I looked into this some more, and found some problems:
* On Solaris we also need to define _POSIX_PTHREAD_SEMANTICS to prefer
POSIX to pre-POSIX semantics for a few functions; see
<http://docs.oracle.com/cd/E19683-01/806-6867/compile-fig-5/index.html>.
The extensions module does this, so a simple fix is to depend on the
extensions module. Almost everybody uses extensions anyway so I don't
view this as being a big issue. (Maybe threadlib should also depend on
extensions, instead its calls to AC_USE_SYSTEM_EXTENSIONS and
AC_GNU_SOURCE?)
* The patch uses $host_os so it should AC_REQUIRE([AC_CANONICAL_HOST]).
But why bother? AC_CANONICAL_HOST is expensive and not every project
needs it. Instead, just define the symbols on all platforms; that's
what 'extensions' does.
* This new behavior should be done in gl_EARLY, as _REENTRANT and
_THREAD_SAFE affect the visibility of many other symbols.
So, how about the attached patch instead? (I haven't tested it.)
From 615308a8efa422d3697ff84afb73c6e8f92b738d Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sat, 14 Jun 2014 10:05:34 -0700
Subject: [PATCH] pthread: port to hosts like AIX that need macros like
_THREAD_SAFE
* modules/pthread (Depends-on): Add 'extensions'.
(configure.ac-early): New section.
---
ChangeLog | 6 ++++++
modules/pthread | 5 +++++
2 files changed, 11 insertions(+)
diff --git a/ChangeLog b/ChangeLog
index cd19897..0ae08ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-06-14 Paul Eggert <egg...@cs.ucla.edu>
+
+ pthread: port to hosts like AIX that need macros like _THREAD_SAFE
+ * modules/pthread (Depends-on): Add 'extensions'.
+ (configure.ac-early): New section.
+
2014-06-13 Paul Eggert <egg...@cs.ucla.edu>
regex: don't be multithreaded if USE_UNLOCKED_IO.
diff --git a/modules/pthread b/modules/pthread
index e583929..3fb3920 100644
--- a/modules/pthread
+++ b/modules/pthread
@@ -7,10 +7,15 @@ lib/pthread.in.h
m4/pthread.m4
Depends-on:
+extensions
extern-inline
sched
time
+configure.ac-early:
+AC_DEFINE([_REENTRANT], 1, [For thread-safety on OSF/1, Solaris.])
+AC_DEFINE([_THREAD_SAFE], 1, [For thread-safety on AIX, FreeBSD.])
+
configure.ac:
gl_PTHREAD_CHECK
gl_MODULE_INDICATOR([pthread])
--
1.9.3
