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, 318 insertions, 0 deletions

diff --git a/tests/t-lock.c b/tests/t-lock.c
new file mode 100644
index 0000000..91923fb
--- /dev/null
+++ b/tests/t-lock.c
@@ -0,0 +1,318 @@
+/* t-lock.c - Check the lock functions
+ * Copyright (C) 2013 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
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#ifdef _WIN32
+# include <windows.h>
+#else
+# include <pthread.h>
+#endif
+
+#define PGM "t-lock"
+
+#include "t-common.h"
+
+#ifdef _WIN32
+# define THREAD_RET_TYPE  DWORD WINAPI
+# define THREAD_RET_VALUE 0
+#else
+# define THREAD_RET_TYPE  void *
+# define THREAD_RET_VALUE NULL
+#endif
+
+
+/* Our tests works by having a a couple of accountant threads which do
+   random transactions between accounts and a revision threads which
+   checks that the balance of all accounts is invariant.  The idea for
+   this check is due to Bruno Haible.  */
+#define N_ACCOUNT 8
+#define ACCOUNT_VALUE 42
+static int account[N_ACCOUNT];
+GPGRT_LOCK_DEFINE (accounts_lock);
+
+/* Number of transactions done by each accountant.  */
+#define N_TRANSACTIONS 1000
+
+/* Number of accountants to run.  */
+#define N_ACCOUNTANTS 5
+
+/* Maximum transaction value.  A quite low value is used so that we
+   would get an integer overflow.  */
+#define MAX_TRANSACTION_VALUE 50
+
+/* Flag to tell the revision thread to finish.  */
+static volatile int stop_revision_thread;
+
+
+/* Initialze all accounts.  */
+static void
+init_accounts (void)
+{
+  int i;
+
+  for (i=0; i < N_ACCOUNT; i++)
+    account[i] = ACCOUNT_VALUE;
+}
+
+
+/* Check that the sum of all accounts matches the intial sum.  */
+static void
+check_accounts (void)
+{
+  int i, sum;
+
+  sum = 0;
+  for (i = 0; i < N_ACCOUNT; i++)
+    sum += account[i];
+  if (sum != N_ACCOUNT * ACCOUNT_VALUE)
+    die ("accounts out of balance");
+}
+
+
+static void
+print_accounts (void)
+{
+  int i;
+
+  for (i=0; i < N_ACCOUNT; i++)
+    printf ("account %d: %6d\n", i, account[i]);
+}
+
+
+/* Get a a random integer value in the range 0 to HIGH.  */
+static unsigned int
+get_rand (int high)
+{
+  return (unsigned int)(1+(int)((double)(high+1)*rand ()/(RAND_MAX+1.0))) - 1;
+}
+
+
+/* Pick a random account.  Note that this fucntion is not
+   thread-safe. */
+static int
+pick_account (void)
+{
+  return get_rand (N_ACCOUNT - 1);
+}
+
+
+/* Pick a random value for a transaction.  This is not thread-safe.  */
+static int
+pick_value (void)
+{
+  return get_rand (MAX_TRANSACTION_VALUE);
+}
+
+
+/* This is the revision department.  */
+static THREAD_RET_TYPE
+revision_thread (void *arg)
+{
+  gpg_err_code_t rc;
+  int i;
+
+  (void)arg;
+
+  while (!stop_revision_thread)
+    {
+      rc = gpgrt_lock_lock (&accounts_lock);
+      if (rc)
+        fail ("gpgrt_lock_lock failed at %d: %s", __LINE__, gpg_strerror (rc));
+
+      check_accounts ();
+      rc = gpgrt_lock_unlock (&accounts_lock);
+      if (rc)
+        fail ("gpgrt_lock_unlock failed at %d: %s", __LINE__,gpg_strerror (rc));
+      if (!(++i%7))
+        gpgrt_yield ();
+    }
+  return THREAD_RET_VALUE;
+}
+
+
+/* This is one of our accountants.  */
+static THREAD_RET_TYPE
+accountant_thread (void *arg)
+{
+  gpg_err_code_t rc;
+  int i;
+  int acc1, acc2;
+  int value;
+
+  (void)arg;
+
+  for (i = 0; i < N_TRANSACTIONS; i++)
+    {
+      rc = gpgrt_lock_lock (&accounts_lock);
+      if (rc)
+        fail ("gpgrt_lock_lock failed at %d: %s", __LINE__, gpg_strerror (rc));
+
