load() — netty Function Reference

Architecture documentation for the load() function in NativeLibraryLoader.java from the netty codebase.

Function java CommonUtil Internal calls 4 called by 1

Entity Profile

CommonUtil→ Internal→ load() — netty Function Reference

Dependency Diagram

graph TD
  d92afe83_049b_d0b5_f35c_dd5834c38908["load()"]
  e940cc67_3be6_5ff3_e560_4d68972dc13b["NativeLibraryLoader"]
  d92afe83_049b_d0b5_f35c_dd5834c38908 -->|defined in| e940cc67_3be6_5ff3_e560_4d68972dc13b
  8ea18f7b_b5e3_b0c6_4ce1_356784300e26["loadFirstAvailable()"]
  8ea18f7b_b5e3_b0c6_4ce1_356784300e26 -->|calls| d92afe83_049b_d0b5_f35c_dd5834c38908
  bafe3f15_b0bf_647a_3a35_cd885f9d3174["loadLibrary()"]
  d92afe83_049b_d0b5_f35c_dd5834c38908 -->|calls| bafe3f15_b0bf_647a_3a35_cd885f9d3174
  de825732_fc04_e1dd_c5ab_9f862f5d6bca["shouldShadedLibraryIdBePatched()"]
  d92afe83_049b_d0b5_f35c_dd5834c38908 -->|calls| de825732_fc04_e1dd_c5ab_9f862f5d6bca
  718b0b6c_05e8_e851_bc3f_0a119eac5245["tryPatchShadedLibraryIdAndSign()"]
  d92afe83_049b_d0b5_f35c_dd5834c38908 -->|calls| 718b0b6c_05e8_e851_bc3f_0a119eac5245
  c99af081_4b91_92aa_6d30_6467f872c8bf["canExecuteExecutable()"]
  d92afe83_049b_d0b5_f35c_dd5834c38908 -->|calls| c99af081_4b91_92aa_6d30_6467f872c8bf
  style d92afe83_049b_d0b5_f35c_dd5834c38908 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

common/src/main/java/io/netty/util/internal/NativeLibraryLoader.java lines 160–256

    public static void load(String originalName, ClassLoader loader) {
        String mangledPackagePrefix = calculateMangledPackagePrefix();
        String name = mangledPackagePrefix + originalName;
        List<Throwable> suppressed = new ArrayList<>();
        try {
            // first try to load from java.library.path
            loadLibrary(loader, name, false);
            return;
        } catch (Throwable ex) {
            suppressed.add(ex);
        }

        String libname = System.mapLibraryName(name);
        String path = NATIVE_RESOURCE_HOME + libname;

        File tmpFile = null;
        URL url = getResource(path, loader);
        try {
            if (url == null) {
                if (PlatformDependent.isOsx()) {
                    String fileName = path.endsWith(".jnilib") ? NATIVE_RESOURCE_HOME + "lib" + name + ".dynlib" :
                            NATIVE_RESOURCE_HOME + "lib" + name + ".jnilib";
                    url = getResource(fileName, loader);
                    if (url == null) {
                        FileNotFoundException fnf = new FileNotFoundException(fileName);
                        ThrowableUtil.addSuppressedAndClear(fnf, suppressed);
                        throw fnf;
                    }
                } else {
                    FileNotFoundException fnf = new FileNotFoundException(path);
                    ThrowableUtil.addSuppressedAndClear(fnf, suppressed);
                    throw fnf;
                }
            }

            int index = libname.lastIndexOf('.');
            String prefix = libname.substring(0, index);
            String suffix = libname.substring(index);

            tmpFile = PlatformDependent.createTempFile(prefix, suffix, WORKDIR);
            try (InputStream in = url.openStream();
                 OutputStream out = new FileOutputStream(tmpFile)) {

                byte[] buffer = new byte[8192];
                int length;
                while ((length = in.read(buffer)) > 0) {
                    out.write(buffer, 0, length);
                }
                out.flush();

                if (shouldShadedLibraryIdBePatched(mangledPackagePrefix)) {
                    // Let's try to patch the id and re-sign it. This is a best-effort and might fail if a
                    // SecurityManager is setup or the right executables are not installed :/
                    tryPatchShadedLibraryIdAndSign(tmpFile, originalName);
                }
            }
            // Close the output stream before loading the unpacked library,
            // because otherwise Windows will refuse to load it when it's in use by other process.
            loadLibrary(loader, tmpFile.getPath(), true);

        } catch (UnsatisfiedLinkError e) {
            try {
                if (tmpFile != null && tmpFile.isFile() && tmpFile.canRead() &&
                    !NoexecVolumeDetector.canExecuteExecutable(tmpFile)) {
                    // Pass "io.netty.native.workdir" as an argument to allow shading tools to see
                    // the string. Since this is printed out to users to tell them what to do next,
                    // we want the value to be correct even when shading.
                    String message = String.format(
                            "%s exists but cannot be executed even when execute permissions set; " +
                                    "check volume for \"noexec\" flag; use -D%s=[path] " +
                                    "to set native working directory separately.",
                            tmpFile.getPath(), "io.netty.native.workdir");
                    logger.info(message);
                    suppressed.add(ThrowableUtil.unknownStackTrace(
                            new UnsatisfiedLinkError(message), NativeLibraryLoader.class, "load"));
                }
            } catch (Throwable t) {
                suppressed.add(t);
                logger.debug("Error checking if {} is on a file store mounted with noexec", tmpFile, t);
            }
            // Re-throw to fail the load