llprocesslauncher.cpp
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上传日期:2021-03-01
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- /**
- * @file llprocesslauncher.cpp
- * @brief Utility class for launching, terminating, and tracking the state of processes.
- *
- * $LicenseInfo:firstyear=2008&license=viewergpl$
- *
- * Copyright (c) 2008-2010, Linden Research, Inc.
- *
- * Second Life Viewer Source Code
- * The source code in this file ("Source Code") is provided by Linden Lab
- * to you under the terms of the GNU General Public License, version 2.0
- * ("GPL"), unless you have obtained a separate licensing agreement
- * ("Other License"), formally executed by you and Linden Lab. Terms of
- * the GPL can be found in doc/GPL-license.txt in this distribution, or
- * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
- *
- * There are special exceptions to the terms and conditions of the GPL as
- * it is applied to this Source Code. View the full text of the exception
- * in the file doc/FLOSS-exception.txt in this software distribution, or
- * online at
- * http://secondlifegrid.net/programs/open_source/licensing/flossexception
- *
- * By copying, modifying or distributing this software, you acknowledge
- * that you have read and understood your obligations described above,
- * and agree to abide by those obligations.
- *
- * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
- * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
- * COMPLETENESS OR PERFORMANCE.
- * $/LicenseInfo$
- */
-
- #include "linden_common.h"
- #include "llprocesslauncher.h"
- #include <iostream>
- #if LL_DARWIN || LL_LINUX
- // not required or present on Win32
- #include <sys/wait.h>
- #endif
- LLProcessLauncher::LLProcessLauncher()
- {
- #if LL_WINDOWS
- mProcessHandle = 0;
- #else
- mProcessID = 0;
- #endif
- }
- LLProcessLauncher::~LLProcessLauncher()
- {
- kill();
- }
- void LLProcessLauncher::setExecutable(const std::string &executable)
- {
- mExecutable = executable;
- }
- void LLProcessLauncher::setWorkingDirectory(const std::string &dir)
- {
- mWorkingDir = dir;
- }
- void LLProcessLauncher::clearArguments()
- {
- mLaunchArguments.clear();
- }
- void LLProcessLauncher::addArgument(const std::string &arg)
- {
- mLaunchArguments.push_back(arg);
- }
- void LLProcessLauncher::addArgument(const char *arg)
- {
- mLaunchArguments.push_back(std::string(arg));
- }
- #if LL_WINDOWS
- int LLProcessLauncher::launch(void)
- {
- // If there was already a process associated with this object, kill it.
- kill();
- orphan();
- int result = 0;
-
- PROCESS_INFORMATION pinfo;
- STARTUPINFOA sinfo;
- memset(&sinfo, 0, sizeof(sinfo));
-
- std::string args = mExecutable;
- for(int i = 0; i < (int)mLaunchArguments.size(); i++)
- {
- args += " ";
- args += mLaunchArguments[i];
- }
-
- // So retarded. Windows requires that the second parameter to CreateProcessA be a writable (non-const) string...
- char *args2 = new char[args.size() + 1];
- strcpy(args2, args.c_str());
- if( ! CreateProcessA( NULL, args2, NULL, NULL, FALSE, 0, NULL, NULL, &sinfo, &pinfo ) )
- {
- // TODO: do better than returning the OS-specific error code on failure...
- result = GetLastError();
- if(result == 0)
- {
- // Make absolutely certain we return a non-zero value on failure.
- result = -1;
- }
- }
- else
- {
- // foo = pinfo.dwProcessId; // get your pid here if you want to use it later on
- // CloseHandle(pinfo.hProcess); // stops leaks - nothing else
- mProcessHandle = pinfo.hProcess;
- CloseHandle(pinfo.hThread); // stops leaks - nothing else
- }
-
- delete[] args2;
-
- return result;
- }
- bool LLProcessLauncher::isRunning(void)
- {
- if(mProcessHandle != 0)
- {
- DWORD waitresult = WaitForSingleObject(mProcessHandle, 0);
- if(waitresult == WAIT_OBJECT_0)
- {
- // the process has completed.
