc,v 1.6 2002/02/11 12:29:13 simonmar Exp $
13 -- The standard CPUTime library.
15 -----------------------------------------------------------------------------
19 getCPUTime, -- :: IO Integer
20 cpuTimePrecision -- :: Integer
32 -- -----------------------------------------------------------------------------
33 -- Computation `getCPUTime' returns the number of picoseconds CPU time
34 -- used by the current program. The precision of this result is
35 -- implementation-dependent.
37 -- The `cpuTimePrecision' constant is the smallest measurable difference
38 -- in CPU time that the implementation can record, and is given as an
39 -- integral number of picoseconds.
41 getCPUTime :: IO Integer
44 #if !defined(mingw32_TARGET_OS) && !defined(cygwin32_TARGET_OS)
45 -- getrusage() is right royal pain to deal with when targetting multiple
46 -- versions of Solaris, since some versions supply it in libc (2.3 and 2.5),
47 -- while 2.4 has got it in libucb (I wouldn't be too surprised if it was back
48 -- again in libucb in 2.6..)
50 -- Avoid the problem by resorting to times() instead.
52 #if defined(HAVE_GETRUSAGE) && ! irix_TARGET_OS && ! solaris2_TARGET_OS
53 allocaBytes (#const sizeof(struct rusage)) $ \ p_rusage -> do
54 getrusage (#const RUSAGE_SELF) p_rusage
56 let ru_utime = (#ptr struct rusage, ru_utime) p_rusage
57 let ru_stime = (#ptr struct rusage, ru_stime) p_rusage
58 u_sec <- (#peek struct timeval,tv_sec) ru_utime :: IO CTime
59 u_usec <- (#peek struct timeval,tv_usec) ru_utime :: IO CTime
60 s_sec <- (#peek struct timeval,tv_sec) ru_stime :: IO CTime
61 s_usec <- (#peek struct timeval,tv_usec) ru_stime :: IO CTime
63 return ((fromIntegral u_sec * 1000000 + fromIntegral u_usec +
64 fromIntegral s_sec * 1000000 + fromIntegral s_usec)
68 foreign import unsafe getrusage :: CInt -> Ptr CRUsage -> IO CInt
70 # if defined(HAVE_TIMES)
71 allocaBytes (#const sizeof(struct tms)) $ \ p_tms -> do
73 u_ticks <- (#peek struct tms,tms_utime) p_tms :: IO CClock
74 s_ticks <- (#peek struct tms,tms_stime) p_tms :: IO CClock
75 return (( (fromIntegral u_ticks + fromIntegral s_ticks) * 1000000000000)
76 `div` fromIntegral clockTicks)
79 foreign import unsafe times :: Ptr CTms -> IO CClock
81 ioException (IOError Nothing UnsupportedOperation
89 allocaBytes (#const sizeof(FILETIME)) $ \ p_creationTime -> do
90 allocaBytes (#const sizeof(FILETIME)) $ \ p_exitTime -> do
91 allocaBytes (#const sizeof(FILETIME)) $ \ p_kernelTime -> do
92 allocaBytes (#const sizeof(FILETIME)) $ \ p_userTime -> do
93 pid <- getCurrentProcess
94 ok <- getProcessTimes pid p_creationTime p_exitTime p_kernelTime p_userTime
96 ut <- ft2psecs p_userTime
97 kt <- ft2psecs p_kernelTime
98 return (fromIntegral (ut + kt))
100 where ft2psecs ft = do
101 high <- (#peek FILETIME,dwHighDateTime) ft :: IO CLong
102 low <- (#peek FILETIME,dwLowDateTime) ft :: IO CLong
103 return (((fromIntegral high) * (2^32) + (fromIntegral low)) * 100000)
105 -- ToDo: pin down elapsed times to just the OS thread(s) that
106 -- are evaluating/managing Haskell code.
110 -- need proper Haskell names (initial lower-case character)
111 foreign import "GetCurrentProcess" unsafe getCurrentProcess :: IO (Ptr HANDLE)
112 foreign import "GetProcessTimes" unsafe getProcessTimes :: Ptr HANDLE -> Ptr FILETIME -> Ptr FILETIME -> Ptr FILETIME -> Ptr FILETIME -> IO CInt
114 #endif /* not _WIN32 */
116 cpuTimePrecision :: Integer
117 cpuTimePrecision = round ((1000000000000::Integer) % fromIntegral (clockTicks))
124 unsafePerformIO (sysconf (#const _SC_CLK_TCK) >>= return . fromIntegral)
125 foreign import unsafe sysconf :: CInt -> IO CLong