Change the triple buffer object interface

serial_link/protocol/triple_buffered_object.c

@@ -43,7 +43,7 @@ void triple_buffer_init(triple_buffer_object_t* object) {
     SET_DATA_AVAILABLE(0);
 }
 
-static bool triple_buffer_begin_read(uint16_t object_size, triple_buffer_object_t* object) {
+void* triple_buffer_read_internal(uint16_t object_size, triple_buffer_object_t* object) {
     serial_link_lock();
     if (GET_DATA_AVAILABLE()) {
         uint8_t shared_index = GET_SHARED_INDEX();
@@ -52,41 +52,25 @@ static bool triple_buffer_begin_read(uint16_t object_size, triple_buffer_object_
         SET_SHARED_INDEX(read_index);
         SET_DATA_AVAILABLE(false);
         serial_link_unlock();
-        return true;
+        return object->buffer + object_size * shared_index;
     }
     else {
         serial_link_unlock();
-        return false;
+        return NULL;
     }
 }
 
-static void triple_buffer_actual_read(uint16_t object_size, triple_buffer_object_t* object, void* dst) {
+void* triple_buffer_begin_write_internal(uint16_t object_size, triple_buffer_object_t* object) {
-    uint8_t read_index = GET_READ_INDEX();
+    uint8_t write_index = GET_WRITE_INDEX();
-    memcpy(dst, object->buffer + object_size*read_index, object_size);
+    return object->buffer + object_size * write_index;
-}
-
-static void triple_buffer_end_read(uint16_t object_size, triple_buffer_object_t* object) {
 }
 
-void triple_buffer_write(uint16_t object_size, triple_buffer_object_t* object, void* src) {
+void triple_buffer_end_write_internal(triple_buffer_object_t* object) {
-
-    uint8_t write_index = GET_WRITE_INDEX();
-    memcpy(object->buffer + object_size * write_index, src, object_size);
     serial_link_lock();
     uint8_t shared_index = GET_SHARED_INDEX();
+    uint8_t write_index = GET_WRITE_INDEX();
     SET_SHARED_INDEX(write_index);
     SET_WRITE_INDEX(shared_index);
     SET_DATA_AVAILABLE(true);
     serial_link_unlock();
 }
-
-bool triple_buffer_read(uint16_t object_size, triple_buffer_object_t* object, void* dst) {
-    if (triple_buffer_begin_read(object_size, object)) {
-        triple_buffer_actual_read(object_size, object, dst);
-        triple_buffer_end_read(object_size, object);
-        return true;
-    }
-    else {
-        return false;
-    }
-}

serial_link/protocol/triple_buffered_object.h

@@ -31,8 +31,19 @@ typedef struct {
 }triple_buffer_object_t;
 
 void triple_buffer_init(triple_buffer_object_t* object);
-void triple_buffer_write(uint16_t object_size, triple_buffer_object_t* object, void* src);
+
-bool triple_buffer_read(uint16_t object_size, triple_buffer_object_t* object, void* dst);
+#define triple_buffer_begin_write(object) \
+    (typeof(*object.buffer[0])*)triple_buffer_begin_write_internal(sizeof(*object.buffer[0]), (triple_buffer_object_t*)object)
+
+#define triple_buffer_end_write(object) \
+    triple_buffer_end_write_internal((triple_buffer_object_t*)object)
+
+#define triple_buffer_read(object) \
+    (typeof(*object.buffer[0])*)triple_buffer_read_internal(sizeof(*object.buffer[0]), (triple_buffer_object_t*)object)
+
+void* triple_buffer_begin_write_internal(uint16_t object_size, triple_buffer_object_t* object);
+void triple_buffer_end_write_internal(triple_buffer_object_t* object);
+void* triple_buffer_read_internal(uint16_t object_size, triple_buffer_object_t* object);
 
