Per Richard, replace LLProcessLauncher with LLProcess.

LLProcessLauncher had the somewhat fuzzy mandate of (1) accumulating
parameters with which to launch a child process and (2) sometimes tracking the
lifespan of the ensuing child process. But a valid LLProcessLauncher object
might or might not have ever been associated with an actual child process.
LLProcess specifically tracks a child process. In effect, it's a fairly thin
wrapper around a process HANDLE (on Windows) or pid_t (elsewhere), with
lifespan management thrown in. A static LLProcess::create() method launches a
new child; create() accepts an LLSD bundle with child parameters. So building
up a parameter bundle is deferred to LLSD rather than conflated with the
process management object.
Reconcile all known LLProcessLauncher consumers in the viewer code base,
notably the class unit tests.

1 files changed, 338 insertions, 0 deletions

diff --git a/indra/llcommon/llprocess.cpp b/indra/llcommon/llprocess.cpp
new file mode 100644
index 0000000000..8c0caca680
--- /dev/null
+++ b/indra/llcommon/llprocess.cpp
@@ -0,0 +1,338 @@
+/** 
+ * @file llprocess.cpp
+ * @brief Utility class for launching, terminating, and tracking the state of processes.
+ *
+ * $LicenseInfo:firstyear=2008&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+#include "llprocess.h"
+#include "llsd.h"
+#include "llsdserialize.h"
+#include "stringize.h"
+
+#include <boost/foreach.hpp>
+#include <iostream>
+#include <stdexcept>
+
+/// Need an exception to avoid constructing an invalid LLProcess object, but
+/// internal use only
+struct LLProcessError: public std::runtime_error
+{
+	LLProcessError(const std::string& msg): std::runtime_error(msg) {}
+};
+
+LLProcessPtr LLProcess::create(const LLSD& params)
+{
+	try
+	{
+		return LLProcessPtr(new LLProcess(params));
+	}
+	catch (const LLProcessError& e)
+	{
+		LL_WARNS("LLProcess") << e.what() << LL_ENDL;
+		return LLProcessPtr();
+	}
+}
+
+LLProcess::LLProcess(const LLSD& params):
+	mProcessID(0),
+	mAutokill(params["autokill"].asBoolean())
+{
+	// nonstandard default bool value
+	if (! params.has("autokill"))
+		mAutokill = true;
+	if (! params.has("executable"))
+	{
+		throw LLProcessError(STRINGIZE("not launched: missing 'executable'\n"
+									   << LLSDNotationStreamer(params)));
+	}
+
+	launch(params);
+}
+
+LLProcess::~LLProcess()
+{
+	if (mAutokill)
+	{
+		kill();
+	}
+}
+
+bool LLProcess::isRunning(void)
+{
+	mProcessID = isRunning(mProcessID);
+	return (mProcessID != 0);
+}
+
+#if LL_WINDOWS
+
+static std::string quote(const std::string& str)
+{
+	std::string::size_type len(str.length());
+	// If the string is already quoted, assume user knows what s/he's doing.
+	if (len >= 2 && str[0] == '"' && str[len-1] == '"')
+	{
+		return str;
+	}
+
+	// Not already quoted: do it.
+	std::string result("\"");
+	for (std::string::const_iterator ci(str.begin()), cend(str.end()); ci != cend; ++ci)
+	{
+		if (*ci == '"')
+		{
+			result.append("\\");
+		}
+		result.push_back(*ci);
+	}
+	return result + "\"";
+}
+
+void LLProcess::launch(const LLSD& params)
+{
+	PROCESS_INFORMATION pinfo;
+	STARTUPINFOA sinfo;
+	memset(&sinfo, 0, sizeof(sinfo));
+	
+	std::string args = quote(params["executable"]);
+	BOOST_FOREACH(const std::string& arg, llsd::inArray(params["args"]))
+	{
+		args += " ";
+		args += quote(arg);
+	}
+	
+	// So retarded.  Windows requires that the second parameter to
+	// CreateProcessA be a writable (non-const) string...
+	std::vector<char> args2(args.begin(), args.end());
+	args2.push_back('\0');
+
+	// Convert wrapper to a real std::string so we can use c_str(); but use a
+	// named variable instead of a temporary so c_str() pointer remains valid.
+	std::string cwd(params["cwd"]);
+	const char * working_directory = 0;
+	if (! cwd.empty())
+		working_directory = cwd.c_str();
+	if( ! CreateProcessA( NULL, &args2[0], NULL, NULL, FALSE, 0, NULL, working_directory, &sinfo, &pinfo ) )
