tildefriends/src/task.c

#include "task.h"

#include "bcrypt.js.h"
#include "database.js.h"
#include "file.js.h"
#include "mem.h"
#include "packetstream.h"
#include "serialize.h"
#include "socket.js.h"
#include "ssb.h"
#include "ssb.js.h"
#include "taskstub.js.h"
#include "tlscontext.js.h"
#include "trace.h"
#include "util.js.h"

#include <assert.h>
#include <malloc.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <uv.h>

#include <sqlite3.h>

#include "quickjs.h"
#include "quickjs-libc.h"

#include <backtrace.h>

#ifndef _WIN32
#ifndef __ANDROID__
#include <execinfo.h>
#endif
#include <unistd.h>
#endif

static const char* k_version = "1.0";

static JSClassID _import_class_id;
static int _count;

extern struct backtrace_state* g_backtrace_state;

typedef struct _export_record_t export_record_t;
typedef struct _import_record_t import_record_t;

typedef struct _task_child_node_t task_child_node_t;

typedef struct _task_child_node_t
{
	taskid_t id;
	tf_taskstub_t* stub;
	task_child_node_t* next;
} task_child_node_t;

typedef struct _promise_t promise_t;
typedef struct _promise_t
{
	promiseid_t id;
	taskid_t task;
	JSValue values[2];
	uint32_t stack_hash;
} promise_t;

typedef struct _promise_stack_t
{
	uint32_t hash;
	const char* stack;
	void* cstack[32];
	int cstack_count;
	int count;
} promise_stack_t;

typedef struct _tf_task_t
{
	taskid_t _nextTask;
	task_child_node_t* _children;
	int _child_count;

	tf_taskstub_t* _stub;
	tf_taskstub_t* _parent;
	const char* _path;

	bool _activated;
	bool _trusted;
	bool _killed;
	int32_t _exitCode;
	char _scriptName[256];

	JSRuntime* _runtime;
	JSContext* _context;

	sqlite3* _db;

	tf_ssb_t* _ssb;

	tf_trace_t* _trace;

	promise_t* _promises;
	int _promise_count;
	promiseid_t _nextPromise;
	uv_loop_t _loop;

	uv_timer_t gc_timer;
	uv_timer_t trace_timer;
	uint64_t last_hrtime;
	uint64_t last_idle_time;
	float idle_percent;

	uv_idle_t idle;
	uv_prepare_t prepare;

	export_record_t** _exports;
	int _export_count;
	exportid_t _nextExport;

	import_record_t** _imports;
	int _import_count;
	JSValue _loadedFiles;

	int _ssb_port;
	int _http_port;
	int _https_port;
	char _db_path[256];
	const char* _args;

	promise_stack_t* _promise_stacks;
	int _promise_stack_count;
} tf_task_t;

typedef struct _export_record_t
{
	taskid_t _taskid;
	exportid_t _export_id;
	JSValue _function;
	int _useCount;
} export_record_t;

static void _export_record_ref(export_record_t* export)
{
	export->_useCount++;
}

static bool _export_record_release(tf_task_t* task, export_record_t** export)
{
	if (--(*export)->_useCount == 0)
	{
		JS_FreeValue(task->_context, (*export)->_function);
		(*export)->_function = JS_UNDEFINED;
		tf_free(*export);
		int index = export - task->_exports;
		if (task->_export_count - index)
		{
			memmove(export, export + 1, sizeof(export_record_t*) * (task->_export_count - index - 1));
		}
		task->_export_count--;
		return true;
	}
	return false;
}

static JSValue _tf_task_version(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
static JSValue _tf_task_get_parent(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
static JSValue _tf_task_exit(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
static JSValue _tf_task_trace(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
static JSValue _tf_task_getStats(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);
static JSValue _tf_task_getFile(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv);

static promise_t* _tf_task_find_promise(tf_task_t* task, promiseid_t id);
static void _tf_task_sendPromiseResolve(tf_task_t* from, tf_taskstub_t* to, promiseid_t promise, JSValue result);
static void _tf_task_sendPromiseReject(tf_task_t* from, tf_taskstub_t* to, promiseid_t promise, JSValue result);

static void _tf_task_sendPromiseExportMessage(tf_task_t* from, tf_taskstub_t* to, tf_task_message_t messageType, promiseid_t promiseId, exportid_t exportId, JSValue result);
static JSValue _tf_task_executeSource(tf_task_t* task, const char* source, const char* name);
static tf_taskstub_t* _tf_task_get_stub(tf_task_t* task, taskid_t id);
static void _tf_task_release_export(tf_taskstub_t* stub, exportid_t exportId);
static bool _tf_task_run_jobs(tf_task_t* task);
static void _tf_task_run_jobs_idle(uv_idle_t* idle);
static void _tf_task_run_jobs_prepare(uv_prepare_t* prepare);

typedef struct _import_record_t
{
	tf_task_t* _owner;
	JSValue _function;
	exportid_t _export;
	taskid_t _task;
	int _useCount;
} import_record_t;

static int _import_compare(const void* a, const void* b)
{
	const import_record_t* ia = a;
	const import_record_t* const* ib = b;
	if (ia->_task != (*ib)->_task)
	{
		return ia->_task < (*ib)->_task ? -1 : 1;
	}
	else if (ia->_export != (*ib)->_export)
	{
		return ia->_export < (*ib)->_export ? -1 : 1;
	}
	else
	{
		return 0;
	}
}

static import_record_t** _tf_task_find_import(tf_task_t* task, taskid_t task_id, exportid_t export_id)
{
	if (!task->_imports)
	{
		return NULL;
	}
	import_record_t search =
	{
		._task = task_id,
		._export = export_id,
	};
	import_record_t** it = bsearch(&search, task->_imports, task->_import_count, sizeof(import_record_t*), _import_compare);
	return it;
}

static bool _import_record_release(import_record_t** import)
{
	import_record_t* record = *import;
	if (--record->_useCount == 0)
	{
		tf_task_t* task = record->_owner;
		JSContext* context = task->_context;
		if (!JS_IsUndefined(record->_function))
		{
			JS_SetOpaque(record->_function, NULL);
			JS_FreeValue(context, record->_function);
			record->_function = JS_UNDEFINED;
		}
		_tf_task_release_export(_tf_task_get_stub(task, record->_task), record->_export);

		int index = import - task->_imports;
		if (task->_import_count - index)
		{
			memmove(import, import + 1, sizeof(import_record_t*) * (task->_import_count - index - 1));
		}
		task->_import_count--;

		tf_free(record);
		return true;
	}
	return false;
}

static void _import_record_release_for_task(tf_task_t* task, taskid_t task_id)
{
	for (int i = 0; i < task->_import_count; i++)
	{
		if (task->_imports[i]->_task == task_id)
		{
			while (!_import_record_release(&task->_imports[i]))
			{
			}
			--i;
		}
	}
}

static int _export_compare(const void* a, const void* b)
{
	exportid_t ia = *(const exportid_t*)a;
	const export_record_t* const* ib = b;
	if (ia != (*ib)->_export_id)
	{
		return ia < (*ib)->_export_id ? -1 : 1;
	}
	else
	{
		return 0;
	}
}

static void _export_record_release_for_task(tf_task_t* task, taskid_t task_id)
{
	for (int i = 0; i < task->_export_count; i++)
	{
		if (task->_exports[i]->_taskid == task_id)
		{
			while (!_export_record_release(task, &task->_exports[i]))
			{
			}
			i--;
		}
	}
}

bool tf_task_send_error_to_parent(tf_task_t* task, JSValue error)
{
	if (task && task->_parent)
	{
		void* buffer = NULL;
		size_t size = 0;
		tf_serialize_store(task, task->_parent, &buffer, &size, error);
		tf_packetstream_send(tf_taskstub_get_stream(task->_parent), kTaskError, buffer, size);
		tf_free(buffer);
		return true;
	}
	return false;
}

static const char* _task_loadFile(const char* fileName)
{
	char* result = NULL;
	FILE* file = fopen(fileName, "rb");
	if (file)
	{
		fseek(file, 0, SEEK_END);
		long fileSize = ftell(file);
		fseek(file, 0, SEEK_SET);
		result = tf_malloc(fileSize + 1);
		int bytes_read = fread(result, 1, fileSize, file);
		result[bytes_read] = '\0';
		fclose(file);
	}
	return result;
}

