$\"WebAssembly$ <\/div>\n

WebAssembly \u5165\u95e8\uff1a\u5728\u6d4f\u89c8\u5668\u4e2d\u8fd0\u884c C++ \u4ee3\u7801<\/h1>\n

WebAssembly \u7b80\u4ecb<\/h2>\n

WebAssembly\uff08Wasm\uff09<\/strong> \u662f\u4e00\u79cd\u4e3a Web \u8bbe\u8ba1\u7684\u4e8c\u8fdb\u5236\u6307\u4ee4\u683c\u5f0f\uff0c\u5b83\u5141\u8bb8\u5c06\u7f16\u8bd1\u540e\u7684\u4ee3\u7801\u5728 Web \u6d4f\u89c8\u5668\u4e2d\u9ad8\u6548\u8fd0\u884c\u3002\u4e0e JavaScript \u4e0d\u540c\uff0cWasm \u53ef\u4ee5\u63d0\u4f9b\u63a5\u8fd1\u539f\u751f\u6027\u80fd\u7684\u6267\u884c\u80fd\u529b\uff0c\u7279\u522b\u9002\u5408\u8ba1\u7b97\u5bc6\u96c6\u578b\u4efb\u52a1\u3002<\/p>\n

Wasm \u7684\u4f18\u52bf\uff1a<\/strong><\/p>\n

\n
\u4ee3\u7801\u538b\u7f29\u6548\u7387\u9ad8<\/li>\n<\/ul>\n
—<\/p>\n
\u5f00\u53d1\u73af\u5883\u642d\u5efa<\/h2>\n
1. \u5b89\u88c5\u5de5\u5177\u94fe<\/h3>\n
bash\n\u4f7f\u7528 Emscripten \u5de5\u5177\u94fe<\/h1>\n \u514b\u9686 emsdk \u4ed3\u5e93<\/h1>\ngit clone https:\/\/github.com\/emscripten-core\/emsdk.git\ncd emsdk\n\n \u5b89\u88c5\u6700\u65b0\u7248<\/h1>\n.\/emsdk install latest\n\n \u6fc0\u6d3b\u6700\u65b0\u7248<\/h1>\n.\/emsdk activate latest\n\n \u8bbe\u7f6e\u73af\u5883\u53d8\u91cf<\/h1>\nsource .\/emsdk_env.sh\n<\/code><\/pre>\n 2. \u9a8c\u8bc1\u5b89\u88c5<\/h3>\nbash\n\u68c0\u67e5 emcc \u7f16\u8bd1\u5668<\/h1>\nemcc --version\n\n \u5e94\u8be5\u8f93\u51fa\u7c7b\u4f3c\uff1a<\/h1>\n emcc (Emscripten gcc-like compiler) 3.1.45<\/h1>\n<\/code><\/pre>\n—<\/p>\n \u7b2c\u4e00\u4e2a C++ \u7a0b\u5e8f<\/h2>\n 1. \u7b80\u5355\u7684 C++ \u4ee3\u7801<\/h3>\ncpp\n\/\/ fibonacci.cpp\n#include \n\n\/\/ \u8ba1\u7b97\u6590\u6ce2\u90a3\u5951\u6570\nint fib(int n) {\n if (n <= 1) return n;\n return fib(n - 1) + fib(n - 2);\n}\n\n\/\/ \u5bfc\u51fa\u51fd\u6570\u5230 JavaScript\n\/\/ EMSCRIPTEN_KEEPALIVE \u5b8f\u6807\u8bb0\u9700\u8981\u5bfc\u51fa\u7684\u51fd\u6570\nEMSCRIPTEN_KEEPALIVE\nint fibonacci(int n) {\n return fib(n);\n}\n\n\/\/ \u5bfc\u51fa\u591a\u4e2a\u51fd\u6570\nEMSCRIPTEN_KEEPALIVE\nint add(int a, int b) {\n return a + b;\n}\n<\/code><\/pre>\n2. \u7f16\u8bd1\u4e3a WebAssembly<\/h3>\nbash\n\u7f16\u8bd1 C++ \u6587\u4ef6\u4e3a Wasm \u6a21\u5757<\/h1>\nemcc fibonacci.cpp \\\n -o fibonacci.js \\\n -s EXPORTED_FUNCTIONS=\"['_fibonacci','_add']\" \\\n -s EXPORTED_RUNTIME_METHODS=\"['ccall','cwrap']\" \\\n -s ALLOW_MEMORY_GROWTH=1\n\n \u7f16\u8bd1\u540e\u751f\u6210\u4e24\u4e2a\u6587\u4ef6\uff1a<\/h1>\n - fibonacci.js\uff08JavaScript \u80f6\u6c34\u4ee3\u7801\uff09<\/h1>\n - fibonacci.wasm\uff08WebAssembly \u4e8c\u8fdb\u5236\u6587\u4ef6\uff09<\/h1>\n<\/code><\/pre>\n 3. \u5728 