+      acc1 = pick_account ();
+      acc2 = pick_account ();
+      value = pick_value ();
+      account[acc1] += value;
+      account[acc2] -= value;
+
+      rc = gpgrt_lock_unlock (&accounts_lock);
+      if (rc)
+        fail ("gpgrt_lock_unlock failed at %d: %s", __LINE__,gpg_strerror (rc));
+      if (i && !(i%8))
+        gpgrt_yield ();
+    }
+  return THREAD_RET_VALUE;
+}
+
+
+static void
+run_test (void)
+{
+#ifdef _WIN32
+  HANDLE rthread;
+  HANDLE athreads[N_ACCOUNTANTS];
+  int i;
+  int rc;
+
+  stop_revision_thread = 0;
+  rthread = CreateThread (NULL, 0, revision_thread, NULL, 0, NULL);
+  if (!rthread)
+    die ("error creating revision thread: rc=%d", (int)GetLastError ());
+
+  for (i=0; i < N_ACCOUNTANTS; i++)
+    {
+      athreads[i] = CreateThread (NULL, 0, accountant_thread, NULL, 0, NULL);
+      if (!athreads[i])
+        die ("error creating accountant thread %d: rc=%d",
+             i, (int)GetLastError ());
+    }
+
+  for (i=0; i < N_ACCOUNTANTS; i++)
+    {
+      rc = WaitForSingleObject (athreads[i], INFINITE);
+      if (rc == WAIT_OBJECT_0)
+        show ("accountant thread %d has terminated", i);
+      else
+        fail ("waiting for accountant thread %d failed: %d",
+              i, (int)GetLastError ());
+      CloseHandle (athreads[i]);
+    }
+  stop_revision_thread = 1;
+
+  rc = WaitForSingleObject (rthread, INFINITE);
+  if (rc == WAIT_OBJECT_0)
+    show ("revision thread has terminated");
+  else
+    fail ("waiting for revision thread failed: %d", (int)GetLastError ());
+  CloseHandle (rthread);
+
+#else /*!_WIN32*/
+  pthread_t rthread;
+  pthread_t athreads[N_ACCOUNTANTS];
+  int i;
+
+  stop_revision_thread = 0;
+  pthread_create (&rthread, NULL, revision_thread, NULL);
+
+  for (i=0; i < N_ACCOUNTANTS; i++)
+    pthread_create (&athreads[i], NULL, accountant_thread, NULL);
+
+  for (i=0; i < N_ACCOUNTANTS; i++)
+    {
+      pthread_join (athreads[i], NULL);
+      show ("accountant thread %d has terminated", i);
+    }
+
+  stop_revision_thread = 1;
+  pthread_join (rthread, NULL);
+  show ("revision thread has terminated");
+
+#endif /*!_WIN32*/
+
+  gpgrt_lock_destroy (&accounts_lock);
+}
+
+
+int
+main (int argc, char **argv)
+{
+  int last_argc = -1;
+  int rc;
+
+  if (argc)
+    {
+      argc--; argv++;
+    }
+  while (argc && last_argc != argc )
+    {
+      last_argc = argc;
+      if (!strcmp (*argv, "--help"))
+        {
+          puts (
+"usage: ./t-lock [options]\n"
+"\n"
+"Options:\n"
+"  --verbose      Show what is going on\n"
+"  --debug        Flyswatter\n"
+);
+          exit (0);
+        }
+      if (!strcmp (*argv, "--verbose"))
+        {
+          verbose = 1;
+          argc--; argv++;
+        }
+      else if (!strcmp (*argv, "--debug"))
+        {
+          verbose = debug = 1;
+          argc--; argv++;
+        }
+    }
+
+  srand (time(NULL)*getpid());
+
+  if (!gpg_error_check_version (GPG_ERROR_VERSION))
+    {
+      die ("gpg_error_check_version returned an error");
+      errorcount++;
+    }
+
+  init_accounts ();
+  check_accounts ();
+  run_test ();
+  check_accounts ();
+  /* Run a second time to check deinit code.  */
+  run_test ();
+  check_accounts ();
+  /* And a third time to test an explicit init.  */
+  rc = gpgrt_lock_init (&accounts_lock);
+  if (rc)
+    fail ("gpgrt_lock_init failed at %d: %s", __LINE__, gpg_strerror (rc));
+  run_test ();
+  check_accounts ();
+  if (verbose)
+    print_accounts ();
+
+  return errorcount ? 1 : 0;
+}