JSValue _tf_task_exit(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	int exitCode = 0;
	JS_ToInt32(task->_context, &exitCode, argv[0]);
	exit(exitCode);
	return JS_UNDEFINED;
}

int tf_task_execute(tf_task_t* task, const char* fileName)
{
	bool executed = false;

	tf_trace_begin(task->_trace, "tf_task_execute");
	const char* source = _task_loadFile(fileName);
	printf("Running script %s\n", fileName);
	if (!*task->_scriptName)
	{
		strncpy(task->_scriptName, fileName, sizeof(task->_scriptName) - 1);
	}
	if (!task->_path)
	{
		char* path = tf_strdup(fileName);
		char* slash = strrchr(path, '/');
		if (slash)
		{
			*slash = '\0';
			task->_path = tf_strdup(path);
		}
		else
		{
			task->_path = tf_strdup("./");
		}
		tf_free(path);
	}
	if (source)
	{
		JSValue result = JS_Eval(task->_context, source, strlen(source), fileName, JS_EVAL_TYPE_MODULE);
		if (tf_util_report_error(task->_context, result))
		{
			printf("Reported an error.\n");
		}
		if (!JS_IsError(task->_context, result) && !JS_IsException(result))
		{
			executed = true;
		}
		JS_FreeValue(task->_context, result);
		tf_free((void*)source);
	}
	else
	{
		printf("Failed to load file: %s.\n", fileName);
	}
	tf_trace_end(task->_trace);
	return executed;
}

static tf_taskstub_t* _tf_task_get_stub(tf_task_t* task, taskid_t id)
{
	if (id == k_task_parent_id)
	{
		return task->_parent;
	}

	for (task_child_node_t* node = task->_children; node; node = node->next)
	{
		if (node->id == id)
		{
			return node->stub;
		}
	}
	return NULL;
}


static JSValue _import_call(JSContext* context, JSValueConst func_obj, JSValueConst this_val, int argc, JSValueConst* argv, int flags)
{
	import_record_t* import = JS_GetOpaque(func_obj, _import_class_id);
	if (!import)
	{
		return JS_ThrowInternalError(context, "Invoking a function that has been released.");
	}
	import->_useCount++;

	JSValue array = JS_NewArray(context);
	JS_SetPropertyUint32(context, array, 0, JS_UNDEFINED);
	for (int i = 0; i < argc; ++i)
	{
		JS_SetPropertyUint32(context, array, i + 1, JS_DupValue(context, argv[i]));
	}

	tf_task_t* sender = JS_GetContextOpaque(context);
	JSValue result;
	tf_taskstub_t* recipient = _tf_task_get_stub(sender, import->_task);
	if (recipient)
	{
		promiseid_t promise = -1;
		result = tf_task_allocate_promise(sender, &promise);
		_tf_task_sendPromiseExportMessage(sender, recipient, kInvokeExport, promise, import->_export, array);
	}
	else
	{
		result = JS_ThrowInternalError(context, "Invoking a function on a nonexistent task.");
	}
	JS_FreeValue(context, array);
	return result;
}

static export_record_t** _task_get_export(tf_task_t* task, exportid_t export_id)
{
	if (!task->_export_count)
	{
		return NULL;
	}
	export_record_t** it = bsearch(&export_id, task->_exports, task->_export_count, sizeof(export_record_t*), _export_compare);
	return it;
}

JSValue _task_invokeExport_internal(tf_taskstub_t* from, tf_task_t* to, exportid_t exportId, const char* buffer, size_t size)
{
	JSValue result = JS_NULL;
	export_record_t** it = _task_get_export(to, exportId);
	export_record_t* export = it ? *it : NULL;
	if (export)
	{
		JSValue arguments = tf_serialize_load(to, from, buffer, size);

		JSValue* argument_array = NULL;
		JSValue this_val = JS_NULL;
		int length = tf_util_get_length(to->_context, arguments);
		if (length > 0)
		{
			this_val = JS_GetPropertyUint32(to->_context, arguments, 0);
			argument_array = alloca(sizeof(JSValue) * (length - 1));
		}
		for (int i = 1; i < length; ++i)
		{
			argument_array[i - 1] = JS_GetPropertyUint32(to->_context, arguments, i);
		}
		JSValue function = export->_function;

		JSPropertyDescriptor desc = { 0 };
		const char* name = NULL;
		JSAtom atom = JS_NewAtom(to->_context, "name");
		if (JS_GetOwnProperty(to->_context, &desc, function, atom) == 1)
		{
			name = JS_ToCString(to->_context, desc.value);
			JS_FreeValue(to->_context, desc.value);
			JS_FreeValue(to->_context, desc.setter);
			JS_FreeValue(to->_context, desc.getter);
		}
		JS_FreeAtom(to->_context, atom);
		tf_trace_begin(to->_trace, name ? name : "_task_invokeExport_internal");
		if (name)
		{
			JS_FreeCString(to->_context, name);
		}

		result = JS_Call(to->_context, function, this_val, length - 1, argument_array);
		tf_trace_end(to->_trace);

		JS_FreeValue(to->_context, this_val);
		for (int i = 0; i < length - 1; i++)
		{
			JS_FreeValue(to->_context, argument_array[i]);
		}
		JS_FreeValue(to->_context, arguments);
	}
	else
	{
		printf("%s: That's not an export we have (exportId=%d, exports=%d)\n", to->_scriptName, exportId, to->_export_count);
	}
	tf_packetstream_send(tf_taskstub_get_stream(from), kReleaseImport, (void*)&exportId, sizeof(exportId));
	return result;
}

static JSValue _invokeThen(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv, int magic, JSValue* func_data)
{
	taskid_t taskid = 0;
	JS_ToInt32(context, &taskid, func_data[0]);
	tf_task_t* from = JS_GetContextOpaque(context);
	tf_taskstub_t* to = _tf_task_get_stub(from, taskid);
	promiseid_t promiseid = 0;
	JS_ToInt32(context, &promiseid, func_data[1]);
	tf_task_send_promise_message(from, to, kResolvePromise, promiseid, argv[0]);
	return JS_DupValue(context, this_val);
}

static JSValue _invokeCatch(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv, int magic, JSValue* func_data)
{
	taskid_t taskid = 0;
	JS_ToInt32(context, &taskid, func_data[0]);
	tf_task_t* from = JS_GetContextOpaque(context);
	tf_taskstub_t* to = _tf_task_get_stub(from, taskid);
	promiseid_t promiseid = 0;
	JS_ToInt32(context, &promiseid, func_data[1]);
	tf_task_send_promise_message(from, to, kRejectPromise, promiseid, argv[0]);
	return JS_DupValue(context, this_val);
}

static void _forward_promise(tf_task_t* from, tf_taskstub_t* to, promiseid_t promise, JSValue result)
{
	// We're not going to serialize/deserialize a promise...
	JSValue data[] =
	{
		JS_NewInt32(from->_context, tf_taskstub_get_id(to)),
		JS_NewInt32(from->_context, promise),
	};
	JSValue promise_then = JS_GetPropertyStr(from->_context, result, "then");
	JSValue promise_catch = JS_GetPropertyStr(from->_context, result, "catch");

