External messaging.

CMakeLists.txt

@@ -99,6 +99,7 @@ endif()
 set(TOIT_GENERIC_FLAGS "${TOIT_GENERIC_FLAGS} -Wall -ffunction-sections -fdata-sections")
 
 include_directories(
+  "${TOIT_SDK_SOURCE_DIR}/include"
   "${IDF_PATH}/components/mbedtls/mbedtls/include"
   )
 

Makefile

@@ -55,11 +55,11 @@ else
 endif
 
 .PHONY: all
-all: sdk
+all: sdk build-test-assets
 
 .PHONY: debug
 debug:
-	LOCAL_CXXFLAGS="-O0" $(MAKE) BUILD_TYPE=Debug
+	cmake -E env LOCAL_CFLAGS="-O0" LOCAL_CXXFLAGS="-O0" $(MAKE) BUILD_TYPE=Debug
 
 .PHONY: sdk
 sdk: tools toit-tools version-file

include/toit/toit.h

@@ -0,0 +1,86 @@
+// Copyright (C) 2024 Toitware ApS.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 only.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// The license can be found in the file `LICENSE` in the top level
+// directory of this repository.
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#else
+#include <stdbool.h>
+#endif
+
+/*
+ * C interface for Toit's external API.
+ */
+
+typedef enum {
+  // The operation succeeded.
+  TOIT_ERR_SUCCESS = 0,
+  // The operation encountered an out-of-memory error.
+  TOIT_ERR_OOM,
+  // An error, for when the receiver of a system message didn't exist.
+  TOIT_ERR_NO_SUCH_RECEIVER,
+  // The corresponding resource was not found.
+  TOIT_ERR_NOT_FOUND,
+  // An unknown error.
+  TOIT_ERR_ERROR,
+} toit_err_t;
+
+const int TOIT_MSG_RESERVED_TYPES = 64;
+
+struct toit_msg_context_t;
+typedef struct toit_msg_context_t toit_msg_context_t;
+
+typedef struct {
+  int sender;
+  int request_handle;
+  toit_msg_context_t* context;
+} toit_msg_request_handle_t;
+
+typedef toit_err_t (*toit_msg_on_created_cb_t)(void* user_data, toit_msg_context_t* context);
+typedef toit_err_t (*toit_msg_on_message_cb_t)(void* user_data, int sender, void* data, int length);
+typedef toit_err_t (*toit_msg_on_request_cb_t)(void* user_data,
+                                               int sender,
+                                               int function,
+                                               toit_msg_request_handle_t rpc_handle,
+                                               void* data, int length);
+typedef toit_err_t (*toit_msg_on_removed_cb_t)(void* user_data);
+
+typedef struct toit_msg_cbs_t {
+  toit_msg_on_created_cb_t on_created;
+  toit_msg_on_message_cb_t on_message;
+  toit_msg_on_request_cb_t on_rpc_request;
+  toit_msg_on_removed_cb_t on_removed;
+} toit_msg_cbs_t;
+
+toit_err_t toit_msg_add_handler(const char* id,
+                                void* user_data,
+                                toit_msg_cbs_t cbs);
+
+toit_err_t toit_msg_remove_handler(toit_msg_context_t* context);
+
+toit_err_t toit_msg_notify(toit_msg_context_t* context,
+                           int target_pid,
+                           void* data, int length,
+                           bool free_on_failure);
+
+toit_err_t toit_msg_request_reply(toit_msg_request_handle_t handle, void* data, int length, bool free_on_failure);
+toit_err_t toit_msg_request_fail(toit_msg_request_handle_t handle, const char* error);
+
+toit_err_t toit_gc();
+
+#ifdef __cplusplus
+}
+#endif

lib/core/message_.toit

@@ -14,6 +14,11 @@ SYSTEM-RPC-CANCEL_            ::= 5
 SYSTEM-RPC-NOTIFY-TERMINATED_ ::= 6
 SYSTEM-RPC-NOTIFY-RESOURCE_   ::= 7
 
+// System message types for external notifications.
+SYSTEM-EXTERNAL_NOTIFICATION_ ::= 8
+
+RESERVED-MESSAGE-TYPES_ ::= 64
+
 /**
 Sends the $message with $type to the process identified by $pid and
   returns whether the $message was delivered.
@@ -29,6 +34,14 @@ process-send_ pid/int type/int message -> bool:
       serialization-failure_ it[0]
     throw it
 
+/**
+Returns the process ID for the process with the given external $id.
+
+If no process with the external ID exists, returns -1.
+*/
+pid-for-external-id_ id/string -> int:
+  #primitive.core.pid-for-external-id
+
 /** Registered system message handlers for this process. */
 system-message-handlers_ ::= {:}
 
@@ -45,6 +58,12 @@ Sets the $handler as the system message handler for message of the $type.
 set-system-message-handler_ type/int handler/SystemMessageHandler_:
   system-message-handlers_[type] = handler
 