+	{
+		int result = GetLastError();
+
+		LPTSTR error_str = 0;
+		if(
+			FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
+				NULL,
+				result,
+				0,
+				(LPTSTR)&error_str,
+				0,
+				NULL) 
+			!= 0) 
+		{
+			char message[256];
+			wcstombs(message, error_str, sizeof(message));
+			message[sizeof(message)-1] = 0;
+			LocalFree(error_str);
+			throw LLProcessError(STRINGIZE("CreateProcessA failed (" << result << "): "
+										   << message));
+		}
+		throw LLProcessError(STRINGIZE("CreateProcessA failed (" << result
+									   << "), but FormatMessage() did not explain"));
+	}
+
+	// foo = pinfo.dwProcessId; // get your pid here if you want to use it later on
+	// CloseHandle(pinfo.hProcess); // stops leaks - nothing else
+	mProcessID = pinfo.hProcess;
+	CloseHandle(pinfo.hThread); // stops leaks - nothing else
+}
+
+LLProcess::id LLProcess::isRunning(id handle)
+{
+	if (! handle)
+		return 0;
+
+	DWORD waitresult = WaitForSingleObject(handle, 0);
+	if(waitresult == WAIT_OBJECT_0)
+	{
+		// the process has completed.
+		return 0;
+	}
+
+	return handle;
+}
+
+bool LLProcess::kill(void)
+{
+	if (! mProcessID)
+		return false;
+
+	TerminateProcess(mProcessID, 0);
+	return ! isRunning();
+}
+
+#else // Mac and linux
+
+#include <signal.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/wait.h>
+
+// 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)
+{
+	pid_t wait_result = ::waitpid(pid, NULL, WNOHANG);
+	if (wait_result == pid)
+	{
+		return true;
+	}
+	if (wait_result == -1 && errno == ECHILD)
+	{
+		// No such process -- this may mean we're ignoring SIGCHILD.
+		return true;
+	}
+	
+	return false;
+}
+
+void LLProcess::launch(const LLSD& params)
+{
+	// flush all buffers before the child inherits them
+	::fflush(NULL);
+
+	pid_t child = vfork();
+	if (child == 0)
+	{
+		// child process
+
+		std::string cwd(params["cwd"]);
+		if (! cwd.empty())
+		{
+			// change to the desired child working directory
+			if (::chdir(cwd.c_str()))
+			{
+				// chdir failed
+				LL_WARNS("LLProcess") << "could not chdir(\"" << cwd << "\")" << LL_ENDL;
+				// pointless to throw; this is child process...
+				_exit(248);
+			}
+		}
+
+		// create an argv vector for the child process
+		std::vector<const char*> fake_argv;
+
+		// add the executable path
+		std::string executable(params["executable"]);
+		fake_argv.push_back(executable.c_str());
+
+		// and any arguments
+		const LLSD& params_args(params["args"]);
+		std::vector<std::string> args(params_args.beginArray(), params_args.endArray());
+		BOOST_FOREACH(const std::string& arg, args)
+		{
+			fake_argv.push_back(arg.c_str());
+		}
+
+		// terminate with a null pointer
+		fake_argv.push_back(NULL);
+
+		::execv(executable.c_str(), const_cast<char* const*>(&fake_argv[0]));
+
+		// If we reach this point, the exec failed.
+		LL_WARNS("LLProcess") << "failed to launch: ";
+		BOOST_FOREACH(const char* arg, fake_argv)
+		{
+			LL_CONT << arg << ' ';
+		}
+		LL_CONT << LL_ENDL;
+		// Use _exit() instead of exit() per the vfork man page. Exit with a
+		// distinctive rc: someday soon we'll be able to retrieve it, and it
+		// would be nice to be able to tell that the child process failed!
+		_exit(249);
+	}
+
+	// parent process
+	mProcessID = child;
+}
+
+LLProcess::id LLProcess::isRunning(id pid)
+{
+	if (! pid)
+		return 0;
+
+	// Check whether the process has exited, and reap it if it has.
+	if(reap_pid(pid))
+	{
+		// the process has exited.
+		return 0;
+	}
+
+	return pid;
+}
+
+bool LLProcess::kill(void)
+{
+	if (! mProcessID)
+		return false;
+
+	// 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.
+	return ! isRunning();
+}
+
+/*==========================================================================*|
+static std::list<pid_t> sZombies;
+
+void LLProcess::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 LLProcess::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