我运行nacl_sdk（pepper_39）的hello_nacl示例，一切都很好。 但我尝试在index.html上添加一些东西来发布消息到PNaCl，它不起作用并得到像这样的“NativeClient：NaCl模块崩溃”的错误。 这是我的index.html，任何人都可以告诉我出了什么问题？
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Expires" content="-1">
<script type="text/javascript">
var HelloTutorialModule = null;
function pageDidLoad() {
appendStatus('Page loaded');
HelloTutorialModule = document.getElementById('nacl_module');
HelloTutorialModule.postMessage('hello from HTML!!');
}
function appendStatus(opt_message) {
var statusField = document.getElementById('statusField');
if (statusField) {
var newElt = document.createElement("opt_message");
newElt.innerHTML = "<br>" + opt_message;
statusField.appendChild(newElt);
}
}
function handleMessage(message_event) {
appendStatus(message_event.data);
}
</script>
</head>
<body>
<div id="listener">
<script type="text/javascript">
var listener = document.getElementById('listener');
listener.addEventListener('message', handleMessage, true);
listener.addEventListener('load', pageDidLoad, true);
</script>
<h2>NaCl Module</h2>
<embed name="nacl_module"
id="nacl_module"
style="border-style: solid;"
width=200
height=200
src="newlib/hello_nacl.nmf"
type="application/x-nacl"/>
</div>
谢谢。
以下代码是我的hello_nacl.c
/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
// This project demonstrates how to migrate a Windows desktop app to Native
// Client, running first as a Win32 application (define STEP1), then as a PPAPI
// plugin (define STEP2 through STEP6), and finally as a Native Client module.
// Start with STEP1 defined and the defines for STEP2 through STEP6 commented
// out. For each step in the process, un-comment the next #define, leaving the
// previous ones on. Ready, set, port!
// *** SELECT THE WIN32 PLATFORM AND RUN WITH #define STEP1 ONLY ***
// #define STEP1
// Launches the original Windows desktop application, Hello World, which runs
// as WinMain. STEP1 encloses Windows-specific functions that are used with
// the WIN32 and PPAPI platforms. These will be removed when the full PPAPI
// port is finished (STEP6)
// *** SELECT THE PPAPI PLATFORM ***
#define STEP2
// What Changed: The platform launches Chrome, which will then load a Native
// Client Module. STEP2 encloses the Native Client module APIs needed to link
// any app to the browser. The module does nothing except report
// starting/ending the function Instance_DidCreate. The Windows app does not
// run because it is not being called.
#define STEP3
// What changed: Replace WinMain with WndProc, and call it from
// Instance_DidCreate, launching hello_nacl in its own window.
// Since WndProc spins in its message loop, the call to Instance_DidCreate
// never returns.
// Close the hello_nacl window and the module initialization will finish.
#define STEP4
// What changed: In WndProc replace the message loop with a callback function.
// Now the app window and the Native Client module are running concurrently.
#define STEP5
// What changed: Instance_DidCreate calls InitInstanceInBrowserWindow rather
// than InitInstanceInPCWindow.
// The InitInstanceInBrowserWindow uses postMessage to place text (now "Hello,
// Native Client") in the web page instead of opening and writing to a window.
#define STEP6
// What changed: All the Windows code is def'd out, to prove we are
// PPAPI-compliant. The functional code that is running is the same as STEP5.
// *** SELECT THE NACL64 PLATFORM AND RUN ***
// What changed: The code is the same as STEP6, but you are using the SDK
// toolchain to compile it into a nexe. The module is now running as a real
// Native Client executable in a NaCl sandbox, with nacl-gdb attached.
// *** RUN YOUR MODULE IN THE WILD ***
// You can run your nexe outside of Visual Studio, directly from Chrome by
// following these steps:
// - Build STEP6 and verify the file
// <project directory>/NaCl64/newlib/Debug/hello_nacl_64.nexe exists
// - Copy the folder <project directory> into your NaCl SDK's example
// directory.
// - Go to the NaCl SDK directory and launch the httpd.py server.
// - Launch Chrome, go to about:flags and enable the Native Client flag and
// relaunch Chrome
// - Point Chrome at http: //localhost:5103/hello_nacl
#ifdef STEP6
// remove Windows-dependent code.
#undef STEP1
#undef STEP3
#undef STEP4
#define NULL 0
#else
// includes for Windows APIs.
