Safe Haskell | Safe-Inferred |
---|
This module makes the operations exported by System.Posix.Unistd
available on all platforms. On POSIX systems it re-exports operations from
System.Posix.Unistd
, on other platforms it emulates the operations as far
as possible.
System environment
data SystemID
Sleeping
Sleep for the specified duration (in seconds). Returns the time remaining (if the sleep was interrupted by a signal, for example).
GHC Note: threadDelay
is a better choice. Since GHC
uses signals for its internal clock, a call to sleep
will usually be
interrupted immediately. That makes sleep
unusable in a program compiled
with GHC, unless the RTS timer is disabled (with +RTS -V0
). Furthermore,
without the -threaded
option, sleep
will block all other user threads.
Even with the -threaded
option, sleep
requires a full OS thread to
itself. threadDelay
has none of these shortcomings.
Sleep for the specified duration (in microseconds).
GHC Note: threadDelay
is a better choice.
Without the -threaded
option, usleep
will block all other user
threads. Even with the -threaded
option, usleep
requires a
full OS thread to itself. threadDelay
has
neither of these shortcomings.