- mProcessHandle = 0;
- }
- }
- return (mProcessHandle != 0);
- }
- bool LLProcessLauncher::kill(void)
- {
- bool result = true;
-
- if(mProcessHandle != 0)
- {
- TerminateProcess(mProcessHandle,0);
- if(isRunning())
- {
- result = false;
- }
- }
-
- return result;
- }
- void LLProcessLauncher::orphan(void)
- {
- // Forget about the process
- mProcessHandle = 0;
- }
- // static
- void LLProcessLauncher::reap(void)
- {
- // No actions necessary on Windows.
- }
- #else // Mac and linux
- #include <signal.h>
- #include <fcntl.h>
- #include <errno.h>
- static std::list<pid_t> sZombies;
- // Attempt to reap a process ID -- returns true if the process has exited and been reaped, false otherwise.
- static bool reap_pid(pid_t pid)
- {
- bool result = false;
-
- pid_t wait_result = ::waitpid(pid, NULL, WNOHANG);
- if(wait_result == pid)
- {
- result = true;
- }
- else if(wait_result == -1)
- {
- if(errno == ECHILD)
- {
- // No such process -- this may mean we're ignoring SIGCHILD.
- result = true;
- }
- }
-
- return result;
- }
- int LLProcessLauncher::launch(void)
- {
- // If there was already a process associated with this object, kill it.
- kill();
- orphan();
-
- int result = 0;
- int current_wd = -1;
-
- // create an argv vector for the child process
- const char ** fake_argv = new const char *[mLaunchArguments.size() + 2]; // 1 for the executable path, 1 for the NULL terminator
- int i = 0;
-
- // add the executable path
- fake_argv[i++] = mExecutable.c_str();
-
- // and any arguments
- for(int j=0; j < mLaunchArguments.size(); j++)
- fake_argv[i++] = mLaunchArguments[j].c_str();
-
- // terminate with a null pointer
- fake_argv[i] = NULL;
-
- if(!mWorkingDir.empty())
- {
- // save the current working directory
- current_wd = ::open(".", O_RDONLY);
-
- // and change to the one the child will be executed in
- if (::chdir(mWorkingDir.c_str()))
- {
- // chdir failed
- }
- }
-
- // flush all buffers before the child inherits them
- ::fflush(NULL);
- pid_t id = vfork();
- if(id == 0)
- {
- // child process
-
- ::execv(mExecutable.c_str(), (char * const *)fake_argv);
-
- // If we reach this point, the exec failed.
- // Use _exit() instead of exit() per the vfork man page.
- _exit(0);
- }
- // parent process
-
- if(current_wd >= 0)
- {
- // restore the previous working directory
- if (::fchdir(current_wd))
- {
- // chdir failed
- }
- ::close(current_wd);
- }
-
- delete[] fake_argv;
-
- mProcessID = id;
-
- // At this point, the child process will have been created (since that's how vfork works -- the child borrowed our execution context until it forked)
- // If the process doesn't exist at this point, the exec failed.
- if(!isRunning())
- {
- result = -1;
- }
-
- return result;
- }
- bool LLProcessLauncher::isRunning(void)
- {
- if(mProcessID != 0)
- {
- // Check whether the process has exited, and reap it if it has.
- if(reap_pid(mProcessID))
- {
- // the process has exited.
- mProcessID = 0;
- }
- }
-
- return (mProcessID != 0);
- }
- bool LLProcessLauncher::kill(void)
- {
- bool result = true;
-
- if(mProcessID != 0)
- {
- // Try to kill the process. We'll do approximately the same thing whether the kill returns an error or not, so we ignore the result.
- (void)::kill(mProcessID, SIGTERM);
-
- // This will have the side-effect of reaping the zombie if the process has exited.
- if(isRunning())
- {
- result = false;
- }
- }
-
- return result;
- }
- void LLProcessLauncher::orphan(void)
- {
- // Disassociate the process from this object
- if(mProcessID != 0)
- {
- // We may still need to reap the process's zombie eventually
- sZombies.push_back(mProcessID);
-
- mProcessID = 0;
- }
- }
- // static
- void LLProcessLauncher::reap(void)
- {
- // Attempt to real all saved process ID's.
-
- std::list<pid_t>::iterator iter = sZombies.begin();
- while(iter != sZombies.end())
- {
- if(reap_pid(*iter))
- {
- iter = sZombies.erase(iter);
- }
- else
- {
- iter++;
- }
- }
- }
- #endif