	JSValue then_handler = JS_NewCFunctionData(from->_context, _invokeThen, 0, 0, 2, data);
	JSValue catch_handler = JS_NewCFunctionData(from->_context, _invokeCatch, 0, 0, 2, data);

	JSValue error = JS_Call(from->_context, promise_then, result, 1, &then_handler);
	tf_util_report_error(from->_context, error);
	JS_FreeValue(from->_context, error);
	error = JS_Call(from->_context, promise_catch, result, 1, &catch_handler);
	tf_util_report_error(from->_context, error);
	JS_FreeValue(from->_context, error);

	JS_FreeValue(from->_context, promise_then);
	JS_FreeValue(from->_context, promise_catch);
	JS_FreeValue(from->_context, then_handler);
	JS_FreeValue(from->_context, catch_handler);
}

static void _tf_task_sendPromiseResolve(tf_task_t* from, tf_taskstub_t* to, promiseid_t promise, JSValue result)
{
	JSValue global = JS_GetGlobalObject(from->_context);
	JSValue promiseType = JS_GetPropertyStr(from->_context, global, "Promise");
	JS_FreeValue(from->_context, global);
	if (JS_IsInstanceOf(from->_context, result, promiseType))
	{
		_forward_promise(from, to, promise, result);
	}
	else
	{
		tf_task_send_promise_message(from, to, kResolvePromise, promise, result);
	}
	JS_FreeValue(from->_context, promiseType);
}

static void _tf_task_sendPromiseReject(tf_task_t* from, tf_taskstub_t* to, promiseid_t promise, JSValue result)
{
	JSValue global = JS_GetGlobalObject(from->_context);
	JSValue promiseType = JS_GetPropertyStr(from->_context, global, "Promise");
	JS_FreeValue(from->_context, global);
	if (JS_IsInstanceOf(from->_context, result, promiseType))
	{
		_forward_promise(from, to, promise, result);
	}
	else
	{
		tf_task_send_promise_message(from, to, kRejectPromise, promise, result);
	}
	JS_FreeValue(from->_context, promiseType);
}

void tf_task_send_promise_message(tf_task_t* from, tf_taskstub_t* to, tf_task_message_t type, promiseid_t promise, JSValue payload)
{
	if (to)
	{
		void* buffer;
		size_t size;
		tf_serialize_store(from, to, &buffer, &size, payload);

		char* copy = tf_malloc(sizeof(promise) + size);
		memcpy(copy, &promise, sizeof(promise));
		memcpy(copy + sizeof(promise), buffer, size);
		tf_packetstream_send(tf_taskstub_get_stream(to), type, copy, size + sizeof(promise));
		tf_free(buffer);
		tf_free(copy);
	}
	else
	{
		printf("Sending to a NULL task.\n");
	}
}

static void _tf_task_sendPromiseExportMessage(tf_task_t* from, tf_taskstub_t* to, tf_task_message_t messageType, promiseid_t promise, exportid_t exportId, JSValue result)
{
	void* buffer;
	size_t size;
	tf_serialize_store(from, to, &buffer, &size, result);
	char* copy = tf_malloc(sizeof(promise) + sizeof(exportId) + size);
	memcpy(copy, &promise, sizeof(promise));
	memcpy(copy + sizeof(promise), &exportId, sizeof(exportId));
	memcpy(copy + sizeof(promise) + sizeof(exportId), buffer, size);
	promise_t* found = _tf_task_find_promise(from, promise);
	if (found)
	{
		found->task = tf_taskstub_get_id(to);
	}
	tf_packetstream_send(tf_taskstub_get_stream(to), messageType, copy, sizeof(promise) + sizeof(exportId) + size);
	tf_free(buffer);
	tf_free(copy);
}

JSValue _tf_task_get_parent(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	return task->_parent ? JS_DupValue(context, tf_taskstub_get_task_object(task->_parent)) : JS_UNDEFINED;
}

static JSValue _tf_task_version(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	return JS_NewString(task->_context, k_version);
}

exportid_t tf_task_export_function(tf_task_t* task, tf_taskstub_t* to, JSValue function)
{
	export_record_t* export = NULL;
	/* TODO: _exports_by_function */
	for (int i = 0; i < task->_export_count; i++)
	{
		if (JS_VALUE_GET_PTR(task->_exports[i]->_function) == JS_VALUE_GET_PTR(function))
		{
			export = task->_exports[i];
			break;
		}
	}

	if (!export)
	{
		int id = -1;
		do {
			id = task->_nextExport++;
		} while (_task_get_export(task, id));

		export = tf_malloc(sizeof(export_record_t));
		*export = (export_record_t)
		{
			._export_id = id,
			._taskid = tf_taskstub_get_id(to),
			._function = JS_DupValue(task->_context, function),
		};

		int index = tf_util_insert_index(&id, task->_exports, task->_export_count, sizeof(export_record_t*), _export_compare);
		task->_exports = tf_resize_vec(task->_exports, sizeof(export_record_t*) * (task->_export_count + 1));
		if (task->_export_count - index)
		{
			memmove(task->_exports + index + 1, task->_exports + index, sizeof(export_record_t*) * (task->_export_count - index));
		}
		task->_exports[index] = export;
		task->_export_count++;
	}

	if (export)
	{
		_export_record_ref(export);
	}

	return export ? export->_export_id : -1;
}

static void _tf_task_release_export(tf_taskstub_t* stub, exportid_t exportId)
{
	if (stub)
	{
		tf_packetstream_t* stream = tf_taskstub_get_stream(stub);
		if (stream)
		{
			tf_packetstream_send(stream, kReleaseExport, (void*)&exportId, sizeof(exportId));
		}
	}
}

static JSValue _tf_task_trace(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	if (!task->_trace)
	{
		return JS_UNDEFINED;
	}

	char* trace = tf_trace_export(task->_trace);
	JSValue result = JS_NewString(context, trace);
	tf_free(trace);
	return result;
}

static JSValue _tf_task_getStats(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	JSValue result = JS_NewObject(context);
	JS_SetPropertyStr(context, result, "child_count", JS_NewInt32(context, task->_child_count));
	JS_SetPropertyStr(context, result, "import_count", JS_NewInt32(context, task->_import_count));
	JS_SetPropertyStr(context, result, "export_count", JS_NewInt32(context, task->_export_count));
	JS_SetPropertyStr(context, result, "promise_count", JS_NewInt32(context, task->_promise_count));

	JS_SetPropertyStr(context, result, "idle_percent", JS_NewFloat64(context, task->idle_percent));

	uint64_t total_memory = uv_get_total_memory();
	size_t rss;
	if (uv_resident_set_memory(&rss) == 0)
	{
		JS_SetPropertyStr(context, result, "memory_percent", JS_NewFloat64(context, 100.0f * rss / total_memory));
	}

