auto scaling of string temp arena

Author: braindigitalis

include/basic/context.h

@@ -385,6 +385,13 @@ typedef struct basic_ctx {
 	 */
 	char* string_gc_storage;
 
+	/**
+	 * @brief Size of string_gc_storage bump allocation.
+	 * This grows when a previous run hits a high water mark when
+	 * the gc() function runs
+	 */
+	size_t string_gc_storage_size;
+
 	/**
 	 * @brief Pointer to the next free position in the garbage-collected string storage.
 	 */

include/string.h

@@ -7,6 +7,10 @@
 #pragma once
 #include "basic.h"
 
+/**
+ * Initial string bump allocator area size for storing temporary
+ * strings used in expressions.
+ */
 #define STRING_GC_AREA_SIZE (1024 * 1024 * 4)
 
 /**

src/basic/function.c

@@ -458,14 +458,15 @@ const char* basic_eval_str_fn(const char* fn_name, struct basic_ctx* ctx)
 			}
 		}
 
-		ctx->int_variables       = atomic->int_variables;
-		ctx->str_variables       = atomic->str_variables;
-		ctx->double_variables    = atomic->double_variables;
-		ctx->sounds              = atomic->sounds;
-		ctx->data_offset         = atomic->data_offset;
-		ctx->graphics_colour     = atomic->graphics_colour;
-		ctx->active_restrictions = atomic->active_restrictions;
-		ctx->child_restrictions  = atomic->child_restrictions;
+		ctx->int_variables           = atomic->int_variables;
+		ctx->str_variables           = atomic->str_variables;
+		ctx->double_variables        = atomic->double_variables;
+		ctx->sounds                  = atomic->sounds;
+		ctx->data_offset             = atomic->data_offset;
+		ctx->graphics_colour         = atomic->graphics_colour;
+		ctx->active_restrictions     = atomic->active_restrictions;
+		ctx->child_restrictions      = atomic->child_restrictions;
+		ctx->string_gc_storage_size  = atomic->string_gc_storage_size;
 
 		memcpy(ctx->audio_streams, atomic->audio_streams, sizeof(ctx->audio_streams));
 		memcpy(ctx->envelopes, atomic->envelopes, sizeof(ctx->envelopes));
@@ -614,14 +615,15 @@ int64_t basic_eval_int_fn(const char* fn_name, struct basic_ctx* ctx)
 		}
 		rv = (int64_t)atomic->fn_return;
 
-		ctx->int_variables       = atomic->int_variables;
-		ctx->str_variables       = atomic->str_variables;
-		ctx->double_variables    = atomic->double_variables;
-		ctx->sounds              = atomic->sounds;
-		ctx->data_offset         = atomic->data_offset;
-		ctx->graphics_colour     = atomic->graphics_colour;
-		ctx->active_restrictions = atomic->active_restrictions;
-		ctx->child_restrictions  = atomic->child_restrictions;
+		ctx->int_variables          = atomic->int_variables;
+		ctx->str_variables          = atomic->str_variables;
+		ctx->double_variables       = atomic->double_variables;
+		ctx->sounds                 = atomic->sounds;
+		ctx->data_offset            = atomic->data_offset;
+		ctx->graphics_colour        = atomic->graphics_colour;
+		ctx->active_restrictions    = atomic->active_restrictions;
+		ctx->child_restrictions     = atomic->child_restrictions;
+		ctx->string_gc_storage_size = atomic->string_gc_storage_size;
 
 		memcpy(ctx->audio_streams, atomic->audio_streams, sizeof(ctx->audio_streams));
 		memcpy(ctx->envelopes, atomic->envelopes, sizeof(ctx->envelopes));
@@ -693,14 +695,15 @@ void basic_eval_double_fn(const char* fn_name, struct basic_ctx* ctx, double* re
 			*res = *((double*)atomic->fn_return);
 		}
 
-		ctx->int_variables       = atomic->int_variables;
-		ctx->str_variables       = atomic->str_variables;
-		ctx->double_variables    = atomic->double_variables;
-		ctx->sounds              = atomic->sounds;
-		ctx->data_offset         = atomic->data_offset;
-		ctx->graphics_colour     = atomic->graphics_colour;
-		ctx->active_restrictions = atomic->active_restrictions;
-		ctx->child_restrictions  = atomic->child_restrictions;
+		ctx->int_variables          = atomic->int_variables;
+		ctx->str_variables          = atomic->str_variables;
+		ctx->double_variables       = atomic->double_variables;
+		ctx->sounds                 = atomic->sounds;
+		ctx->data_offset            = atomic->data_offset;
+		ctx->graphics_colour        = atomic->graphics_colour;
+		ctx->active_restrictions    = atomic->active_restrictions;
+		ctx->child_restrictions     = atomic->child_restrictions;
+		ctx->string_gc_storage_size = atomic->string_gc_storage_size;
 
