960b613d10
Real world native libs likely need to access the wasm_runtime_xxx API. This example demonstrates it. Build vmlib as a shared lib to make it straightforward to share a single runtime instance between iwasm and native libs.
77 lines
2.1 KiB
Markdown
77 lines
2.1 KiB
Markdown
# "native-lib" sample introduction
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This sample demonstrates how to write required interfaces in native library, build it into a shared library and register the shared library to iwasm.
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The native library should provide `get_native_lib` API for iwasm to return the native library info, including the module name, the native symbol list and the native symbol count, so that iwasm can use them to regiter the native library, for example:
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```C
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static int
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foo_wrapper(wasm_exec_env_t exec_env, int x, int y)
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{
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return x + y;
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}
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#define REG_NATIVE_FUNC(func_name, signature) \
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{ #func_name, func_name##_wrapper, signature, NULL }
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static NativeSymbol native_symbols[] = {
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REG_NATIVE_FUNC(foo, "(ii)i")
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};
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uint32_t
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get_native_lib(char **p_module_name, NativeSymbol **p_native_symbols)
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{
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*p_module_name = "env";
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*p_native_symbols = native_symbols;
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return sizeof(native_symbols) / sizeof(NativeSymbol);
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}
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```
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## Preparation
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Please install WASI SDK, download the [wasi-sdk release](https://github.com/CraneStation/wasi-sdk/releases) and extract the archive to default path `/opt/wasi-sdk`.
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## Build the sample
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```bash
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mkdir build
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cd build
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cmake ..
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make
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```
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`iwasm`, one wasm module `test.wasm` and two shared libraries `libtest_add.so`, `libtest_sqrt.so`
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will be generated.
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## Run workload
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### Linux
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```bash
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cd build
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./iwasm --native-lib=./libtest_add.so --native-lib=./libtest_sqrt.so --native-lib=./libtest_hello.so --native-lib=./libtest_hello2.so wasm-app/test.wasm
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```
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### macOS
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```bash
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cd build
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./iwasm --native-lib=libtest_add.dylib --native-lib=libtest_sqrt.dylib --native-lib=libtest_hello.dylib --native-lib=libtest_hello2.dylib wasm-app/test.wasm
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```
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The output is:
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```bash
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Hello World!
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10 + 20 = 30
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sqrt(10, 20) = 500
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test_hello("main", 0x0, 0) = 41
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malloc(42) = 0x24e8
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test_hello("main", 0x24e8, 42) = 41
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Message from test_hello: Hello, main. This is test_hello_wrapper!
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test_hello2("main", 0x0, 0) = 85
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malloc(86) = 0x24e8
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test_hello2("main", 0x24e8, 86) = 85
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Message from test_hello2: Hello, main. This is test_hello2_wrapper! Your wasm_module_inst_t is 0x7fd443704990.
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```
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