From 57d95388b1f4b04d868e8b2adfd28632885a29c7 Mon Sep 17 00:00:00 2001
From: Sean McBride <spmcbride1201@gmail.com>
Date: Fri, 10 Dec 2021 19:49:10 +0000
Subject: [PATCH] refactor: wasm_table

---
 .vscode/settings.json        |  1 +
 runtime/include/vec_u8.h     |  2 ++
 runtime/include/wasm_table.h | 68 +++++++++++++++++++++++++++++++-----
 runtime/src/module.c         |  2 +-
 4 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 52765fc70..b40a8af41 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -102,6 +102,7 @@
 		"software_interrupt_counts.h": "c",
 		"sandbox_set_as_running_sys.h": "c",
 		"wasm_module_instance.h": "c",
+		"wasm_table.h": "c"
 	},
 	"files.exclude": {
 		"**/.git": true,
diff --git a/runtime/include/vec_u8.h b/runtime/include/vec_u8.h
index 2a43e9e98..39b8f549c 100644
--- a/runtime/include/vec_u8.h
+++ b/runtime/include/vec_u8.h
@@ -78,8 +78,10 @@ vec_u8_deinit(struct vec_u8 *self)
 	if (self->capacity == 0) {
 		assert(self->buffer == NULL);
 		assert(self->length == 0);
+		return;
 	}
 
+	assert(self->buffer != NULL);
 	free(self->buffer);
 	self->buffer   = NULL;
 	self->length   = 0;
diff --git a/runtime/include/wasm_table.h b/runtime/include/wasm_table.h
index e2f19d40f..33b0b50fe 100644
--- a/runtime/include/wasm_table.h
+++ b/runtime/include/wasm_table.h
@@ -15,23 +15,73 @@ struct wasm_table_entry {
 };
 
 struct wasm_table {
-	uint32_t                length;
-	uint32_t                capacity;
-	struct wasm_table_entry data[];
+	uint32_t                 length;
+	uint32_t                 capacity;
+	struct wasm_table_entry *buffer;
 };
 
+static INLINE struct wasm_table *wasm_table_alloc(void);
+static INLINE int                wasm_table_init(struct wasm_table *self, size_t capacity);
+static INLINE struct wasm_table *wasm_table_new(size_t capacity);
+static INLINE void               wasm_table_deinit(struct wasm_table *self);
+static INLINE void               wasm_table_free(struct wasm_table *self);
+static INLINE void               wasm_table_delete(struct wasm_table *self);
+
 static INLINE struct wasm_table *
-wasm_table_allocate(size_t capacity)
+wasm_table_alloc(void)
 {
-	struct wasm_table *self = (struct wasm_table *)malloc(sizeof(struct wasm_table)
-	                                                      + capacity * sizeof(struct wasm_table_entry));
+	return (struct wasm_table *)malloc(sizeof(struct wasm_table));
+}
+
+static INLINE int
+wasm_table_init(struct wasm_table *self, size_t capacity)
+{
+	assert(self != NULL);
+
+	if (capacity > 0) {
+		self->buffer = calloc(capacity, sizeof(struct wasm_table_entry));
+		if (self->buffer == NULL) return -1;
+	}
 
 	self->capacity = capacity;
 	self->length   = 0;
 
+	return 0;
+}
+
+static INLINE struct wasm_table *
+wasm_table_new(size_t capacity)
+{
+	struct wasm_table *self = wasm_table_alloc();
+	if (self == NULL) return NULL;
+
+	int rc = wasm_table_init(self, capacity);
+	if (rc < 0) {
+		wasm_table_free(self);
+		return NULL;
+	}
+
 	return self;
 }
 
+static INLINE void
+wasm_table_deinit(struct wasm_table *self)
+{
+	assert(self != NULL);
+
+	if (self->capacity > 0) {
+		assert(self->buffer == NULL);
+		assert(self->length == 0);
+		return;
+	}
+
+	assert(self->buffer != NULL);
+	free(self->buffer);
+	self->buffer   = NULL;
+	self->length   = 0;
+	self->capacity = 0;
+}
+
 static INLINE void
 wasm_table_free(struct wasm_table *self)
 {
@@ -45,7 +95,7 @@ wasm_table_get(struct wasm_table *self, uint32_t idx, uint32_t type_id)
 	assert(self != NULL);
 	assert(idx < self->capacity);
 
-	struct wasm_table_entry f = self->data[idx];
+	struct wasm_table_entry f = self->buffer[idx];
 	// FIXME: Commented out function type check because of gocr
 	// assert(f.type_id == type_id);
 
@@ -62,7 +112,7 @@ wasm_table_set(struct wasm_table *self, uint32_t idx, uint32_t type_id, char *po
 	assert(pointer != NULL);
 
 	/* TODO: atomic for multiple concurrent invocations? Issue #97 */
-	if (self->data[idx].type_id == type_id && self->data[idx].func_pointer == pointer) return;
+	if (self->buffer[idx].type_id == type_id && self->buffer[idx].func_pointer == pointer) return;
 
-	self->data[idx] = (struct wasm_table_entry){ .type_id = type_id, .func_pointer = pointer };
+	self->buffer[idx] = (struct wasm_table_entry){ .type_id = type_id, .func_pointer = pointer };
 }
diff --git a/runtime/src/module.c b/runtime/src/module.c
index f4fe23a72..8e8ad9a10 100644
--- a/runtime/src/module.c
+++ b/runtime/src/module.c
@@ -186,7 +186,7 @@ module_new(char *name, char *path, uint32_t stack_size, uint32_t max_memory, uin
 	/* WebAssembly Indirect Table */
 	/* TODO: Should this be part of the module or per-sandbox? */
 	/* TODO: How should this table be sized? */
-	module->indirect_table = wasm_table_allocate(INDIRECT_TABLE_SIZE);
+	module->indirect_table = wasm_table_new(INDIRECT_TABLE_SIZE);
 
 	/* Request Response Buffer */
 	if (request_size == 0) request_size = MODULE_DEFAULT_REQUEST_RESPONSE_SIZE;