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-rw-r--r--misc/tst-allocate_once.c181
1 files changed, 181 insertions, 0 deletions
diff --git a/misc/tst-allocate_once.c b/misc/tst-allocate_once.c
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+++ b/misc/tst-allocate_once.c
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+/* Test the allocate_once function.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library 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.
+
+   The GNU C Library 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 the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <allocate_once.h>
+#include <mcheck.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+
+/* Allocate a new string.  */
+static void *
+allocate_string (void *closure)
+{
+  return xstrdup (closure);
+}
+
+/* Allocation and deallocation functions which are not expected to be
+   called.  */
+
+static void *
+allocate_not_called (void *closure)
+{
+  FAIL_EXIT1 ("allocation function called unexpectedly (%p)", closure);
+}
+
+static void
+deallocate_not_called (void *closure, void *ptr)
+{
+  FAIL_EXIT1 ("deallocate function called unexpectedly (%p, %p)",
+              closure, ptr);
+}
+
+/* Counter for various function calls.  */
+static int function_called;
+
+/* An allocation function which returns NULL and records that it has
+   been called.  */
+static void *
+allocate_return_null (void *closure)
+{
+  /* The function should only be called once.  */
+  TEST_COMPARE (function_called, 0);
+  ++function_called;
+  return NULL;
+}
+
+
+/* The following is used to check the retry logic, by causing a fake
+   race condition.  */
+static void *fake_race_place;
+static char fake_race_region[3]; /* To obtain unique addresses.  */
+
+static void *
+fake_race_allocate (void *closure)
+{
+  TEST_VERIFY (closure == &fake_race_region[0]);
+  TEST_COMPARE (function_called, 0);
+  ++function_called;
+  /* Fake allocation by another thread.  */
+  fake_race_place = &fake_race_region[1];
+  return &fake_race_region[2];
+}
+
+static void
+fake_race_deallocate (void *closure, void *ptr)
+{
+  /* Check that the pointer returned from fake_race_allocate is
+     deallocated (and not the one stored in fake_race_place).  */
+  TEST_VERIFY (ptr == &fake_race_region[2]);
+
+  TEST_VERIFY (fake_race_place == &fake_race_region[1]);
+  TEST_VERIFY (closure == &fake_race_region[0]);
+  TEST_COMPARE (function_called, 1);
+  ++function_called;
+}
+
+/* Similar to fake_race_allocate, but expects to be paired with free
+   as the deallocation function.  */
+static void *
+fake_race_allocate_for_free (void *closure)
+{
+  TEST_VERIFY (closure == &fake_race_region[0]);
+  TEST_COMPARE (function_called, 0);
+  ++function_called;
+  /* Fake allocation by another thread.  */
+  fake_race_place = &fake_race_region[1];
+  return xstrdup ("to be freed");
+}
+
+static int
+do_test (void)
+{
+  mtrace ();
+
+  /* Simple allocation.  */
+  void *place1 = NULL;
+  char *string1 = allocate_once (&place1, allocate_string,
+                                   deallocate_not_called,
+                                   (char *) "test string 1");
+  TEST_VERIFY_EXIT (string1 != NULL);
+  TEST_VERIFY (strcmp ("test string 1", string1) == 0);
+  /* Second call returns the first pointer, without calling any
+     callbacks.  */
+  TEST_VERIFY (string1
+               == allocate_once (&place1, allocate_not_called,
+                                 deallocate_not_called,
+                                 (char *) "test string 1a"));
+
+  /* Different place should result in another call.  */
+  void *place2 = NULL;
+  char *string2 = allocate_once (&place2, allocate_string,
+                                 deallocate_not_called,
+                                 (char *) "test string 2");
+  TEST_VERIFY_EXIT (string2 != NULL);
+  TEST_VERIFY (strcmp ("test string 2", string2) == 0);
+  TEST_VERIFY (string1 != string2);
+
+  /* Check error reporting (NULL return value from the allocation
+     function).  */
+  void *place3 = NULL;
+  char *string3 = allocate_once (&place3, allocate_return_null,
+                                 deallocate_not_called, NULL);
+  TEST_VERIFY (string3 == NULL);
+  TEST_COMPARE (function_called, 1);
+
+  /* Check that the deallocation function is called if the race is
+     lost.  */
+  function_called = 0;
+  TEST_VERIFY (allocate_once (&fake_race_place,
+                              fake_race_allocate,
+                              fake_race_deallocate,
+                              &fake_race_region[0])
+               == &fake_race_region[1]);
+  TEST_COMPARE (function_called, 2);
+  function_called = 3;
+  TEST_VERIFY (allocate_once (&fake_race_place,
+                              fake_race_allocate,
+                              fake_race_deallocate,
+                              &fake_race_region[0])
+               == &fake_race_region[1]);
+  TEST_COMPARE (function_called, 3);
+
+  /* Similar, but this time rely on that free is called.  */
+  function_called = 0;
+  fake_race_place = NULL;
+  TEST_VERIFY (allocate_once (&fake_race_place,
+                                fake_race_allocate_for_free,
+                                NULL,
+                                &fake_race_region[0])
+               == &fake_race_region[1]);
+  TEST_COMPARE (function_called, 1);
+  function_called = 3;
+  TEST_VERIFY (allocate_once (&fake_race_place,
+                              fake_race_allocate_for_free,
+                              NULL,
+                              &fake_race_region[0])
+               == &fake_race_region[1]);
+  TEST_COMPARE (function_called, 3);
+
+  free (place2);
+  free (place1);
+
+  return 0;
+}
+
+#include <support/test-driver.c>