#include <windows.h>
#include <stdlib.h>
#include <tchar.h>
#endif
#ifdef STEP2
// includes for PPAPI
#include "ppapi/c/pp_errors.h"
#include "ppapi/c/pp_module.h"
#include "ppapi/c/pp_var.h"
#include "ppapi/c/ppb.h"
#include "ppapi/c/ppb_instance.h"
#include "ppapi/c/ppb_messaging.h"
#include "ppapi/c/ppb_var.h"
#include "ppapi/c/ppb_core.h"
#include "ppapi/c/ppp.h"
#include "ppapi/c/ppp_instance.h"
#include "ppapi/c/ppp_messaging.h"
#include <string.h>
#include <stdio.h>
#include <time.h>
// Native Client APIs
static PPB_Messaging* ppb_messaging_interface = NULL;
static PPB_Var* ppb_var_interface = NULL;
static PPB_Core* ppb_core_interface = NULL;
PP_Instance myInstance;
int InitInstanceInPCWindow();
void InitInstanceInBrowserWindow();
#endif
#ifdef STEP4
// Implements message handling in a callback function.
void HelloWorldCallbackFun(void* user_data, int32_t result);
struct PP_CompletionCallback HelloWorldCallback = {
HelloWorldCallbackFun, NULL };
void HelloWorldCallbackFun(void* user_data, int32_t result) {
MSG uMsg;
if (PeekMessage(&uMsg, NULL, 0, 0, PM_REMOVE)) {
TranslateMessage(&uMsg);
DispatchMessage(&uMsg);
}
ppb_core_interface->CallOnMainThread(100, HelloWorldCallback, 0);
}
#endif
#ifdef STEP2
// The basic framework needed for all Native Client Modules. Handles creation
// of the module instance and initial handshake with the browser.
/**
* Creates new string PP_Var from C string. Useful utility for
* message-handling.
*/
static struct PP_Var CStrToVar(const char* str) { if (ppb_var_interface !=
NULL) { return ppb_var_interface->VarFromUtf8(str, strlen(str)); } return
PP_MakeUndefined(); }
void InitInstanceInBrowserWindow() {
// Pass the text to the browser page, there is no separate app window
// anymore. The text is added as a new element to the page, it does not
// appear in the module's embed view.
ppb_messaging_interface->PostMessage(myInstance, CStrToVar("Hello, Native Client! XDDXDXD"));
}
/**
* Called when the NaCl module is instantiated on the web page.
*/
static PP_Bool Instance_DidCreate(PP_Instance instance,
uint32_t argc,
const char* argn[],
const char* argv[]) {
myInstance = instance;
ppb_messaging_interface->PostMessage(instance,
CStrToVar("Start Instance_DidCreate"));
#ifdef STEP5
// Will be included in STEP5 and STEP6
// Uses messaging to relay text to the module's view on the web page
InitInstanceInBrowserWindow();
#else
#ifdef STEP3
// Will be included in STEP3 and STEP4 only
// Uses WndProc to place text in a window separate from the browser.
InitInstanceInPCWindow();
#endif
#endif
ppb_messaging_interface->PostMessage(instance,
CStrToVar("End Instance_DidCreate"));
return PP_TRUE;
}
/**
* Called when the NaCl module is destroyed.
*/
static void Instance_DidDestroy(PP_Instance instance) {
ppb_messaging_interface->PostMessage(instance,
CStrToVar("Instance_DidDestroy"));
}
/**
* Called when the position, the size, or the clip rect of the element in the
* browser that corresponds to this NaCl module has changed.
*/
static void Instance_DidChangeView(PP_Instance instance,
PP_Resource view_resource) {
ppb_messaging_interface->PostMessage(instance,
CStrToVar("Instance_DidChangeView"));
}
/**
* Notification that the given NaCl module has gained or lost focus.
*/
static void Instance_DidChangeFocus(PP_Instance instance,
PP_Bool has_focus) {
ppb_messaging_interface->PostMessage(instance,
CStrToVar("Instance_DidChangeFocus"));
}
/**
* Handler that gets called after a full-frame module is instantiated based on
* registered MIME types. This function is not called on NaCl modules. This
* function is essentially a place-holder for the required function pointer in
* the PPP_Instance structure.
*/
static PP_Bool Instance_HandleDocumentLoad(PP_Instance instance,
PP_Resource url_loader) {
/* NaCl modules do not need to handle the document load function. */
ppb_messaging_interface->PostMessage(instance,
CStrToVar("Instance_HandleDocumentLoad...."));
return PP_FALSE;
}
static void HandleMessage(PP_Instance instance, struct PP_Var message){
//ppb_messaging_interface->PostMessage(instance, CStrToVar("Get Message From HTML"));
}
/**
* Entry points for the module.
* Initialize needed interfaces: PPB_Core, PPB_Messaging and PPB_Var.
*/
PP_EXPORT int32_t PPP_InitializeModule(PP_Module a_module_id,
PPB_GetInterface get_browser) {
ppb_messaging_interface = (PPB_Messaging*)
get_browser(PPB_MESSAGING_INTERFACE);
ppb_var_interface = (PPB_Var*)get_browser(PPB_VAR_INTERFACE);
ppb_core_interface = (PPB_Core*)get_browser(PPB_CORE_INTERFACE);
return PP_OK;
}
/**
* Returns an interface pointer for the interface of the given name, or NULL
* if the interface is not supported.