	JS_SetPropertyStr(context, result, "sqlite3_memory_percent", JS_NewFloat64(context, 100.0f * sqlite3_memory_used() / total_memory));
	JS_SetPropertyStr(context, result, "js_malloc_percent", JS_NewFloat64(context, 100.0f * tf_mem_get_js_malloc_size() / total_memory));
	JS_SetPropertyStr(context, result, "uv_malloc_percent", JS_NewFloat64(context, 100.0f * tf_mem_get_uv_malloc_size() / total_memory));
	JS_SetPropertyStr(context, result, "tls_malloc_percent", JS_NewFloat64(context, 100.0f * tf_mem_get_tls_malloc_size() / total_memory));
	JS_SetPropertyStr(context, result, "tf_malloc_percent", JS_NewFloat64(context, 100.0f * tf_mem_get_tf_malloc_size() / total_memory));

	JS_SetPropertyStr(context, result, "socket_count", JS_NewInt32(context, tf_socket_get_count()));
	JS_SetPropertyStr(context, result, "socket_open_count", JS_NewInt32(context, tf_socket_get_open_count()));

	if (task->_ssb)
	{
		tf_ssb_stats_t ssb_stats = { 0 };
		tf_ssb_get_stats(task->_ssb, &ssb_stats);

		JS_SetPropertyStr(context, result, "messages_stored", JS_NewInt32(context, ssb_stats.messages_stored));
		JS_SetPropertyStr(context, result, "blobs_stored", JS_NewInt32(context, ssb_stats.blobs_stored));
		JS_SetPropertyStr(context, result, "rpc_in", JS_NewInt32(context, ssb_stats.rpc_in));
		JS_SetPropertyStr(context, result, "rpc_out", JS_NewInt32(context, ssb_stats.rpc_out));
		JS_SetPropertyStr(context, result, "requests", JS_NewInt32(context, ssb_stats.request_count));
	}

	return result;
}

typedef struct _backtrace_t
{
	JSContext* context;
	JSValue array;
	int count;
} backtrace_t;

static int _tf_backtrace_callback(void* data, uintptr_t pc, const char* filename, int line_number, const char* function)
{
	backtrace_t* bt = data;
	JSValue entry = JS_NewObject(bt->context);
	JS_SetPropertyStr(bt->context, entry, "pc", JS_NewInt64(bt->context, (int64_t)(intptr_t)pc));
	if (filename)
	{
		JS_SetPropertyStr(bt->context, entry, "filename", JS_NewString(bt->context, filename));
	}
	JS_SetPropertyStr(bt->context, entry, "line_number", JS_NewInt32(bt->context, line_number));
	if (function)
	{
		JS_SetPropertyStr(bt->context, entry, "function", JS_NewString(bt->context, function));
	}
	JS_SetPropertyUint32(bt->context, bt->array, bt->count++, entry);
	return 0;
}

static void _tf_backtrace_error(void* data, const char* message, int error)
{
	backtrace_t* bt = data;
	JSValue entry = JS_NewObject(bt->context);
	if (message)
	{
		JS_SetPropertyStr(bt->context, entry, "error", JS_NewString(bt->context, message));
	}
	JS_SetPropertyStr(bt->context, entry, "code", JS_NewInt32(bt->context, error));
	JS_SetPropertyUint32(bt->context, bt->array, bt->count++, entry);
}

static JSValue _tf_task_getDebug(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	JSValue result = JS_NewObject(context);

	JSValue promises = JS_NewArray(context);
	JS_SetPropertyStr(context, result, "promises", promises);
	int j = 0;
	for (int i = 0; i < task->_promise_stack_count; i++)
	{
		if (task->_promise_stacks[i].count)
		{
			JSValue entry = JS_NewObject(context);
			JS_SetPropertyStr(context, entry, "stack", JS_NewString(context, task->_promise_stacks[i].stack));
			if (task->_promise_stacks[i].cstack_count)
			{
				JSValue cstack = JS_NewArray(context);
				backtrace_t bt =
				{
					.context = context,
					.array = cstack,
				};
				for (int k = 0; k < task->_promise_stacks[i].cstack_count; k++)
				{
					backtrace_pcinfo(
						g_backtrace_state, 
						(uintptr_t)task->_promise_stacks[i].cstack[k],
						_tf_backtrace_callback,
						_tf_backtrace_error,
						&bt);

				}
				JS_SetPropertyStr(context, entry, "cstack", cstack);
			}
			JS_SetPropertyStr(context, entry, "count", JS_NewInt32(context, task->_promise_stacks[i].count));
			JS_SetPropertyUint32(context, promises, j++, entry);
		}
	}

	return result;
}

static JSValue _tf_task_getFile(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
{
	tf_task_t* task = JS_GetContextOpaque(context);
	const char* name = JS_ToCString(context, argv[0]);
	JSValue result = JS_GetPropertyStr(context, task->_loadedFiles, name);
	JS_FreeCString(context, name);
	return result;
}

const char* _tf_task_get_message_type(tf_task_message_t type)
{
	switch (type)
	{
	case kResolvePromise: return "kResolvePromise";
	case kRejectPromise: return "kRejectPromise";
	case kInvokeExport: return "kInvokeExport";
	case kReleaseExport: return "kReleaseExport";
	case kReleaseImport: return "kReleaseImport";
	case kActivate: return "kActivate";
	case kExecute: return "kExecute";
	case kKill: return "kKill";
	case kSetImports: return "kSetImports";
	case kGetExports: return "kGetExports";
	case kLoadFile: return "kLoadFile";
	case kTaskError: return "kTaskError";
	case kTaskTrace: return "kTaskTrace";
	case kPrint: return "kPrint";
	}
	return "unknown";
}

void tf_task_on_receive_packet(int packetType, const char* begin, size_t length, void* userData)
{
	tf_taskstub_t* stub = userData;
	tf_taskstub_t* from = stub;
	tf_task_t* to = tf_taskstub_get_owner(stub);
	tf_trace_begin(to->_trace, _tf_task_get_message_type(packetType));

	switch (packetType)
	{
	case kInvokeExport:
		{
			promiseid_t promise;
			exportid_t exportId;
			memcpy(&promise, begin, sizeof(promise));
			memcpy(&exportId, begin + sizeof(promise), sizeof(exportId));