 
 #endif

serial_link/tests/triple_buffered_object_tests.c

@@ -40,67 +40,43 @@ AfterEach(TripleBufferedObject) {}
 
 
 Ensure(TripleBufferedObject, writes_and_reads_object) {
-    uint32_t src = 0x3456ABCC;
+    *triple_buffer_begin_write(&test_object) = 0x3456ABCC;
-    uint32_t dst;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    assert_that(*triple_buffer_read(&test_object), is_equal_to(0x3456ABCC));
-    triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    assert_that(dst, is_equal_to(src));
 }
 
 Ensure(TripleBufferedObject, does_not_read_empty) {
-    uint32_t dst;
+    assert_that(triple_buffer_read(&test_object), is_equal_to(NULL));
-    bool res = triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    assert_that(res, is_equal_to(false));
-}
-
-Ensure(TripleBufferedObject, writes_and_reads_object_decomposed) {
-    uint32_t src = 0x3456ABCC;
-    uint32_t dst;
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
-    triple_buffer_begin_read(4, (triple_buffer_object_t*)&test_object);
-    triple_buffer_actual_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    triple_buffer_end_read(4, (triple_buffer_object_t*)&test_object);
-    assert_that(dst, is_equal_to(src));
 }
 
 Ensure(TripleBufferedObject, writes_twice_and_reads_object) {
-    uint32_t src = 0x3456ABCC;
+    *triple_buffer_begin_write(&test_object) = 0x3456ABCC;
-    uint32_t dst;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    *triple_buffer_begin_write(&test_object) = 0x44778899;
-    src = 0x44778899;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    assert_that(*triple_buffer_read(&test_object), is_equal_to(0x44778899));
-    triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    assert_that(dst, is_equal_to(src));
 }
 
 Ensure(TripleBufferedObject, performs_another_write_in_the_middle_of_read) {
-    uint32_t src = 1;
+    *triple_buffer_begin_write(&test_object) = 1;
-    uint32_t dst;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    uint32_t* read = triple_buffer_read(&test_object);
-    src = 2;
+    *triple_buffer_begin_write(&test_object) = 2;
-    triple_buffer_begin_read(4, (triple_buffer_object_t*)&test_object);
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    assert_that(*read, is_equal_to(1));
-    triple_buffer_actual_read(4, (triple_buffer_object_t*)&test_object, &dst);
+    assert_that(*triple_buffer_read(&test_object), is_equal_to(2));
-    triple_buffer_end_read(4, (triple_buffer_object_t*)&test_object);
+    assert_that(triple_buffer_read(&test_object), is_equal_to(NULL));
-    assert_that(dst, is_equal_to(1));
-    triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    assert_that(dst, is_equal_to(2));
-    assert_that(triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst), is_equal_to(false));
 }
 
 Ensure(TripleBufferedObject, performs_two_writes_in_the_middle_of_read) {
-    uint32_t src = 1;
+    *triple_buffer_begin_write(&test_object) = 1;
-    uint32_t dst;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    uint32_t* read = triple_buffer_read(&test_object);
-    triple_buffer_begin_read(4, (triple_buffer_object_t*)&test_object);
+    *triple_buffer_begin_write(&test_object) = 2;
-    src = 2;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    *triple_buffer_begin_write(&test_object) = 3;
-    src = 3;
+    triple_buffer_end_write(&test_object);
-    triple_buffer_write(4, (triple_buffer_object_t*)&test_object, &src);
+    assert_that(*read, is_equal_to(1));
-    triple_buffer_actual_read(4, (triple_buffer_object_t*)&test_object, &dst);
+    assert_that(*triple_buffer_read(&test_object), is_equal_to(3));
-    triple_buffer_end_read(4, (triple_buffer_object_t*)&test_object);
+    assert_that(triple_buffer_read(&test_object), is_equal_to(NULL));
-    assert_that(dst, is_equal_to(1));
-    triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst);
-    assert_that(dst, is_equal_to(3));
-    assert_that(triple_buffer_read(4, (triple_buffer_object_t*)&test_object, &dst), is_equal_to(false));
 }