Add gpgrt_lock_ functions.

* src/gpg-error.h.in (GPGRT_LOCK_DEFINE): New.
(gpgrt_lock_init): New.
(gpgrt_lock_lock): New.
(gpgrt_lock_unlock): New.
(gpgrt_lock_destroy): New.
(gpgrt_yield): New.
* src/gpg-error.def.in: Add new functions.
* m4/lock.m4, m4/threadlib.m4: New. Taken from current gnulib.
* configure.ac: Call gl_LOCK.  Check size of pthread_mutex_t. Add
LIBTHREAD to GPG_ERROR_CONFIG_LIBS.
* src/err-codes.h.in (GPG_ERR_INV_LOCK_OBJ): New.
* src/gen-posix-lock-obj.c: New.
* src/gen-w32-lock-obj.c: New.
* src/lock.h, src/thread.h: New.
* src/posix-lock-obj.h, src/w32-lock-obj.h: New.
* src/posix-lock.c, src/w32-lock.c: New.
* src/posix-thread.c, src/w32-thread.c:
* src/w32-lock-obj-pub.in: New.
* src/mkheader.c (include_file): Support build time include files.
(write_special): Add keyword "include:lock-obj".
* src/Makefile.am:
(posix-lock-obj-pub.in): New rule.
(noinst_PROGRAMS): Add gen-*-lock-obj helpers.

* tests/t-common.h: New.
* tests/t-lock.c: New.
* tests/Makefile.am (t_lock_LDADD): Add new test.

--

This patch introduces the gpgrt_ functions which will be extended over
time to provide a library of commonly used code in GnuPG and
Libgcrypt.  Having them in a library named libgpg-error is a misnomer
but this way we can achieve a smooth upgrade path.

In contrasts to other GnuPG libraries, the gpgrt_ functions return a
simple gpg_err_code_t and not gpg_error_t.  The rationale for this is
that a source of error identifier does not make sense here; it is
better to use the source of error identifier of the caller.  This can
easily be achieved in a component by wrapping these function in a
gpg_error macro/inline.

There is no cross-compiling support for Posix platforms; the
gen-posix-lock-obj tool must be run on the target system.

Note that the gen-w32-lock-obj tool is not needed at build time but
was used to figure out ABI definitions for Windows.

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 119 insertions, 0 deletions

diff --git a/src/w32-lock.c b/src/w32-lock.c
new file mode 100644
index 0000000..0ad9409
--- /dev/null
+++ b/src/w32-lock.c
@@ -0,0 +1,119 @@
+/* w32-lock.c - GPGRT lock functions for Windows
+   Copyright (C) 2014 g10 Code GmbH
+
+   This file is part of libgpg-error.
+
+   libgpg-error is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License
+   as published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   libgpg-error 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifndef HAVE_W32_SYSTEM
+# error This module may only be build for Windows.
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <gpg-error.h>
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#include "lock.h"
+#include "w32-lock-obj.h"
+
+
+static _gpgrt_lock_t *
+get_lock_object (gpgrt_lock_t *lockhd)
+{
+  _gpgrt_lock_t *lock = (_gpgrt_lock_t*)lockhd;
+
+  if (lock->vers != LOCK_ABI_VERSION)
+    abort ();
+
+  return lock;
+}
+
+
+gpg_err_code_t
+gpgrt_lock_init (gpgrt_lock_t *lockhd)
+{
+  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+
+  if (sizeof (gpgrt_lock_t) < sizeof (_gpgrt_lock_t))
+    abort ();
+  InitializeCriticalSection (&lock->csec);
+  lock->initdone = 1;
+}
+
+
+gpg_err_code_t
+gpgrt_lock_lock (gpgrt_lock_t *lockhd)
+{
+  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+
+  if (!lock->initdone)
+    {
+      if (!InterlockedIncrement (&lock->started))
+        {
+          /* The new value of started is 0.  Because the initial value
+             if the variable was -1 we known that this thread is the
+             first who needs this lock.  Thus we initialize now.  All
+             other threads won't get 0 back from InterlockedIncrement
+             and thus fall into the wait loop below.  We ignore that
+             STARTED may in theory overflow if this thread starves for
+             too long.  */
+          gpgrt_lock_init (lockhd);
+        }
+      else
+        {
+          while (!lock->initdone)
+            Sleep (0);
+        }
+    }
+
+  EnterCriticalSection (&lock->csec);
+  return 0;
+}
+
+
+gpg_err_code_t
+gpgrt_lock_unlock (gpgrt_lock_t *lockhd)
+{
+  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+
+  if (!lock->initdone)
+    return GPG_ERR_INV_LOCK_OBJ;
+  LeaveCriticalSection (&lock->csec);
+  return 0;
+}
+
+
+/* Note: Use this function only if no other thread holds or waits for
+   this lock.  */
+gpg_err_code_t
+gpgrt_lock_destroy (gpgrt_lock_t *lockhd)
+{
+  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+
+  if (!lock->initdone)
+    return GPG_ERR_INV_LOCK_OBJ;
+  DeleteCriticalSection (&lock->csec);
+  lock->initdone = 0;
+  lock->started = -1;
+  return 0;
+}