			JSValue result = _task_invokeExport_internal(from, to, exportId, begin + sizeof(promiseid_t) + sizeof(exportid_t), length - sizeof(promiseid_t) - sizeof(exportid_t));
			if (JS_IsException(result))
			{
				_tf_task_sendPromiseReject(to, from, promise, result);
			}
			else
			{
				_tf_task_sendPromiseResolve(to, from, promise, result);
			}
			JS_FreeValue(to->_context, result);
		}
		break;
	case kResolvePromise:
	case kRejectPromise:
		{
			JSValue arg = JS_UNDEFINED;
			promiseid_t promise;
			memcpy(&promise, begin, sizeof(promiseid_t));
			if (length > sizeof(promiseid_t))
			{
				arg = tf_serialize_load(to, from, begin + sizeof(promiseid_t), length - sizeof(promiseid_t));
			}
			if (packetType == kResolvePromise)
			{
				tf_task_resolve_promise(to, promise, arg);
			}
			else
			{
				tf_task_reject_promise(to, promise, arg);
			}
			JS_FreeValue(to->_context, arg);
		}
		break;
	case kReleaseExport:
		{
			assert(length == sizeof(exportid_t));
			exportid_t exportId;
			memcpy(&exportId, begin, sizeof(exportId));
			export_record_t** it = _task_get_export(to, exportId);
			if (it)
			{
				_export_record_release(to, it);
			}
		}
		break;
	case kReleaseImport:
		{
			assert(length == sizeof(exportid_t));
			exportid_t exportId;
			memcpy(&exportId, begin, sizeof(exportId));
			import_record_t** it = _tf_task_find_import(to, tf_taskstub_get_id(from), exportId);
			if (it)
			{
				_import_record_release(it);
			}
		}
		break;
	case kLoadFile:
		{
			JSValue args = tf_serialize_load(to, from, begin, length);
			JSValue key = JS_GetPropertyUint32(to->_context, args, 0);
			JSValue content = JS_GetPropertyUint32(to->_context, args, 1);
			const char* name = JS_ToCString(to->_context, key);
			JS_SetPropertyStr(to->_context, to->_loadedFiles, name, JS_DupValue(to->_context, content));
			JS_FreeCString(to->_context, name);
			JS_FreeValue(to->_context, key);
			JS_FreeValue(to->_context, content);
			JS_FreeValue(to->_context, args);
		}
		break;
	case kActivate:
		tf_task_activate(to);
		break;
	case kExecute:
		{
			assert(length >= sizeof(promiseid_t));
			promiseid_t promise;
			memcpy(&promise, begin, sizeof(promiseid_t));
			JSValue value = tf_serialize_load(to, from, begin + sizeof(promiseid_t), length - sizeof(promiseid_t));
			JSValue source = JS_GetPropertyStr(to->_context, value, "source");
			JSValue name_val = JS_GetPropertyStr(to->_context, value, "name");
			const char* name = JS_ToCString(to->_context, name_val);
			JS_FreeValue(to->_context, name_val);
			JS_FreeValue(to->_context, value);

			JSValue utf8 = tf_util_utf8_decode(to->_context, source);
			JS_FreeValue(to->_context, source);
			const char* source_str = JS_ToCString(to->_context, utf8);
			JS_FreeValue(to->_context, utf8);
			JSValue result = _tf_task_executeSource(to, source_str, name);
			if (JS_IsException(result))
			{
				JSValue exception = JS_GetException(to->_context);
				_tf_task_sendPromiseReject(to, from, promise, exception);
				JS_FreeValue(to->_context, exception);
			}
			else
			{
				_tf_task_sendPromiseResolve(to, from, promise, result);
			}
			JS_FreeValue(to->_context, result);
			JS_FreeCString(to->_context, source_str);
			JS_FreeCString(to->_context, name);
		}
		break;
	case kKill:
		exit(1);
		break;
	case kSetImports:
		{
			JSValue global = JS_GetGlobalObject(to->_context);
			JSValue imports = tf_serialize_load(to, from, begin, length);

			JSPropertyEnum* ptab;
			uint32_t plen;
			JS_GetOwnPropertyNames(to->_context, &ptab, &plen, imports, JS_GPN_STRING_MASK);
			for (uint32_t i = 0; i < plen; ++i)
			{
				JSPropertyDescriptor desc;
				if (JS_GetOwnProperty(to->_context, &desc, imports, ptab[i].atom) == 1)
				{
					JS_SetProperty(to->_context, global, ptab[i].atom, desc.value);
					JS_FreeValue(to->_context, desc.setter);
					JS_FreeValue(to->_context, desc.getter);
				}
				JS_FreeAtom(to->_context, ptab[i].atom);
			}
			js_free(to->_context, ptab);

			JS_FreeValue(to->_context, imports);
			JS_FreeValue(to->_context, global);
		}
		break;
	case kGetExports:
		{
			promiseid_t promise;
			assert(length >= sizeof(promise));
			memcpy(&promise, begin, sizeof(promiseid_t));
			JSValue global = JS_GetGlobalObject(to->_context);
			JSValue exportObject = JS_GetPropertyStr(to->_context, global, "exports");
			_tf_task_sendPromiseResolve(to, from, promise, exportObject);
			JS_FreeValue(to->_context, exportObject);
			JS_FreeValue(to->_context, global);
		}
		break;
	case kTaskError:
		{
			JSValue error = tf_serialize_load(to, from, begin, length);
			tf_taskstub_on_error(from, error);
			JS_FreeValue(to->_context, error);
		}
		break;
	case kPrint:
		{
			JSValue arguments = tf_serialize_load(to, from, begin, length);
			tf_taskstub_on_print(from, arguments);
			JS_FreeValue(to->_context, arguments);
		}
		break;
	case kTaskTrace:
		tf_trace_raw(to->_trace, begin, length);
		break;
	}
	tf_trace_end(to->_trace);
}

static JSValue _tf_task_executeSource(tf_task_t* task, const char* source, const char* name)
{
	tf_trace_begin(task->_trace, "_tf_task_executeSource");
	JSValue result = JS_Eval(task->_context, source, strlen(source), name, JS_EVAL_TYPE_MODULE);
	if (!*task->_scriptName)
	{
		snprintf(task->_scriptName, sizeof(task->_scriptName), "%s", name);
	}
	tf_trace_end(task->_trace);
	return result;
}

uv_loop_t* tf_task_get_loop(tf_task_t* task)
{
	return &task->_loop;
}

tf_trace_t* tf_task_get_trace(tf_task_t* task)
{
	return task->_trace;
}

static int _promise_compare(const void* a, const void* b)
{
	promiseid_t ida = (promiseid_t)(intptr_t)a;
	const promise_t* pb = b;
	return ida < pb->id ? -1 : pb->id < ida ? 1 : 0;
}

static promise_t* _tf_task_find_promise(tf_task_t* task, promiseid_t id)
{
	if (!task->_promises)
	{
		return NULL;
	}
	promise_t* it = bsearch((void*)(intptr_t)id, task->_promises, task->_promise_count, sizeof(promise_t), _promise_compare);
	return it ? it : NULL;
}

static int _promise_stack_compare(const void* a, const void* b)
{
	const uint32_t* pa = a;
	const promise_stack_t* pb = b;
	return *pa < pb->hash ? -1 : *pa > pb->hash ? 1 : 0;
}

static void _add_promise_stack(tf_task_t* task, uint32_t hash, const char* stack, void** buffer, int count)
{
	int index = tf_util_insert_index(&hash, task->_promise_stacks, task->_promise_stack_count, sizeof(promise_stack_t), _promise_stack_compare);
	if (index < task->_promise_stack_count && task->_promise_stacks[index].hash == hash)
	{
		task->_promise_stacks[index].count++;
	}
	else
	{
		task->_promise_stacks = tf_resize_vec(task->_promise_stacks, sizeof(promise_stack_t) * (task->_promise_stack_count + 1));
		if (task->_promise_stack_count - index)
		{
			memmove(task->_promise_stacks + index + 1, task->_promise_stacks + index, sizeof(promise_stack_t) * (task->_promise_stack_count - index));
		}
		task->_promise_stacks[index] = (promise_stack_t) { .hash = hash, .stack = tf_strdup(stack), .count = 1, .cstack_count = count };
		memcpy(task->_promise_stacks[index].cstack, buffer, sizeof(void*) * count);
		task->_promise_stack_count++;
	}
}

static void _remove_promise_stack(tf_task_t* task, uint32_t hash)
{
	promise_stack_t* found = bsearch(&hash, task->_promise_stacks, task->_promise_stack_count, sizeof(promise_stack_t), _promise_stack_compare);
	if (found)
	{
		found->count--;
	}
}

static void _tf_task_free_promise(tf_task_t* task, promiseid_t id)
{
	promise_t* it = bsearch((void*)(intptr_t)id, task->_promises, task->_promise_count, sizeof(promise_t), _promise_compare);
	if (it)
	{
		_remove_promise_stack(task, it->stack_hash);
		int index = it - task->_promises;
		memmove(it, it + 1, sizeof(promise_t) * (task->_promise_count - index - 1));
		task->_promise_count--;
	}
}

uint32_t fnv32a(const void* buffer, int length, uint32_t start)
{
	uint32_t result = 0x811c9dc5;
	for (int i = 0; i < length; i++)
	{
		result ^= ((const uint8_t*)buffer)[i];
		result += (result << 1) + (result << 4) + (result << 7) + (result << 8) + (result << 24);
	}
	return result;
}

