fix memtrace bug

source/memtrace.c

@@ -438,11 +438,18 @@ static void s_trace_mem_release(struct aws_allocator *allocator, void *ptr) {
 static void *s_trace_mem_realloc(struct aws_allocator *allocator, void *old_ptr, size_t old_size, size_t new_size) {
     struct alloc_tracer *tracer = allocator->impl;
     void *new_ptr = old_ptr;
-    if (aws_mem_realloc(tracer->traced_allocator, &new_ptr, old_size, new_size)) {
-        return NULL;
-    }
 
+    /*
+    * Careful with the ordering of state clean up here.
+    * Tracer keeps a hash table (alloc ptr as key) of meta info about each allocation.
+    * To avoid race conditions during realloc state update needs to be done in
+    * following order to avoid race conditions:
+    * - remove meta info (other threads cant reuse that key, cause ptr is still valid )
+    * - realloc (cant fail, ptr might remain the same)
+    * - add meta info for reallocated mem
+    */
     s_alloc_tracer_untrack(tracer, old_ptr);
+    aws_mem_realloc(tracer->traced_allocator, &new_ptr, old_size, new_size);
     s_alloc_tracer_track(tracer, new_ptr, new_size);
 
     return new_ptr;

tests/CMakeLists.txt

@@ -317,6 +317,8 @@ add_test_case(sba_threaded_allocs_and_frees)
 add_test_case(sba_threaded_reallocs)
 add_test_case(sba_churn)
 add_test_case(sba_metrics)
+add_test_case(default_threaded_reallocs)
+add_test_case(default_threaded_allocs_and_frees)
 
 add_test_case(test_memtrace_none)
 add_test_case(test_memtrace_count)

tests/alloc_test.c

@@ -126,39 +126,39 @@ static int s_sba_random_reallocs(struct aws_allocator *allocator, void *ctx) {
 }
 AWS_TEST_CASE(sba_random_reallocs, s_sba_random_reallocs)
 
-struct sba_thread_test_data {
-    struct aws_allocator *sba;
+struct allocator_thread_test_data {
+    struct aws_allocator *test_allocator;
     uint32_t thread_idx;
 };
 
-static void s_sba_threaded_alloc_worker(void *user_data) {
-    struct aws_allocator *sba = ((struct sba_thread_test_data *)user_data)->sba;
+static void s_threaded_alloc_worker(void *user_data) {
+    struct aws_allocator *test_allocator = ((struct allocator_thread_test_data *)user_data)->test_allocator;
 
     void *allocs[NUM_TEST_ALLOCS];
     for (size_t count = 0; count < NUM_TEST_ALLOCS / NUM_TEST_THREADS; ++count) {
         size_t size = aws_max_size(rand() % 512, 1);
-        void *alloc = aws_mem_acquire(sba, size);
+        void *alloc = aws_mem_acquire(test_allocator, size);
         AWS_FATAL_ASSERT(alloc);
         allocs[count] = alloc;
     }
 
     for (size_t count = 0; count < NUM_TEST_ALLOCS / NUM_TEST_THREADS; ++count) {
         void *alloc = allocs[count];
-        aws_mem_release(sba, alloc);
+        aws_mem_release(test_allocator, alloc);
     }
 }
 
-static void s_sba_thread_test(struct aws_allocator *allocator, void (*thread_fn)(void *), struct aws_allocator *sba) {
+static void s_thread_test(struct aws_allocator *allocator, void (*thread_fn)(void *), struct aws_allocator *test_allocator) {
     const struct aws_thread_options *thread_options = aws_default_thread_options();
     struct aws_thread threads[NUM_TEST_THREADS];
-    struct sba_thread_test_data thread_data[NUM_TEST_THREADS];
+    struct allocator_thread_test_data thread_data[NUM_TEST_THREADS];
     AWS_ZERO_ARRAY(threads);
     AWS_ZERO_ARRAY(thread_data);
     for (size_t thread_idx = 0; thread_idx < AWS_ARRAY_SIZE(threads); ++thread_idx) {
         struct aws_thread *thread = &threads[thread_idx];
         aws_thread_init(thread, allocator);
-        struct sba_thread_test_data *data = &thread_data[thread_idx];
-        data->sba = sba;
+        struct allocator_thread_test_data *data = &thread_data[thread_idx];
+        data->test_allocator = test_allocator;
         data->thread_idx = (uint32_t)thread_idx;
         aws_thread_launch(thread, thread_fn, data, thread_options);
     }
@@ -175,7 +175,7 @@ static int s_sba_threaded_allocs_and_frees(struct aws_allocator *allocator, void
 
     struct aws_allocator *sba = aws_small_block_allocator_new(allocator, true);
 
