From: Daniel Fischer Date: Mon, 30 May 2011 08:50:22 +0000 (+0200) Subject: ffi-chap.xml whitespace X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=9613bb41e2d905563bddcb18ea0265d69c761994 ffi-chap.xml whitespace --- diff --git a/docs/users_guide/ffi-chap.xml b/docs/users_guide/ffi-chap.xml index 97a2378..fa41864 100644 --- a/docs/users_guide/ffi-chap.xml +++ b/docs/users_guide/ffi-chap.xml @@ -51,7 +51,7 @@ Foreign function interface (FFI) calling arbitrary IO procedures in some part of the program.) The Haskell FFI already specifies that arguments and results of -foreign imports and exports will be automatically unwrapped if they are +foreign imports and exports will be automatically unwrapped if they are newtypes (Section 3.2 of the FFI addendum). GHC extends the FFI by automatically unwrapping any newtypes that wrap the IO monad itself. More precisely, wherever the FFI specification requires an IO type, GHC will @@ -96,7 +96,7 @@ OK: the time, then the program will not respond to the user interrupt. - + The problem is that it is not possible in general to interrupt a foreign call safely. However, GHC does provide @@ -106,7 +106,7 @@ OK: of safe or unsafe: -foreign import ccall interruptible +foreign import ccall interruptible "sleep" :: CUint -> IO CUint @@ -174,7 +174,7 @@ foreign import ccall interruptible When GHC compiles a module (say M.hs) - which uses foreign export or + which uses foreign export or foreign import "wrapper", it generates two additional files, M_stub.c and M_stub.h. GHC will automatically compile @@ -223,7 +223,7 @@ extern HsInt foo(HsInt a0); ––make, as GHC will automatically link in the correct bits). - + Using your own <literal>main()</literal> Normally, GHC's runtime system provides a @@ -371,7 +371,7 @@ int main(int argc, char *argv[]) - + Using header files @@ -396,7 +396,7 @@ int main(int argc, char *argv[]) available when compiling an inlined version of a foreign call, so the compiler is free to inline foreign calls in any context. - + The -#include option is now deprecated, and the include-files field in a Cabal package specification is ignored. @@ -481,17 +481,17 @@ int main(int argc, char *argv[]) - + Multi-threading and the FFI - + In order to use the FFI in a multi-threaded setting, you must use the option (see ). - + Foreign imports and multi-threading - + When you call a foreign imported function that is annotated as safe (the default), and the program was linked @@ -500,7 +500,7 @@ int main(int argc, char *argv[]) program was linked without , then the other Haskell threads will be blocked until the call returns. - + This means that if you need to make a foreign call to a function that takes a long time or blocks indefinitely, then you should mark it safe and @@ -540,7 +540,7 @@ int main(int argc, char *argv[]) The relationship between Haskell threads and OS threads - + Normally there is no fixed relationship between Haskell threads and OS threads. This means that when you make a foreign call, that call may take place in an unspecified OS @@ -560,10 +560,10 @@ int main(int argc, char *argv[]) for the Control.Concurrent module. - + Foreign exports and multi-threading - + When the program is linked with , then you may invoke foreign exported functions from @@ -612,7 +612,7 @@ int main(int argc, char *argv[]) isn't necessary to ensure that the threads have exited first. (Unofficially, if you want to use this fast and loose version of hs_exit(), then call - shutdownHaskellAndExit() instead). + shutdownHaskellAndExit() instead).