[starter] Add a process starter for use by the installer for launching tools (#4931)

processstarter/src/main/native/linux/main.cpp

@@ -0,0 +1,86 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <poll.h>
+#include <spawn.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <climits>
+#include <cstdio>
+#include <cstring>
+#include <filesystem>
+
+int main(int argc, char* argv[]) {
+  char path[PATH_MAX];
+  char dest[PATH_MAX];
+  std::memset(dest, 0, sizeof(dest));  // readlink does not null terminate!
+  pid_t pid = getpid();
+  std::snprintf(path, PATH_MAX, "/proc/%d/exe", pid);
+  int readlink_len = readlink(path, dest, PATH_MAX);
+  if (readlink_len < 0) {
+    std::perror("readlink");
+    return 1;
+  } else if (readlink_len == PATH_MAX) {
+    std::printf("Truncation occured\n");
+    return 1;
+  }
+
+  std::filesystem::path exePath{dest};
+  if (exePath.empty()) {
+    return 1;
+  }
+
+  if (!exePath.has_stem()) {
+    return 1;
+  }
+
+  if (!exePath.has_parent_path()) {
+    return 1;
+  }
+
+  std::filesystem::path jarPath{exePath};
+  jarPath.replace_extension("jar");
+  std::filesystem::path parentPath{exePath.parent_path()};
+
+  if (!parentPath.has_parent_path()) {
+    return 1;
+  }
+  std::filesystem::path toolsFolder{parentPath.parent_path()};
+
+  std::filesystem::path Java = toolsFolder / "jdk" / "bin" / "java";
+
+  pid = 0;
+  std::string data = jarPath;
+  std::string jarArg = "-jar";
+  char* const arguments[] = {jarArg.data(), data.data(), nullptr};
+
+  int status =
+      posix_spawn(&pid, Java.c_str(), nullptr, nullptr, arguments, environ);
+  if (status != 0) {
+    char* home = std::getenv("JAVA_HOME");
+    std::string javaLocal = "java";
+    if (home != nullptr) {
+      std::filesystem::path javaHomePath{home};
+      javaHomePath /= "bin";
+      javaHomePath /= "java";
+      javaLocal = javaHomePath;
+    }
+
+    status = posix_spawn(&pid, javaLocal.c_str(), nullptr, nullptr, arguments,
+                         environ);
+    if (status != 0) {
+      return 1;
+    }
+  }
+
+  int childPid = syscall(SYS_pidfd_open, pid, 0);
+  if (childPid <= 0) {
+    return 1;
+  }
+
+  struct pollfd pfd = {childPid, POLLIN, 0};
+  return poll(&pfd, 1, 3000);
+}

processstarter/src/main/native/osx/main.mm

@@ -0,0 +1,80 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#import <Foundation/Foundation.h>
+#include <string>
+#include <filesystem>
+
+int main(int argc, char* argv[]) {
+  (void)argc;
+  (void)argv;
+  NSString* exePathPlat = [[NSBundle mainBundle] bundlePath];
+  NSString* identifier = [[NSBundle mainBundle] bundleIdentifier];
+  if (identifier == nil) {
+    exePathPlat = [[NSBundle mainBundle] executablePath];
+  }
+
+  std::filesystem::path exePath{[exePathPlat UTF8String]};
+  if (exePath.empty()) {
+    return 1;
+  }
+
+  if (!exePath.has_stem()) {
+    return 1;
+  }
+
+  if (!exePath.has_parent_path()) {
+    return 1;
+  }
+
+  std::filesystem::path jarPath{exePath};
+  jarPath.replace_extension("jar");
+  std::filesystem::path parentPath{exePath.parent_path()};
+
+  if (!parentPath.has_parent_path()) {
+    return 1;
+  }
+  std::filesystem::path toolsFolder{parentPath.parent_path()};
+
+  std::filesystem::path java = toolsFolder / "jdk" / "bin" / "java";
+
+  NSArray<NSString*>* Arguments =
+      @[ @"-jar", [NSString stringWithFormat:@"%s", jarPath.c_str()] ];
+
+  NSTask* task = [[NSTask alloc] init];
+  task.launchPath = [NSString stringWithFormat:@"%s", java.c_str()];
+  task.arguments = Arguments;
+  task.terminationHandler = ^(NSTask* t) {
+    (void)t;
+    CFRunLoopStop(CFRunLoopGetMain());
+  };
+
+  if (![task launchAndReturnError:nil]) {
+    task.terminationHandler = nil;
+
+    NSString* javaHome =
+        [[[NSProcessInfo processInfo] environment] objectForKey:@"JAVA_HOME"];
+    task = [[NSTask alloc] init];
+    task.launchPath = @"java";
+    if (javaHome != nil) {
+      std::filesystem::path javaHomePath{[javaHome UTF8String]};
+      javaHomePath /= "bin";
+      javaHomePath /= "java";
+      task.launchPath = [NSString stringWithFormat:@"%s", javaHomePath.c_str()];
+    }
+    task.arguments = Arguments;
+    task.terminationHandler = ^(NSTask* t) {
+      (void)t;
+      CFRunLoopStop(CFRunLoopGetMain());
+    };
+
+    if (![task launchAndReturnError:nil]) {
+      return 1;
+    }
+  }
+
+  CFRunLoopRunInMode(kCFRunLoopDefaultMode, 3, false);
+
+  return task.running ? 0 : 1;
+}

