]> Savannah Git Hosting - gnulib.git/commitdiff
windows-spin: New module.
authorBruno Haible <bruno@clisp.org>
Mon, 15 Jul 2019 00:36:08 +0000 (02:36 +0200)
committerBruno Haible <bruno@clisp.org>
Mon, 15 Jul 2019 00:36:08 +0000 (02:36 +0200)
* lib/windows-spin.h: New file.
* lib/windows-spin.c: New file.
* modules/windows-spin: New file.

ChangeLog
lib/windows-spin.c [new file with mode: 0644]
lib/windows-spin.h [new file with mode: 0644]
modules/windows-spin [new file with mode: 0644]

index 1d9caebac8ef9cd128f8c1f73ed81bc9a371b6f3..6616163abb7bbb675a40ecb72f3343c33d76a47f 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2019-07-14  Bruno Haible  <bruno@clisp.org>
+
+       windows-spin: New module.
+       * lib/windows-spin.h: New file.
+       * lib/windows-spin.c: New file.
+       * modules/windows-spin: New file.
+
 2019-07-14  Bruno Haible  <bruno@clisp.org>
 
        windows-timedrwlock: New module.
diff --git a/lib/windows-spin.c b/lib/windows-spin.c
new file mode 100644 (file)
index 0000000..bccef07
--- /dev/null
@@ -0,0 +1,69 @@
+/* Spin locks (native Windows implementation).
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2019.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "windows-spin.h"
+
+#include <errno.h>
+
+void
+glwthread_spin_init (glwthread_spinlock_t *lock)
+{
+  lock->word = 0;
+}
+
+int
+glwthread_spin_lock (glwthread_spinlock_t *lock)
+{
+  /* Wait until lock->word becomes 0, then replace it with 1.  */
+  /* InterlockedCompareExchange
+     <https://docs.microsoft.com/en-us/windows/win32/api/winnt/nf-winnt-interlockedcompareexchange> */
+  while (InterlockedCompareExchange (&lock->word, 1, 0))
+    ;
+  return 0;
+}
+
+int
+glwthread_spinlock_trylock (glwthread_spinlock_t *lock)
+{
+  /* If lock->word is 0, then replace it with 1.  */
+  /* InterlockedCompareExchange
+     <https://docs.microsoft.com/en-us/windows/win32/api/winnt/nf-winnt-interlockedcompareexchange> */
+  if (InterlockedCompareExchange (&lock->word, 1, 0))
+    return EBUSY;
+  return 0;
+}
+
+int
+glwthread_spin_unlock (glwthread_spinlock_t *lock)
+{
+  /* If lock->word is 1, then replace it with 0.  */
+  /* InterlockedCompareExchange
+     <https://docs.microsoft.com/en-us/windows/win32/api/winnt/nf-winnt-interlockedcompareexchange> */
+  if (!InterlockedCompareExchange (&lock->word, 0, 1))
+    return EINVAL;
+  return 0;
+}
+
+int
+glwthread_spin_destroy (glwthread_spinlock_t *lock)
+{
+  return 0;
+}
diff --git a/lib/windows-spin.h b/lib/windows-spin.h
new file mode 100644 (file)
index 0000000..47690f9
--- /dev/null
@@ -0,0 +1,47 @@
+/* Spin locks (native Windows implementation).
+   Copyright (C) 2019 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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 <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2019.  */
+
+#ifndef _WINDOWS_SPIN_H
+#define _WINDOWS_SPIN_H
+
+#define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#include <windows.h>
+
+typedef struct
+        {
+          LONG volatile word;
+        }
+        glwthread_spinlock_t;
+
+#define GLWTHREAD_SPIN_INIT { 0 }
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern void glwthread_spin_init (glwthread_spinlock_t *lock);
+extern int glwthread_spin_lock (glwthread_spinlock_t *lock);
+extern int glwthread_spin_trylock (glwthread_spinlock_t *lock);
+extern int glwthread_spin_unlock (glwthread_spinlock_t *lock);
+extern int glwthread_spin_destroy (glwthread_spinlock_t *lock);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _WINDOWS_SPIN_H */
diff --git a/modules/windows-spin b/modules/windows-spin
new file mode 100644 (file)
index 0000000..687385a
--- /dev/null
@@ -0,0 +1,27 @@
+Description:
+Spin locks (native Windows implementation).
+
+Files:
+lib/windows-spin.h
+lib/windows-spin.c
+
+Depends-on:
+
+configure.ac:
+AC_REQUIRE([AC_CANONICAL_HOST])
+case "$host_os" in
+  mingw*)
+    AC_LIBOBJ([windows-spin])
+    ;;
+esac
+
+Makefile.am:
+
+Include:
+"windows-spin.h"
+
+License:
+LGPLv2+
+
+Maintainer:
+all