+/**
+Removes the handler for the given $type.
+*/
+clear-system-message-handler_ type/int:
+  system-message-handlers_.remove type
+
 /** Flag to track if we're currently processing messages. */
 is-processing-messages_ := false
 

lib/system/external.toit

@@ -0,0 +1,83 @@
+// Copyright (C) 2024 Toitware ApS. All rights reserved.
+// Use of this source code is governed by an MIT-style license that can be
+// found in the lib/LICENSE file.
+
+import io
+import rpc
+
+clients_ ::= {:}
+notification-listeners_ := 0
+notification-handler_/ExternalMessageHandler_? := null
+
+class Client:
+  pid/int
+  id/string
+  on-notify_/Lambda? := null
+  is-closed_/bool := false
+
+  constructor.private_ .pid .id .on-notify_:
+
+  static open id/string --on-notify/Lambda?=null -> Client?:
+    pid := pid-for-external-id_ id
+    if pid == -1: throw "NOT_FOUND"
+    if clients_.contains pid: throw "ALREADY_IN_USE"
+    result := Client.private_ pid id on-notify
+    clients_[pid] = result
+    return result
+
+  close -> none:
+    if is-closed_: return
+    // Go through the function so that the ref-counting is correct.
+    set-on-notify null
+    is-closed_ = true
+
+  is-closed -> bool:
+    return is-closed_
+
+  /** Helper to convert the $message to a ByteArray. */
+  encode-message_ message/io.Data --copy/bool -> ByteArray:
+    bytes/ByteArray := ?
+    if copy or message is not ByteArray:
+      bytes = ByteArray message.byte-size
+      message.write-to-byte-array bytes --at=0 0 message.byte-size
+    else:
+      bytes = message as ByteArray
+    return bytes
+
+  notify message/io.Data --copy/bool=true:
+    if is-closed_: throw "ALREADY_CLOSED"
+    bytes := encode-message_ message --copy=copy
+    process-send_ pid SYSTEM-EXTERNAL-NOTIFICATION_ bytes
+
+  request function/int message/ByteArray --copy/bool=true -> any:
+    if is-closed_: throw "ALREADY_CLOSED"
+    bytes := encode-message_ message --copy=copy
+    return rpc.invoke pid function bytes
+
+  set-on-notify callback/Lambda? -> none:
+    if is-closed_: throw "ALREADY_CLOSED"
+    if on-notify_ != null: notification-listeners_--
+    on-notify_ = callback
+    if callback:
+      notification-listeners_++
+    ExternalMessageHandler_.handle-listener-change
+
+class ExternalMessageHandler_ implements SystemMessageHandler_:
+  static TYPE ::= SYSTEM-EXTERNAL-NOTIFICATION_
+
+  close -> none:
+    clear-system-message-handler_ TYPE
+
+  on-message type/int gid/int pid/int argument -> none:
+    client/Client? := clients_.get pid
+    if not client: return
+    if client.on-notify_:
+      client.on-notify_.call argument
+
+  static handle-listener-change -> none:
+    if notification-listeners_ > 0 and not notification-handler_:
+      notification-handler_ = ExternalMessageHandler_
+      set-system-message-handler_ TYPE notification-handler_
+    else if notification-listeners_ <= 0 and notification-handler_:
+      notification-handler_.close
+      notification-handler_ = null

src/CMakeLists.txt

@@ -116,7 +116,6 @@ set_source_files_properties(interpreter_run.cc PROPERTIES COMPILE_OPTIONS "-O3;$
 set_source_files_properties(utils.cc PROPERTIES COMPILE_FLAGS "-DTOIT_MODEL=\"\\\"${TOIT_MODEL}\\\"\" -DVM_GIT_INFO=\"\\\"${VM_GIT_INFO}\\\"\" -DVM_GIT_VERSION=\"\\\"${TOIT_GIT_VERSION}\\\"\"")
 
 set(GEN_DIR "${PROJECT_BINARY_DIR}/generated")
-
 set(BOOT_SNAPSHOT ${GEN_DIR}/toit.run.snapshot)
 set(BOOT_SNAPSHOT_CC ${GEN_DIR}/toit.run.snapshot.cc)
 set(TOIT_SNAPSHOT ${GEN_DIR}/toit.snapshot)
@@ -131,6 +130,8 @@ add_custom_command(
   WORKING_DIRECTORY "${GEN_DIR}"
 )
 
+add_custom_target(build_boot_snapshot DEPENDS ${BOOT_SNAPSHOT_CC})
+
 add_custom_command(
   OUTPUT "${TOIT_SNAPSHOT_CC}"
   # We can't use ${TOIT_SNAPSHOT} here, as that would include the full path.

src/compiler/propagation/type_primitive_core.cc

@@ -248,6 +248,8 @@ TYPE_PRIMITIVE(process_send) {
   failure.add_array(program);
 }
 
+TYPE_PRIMITIVE_INT(pid_for_external_id)
+
 TYPE_PRIMITIVE(spawn) {
   result.add_smi(program);
   failure.add_string(program);