JSValue tf_task_allocate_promise(tf_task_t* task, promiseid_t* out_promise)
{
	JSValue error = JS_ThrowInternalError(task->_context, "promise callstack");
	JSValue exception = JS_GetException(task->_context);
	JSValue stack_value = JS_GetPropertyStr(task->_context, exception, "stack");
	size_t length = 0;
	const char* stack = JS_ToCStringLen(task->_context, &length, stack_value);
	uint32_t stack_hash = fnv32a((const void*)stack, (int)length, 0);
	int count = 0;
	void* buffer[32];
#ifdef _WIN32
	count = CaptureStackBackTrace(0, sizeof(buffer) / sizeof(*buffer), buffer, NULL);
	stack_hash = fnv32a((const void*)buffer, sizeof(void*) * count, stack_hash);
#elif !defined(__ANDROID__)
	count = backtrace(buffer, sizeof(buffer) / sizeof(*buffer));
	stack_hash = fnv32a((const void*)buffer, sizeof(void*) * count, stack_hash);
#endif
	_add_promise_stack(task, stack_hash, stack, buffer, count);
	JS_FreeCString(task->_context, stack);
	JS_FreeValue(task->_context, stack_value);
	JS_FreeValue(task->_context, exception);
	JS_FreeValue(task->_context, error);

	promiseid_t promiseId;
	do {
		promiseId = task->_nextPromise++;
	} while (_tf_task_find_promise(task, promiseId) || !promiseId);

	promise_t promise =
	{
		.id = promiseId,
		.values = { JS_NULL, JS_NULL },
		.stack_hash = stack_hash,
	};
	JSValue result = JS_NewPromiseCapability(task->_context, promise.values);
	int index = tf_util_insert_index((void*)(intptr_t)promiseId, task->_promises, task->_promise_count, sizeof(promise_t), _promise_compare);
	task->_promises = tf_resize_vec(task->_promises, sizeof(promise_t) * (task->_promise_count + 1));
	if (task->_promise_count - index)
	{
		memmove(task->_promises + index + 1, task->_promises + index, sizeof(promise_t) * (task->_promise_count - index));
	}
	task->_promises[index] = promise;
	task->_promise_count++;
	*out_promise = promiseId;
	return result;
}

void tf_task_resolve_promise(tf_task_t* task, promiseid_t promise, JSValue value)
{
	promise_t* it = _tf_task_find_promise(task, promise);
	if (it)
	{
		JSValue result = JS_Call(task->_context, it->values[0], JS_UNDEFINED, 1, &value);
		tf_util_report_error(task->_context, result);
		JS_FreeValue(task->_context, it->values[0]);
		JS_FreeValue(task->_context, it->values[1]);
		JS_FreeValue(task->_context, result);
		_tf_task_free_promise(task, promise);
	}
	else
	{
		printf("Didn't find promise %d to resolve.\n", promise);
		abort();
	}
}

void tf_task_reject_promise(tf_task_t* task, promiseid_t promise, JSValue value)
{
	promise_t* it = _tf_task_find_promise(task, promise);
	if (it)
	{
		JSValue arg = value;
		bool free_arg = false;
		if (JS_IsException(value))
		{
			arg = JS_GetException(task->_context);
			free_arg = true;
		}
		JSValue result = JS_Call(task->_context, it->values[1], JS_UNDEFINED, 1, &arg);
		tf_util_report_error(task->_context, result);
		if (free_arg)
		{
			JS_FreeValue(task->_context, arg);
		}
		JS_FreeValue(task->_context, it->values[0]);
		JS_FreeValue(task->_context, it->values[1]);
		JS_FreeValue(task->_context, result);
		_tf_task_free_promise(task, promise);
	}
	else
	{
		printf("Didn't find promise %d to reject.\n", promise);
		abort();
	}
}

static void _promise_release_for_task(tf_task_t* task, taskid_t task_id)
{
	bool more = true;
	while (more)
	{
		more = false;
		for (int i = 0; i < task->_promise_count; i++)
		{
			const promise_t* promise = &task->_promises[i];
			if (promise->task == task_id)
			{
				tf_task_reject_promise(task, promise->id, JS_ThrowInternalError(task->_context, "Task is gone."));
				more = true;
			}
		}
	}
}

taskid_t tf_task_allocate_task_id(tf_task_t* task, tf_taskstub_t* stub)
{
	taskid_t id = 0;
	do {
		id = task->_nextTask++;
	} while (id == k_task_parent_id || _tf_task_get_stub(task, id));

	task_child_node_t* node = tf_malloc(sizeof(task_child_node_t));
	*node = (task_child_node_t)
	{
		.id = id,
		.stub = stub,
		.next = task->_children,
	};
	task->_children = node;
	task->_child_count++;
	return id;
}

void tf_task_remove_child(tf_task_t* task, tf_taskstub_t* child)
{
	_import_record_release_for_task(task, tf_taskstub_get_id(child));
	_export_record_release_for_task(task, tf_taskstub_get_id(child));
	_promise_release_for_task(task, tf_taskstub_get_id(child));
	for (task_child_node_t** it = &task->_children;
		*it;
		it = &(*it)->next)
	{
		if ((*it)->stub == child)
		{
			task_child_node_t* node = *it;
			*it = node->next;
			tf_free(node);
			task->_child_count--;
			break;
		}
	}
}

static void _import_finalizer(JSRuntime* runtime, JSValue value)
{
	import_record_t* import = JS_GetOpaque(value, _import_class_id);
	if (import)
	{
		import->_function = JS_UNDEFINED;
		import_record_t** it = _tf_task_find_import(import->_owner, import->_task, import->_export);
		_import_record_release(it);
	}
}

static void _import_mark_func(JSRuntime* runtime, JSValueConst value, JS_MarkFunc mark_func)
{
	import_record_t* import = JS_GetOpaque(value, _import_class_id);
	if (import && import->_useCount > 0)
	{
		JS_MarkValue(runtime, import->_function, mark_func);
	}
}

static void _tf_task_promise_rejection_tracker(JSContext* context, JSValueConst promise, JSValueConst reason, JS_BOOL is_handled, void* user_data)
{
	if (!is_handled)
	{
		tf_util_report_error(context, reason);
	}
}

static void _tf_task_gc_timer(uv_timer_t* timer)
{
	tf_task_t* task = timer->data;
	JS_RunGC(task->_runtime);
}

static void _tf_task_trace_timer(uv_timer_t* timer)
{
	tf_task_t* task = timer->data;
	uint64_t hrtime = uv_hrtime();
	uint64_t idle_time = uv_metrics_idle_time(&task->_loop);
	task->idle_percent = (hrtime - task->last_hrtime) ? 100.0f * (idle_time - task->last_idle_time) / (hrtime - task->last_hrtime) : 0.0f;
	task->last_hrtime = hrtime;
	task->last_idle_time = idle_time;
	const char* k_names[] =
	{
		"child_tasks",
		"imports",
		"exports",
		"promises",
		"idle_percent",
	};
	int64_t values[] =
	{
		task->_child_count,
		task->_import_count,
		task->_export_count,
		task->_promise_count,
		(int64_t)task->idle_percent,
	};
	tf_trace_counter(task->_trace, "task", sizeof(k_names) / sizeof(*k_names), k_names, values);
}