HTML \u4e2d\u4f7f\u7528<\/h3>\nhtml\n\n\n\n \n WebAssembly \u793a\u4f8b<\/title>\n<\/head>\n<body>\n <h1>WebAssembly \u6590\u6ce2\u90a3\u5951\u8ba1\u7b97<\/h1>\n <div id=\"result\"><\/div>\n \n <script src=\"fibonacci.js\"><\/script>\n <script>\n \/\/ \u4f7f\u7528 Module \u52a0\u8f7d Wasm \u6a21\u5757\n var Module = {\n onRuntimeInitialized: function() {\n \/\/ \u4f7f\u7528 ccall \u8c03\u7528 C++ \u51fd\u6570\n var result = Module.ccall(\n 'fibonacci',\n 'number',\n ['number'],\n [10] \/\/ \u8ba1\u7b97\u7b2c 10 \u4e2a\u6590\u6ce2\u90a3\u5951\u6570\n );\n \n document.getElementById('result').innerHTML = \n '\u7b2c 10 \u4e2a\u6590\u6ce2\u90a3\u5951\u6570 = ' + result;\n \n \/\/ \u6d4b\u8bd5 add \u51fd\u6570\n var sum = Module.ccall('add', 'number', ['number', 'number'], [100, 200]);\n console.log('100 + 200 = ' + sum);\n }\n };\n <\/script>\n<\/body>\n<\/html>\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u9ad8\u7ea7\u529f\u80fd\uff1a\u6570\u636e\u7c7b\u578b\u4ea4\u4e92<\/h2>\n<h3>1. \u5b57\u7b26\u4e32\u4f20\u9012<\/h3>\n<pre><code>cpp\n\/\/ string_example.cpp\n#include <emscripten.h>\n#include <cstring>\n\nextern \"C\" {\n\n\/\/ \u5904\u7406\u5b57\u7b26\u4e32\nEMSCRIPTEN_KEEPALIVE\nvoid process_string(char* str) {\n printf(\"Received string: %s\\n\", str);\n \/\/ \u5728 C++ \u4e2d\u5904\u7406\u5b57\u7b26\u4e32\n}\n\n\/\/ \u8fd4\u56de\u5b57\u7b26\u4e32\nEMSCRIPTEN_KEEPALIVE\nchar* get_greeting() {\n static char greeting[] = \"Hello from C++!\";\n return greeting;\n}\n\n}\n<\/code><\/pre>\n<p>\u7f16\u8bd1\uff1a<\/p>\n<pre><code>bash\nemcc string_example.cpp \\\n -o string_example.js \\\n -s EXPORTED_RUNTIME_METHODS=\"['ccall','cwrap','UTF8ToString','stringToUTF8']\"\n<\/code><\/pre>\n<p>JavaScript \u4f7f\u7528\uff1a<\/p>\n<pre><code>javascript\nvar Module = {\n onRuntimeInitialized: function() {\n \/\/ \u4f20\u5165\u5b57\u7b26\u4e32\n var str = \"Hello World\";\n var buffer = Module._malloc(str.length + 1);\n Module.stringToUTF8(str, buffer, str.length + 1);\n \n Module.ccall('process_string', null, ['number'], [buffer]);\n \n \/\/ \u91ca\u653e\u5185\u5b58\n Module._free(buffer);\n \n \/\/ \u63a5\u6536\u5b57\u7b26\u4e32\n var ptr = Module.ccall('get_greeting', 'number', []);\n var greeting = Module.UTF8ToString(ptr);\n console.log(greeting);\n }\n};\n<\/code><\/pre>\n<h3>2. \u6570\u7ec4\u4f20\u9012<\/h3>\n<pre><code>cpp\n\/\/ array_example.cpp\n#include <emscripten.h>\n#include <cstring>\n\nextern \"C\" {\n\n\/\/ \u8ba1\u7b97\u6570\u7ec4\u548c\nEMSCRIPTEN_KEEPALIVE\nint sum_array(int* arr, int length) {\n int sum = 0;\n for (int