*/
PP_EXPORT const void* PPP_GetInterface(const char* interface_name) {
if (strcmp(interface_name, PPP_INSTANCE_INTERFACE) == 0) {
static PPP_Instance instance_interface = {
&Instance_DidCreate,
&Instance_DidDestroy,
&Instance_DidChangeView,
&Instance_DidChangeFocus,
&Instance_HandleDocumentLoad,
//&HandleMessage,
};
return &instance_interface;
}
return NULL;
}
/**
* Called before the plugin module is unloaded.
*/
PP_EXPORT void PPP_ShutdownModule() {
}
#endif
// **** Application Code ****
#ifdef STEP1
// Desktop Windows Hello World app. Native Client agnostic.
static TCHAR szWindowClass[] = _T("win32app");
static TCHAR szTitle[] = _T("hello_nacl");
HINSTANCE hInst;
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
// WinMain
int WINAPI WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow) {
WNDCLASSEX wcex;
HWND hWnd;
MSG msg;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_APPLICATION));
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = szWindowClass;
wcex.hIconSm = LoadIcon(wcex.hInstance,
MAKEINTRESOURCE(IDI_APPLICATION));
if (!RegisterClassEx(&wcex)) {
MessageBox(NULL,
_T("Call to RegisterClassEx failed!"),
_T("hello_nacl"),
0);
return 1;
}
hInst = hInstance;
hWnd = CreateWindow(
szWindowClass,
szTitle,
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
500, 100,
NULL,
NULL,
hInstance,
NULL);
if (!hWnd) {
MessageBox(NULL,
_T("Call to CreateWindow failed!"),
_T("hello_nacl"),
0);
return 1;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
// Main message loop:
while (GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
// WndProc
LRESULT CALLBACK WndProc(HWND hWnd, UINT message,
WPARAM wParam, LPARAM lParam) {
PAINTSTRUCT ps;
HDC hdc;
TCHAR greeting[] = _T("Hello, World!");
switch (message) {
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
TextOut(hdc, 5, 5, greeting, _tcslen(greeting));
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
break;
}
return 0;
}
#endif
#ifdef STEP3
// Replace WinMain with InitInstanceInPCWindow so the Native Client Module can
// launch the original application. Note the inclusion of a message-handling
// loop. STEP4 will replace the loop with a callback.
HINSTANCE g_hInstance = NULL;
HWND g_hWnd = NULL;
int InitInstanceInPCWindow() {
WNDCLASSEX winClass; MSG uMsg;
memset(&uMsg,0,sizeof(uMsg));
winClass.lpszClassName = _T("MY_WINDOWS_CLASS");
winClass.cbSize = sizeof(WNDCLASSEX);
winClass.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
winClass.lpfnWndProc = WndProc;
winClass.hInstance = g_hInstance;
winClass.hIcon = NULL;
winClass.hIconSm = NULL;
winClass.hCursor = LoadCursor(NULL, IDC_ARROW);
winClass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
winClass.lpszMenuName = NULL;
winClass.cbClsExtra = 0;
winClass.cbWndExtra = 0;
if (!RegisterClassEx(&winClass))
return E_FAIL;
g_hWnd = CreateWindowEx(
0, _T("MY_WINDOWS_CLASS"),
_T("hello_nacl"), WS_OVERLAPPEDWINDOW,
0, 0, 640, 480, NULL, NULL, g_hInstance, NULL);
if (g_hWnd == NULL)
return E_FAIL;
ShowWindow(g_hWnd, 1);
UpdateWindow(g_hWnd);
#ifdef STEP4
// Skip the message loop, schedule a callback instead to periodically check
// for messages. Here we schedule at 100ms intervals.
ppb_core_interface->CallOnMainThread(100, HelloWorldCallback, 0);
return 0;
#else
// Main message loop, Windows style.
while(uMsg.message != WM_QUIT) {
if (PeekMessage(&uMsg, NULL, 0, 0, PM_REMOVE)) {
TranslateMessage( &uMsg );
DispatchMessage( &uMsg );
}
}
return uMsg.wParam;
#endif
}
#endif
答案 0 :(得分：1)
此示例中有许多额外的代码，但问题出在此处：
PP_EXPORT const void* PPP_GetInterface(const char* interface_name) {
if (strcmp(interface_name, PPP_INSTANCE_INTERFACE) == 0) {
static PPP_Instance instance_interface = {
&Instance_DidCreate,
&Instance_DidDestroy,
&Instance_DidChangeView,
&Instance_DidChangeFocus,
&Instance_HandleDocumentLoad,
//&HandleMessage,
};
return &instance_interface;
}
return NULL;
}
当您向模块发布消息时，此函数被称为请求PPP_Messaging;1.0接口。此代码不处理这种情况，因此它会向调用者返回NULL，然后崩溃。
这不是理想的行为（它应该会产生错误），但这并不奇怪。
要修复此错误，您需要在请求PPP_MESSAGING_INTERFACE时返回界面：
...
} else if (strcmp(interface_name, PPP_MESSAGING_INTERFACE) == 0) {
static PPP_Messaging messaging_interface = {
&HandleMessage,
};
return &messaging_interface;
}