Rearrange and fixup abstraction layer

- Replace os_result by dds_retcode_t and move DDS return code defines down.
  Eliminates the need to convert between different return code types.

- Move dds_time_t down and remove os_time.
  Eliminates the need to convert between different time representations and
  reduces code duplication.

- Remove use of Microsoft source-code annotation language (SAL).
  SAL annotations are Microsoft specific and not very well documented. This
  makes it very difficult for contributers to write.

- Rearrange the abstraction layer to be feature-based. The previous layout
  falsely assumed that the operating system dictates which implementation is
  best suited. For general purpose operating systems this is mostly true, but
  embedded targets require a slightly different approach and may not even offer
  all features. The new layout makes it possible to mix-and-match feature
  implementations and allows for features to not be implemented at all.

- Replace the os prefix by ddsrt to avoid name collisions.

- Remove various portions of unused and unwanted code.

- Export thread names on all supported platforms.

- Return native thread identifier on POSIX compatible platforms.

- Add timed wait for condition variables that takes an absolute time.

- Remove system abstraction for errno. The os_getErrno and os_setErrno were
  incorrect. Functions that might fail now simply return a DDS return code
  instead.

- Remove thread-specific memory abstraction. os_threadMemGet and accompanying
  functions were a mess and their use has been eliminated by other changes in
  this commit.

- Replace attribute (re)defines by ddsrt_ prefixed equivalents to avoid name
  collisions and problems with faulty __nonnull__ attributes.

Signed-off-by: Jeroen Koekkoek <jeroen@koekkoek.nl>

src/ddsrt/tests/strlcpy.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright(c) 2006 to 2018 ADLINK Technology Limited and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Eclipse Distribution License
+ * v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+#include <stdio.h>
+#include <string.h>
+
+#include "CUnit/Theory.h"
+#include "dds/ddsrt/string.h"
+
+CU_TheoryDataPoints(ddsrt_strlcpy, dest_size) = {
+  CU_DataPoints(char *, "foo", "foo", "foo", "foo", "foo", "", "", ""),
+  CU_DataPoints(size_t, 0,     1,     3,     4,     5,     0,  1,  2)
+};
+
+CU_Theory((char *src, size_t size), ddsrt_strlcpy, dest_size)
+{
+  char dest[] = "................";
+  size_t len, srclen;
+
+  srclen = strlen(src);
+  len = ddsrt_strlcpy(dest, src, size);
+  CU_ASSERT_EQUAL(len, srclen);
+  if (size > 0) {
+    if ((size - 1) < len) {
+      len = size - 1;
+    }
+    CU_ASSERT_EQUAL(dest[len], '\0');
+    CU_ASSERT_EQUAL(dest[len+1], '.');
+    CU_ASSERT((strncmp(dest, src, len) == 0));
+  } else {
+    CU_ASSERT_EQUAL(dest[0], '.');
+  }
+}
+
+CU_TheoryDataPoints(ddsrt_strlcat, dest_size) = {
+  CU_DataPoints(char *, "",    "",    "",    "",    "foo", "foo", "foo", "foo", "foo", "foo", "foo", "", "", "foo", "foo", "foo"),
+  CU_DataPoints(char *, "bar", "bar", "bar", "bar", "bar", "bar", "bar", "bar", "bar", "bar", "bar", "", "", "",    "",    ""),
+  CU_DataPoints(size_t, 0,     1,     3,     4,     0,     1,     3,     4,     5,     6,     7,     0,  1,  3,     4,     5)
+};
+
+CU_Theory((char *seed, char *src, size_t size), ddsrt_strlcat, dest_size)
+{
+  char dest[] = "................";
+  size_t len, seedlen, srclen;
+  seedlen = strlen(seed);
+  srclen = strlen(src);
+  memcpy(dest, seed, seedlen);
+  dest[seedlen] = '\0';
+
+  len = ddsrt_strlcat(dest, src, size);
+  CU_ASSERT_EQUAL(len, (seedlen + srclen));
+  if (size > 0) {
+    char foobar[sizeof(dest)];
+
+    if ((size - 1) <= seedlen) {
+      len = seedlen;
+    } else if ((size - 1) <= len) {
+      len = size - 1;
+    }
+
+    CU_ASSERT_EQUAL(dest[len], '\0');
+
+    if (seedlen < (size - 1)) {
+      CU_ASSERT_EQUAL(dest[len+1], '.');
+    }
+
+    (void)snprintf(foobar, len+1, "%s%s", seed, src);
+    CU_ASSERT((strncmp(dest, foobar, len) == 0));
+  } else {
+    CU_ASSERT((strcmp(dest, seed) == 0));
+  }
+}