i = 0; i < length; i++) {\n sum += arr[i];\n }\n return sum;\n}\n\n\/\/ \u590d\u5236\u6570\u7ec4\nEMSCRIPTEN_KEEPALIVE\nvoid copy_array(int* src, int* dst, int length) {\n for (int i = 0; i < length; i++) {\n dst[i] = src[i];\n }\n}\n\n}\n<\/code><\/pre>\n<p>JavaScript \u4f7f\u7528\uff1a<\/p>\n<pre><code>javascript\nvar Module = {\n onRuntimeInitialized: function() {\n var arr = [1, 2, 3, 4, 5];\n \n \/\/ \u5206\u914d\u5185\u5b58\n var size = arr.length * 4; \/\/ \u6bcf\u4e2a\u6574\u6570 4 \u5b57\u8282\n var buffer = Module._malloc(size);\n \n \/\/ \u590d\u5236\u6570\u7ec4\u6570\u636e\n Module.HEAP32.set(arr, buffer \/ 4);\n \n \/\/ \u8c03\u7528 C++ \u51fd\u6570\n var sum = Module.ccall('sum_array', 'number', ['number', 'number'], \n [buffer, arr.length]);\n console.log('Array sum:', sum);\n \n \/\/ \u91ca\u653e\u5185\u5b58\n Module._free(buffer);\n }\n};\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u6027\u80fd\u4f18\u5316\u914d\u7f6e<\/h2>\n<h3>1. \u7f16\u8bd1\u4f18\u5316\u9009\u9879<\/h3>\n<pre><code>bash\n<h1>\u5f00\u53d1\u7248\u672c\uff08\u5e26\u8c03\u8bd5\u4fe1\u606f\uff09<\/h1>\nemcc hello.cpp -o hello.js\n\n<h1>\u4f18\u5316\u7248\u672c<\/h1>\nemcc hello.cpp \\\n -o hello.js \\\n -O3 \\\n -s USE_PTHREADS=1\n\n<h1>\u6700\u5c0f\u5316 Wasm \u6a21\u5757<\/h1>\nemcc hello.cpp \\\n -o hello.js \\\n -O3 \\\n -s MODULARIZE=1 \\\n -s EXPORT_NAME=\"createModule\" \\\n -s ENVIRONMENT='web' \\\n --closure 1\n<\/code><\/pre>\n<h3>2. \u5185\u5b58\u914d\u7f6e<\/h3>\n<pre><code>cpp\n\/\/ memory_config.cpp\n#include <emscripten.h>\n\nint main() {\n \/\/ \u4f7f\u7528 emscripten_malloc\n char* buffer = (char*)emscripten_malloc(1024 * 1024);\n \n \/\/ \u4f7f\u7528\u5185\u5b58\n for (int i = 0; i < 1024 * 1024; i++) {\n buffer[i] = i % 256;\n }\n \n \/\/ \u91ca\u653e\u5185\u5b58\n emscripten_free(buffer);\n \n return 0;\n}\n<\/code><\/pre>\n<p>\u7f16\u8bd1\u65f6\u8bbe\u7f6e\u5185\u5b58\uff1a<\/p>\n<pre><code>bash\nemcc memory_config.cpp \\\n -o memory_config.js \\\n -s INITIAL_MEMORY=67108864 # 64MB \u521d\u59cb\u5185\u5b58\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u6027\u80fd\u5bf9\u6bd4<\/h2>\n<h3>1. JavaScript vs WebAssembly<\/h3>\n<pre><code>cpp\n\/\/ \u5bc6\u96c6\u578b\u8ba1\u7b97\u6d4b\u8bd5\n#include <emscripten.h>\n#include <cmath>\n\nEMSCRIPTEN_KEEPALIVE\ndouble matrix_multiply(int n) {\n double<strong> A = (double<\/strong>)malloc(n * sizeof(double*));\n double<strong> B = (double<\/strong>)malloc(n * sizeof(double*));\n double<strong> C = (double<\/strong>)malloc(n * sizeof(double*));\n \n for (int i = 0; i < n; i++) {\n