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-rw-r--r--lib/libthr/libthr.342
1 files changed, 11 insertions, 31 deletions
diff --git a/lib/libthr/libthr.3 b/lib/libthr/libthr.3
index 4b636ce3fb6c..8108e2f6d66d 100644
--- a/lib/libthr/libthr.3
+++ b/lib/libthr/libthr.3
@@ -1,5 +1,5 @@
.\" Copyright (c) 2005 Robert N. M. Watson
-.\" Copyright (c) 2014 The FreeBSD Foundation, Inc.
+.\" Copyright (c) 2014,2015 The FreeBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" Part of this documentation was written by
@@ -29,7 +29,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd September 26, 2014
+.Dd February 12, 2015
.Dt LIBTHR 3
.Os
.Sh NAME
@@ -200,45 +200,25 @@ Bigger values reduce the frequency of the FIFO discipline.
The value must be between 0 and 255.
.El
.Sh INTERACTION WITH RUN-TIME LINKER
-The
+On load,
.Nm
-library must appear before
-.Li libc
-in the global order of depended objects.
-.Pp
-Loading
-.Nm
-with the
-.Xr dlopen 3
-call in the process after the program binary is activated
-is not supported, and causes miscellaneous and hard-to-diagnose misbehaviour.
-This is due to
-.Nm
-interposing several important
-.Li libc
-symbols to provide thread-safe services.
-In particular,
-.Dv errno
-and the locking stubs from
-.Li libc
-are affected.
-This requirement is currently not enforced.
-.Pp
-If the program loads any modules at run-time, and those modules may require
-threading services, the main program binary must be linked with
-.Li libpthread ,
-even if it does not require any services from the library.
+installs interposing handlers into the hooks exported by
+.Li libc .
+The interposers provide real locking implementation instead of the
+stubs for single-threaded processes in
+.Li ,
+cancellation support and some modifications to the signal operations.
.Pp
.Nm
cannot be unloaded; the
.Xr dlclose 3
function does not perform any action when called with a handle for
.Nm .
-One of the reasons is that the interposing of
+One of the reasons is that the internal interposing of
.Li libc
functions cannot be undone.
.Sh SIGNALS
-The implementation also interposes the user-installed
+The implementation interposes the user-installed
.Xr signal 3
handlers.
This interposing is done to postpone signal delivery to threads which