static bool _tf_task_run_jobs(tf_task_t* task)
{
	if (JS_IsJobPending(task->_runtime))
	{
		JSContext* context = NULL;
		int r = JS_ExecutePendingJob(task->_runtime, &context);
		JSValue result = JS_GetException(context);
		if (context)
		{
			tf_util_report_error(context, result);
			JS_FreeValue(context, result);
		}
		if (r < 0)
		{
			js_std_dump_error(context);
		}
		else
		{
			return r != 0;
		}
	}
	return 0;
}

static void _tf_task_run_jobs_idle(uv_idle_t* idle)
{
	tf_task_t* task = idle->data;
	if (!_tf_task_run_jobs(task))
	{
		/* No more jobs.  Don't try again as actively. */
		uv_idle_stop(&task->idle);
		uv_prepare_start(&task->prepare, _tf_task_run_jobs_prepare);
	}
}

static void _tf_task_run_jobs_prepare(uv_prepare_t* prepare)
{
	tf_task_t* task = prepare->data;
	if (_tf_task_run_jobs(task))
	{
		/* More jobs.  We can run again immediately. */
		uv_idle_start(&task->idle, _tf_task_run_jobs_idle);
		uv_prepare_stop(&task->prepare);
	}
}

JSModuleDef* _tf_task_module_loader(JSContext* context, const char* module_name, void* opaque)
{
	tf_task_t* task = opaque;
	JSValue source_value = JS_GetPropertyStr(context, task->_loadedFiles, module_name);
	char* source = NULL;
	size_t length = 0;

	if (!JS_IsUndefined(source_value))
	{
		uint8_t* array = tf_util_try_get_array_buffer(context, &length, source_value);
		if (array)
		{
			source = tf_malloc(length + 1);
			memcpy(source, array, length);
			source[length] = '\0';
		}
		JS_FreeValue(context, source_value);
	}

	if (!source && task->_trusted)
	{
		source = (char*)_task_loadFile(module_name);
		length = source ? strlen(source) : 0;
	}

	if (!source)
	{
		JS_ThrowReferenceError(context, "Could not load '%s'.", module_name);
		return NULL;
	}

	JSValue result = JS_Eval(context, source, length, module_name, JS_EVAL_TYPE_MODULE | JS_EVAL_FLAG_COMPILE_ONLY);
	tf_free(source);
	if (tf_util_report_error(task->_context, result))
	{
		return NULL;
	}

	JSModuleDef* module = JS_VALUE_GET_PTR(result);
	JS_FreeValue(context, result);
	return module;
}

tf_task_t* tf_task_create()
{
	tf_task_t* task = tf_malloc(sizeof(tf_task_t));
	*task = (tf_task_t) { 0 };
	++_count;

	JSMallocFunctions funcs = { 0 };
	tf_get_js_malloc_functions(&funcs);
	task->_runtime = JS_NewRuntime2(&funcs, NULL);
	task->_context = JS_NewContext(task->_runtime);
	JS_SetContextOpaque(task->_context, task);

	JS_SetHostPromiseRejectionTracker(task->_runtime, _tf_task_promise_rejection_tracker, task);

	JS_SetModuleLoaderFunc(task->_runtime, NULL, _tf_task_module_loader, task);

	JS_NewClassID(&_import_class_id);
	JSClassDef def =
	{
		.class_name = "imported_function",
		.finalizer = _import_finalizer,
		.gc_mark = _import_mark_func,
		.call = _import_call,
	};
	JS_NewClass(task->_runtime, _import_class_id, &def);
	task->_loadedFiles = JS_NewObject(task->_context);
	uv_loop_init(&task->_loop);
	uv_loop_configure(&task->_loop, UV_METRICS_IDLE_TIME);
	task->_loop.data = task;
	task->trace_timer.data = task;
	uv_timer_init(&task->_loop, &task->trace_timer);
	uv_timer_start(&task->trace_timer, _tf_task_trace_timer, 100, 100);
	uv_unref((uv_handle_t*)&task->trace_timer);
	task->gc_timer.data = task;
	uv_timer_init(&task->_loop, &task->gc_timer);
	uv_timer_start(&task->gc_timer, _tf_task_gc_timer, 10000, 10000);
	uv_unref((uv_handle_t*)&task->gc_timer);
	task->idle.data = task;
	uv_idle_init(&task->_loop, &task->idle);
	uv_unref((uv_handle_t*)&task->idle);
	task->prepare.data = task;
	uv_prepare_init(&task->_loop, &task->prepare);
	uv_unref((uv_handle_t*)&task->prepare);
	uv_idle_start(&task->idle, _tf_task_run_jobs_idle);
	return task;
}

void tf_task_configure_from_stdin(tf_task_t* task)
{
	task->_parent = tf_taskstub_create_parent(task, STDIN_FILENO);
}

static void _tf_task_trace_to_parent(tf_trace_t* trace, const char* buffer, size_t size, void* user_data)
{
	tf_task_t* task = user_data;
	tf_packetstream_send(tf_taskstub_get_stream(task->_parent), kTaskTrace, buffer, size);
}

void tf_task_activate(tf_task_t* task)
{
	assert(!task->_activated);
	task->_activated = true;

	JSContext* context = task->_context;
	JSValue global = JS_GetGlobalObject(context);
	JSValue e = JS_NewObject(context);
	JS_SetPropertyStr(context, global, "exports", e);

	JSAtom atom = JS_NewAtom(context, "parent");
	JS_DefinePropertyGetSet(context, global, atom, JS_NewCFunction(context, _tf_task_get_parent, "parent", 0), JS_UNDEFINED, 0);
	JS_FreeAtom(context, atom);

	JSValue tildefriends = JS_NewObject(context);
	JS_SetPropertyStr(context, tildefriends, "ssb_port", JS_NewInt32(context, task->_ssb_port));
	JS_SetPropertyStr(context, tildefriends, "http_port", JS_NewInt32(context, task->_http_port));
	JS_SetPropertyStr(context, tildefriends, "https_port", JS_NewInt32(context, task->_https_port));
	JSValue args = JS_NewObject(context);
	JS_SetPropertyStr(context, tildefriends, "args", args);
	if (task->_args)
	{
		char* saveptr = NULL;
		char* copy = tf_strdup(task->_args);
		char* start = copy;
		while (true)
		{
			char* assignment = strtok_r(start, ",", &saveptr);
			start = NULL;
			if (!assignment)
			{
				break;
			}
			char* equals = strchr(assignment, '=');
			if (equals)
			{
				*equals = '\0';
				JS_SetPropertyStr(context, args, assignment, JS_NewString(context, equals + 1));
			}
			else
			{
				printf("Assignment missing '=': %s.\n", assignment);
				exit(1);
			}
		}
		tf_free(copy);
	}
	JS_SetPropertyStr(context, global, "tildefriends", tildefriends);

	task->_trace = tf_trace_create();
	if (task->_trusted)
	{
		sqlite3_open(*task->_db_path ? task->_db_path : "db.sqlite", &task->_db);