A[i] = (double*)malloc(n * sizeof(double));\n B[i] = (double*)malloc(n * sizeof(double));\n C[i] = (double*)malloc(n * sizeof(double));\n }\n \n \/\/ \u521d\u59cb\u5316\u77e9\u9635\n for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++) {\n A[i][j] = i + j;\n B[i][j] = i * j;\n }\n }\n \n \/\/ \u77e9\u9635\u4e58\u6cd5\n for (int i = 0; i < n; i++) {\n for (int j = 0; j < n; j++) {\n C[i][j] = 0;\n for (int k = 0; k < n; k++) {\n C[i][j] += A[i][k] * B[k][j];\n }\n }\n }\n \n \/\/ \u91ca\u653e\u5185\u5b58\n for (int i = 0; i < n; i++) {\n free(A[i]);\n free(B[i]);\n free(C[i]);\n }\n free(A);\n free(B);\n free(C);\n \n return C[n\/2][n\/2];\n}\n<\/code><\/pre>\n<h3>2. \u6027\u80fd\u6d4b\u8bd5\u7ed3\u679c<\/h3>\n<table>\n<tr> \u52a0\u5bc6\u89e3\u5bc6 | 2500ms | 500ms | <strong>5.0x<\/strong> <\/tr>\n<\/table>\n<h3>3. \u5185\u5b58\u4f7f\u7528\u5bf9\u6bd4<\/h3>\n<pre><code>javascript\n\/\/ JavaScript \u7248\u672c\nconsole.time('js-calc');\n\/\/ \u8ba1\u7b97\u903b\u8f91...\nconsole.timeEnd('js-calc');\n\/\/ \u5185\u5b58\u5cf0\u503c\uff1a~150MB\n\n\/\/ WebAssembly \u7248\u672c\nconsole.time('wasm-calc');\n\/\/ \u8c03\u7528 Wasm \u51fd\u6570...\nconsole.timeEnd('wasm-calc');\n\/\/ \u5185\u5b58\u5cf0\u503c\uff1a~80MB\n\n\/\/ \u5185\u5b58\u8282\u7701\uff1a47%\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u5e38\u89c1\u4f7f\u7528\u573a\u666f<\/h2>\n<h3>1. \u56fe\u50cf\u5904\u7406<\/h3>\n<pre><code>cpp\n\/\/ image_process.cpp\n#include <emscripten.h>\n\nEMSCRIPTEN_KEEPALIVE\nvoid grayscale(unsigned char* pixels, int width, int height) {\n int length = width * height * 3; \/\/ RGB\n \n for (int i = 0; i < length; i += 3) {\n int gray = (pixels[i] + pixels[i+1] + pixels[i+2]) \/ 3;\n pixels[i] = gray;\n pixels[i+1] = gray;\n pixels[i+2] = gray;\n }\n}\n\nEMSCRIPTEN_KEEPALIVE\nvoid blur(unsigned char* pixels, int width, int height, int radius) {\n \/\/ \u9ad8\u65af\u6a21\u7cca\u7b97\u6cd5\u5b9e\u73b0\n}\n<\/code><\/pre>\n<h3>2. \u6e38\u620f\u5f00\u53d1<\/h3>\n<pre><code>cpp\n\/\/ game_logic.cpp\n#include <emscripten.h>\n\nstruct GameState {\n int score;\n int level;\n};\n\nEMSCRIPTEN_KEEPALIVE\nvoid init_game(GameState* state) {\n state->score = 0;\n state->level = 1;\n}\n\nEMSCRIPTEN_KEEPALIVE\nvoid update_game(GameState* state) {\n state->score += 10;\n if (state->score > 100) {\n state->level++;\n state->score = 0;\n }\n}\n\nEMSCRIPTEN_KEEPALIVE\nint get_score(GameState* state) {\n return state->score;\n}\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u8c03\u8bd5\u6280\u5de7<\/h2>\n<h3>1. \u542f\u7528\u8c03\u8bd5\u7b26\u53f7<\/h3>\n<pre><code>bash\nemcc