CDRIVER-5702 deprecate bson-cmp.h and bson-atomic.h (#1762)

* copy `bson-cmp.h` to internal `common-cmp-private.h`
* copy `bson-atomic.(h|c)` to internal `common-atomic-private.(h|c)`

---------

Co-authored-by: Ezra Chung <[email protected]>

Author: kevinAlbs

NEWS

@@ -1,10 +1,6 @@
 libmongoc 1.29.0 (unreleased)
 =============================
 
-Deprecated:
-
-  * Compiling with `BSON_MEMCHECK` defined is deprecated.
-  * `bson_string_t` and associated functions.
 
 Platform Support:
 

src/common/bson-dsl.h

@@ -14,6 +14,7 @@
  */
 
 #include "bson/bson.h"
+#include <common-cmp-private.h>
 
 enum {
    /// Toggle this value to enable/disable debug output for all bsonDSL
@@ -118,7 +119,7 @@ BSON_IF_GNU_LIKE (_Pragma ("GCC diagnostic ignored \"-Wshadow\""))
    _bsonDSL_begin ("\"%s\" => [%s]", String, _bsonDSL_strElide (30, Element)); \
    const char *_bbString = (String);                                           \
    const uint64_t length = (Len);                                              \
-   if (bson_in_range_unsigned (int, length)) {                                 \
+   if (mcommon_in_range_unsigned (int, length)) {                              \
       _bbCtx.key = _bbString;                                                  \
       _bbCtx.key_len = (int) length;                                           \
       _bsonValueOperation (Element);                                           \

src/common/common-atomic-private.h

@@ -0,0 +1,251 @@
+/*
+ * Copyright 2009-present MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include <common-atomic-private.h>
+
+#ifdef BSON_OS_UNIX
+/* For sched_yield() */
+#include <sched.h>
+#endif
+
+void
+mcommon_thrd_yield (void)
+{
+   BSON_IF_WINDOWS (SwitchToThread ();)
+   BSON_IF_POSIX (sched_yield ();)
+}
+
+/**
+ * Some platforms do not support compiler intrinsics for atomic operations.
+ * We emulate that here using a spin lock and regular arithmetic operations
+ */
+static int8_t gEmulAtomicLock = 0;
+
+static void
+_lock_emul_atomic (void)
+{
+   int i;
+   if (mcommon_atomic_int8_compare_exchange_weak (&gEmulAtomicLock, 0, 1, mcommon_memory_order_acquire) == 0) {
+      /* Successfully took the spinlock */
+      return;
+   }
+   /* Failed. Try taking ten more times, then begin sleeping. */
+   for (i = 0; i < 10; ++i) {
+      if (mcommon_atomic_int8_compare_exchange_weak (&gEmulAtomicLock, 0, 1, mcommon_memory_order_acquire) == 0) {
+         /* Succeeded in taking the lock */
+         return;
+      }
+   }
+   /* Still don't have the lock. Spin and yield */
+   while (mcommon_atomic_int8_compare_exchange_weak (&gEmulAtomicLock, 0, 1, mcommon_memory_order_acquire) != 0) {
+      mcommon_thrd_yield ();
+   }
+}
+
+static void
+_unlock_emul_atomic (void)
+{
+   int64_t rv = mcommon_atomic_int8_exchange (&gEmulAtomicLock, 0, mcommon_memory_order_release);
+   BSON_ASSERT (rv == 1 && "Released atomic lock while not holding it");
+}
+
+int64_t
+_mcommon_emul_atomic_int64_fetch_add (volatile int64_t *p, int64_t n, enum mcommon_memory_order _unused)
+{
+   int64_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p += n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int64_t
+_mcommon_emul_atomic_int64_exchange (volatile int64_t *p, int64_t n, enum mcommon_memory_order _unused)
+{
+   int64_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p = n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int64_t
+_mcommon_emul_atomic_int64_compare_exchange_strong (volatile int64_t *p,
+                                                    int64_t expect_value,
+                                                    int64_t new_value,
+                                                    enum mcommon_memory_order _unused)
+{
+   int64_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   if (ret == expect_value) {
+      *p = new_value;
+   }
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int64_t
+_mcommon_emul_atomic_int64_compare_exchange_weak (volatile int64_t *p,
+                                                  int64_t expect_value,
+                                                  int64_t new_value,
+                                                  enum mcommon_memory_order order)
+{
+   /* We're emulating. We can't do a weak version. */
+   return _mcommon_emul_atomic_int64_compare_exchange_strong (p, expect_value, new_value, order);
+}
+
+
+int32_t
+_mcommon_emul_atomic_int32_fetch_add (volatile int32_t *p, int32_t n, enum mcommon_memory_order _unused)
+{
+   int32_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p += n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int32_t
+_mcommon_emul_atomic_int32_exchange (volatile int32_t *p, int32_t n, enum mcommon_memory_order _unused)
+{
+   int32_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p = n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int32_t
+_mcommon_emul_atomic_int32_compare_exchange_strong (volatile int32_t *p,
+                                                    int32_t expect_value,
+                                                    int32_t new_value,
+                                                    enum mcommon_memory_order _unused)
+{
+   int32_t ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   if (ret == expect_value) {
+      *p = new_value;
+   }
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int32_t
+_mcommon_emul_atomic_int32_compare_exchange_weak (volatile int32_t *p,
+                                                  int32_t expect_value,
+                                                  int32_t new_value,
+                                                  enum mcommon_memory_order order)
+{
+   /* We're emulating. We can't do a weak version. */
+   return _mcommon_emul_atomic_int32_compare_exchange_strong (p, expect_value, new_value, order);
+}
+
+
+int
+_mcommon_emul_atomic_int_fetch_add (volatile int *p, int n, enum mcommon_memory_order _unused)
+{
+   int ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p += n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int
+_mcommon_emul_atomic_int_exchange (volatile int *p, int n, enum mcommon_memory_order _unused)
+{
+   int ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p = n;
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int
+_mcommon_emul_atomic_int_compare_exchange_strong (volatile int *p,
+                                                  int expect_value,
+                                                  int new_value,
+                                                  enum mcommon_memory_order _unused)
+{
+   int ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   if (ret == expect_value) {
+      *p = new_value;
+   }
+   _unlock_emul_atomic ();
+   return ret;
+}
+
+int
+_mcommon_emul_atomic_int_compare_exchange_weak (volatile int *p,
+                                                int expect_value,
+                                                int new_value,
+                                                enum mcommon_memory_order order)
+{
+   /* We're emulating. We can't do a weak version. */
+   return _mcommon_emul_atomic_int_compare_exchange_strong (p, expect_value, new_value, order);
+}
+
+void *
+_mcommon_emul_atomic_ptr_exchange (void *volatile *p, void *n, enum mcommon_memory_order _unused)
+{
+   void *ret;
+
+   BSON_UNUSED (_unused);
+
+   _lock_emul_atomic ();
+   ret = *p;
+   *p = n;
+   _unlock_emul_atomic ();
+   return ret;
+}