		JS_SetPropertyStr(context, global, "Task", tf_taskstub_register(context));
		JS_SetPropertyStr(context, global, "Socket", tf_socket_register(context));
		JS_SetPropertyStr(context, global, "TlsContext", tf_tls_context_register(context));
		tf_file_register(context);
		tf_database_register(context, task->_db);

		task->_ssb = tf_ssb_create(&task->_loop, task->_context, task->_db);
		tf_ssb_set_trace(task->_ssb, task->_trace);
		tf_ssb_register(context, task->_ssb);

		if (task->_ssb_port)
		{
			tf_ssb_broadcast_listener_start(task->_ssb, false);
			tf_ssb_broadcast_sender_start(task->_ssb);
			tf_ssb_server_open(task->_ssb, task->_ssb_port);
		}

		JS_SetPropertyStr(context, global, "trace", JS_NewCFunction(context, _tf_task_trace, "trace", 1));
		JS_SetPropertyStr(context, global, "getStats", JS_NewCFunction(context, _tf_task_getStats, "getStats", 0));
		JS_SetPropertyStr(context, global, "getDebug", JS_NewCFunction(context, _tf_task_getDebug, "getDebug", 0));
	}
	else
	{
		tf_trace_set_write_callback(task->_trace, _tf_task_trace_to_parent, task);
	}

	tf_bcrypt_register(context);
	tf_util_register(context);
	JS_SetPropertyStr(context, global, "exit", JS_NewCFunction(context, _tf_task_exit, "exit", 1));
	JS_SetPropertyStr(context, global, "version", JS_NewCFunction(context, _tf_task_version, "version", 0));
	JS_SetPropertyStr(context, global, "getFile", JS_NewCFunction(context, _tf_task_getFile, "getFile", 1));
	JS_FreeValue(context, global);
}

void tf_task_run(tf_task_t* task)
{
	do
	{
		uv_run(&task->_loop, UV_RUN_DEFAULT);
	} while (_tf_task_run_jobs(task));
}

void tf_task_set_trusted(tf_task_t* task, bool trusted)
{
	task->_trusted = trusted;
}

JSContext* tf_task_get_context(tf_task_t* task)
{
	return task->_context;
}

tf_ssb_t* tf_task_get_ssb(tf_task_t* task)
{
	return task->_ssb;
}

static void _tf_task_on_handle_close(uv_handle_t* handle)
{
	handle->data = NULL;
}

void tf_task_destroy(tf_task_t* task)
{
	for (int i = 0; i < task->_import_count; i++)
	{
		JS_FreeValue(task->_context, task->_imports[i]->_function);
		tf_free(task->_imports[i]);
	}
	tf_free(task->_imports);
	task->_imports = NULL;
	task->_import_count = 0;

	for (int i = 0; i < task->_export_count; i++)
	{
		JS_FreeValue(task->_context, task->_exports[i]->_function);
		tf_free(task->_exports[i]);
	}
	tf_free(task->_exports);
	task->_exports = NULL;
	task->_export_count = 0;

	while (task->_children)
	{
		task_child_node_t* node = task->_children;
		tf_taskstub_destroy(node->stub);
		task->_children = node->next;
		tf_free(node);
	}
	if (task->_parent)
	{
		JS_FreeValue(task->_context, tf_taskstub_get_task_object(task->_parent));
	}
	while (task->_promise_count)
	{
		tf_task_reject_promise(task, task->_promises[task->_promise_count - 1].id, JS_NULL);
	}
	tf_free(task->_promises);
	task->_promises = NULL;
	JS_FreeValue(task->_context, task->_loadedFiles);

	if (task->_ssb)
	{
		tf_ssb_destroy(task->_ssb);
	}
	JS_FreeContext(task->_context);
	JS_FreeRuntime(task->_runtime);

	if (task->_db)
	{
		sqlite3_close(task->_db);
	}

	if (task->trace_timer.data && !uv_is_closing((uv_handle_t*)&task->trace_timer))
	{
		uv_close((uv_handle_t*)&task->trace_timer, _tf_task_on_handle_close);
	}
	if (task->gc_timer.data && !uv_is_closing((uv_handle_t*)&task->gc_timer))
	{
		uv_close((uv_handle_t*)&task->gc_timer, _tf_task_on_handle_close);
	}
	uv_close((uv_handle_t*)&task->idle, _tf_task_on_handle_close);
	uv_close((uv_handle_t*)&task->prepare, _tf_task_on_handle_close);

	while (task->trace_timer.data ||
		task->gc_timer.data ||
		task->idle.data ||
		task->prepare.data)
	{
		uv_run(&task->_loop, UV_RUN_ONCE);
	}

	if (uv_loop_close(&task->_loop) != 0)
	{
		uv_print_all_handles(&task->_loop, stdout);
	}
	if (task->_trace)
	{
		tf_trace_destroy(task->_trace);
	}
	--_count;
	for (int i = 0; i < task->_promise_stack_count; i++)
	{
		tf_free((void*)task->_promise_stacks[i].stack);
	}
	tf_free(task->_promise_stacks);
	tf_free((void*)task->_path);
	tf_free(task);
}

JSValue tf_task_add_import(tf_task_t* task, taskid_t stub_id, exportid_t export_id)
{
	import_record_t** it = _tf_task_find_import(task, stub_id, export_id);
	if (it)
	{
		(*it)->_useCount++;
		return JS_DupValue(task->_context, (*it)->_function);
	}

	JSValue function = JS_NewObjectClass(task->_context, _import_class_id);
	import_record_t* import = tf_malloc(sizeof(import_record_t));
	JS_SetOpaque(function, import);
	*import = (import_record_t)
	{
		._function = function,
		._export = export_id,
		._owner = task,
		._task = stub_id,
		._useCount = 1,
	};

	int index = tf_util_insert_index(import, task->_imports, task->_import_count, sizeof(import_record_t*), _import_compare);
	task->_imports = tf_resize_vec(task->_imports, sizeof(import_record_t*) * (task->_import_count + 1));
	if (task->_import_count - index)
	{
		memmove(task->_imports + index + 1, task->_imports + index, sizeof(import_record_t*) * (task->_import_count - index));
	}
	task->_imports[index] = import;
	task->_import_count++;
	return JS_DupValue(task->_context, function);
}

void tf_task_print(tf_task_t* task, int argc, JSValueConst* argv)
{
	if (task->_parent)
	{
		JSValue array = JS_NewArray(task->_context);
		for (int i = 0; i < argc; i++)
		{
			JS_SetPropertyUint32(task->_context, array, i, JS_DupValue(task->_context, argv[i]));
		}

		void* buffer;
		size_t size;
		tf_serialize_store(task, task->_parent, &buffer, &size, array);
		tf_packetstream_send(tf_taskstub_get_stream(task->_parent), kPrint, buffer, size);
		tf_free(buffer);

		JS_FreeValue(task->_context, array);
	}
}

tf_task_t* tf_task_get(JSContext* context)
{
	return JS_GetContextOpaque(context);
}

void tf_task_set_ssb_port(tf_task_t* task, int port)
{
	task->_ssb_port = port;
}

void tf_task_set_http_port(tf_task_t* task, int port)
{
	task->_http_port = port;
}

void tf_task_set_https_port(tf_task_t* task, int port)
{
	task->_https_port = port;
}

void tf_task_set_db_path(tf_task_t* task, const char* db_path)
{
	snprintf(task->_db_path, sizeof(task->_db_path), "%s", db_path);
}

void tf_task_set_args(tf_task_t* task, const char* args)
{
	task->_args = args;
}

const char* tf_task_get_name(tf_task_t* task)
{
	return task->_scriptName;
}