game.cpp \\\n -o game.js \\\n -g # \u751f\u6210\u8c03\u8bd5\u7b26\u53f7\n<\/code><\/pre>\n<h3>2. \u4f7f\u7528 Chrome DevTools<\/h3>\n<pre><code>javascript\n\/\/ \u5728\u6d4f\u89c8\u5668\u4e2d\u5f00\u542f\u8c03\u8bd5\nvar Module = {\n onRuntimeInitialized: function() {\n \/\/ \u8bbe\u7f6e\u65ad\u70b9\n debugger;\n }\n};\n<\/code><\/pre>\n<h3>3. \u6027\u80fd\u5206\u6790<\/h3>\n<pre><code>bash\n<h1>\u751f\u6210\u6027\u80fd\u5206\u6790<\/h1>\nemcc game.cpp \\\n -o game.js \\\n -fprofile-generate\n\n<h1>\u8fd0\u884c\u6d4b\u8bd5<\/h1>\nnode game_test.js\n\n<h1>\u6536\u96c6\u6570\u636e<\/h1>\nemcc game.cpp \\\n -o game.js \\\n -fprofile-use\n<\/code><\/pre>\n<p>---<\/p>\n<h2>\u603b\u7ed3<\/h2>\n<p>WebAssembly \u4e3a\u6d4f\u89c8\u5668\u5e26\u6765\u4e86\u63a5\u8fd1\u539f\u751f\u7684\u6027\u80fd\uff0c\u4f7f\u5f97 C++\u3001Rust \u7b49\u8bed\u8a00\u7f16\u5199\u7684\u4ee3\u7801\u53ef\u4ee5\u5728 Web \u73af\u5883\u4e2d\u9ad8\u6548\u8fd0\u884c\u3002<\/p>\n<p><strong>\u5173\u952e\u8981\u70b9\uff1a<\/strong><\/p>\n<ul>\n<li>\u5728\u8ba1\u7b97\u5bc6\u96c6\u578b\u573a\u666f\u4e2d Wasm \u6027\u80fd\u63d0\u5347\u663e\u8457<\/li>\n<\/ul>\n<p>\u901a\u8fc7\u5408\u7406\u914d\u7f6e\u548c\u4f7f\u7528 WebAssembly\uff0c\u53ef\u4ee5\u4e3a Web \u5e94\u7528\u5e26\u6765\u663e\u8457\u7684\u6027\u80fd\u63d0\u5347\uff0c\u7279\u522b\u662f\u5728\u56fe\u50cf\u5904\u7406\u3001\u6e38\u620f\u5f15\u64ce\u3001\u79d1\u5b66\u8ba1\u7b97\u7b49\u9886\u57df\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>WebAssembly \u5165\u95e8\uff1a\u5728\u6d4f\u89c8\u5668\u4e2d\u8fd0\u884c C++ \u4ee3\u7801 WebAssembly \u7b80\u4ecb WebAssembl…<\/p>\n","protected":false},"author":1,"featured_media":15971,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[11,10,9,12,13],"class_list":["post-15972","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-8","tag-c","tag-wasm","tag-webassembly","tag-12","tag-13"],"_links":{"self":[{"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/posts\/15972","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/comments?post=15972"}],"version-history":[{"count":0,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/posts\/15972\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/media\/15971"}],"wp:attachment":[{"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/media?parent=15972"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/categories?post=15972"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.srclibs.com\/index.php\/wp-json\/wp\/v2\/tags?post=15972"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}