[project @ 1999-07-06 15:24:01 by simonmar]

Add a note about @raiseInThread@.

diff --git a/ghc/docs/users_guide/parallel.vsgml b/ghc/docs/users_guide/parallel.vsgml
index 05e74c1..a30120c 100644 (file)
--- a/ghc/docs/users_guide/parallel.vsgml
+++ b/ghc/docs/users_guide/parallel.vsgml
@@ -85,6 +85,26 @@ isn't lost: the computation is suspended until required by another
 thread.  The memory used by the thread will be garbage collected if it
 isn't referenced from anywhere else.
 
 thread.  The memory used by the thread will be garbage collected if it
 isn't referenced from anywhere else.
 

+More generally, an arbitrary exception may be raised in any thread for
+which we have a <tt/ThreadId/, with <tt/raiseInThread/:
+
+<tscreen><verb>
+raiseInThread :: ThreadId -> Exception -> IO ()
+</verb></tscreen>
+
+Actually <tt/killThread/ just raises the <tt/ThreadKilled/ exception
+in the target thread, the normal action of which is to just terminate
+the thread.  The target thread will stop whatever it was doing (even
+if it was blocked on an <tt/MVar/ or other computation) and handle the
+exception.
+
+The <tt/ThreadId/ for the current thread can be obtained with
+<tt/myThreadId/:
+
+<tscreen><verb>
+myThreadId :: IO ThreadId
+</verb></tscreen>
+

 NOTE: if you have a @ThreadId@, you essentially have a pointer to the
 thread itself.  This means the thread itself can't be garbage
 collected until you drop the @ThreadId@.  This misfeature will
 NOTE: if you have a @ThreadId@, you essentially have a pointer to the
 thread itself.  This means the thread itself can't be garbage
 collected until you drop the @ThreadId@.  This misfeature will