 		memcpy(ctx->audio_streams, atomic->audio_streams, sizeof(ctx->audio_streams));
 		memcpy(ctx->envelopes, atomic->envelopes, sizeof(ctx->envelopes));

src/basic/main.c

@@ -336,7 +336,8 @@ struct basic_ctx *basic_init(const char *program, uint32_t pid, const char *file
 		*error = "Out of memory";
 		return NULL;
 	}
-	ctx->string_gc_storage = buddy_malloc(ctx->allocator, STRING_GC_AREA_SIZE);
+	ctx->string_gc_storage_size = STRING_GC_AREA_SIZE;
+	ctx->string_gc_storage = buddy_malloc(ctx->allocator, ctx->string_gc_storage_size);
 	if (!ctx->string_gc_storage) {
 		buddy_free(ctx->allocator, ctx->program_ptr);
 		kfree_null(&ctx);
@@ -560,6 +561,7 @@ struct basic_ctx *basic_clone(struct basic_ctx *old) {
 	ctx->string_array_variables = old->string_array_variables;
 	ctx->double_array_variables = old->double_array_variables;
 	ctx->string_gc_storage = old->string_gc_storage;
+	ctx->string_gc_storage_size = old->string_gc_storage_size;
 	ctx->string_gc_storage_next = old->string_gc_storage_next;
 	ctx->lines = old->lines;
 	ctx->highest_line = old->highest_line;

src/string.c

@@ -189,7 +189,7 @@ char* strdup(const char* string)
 
 const char* gc_try_concat(struct basic_ctx *ctx, const char* s1, const char* s2) {
 	char* dest = ctx->string_gc_storage_next;
-	char* end = ctx->string_gc_storage + STRING_GC_AREA_SIZE;
+	char* end = ctx->string_gc_storage + ctx->string_gc_storage_size;
 	char* out = dest;
 
 	while (*s1) {
@@ -220,7 +220,7 @@ const char* gc_strdup(basic_ctx* ctx, const char* string)
 		return ctx->string_gc_storage;
 	}
 	char* dest = ctx->string_gc_storage_next;
-	size_t remaining = (size_t)((ctx->string_gc_storage + STRING_GC_AREA_SIZE) - dest);
+	size_t remaining = (size_t)((ctx->string_gc_storage + ctx->string_gc_storage_size) - dest);
 	size_t len = strlcpy(dest, string, remaining);
 	if (len >= remaining) {
 		tokenizer_error_printf(ctx, "Out of string area allocator space storing '%s'", string);
@@ -232,7 +232,7 @@ const char* gc_strdup(basic_ctx* ctx, const char* string)
 
 const char* gc_from_tokenizer_string(struct basic_ctx *ctx) {
 	char* dest = ctx->string_gc_storage_next;
-	char* end = ctx->string_gc_storage + STRING_GC_AREA_SIZE;
+	char* end = ctx->string_gc_storage + ctx->string_gc_storage_size;
 	char* out = dest;
 
 	if (*ctx->ptr == '"') {
@@ -255,10 +255,19 @@ const char* gc_from_tokenizer_string(struct basic_ctx *ctx) {
 }
 
 int gc(basic_ctx* ctx) {
-	if (ctx->string_gc_storage && ctx->string_gc_storage_next) {
-		/* Strings start at +1 as the base ptr is for empties */
-		ctx->string_gc_storage_next = ctx->string_gc_storage + 1;
+	size_t used = ctx->string_gc_storage_next - ctx->string_gc_storage;
+	if (used >= (ctx->string_gc_storage_size * 75) / 100 && !ctx->errored && !ctx->ended) {
+		size_t new_size = ctx->string_gc_storage_size * 2;
+		char* new_storage = buddy_realloc(ctx->allocator, ctx->string_gc_storage, new_size);
+		if (new_storage) {
+			ctx->string_gc_storage = new_storage;
+			ctx->string_gc_storage_size = new_size;
+			*ctx->string_gc_storage = 0;
+		} else {
+			tokenizer_error_printf(ctx, "Out of memory growing string area to %lu MB", new_size / 1024 / 1024);
+		}
 	}
+	ctx->string_gc_storage_next = ctx->string_gc_storage + 1;
 	return 1;
 }