processstarter/src/main/native/windows/main.cpp

@@ -0,0 +1,85 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <filesystem>
+
+#include "Windows.h"
+
+int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
+                   LPTSTR pCmdLine, int nCmdShow) {
+  DWORD Status;
+  WCHAR ExePathRaw[1024];
+  Status = GetModuleFileNameW(NULL, ExePathRaw, 1024);
+  if (Status == 0) {
+    DWORD LastError = GetLastError();
+    return LastError;
+  }
+
+  std::filesystem::path ExePath{ExePathRaw};
+  if (ExePath.empty()) {
+    return 1;
+  }
+
+  if (!ExePath.has_stem()) {
+    return 1;
+  }
+
+  if (!ExePath.has_parent_path()) {
+    return 1;
+  }
+
+  std::filesystem::path JarPath{ExePath};
+  JarPath.replace_extension(L"jar");
+  std::filesystem::path ParentPath{ExePath.parent_path()};
+
+  if (!ParentPath.has_parent_path()) {
+    return 1;
+  }
+  std::filesystem::path ToolsFolder{ParentPath.parent_path()};
+
+  std::filesystem::path Javaw = ToolsFolder / L"jdk" / L"bin" / L"javaw.exe";
+
+  std::wstring ToRun = L" -jar \"";
+  ToRun += JarPath;
+  ToRun += L"\"";
+
+  STARTUPINFOW StartupInfo;
+  PROCESS_INFORMATION ProcessInfo;
+
+  ZeroMemory(&StartupInfo, sizeof(StartupInfo));
+  StartupInfo.cb = sizeof(StartupInfo);
+  ZeroMemory(&ProcessInfo, sizeof(ProcessInfo));
+
+  if (!CreateProcessW(Javaw.c_str(), ToRun.data(), NULL, NULL, FALSE, 0, NULL,
+                      NULL, &StartupInfo, &ProcessInfo)) {
+    ZeroMemory(&StartupInfo, sizeof(StartupInfo));
+    StartupInfo.cb = sizeof(StartupInfo);
+    ZeroMemory(&ProcessInfo, sizeof(ProcessInfo));
+
+    ToRun = L" -jar \"";
+    ToRun += JarPath;
+    ToRun += L"\"";
+
+    Status = GetEnvironmentVariableW(L"JAVA_HOME", ExePathRaw, 1024);
+    std::wstring JavawLocal = L"javaw";
+    if (Status != 0 && Status < 1024) {
+      std::filesystem::path JavaHomePath{ExePathRaw};
+      JavaHomePath /= "bin";
+      JavaHomePath /= "javaw.exe";
+      JavawLocal = JavaHomePath;
+    }
+
+    if (!CreateProcessW(JavawLocal.c_str(), ToRun.data(), NULL, NULL, FALSE, 0,
+                        NULL, NULL, &StartupInfo, &ProcessInfo)) {
+      return 1;
+    }
+  }
+
+  Status =
+      WaitForSingleObject(ProcessInfo.hProcess, 3000);  // Wait for 3 seconds
+  CloseHandle(ProcessInfo.hProcess);
+  CloseHandle(ProcessInfo.hThread);
+
+  return Status == WAIT_TIMEOUT ? 0 : 1;
+}