-    s_sba_thread_test(allocator, s_sba_threaded_alloc_worker, sba);
+    s_thread_test(allocator, s_threaded_alloc_worker, sba);
 
     aws_small_block_allocator_destroy(sba);
 
@@ -184,8 +184,8 @@ static int s_sba_threaded_allocs_and_frees(struct aws_allocator *allocator, void
 AWS_TEST_CASE(sba_threaded_allocs_and_frees, s_sba_threaded_allocs_and_frees)
 
 static void s_sba_threaded_realloc_worker(void *user_data) {
-    struct sba_thread_test_data *thread_data = user_data;
-    struct aws_allocator *sba = thread_data->sba;
+    struct allocator_thread_test_data *thread_data = user_data;
+    struct aws_allocator *test_allocator = thread_data->test_allocator;
     void *alloc = NULL;
     size_t size = 0;
     for (size_t count = 0; count < NUM_TEST_ALLOCS / NUM_TEST_THREADS; ++count) {
@@ -194,7 +194,7 @@ static void s_sba_threaded_realloc_worker(void *user_data) {
         if (old_size) {
             AWS_FATAL_ASSERT(0 == memcmp(alloc, &thread_data->thread_idx, 1));
         }
-        AWS_FATAL_ASSERT(0 == aws_mem_realloc(sba, &alloc, old_size, size));
+        AWS_FATAL_ASSERT(0 == aws_mem_realloc(test_allocator, &alloc, old_size, size));
         /* If there was a value, make sure it's still there */
         if (old_size && size) {
             AWS_FATAL_ASSERT(0 == memcmp(alloc, &thread_data->thread_idx, 1));
@@ -203,7 +203,7 @@ static void s_sba_threaded_realloc_worker(void *user_data) {
             memset(alloc, (int)thread_data->thread_idx, size);
         }
     }
-    AWS_FATAL_ASSERT(0 == aws_mem_realloc(sba, &alloc, size, 0));
+    AWS_FATAL_ASSERT(0 == aws_mem_realloc(test_allocator, &alloc, size, 0));
 }
 
 static int s_sba_threaded_reallocs(struct aws_allocator *allocator, void *ctx) {
@@ -212,7 +212,7 @@ static int s_sba_threaded_reallocs(struct aws_allocator *allocator, void *ctx) {
 
     struct aws_allocator *sba = aws_small_block_allocator_new(allocator, true);
 
-    s_sba_thread_test(allocator, s_sba_threaded_realloc_worker, sba);
+    s_thread_test(allocator, s_sba_threaded_realloc_worker, sba);
 
     aws_small_block_allocator_destroy(sba);
 
@@ -313,10 +313,34 @@ static int s_sba_metrics_test(struct aws_allocator *allocator, void *ctx) {
 
     ASSERT_INT_EQUALS(0, aws_small_block_allocator_bytes_active(sba));
 
-    /* after freeing everything, we should have reliniquished all but one page in each bin */
+    /* after freeing everything, we should have relinquished all but one page in each bin */
     ASSERT_INT_EQUALS(5 * aws_small_block_allocator_page_size(sba), aws_small_block_allocator_bytes_reserved(sba));
 
     aws_small_block_allocator_destroy(sba);
     return 0;
 }
 AWS_TEST_CASE(sba_metrics, s_sba_metrics_test)
+
+/*
+ * Default allocator tests.
+ */
+static int s_default_threaded_reallocs(struct aws_allocator *allocator, void *ctx) {
+    (void)ctx;
+    srand(15);
+
+    s_thread_test(allocator, s_sba_threaded_realloc_worker, allocator);
+
+    return 0;
+}
+AWS_TEST_CASE(default_threaded_reallocs, s_default_threaded_reallocs)
+
+static int s_default_threaded_allocs_and_frees(struct aws_allocator *allocator, void *ctx) {
+    (void)ctx;
+    srand(99);
+
+    s_thread_test(allocator, s_threaded_alloc_worker, allocator);
+
+
+    return 0;
+}
+AWS_TEST_CASE(default_threaded_allocs_and_frees, s_default_threaded_allocs_and_frees)