summaryrefslogtreecommitdiff
path: root/lib/glthread/lock.h
diff options
context:
space:
mode:
Diffstat (limited to 'lib/glthread/lock.h')
-rw-r--r--lib/glthread/lock.h66
1 files changed, 59 insertions, 7 deletions
diff --git a/lib/glthread/lock.h b/lib/glthread/lock.h
index 2e00168..0628555 100644
--- a/lib/glthread/lock.h
+++ b/lib/glthread/lock.h
@@ -1,5 +1,5 @@
/* Locking in multithreaded situations.
- Copyright (C) 2005-2016 Free Software Foundation, Inc.
+ Copyright (C) 2005-2017 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or
modify it under the terms of either:
@@ -21,7 +21,7 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, see <http://www.gnu.org/licenses/>. */
+ along with this program; if not, see <https://www.gnu.org/licenses/>. */
/* Written by Bruno Haible <bruno@clisp.org>, 2005.
Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-solaris.h,
@@ -148,6 +148,11 @@ extern int glthread_in_use (void);
# pragma weak pthread_mutexattr_init
# pragma weak pthread_mutexattr_settype
# pragma weak pthread_mutexattr_destroy
+# pragma weak pthread_rwlockattr_init
+# if __GNU_LIBRARY__ > 1
+# pragma weak pthread_rwlockattr_setkind_np
+# endif
+# pragma weak pthread_rwlockattr_destroy
# ifndef pthread_self
# pragma weak pthread_self
# endif
@@ -185,7 +190,7 @@ typedef pthread_mutex_t gl_lock_t;
/* ------------------------- gl_rwlock_t datatype ------------------------- */
-# if HAVE_PTHREAD_RWLOCK
+# if HAVE_PTHREAD_RWLOCK && (HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER || (defined PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP && (__GNU_LIBRARY__ > 1)))
# ifdef PTHREAD_RWLOCK_INITIALIZER
@@ -194,10 +199,18 @@ typedef pthread_rwlock_t gl_rwlock_t;
STORAGECLASS pthread_rwlock_t NAME;
# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
STORAGECLASS pthread_rwlock_t NAME = gl_rwlock_initializer;
-# define gl_rwlock_initializer \
- PTHREAD_RWLOCK_INITIALIZER
-# define glthread_rwlock_init(LOCK) \
- (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
+# if HAVE_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER
+# define gl_rwlock_initializer \
+ PTHREAD_RWLOCK_INITIALIZER
+# define glthread_rwlock_init(LOCK) \
+ (pthread_in_use () ? pthread_rwlock_init (LOCK, NULL) : 0)
+# else /* glibc with bug https://sourceware.org/bugzilla/show_bug.cgi?id=13701 */
+# define gl_rwlock_initializer \
+ PTHREAD_RWLOCK_WRITER_NONRECURSIVE_INITIALIZER_NP
+# define glthread_rwlock_init(LOCK) \
+ (pthread_in_use () ? glthread_rwlock_init_for_glibc (LOCK) : 0)
+extern int glthread_rwlock_init_for_glibc (pthread_rwlock_t *lock);
+# endif
# define glthread_rwlock_rdlock(LOCK) \
(pthread_in_use () ? pthread_rwlock_rdlock (LOCK) : 0)
# define glthread_rwlock_wrlock(LOCK) \
@@ -436,6 +449,9 @@ typedef pth_mutex_t gl_lock_t;
/* ------------------------- gl_rwlock_t datatype ------------------------- */
+/* Pth pth_rwlock_acquire always prefers readers. No autoconf test so far. */
+# if HAVE_PTH_RWLOCK_ACQUIRE_PREFER_WRITER
+
typedef pth_rwlock_t gl_rwlock_t;
# define gl_rwlock_define(STORAGECLASS, NAME) \
STORAGECLASS pth_rwlock_t NAME;
@@ -454,6 +470,42 @@ typedef pth_rwlock_t gl_rwlock_t;
# define glthread_rwlock_destroy(LOCK) \
((void)(LOCK), 0)
+# else
+
+typedef struct
+ {
+ int initialized;
+ pth_mutex_t lock; /* protects the remaining fields */
+ pth_cond_t waiting_readers; /* waiting readers */
+ pth_cond_t waiting_writers; /* waiting writers */
+ unsigned int waiting_writers_count; /* number of waiting writers */
+ int runcount; /* number of readers running, or -1 when a writer runs */
+ }
+ gl_rwlock_t;
+# define gl_rwlock_define(STORAGECLASS, NAME) \
+ STORAGECLASS gl_rwlock_t NAME;
+# define gl_rwlock_define_initialized(STORAGECLASS, NAME) \
+ STORAGECLASS gl_rwlock_t NAME = gl_rwlock_initializer;
+# define gl_rwlock_initializer \
+ { 0 }
+# define glthread_rwlock_init(LOCK) \
+ (pth_in_use () ? glthread_rwlock_init_multithreaded (LOCK) : 0)
+# define glthread_rwlock_rdlock(LOCK) \
+ (pth_in_use () ? glthread_rwlock_rdlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_wrlock(LOCK) \
+ (pth_in_use () ? glthread_rwlock_wrlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_unlock(LOCK) \
+ (pth_in_use () ? glthread_rwlock_unlock_multithreaded (LOCK) : 0)
+# define glthread_rwlock_destroy(LOCK) \
+ (pth_in_use () ? glthread_rwlock_destroy_multithreaded (LOCK) : 0)
+extern int glthread_rwlock_init_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_rdlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_wrlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_unlock_multithreaded (gl_rwlock_t *lock);
+extern int glthread_rwlock_destroy_multithreaded (gl_rwlock_t *lock);
+
+# endif
+
/* --------------------- gl_recursive_lock_t datatype --------------------- */
/* In Pth, mutexes are recursive by default. */