From 59629c1d8baeb7407b419cce3b59bea0bb4a2bd9 Mon Sep 17 00:00:00 2001 From: David Greene Date: Wed, 8 Jul 2009 21:46:40 +0000 Subject: [PATCH] Add an ExecuteNoWait interface to support asynchronous process spawning. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75055 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/System/Program.h | 37 ++++++++ lib/System/Unix/Program.inc | 72 +++++++++++++++ lib/System/Win32/Program.inc | 165 ++++++++++++++++++++++++++++++++++ 3 files changed, 274 insertions(+) diff --git a/include/llvm/System/Program.h b/include/llvm/System/Program.h index 37f55466a50..49de7cf159f 100644 --- a/include/llvm/System/Program.h +++ b/include/llvm/System/Program.h @@ -87,6 +87,43 @@ namespace sys { static bool ChangeStdinToBinary(); static bool ChangeStdoutToBinary(); /// @} + + /// This function executes the program using the \p arguments provided and + /// waits for the program to exit. This function will block the current + /// program until the invoked program exits. The invoked program will + /// inherit the stdin, stdout, and stderr file descriptors, the + /// environment and other configuration settings of the invoking program. + /// If Path::executable() does not return true when this function is + /// called then a std::string is thrown. + /// @returns an integer result code indicating the status of the program. + /// A zero or positive value indicates the result code of the program. A + /// negative value is the signal number on which it terminated. + /// @see FindProgrambyName + /// @brief Executes the program with the given set of \p args. + static void ExecuteNoWait( + const Path& path, ///< sys::Path object providing the path of the + ///< program to be executed. It is presumed this is the result of + ///< the FindProgramByName method. + const char** args, ///< A vector of strings that are passed to the + ///< program. The first element should be the name of the program. + ///< The list *must* be terminated by a null char* entry. + const char ** env = 0, ///< An optional vector of strings to use for + ///< the program's environment. If not provided, the current program's + ///< environment will be used. + const sys::Path** redirects = 0, ///< An optional array of pointers to + ///< Paths. If the array is null, no redirection is done. The array + ///< should have a size of at least three. If the pointer in the array + ///< are not null, then the inferior process's stdin(0), stdout(1), + ///< and stderr(2) will be redirected to the corresponding Paths. + unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount + ///< of memory can be allocated by process. If memory usage will be + ///< higher limit, the child is killed and this call returns. If zero - + ///< no memory limit. + std::string* ErrMsg = 0 ///< If non-zero, provides a pointer to a string + ///< instance in which error messages will be returned. If the string + ///< is non-empty upon return an error occurred while invoking the + ///< program. + ); }; } } diff --git a/lib/System/Unix/Program.inc b/lib/System/Unix/Program.inc index cdc6fee6094..7e196b08fed 100644 --- a/lib/System/Unix/Program.inc +++ b/lib/System/Unix/Program.inc @@ -274,6 +274,78 @@ Program::ExecuteAndWait(const Path& path, } +void +Program::ExecuteNoWait(const Path& path, + const char** args, + const char** envp, + const Path** redirects, + unsigned memoryLimit, + std::string* ErrMsg) +{ + if (!path.canExecute()) { + if (ErrMsg) + *ErrMsg = path.toString() + " is not executable"; + return; + } + + // Create a child process. + int child = fork(); + switch (child) { + // An error occured: Return to the caller. + case -1: + MakeErrMsg(ErrMsg, "Couldn't fork"); + return; + + // Child process: Execute the program. + case 0: { + // Redirect file descriptors... + if (redirects) { + // Redirect stdin + if (RedirectIO(redirects[0], 0, ErrMsg)) { return; } + // Redirect stdout + if (RedirectIO(redirects[1], 1, ErrMsg)) { return; } + if (redirects[1] && redirects[2] && + *(redirects[1]) == *(redirects[2])) { + // If stdout and stderr should go to the same place, redirect stderr + // to the FD already open for stdout. + if (-1 == dup2(1,2)) { + MakeErrMsg(ErrMsg, "Can't redirect stderr to stdout"); + return; + } + } else { + // Just redirect stderr + if (RedirectIO(redirects[2], 2, ErrMsg)) { return; } + } + } + + // Set memory limits + if (memoryLimit!=0) { + SetMemoryLimits(memoryLimit); + } + + // Execute! + if (envp != 0) + execve (path.c_str(), (char**)args, (char**)envp); + else + execv (path.c_str(), (char**)args); + // If the execve() failed, we should exit and let the parent pick up + // our non-zero exit status. + exit (errno); + } + + // Parent process: Break out of the switch to do our processing. + default: + break; + } + + // Make sure stderr and stdout have been flushed + std::cerr << std::flush; + std::cout << std::flush; + fsync(1); + fsync(2); + +} + bool Program::ChangeStdinToBinary(){ // Do nothing, as Unix doesn't differentiate between text and binary. return false; diff --git a/lib/System/Win32/Program.inc b/lib/System/Win32/Program.inc index 49086b8348e..71f686ca02d 100644 --- a/lib/System/Win32/Program.inc +++ b/lib/System/Win32/Program.inc @@ -303,6 +303,171 @@ Program::ExecuteAndWait(const Path& path, return status; } +void +Program::ExecuteNoWait(const Path& path, + const char** args, + const char** envp, + const Path** redirects, + unsigned memoryLimit, + std::string* ErrMsg) { + if (!path.canExecute()) { + if (ErrMsg) + *ErrMsg = "program not executable"; + return; + } + + // Windows wants a command line, not an array of args, to pass to the new + // process. We have to concatenate them all, while quoting the args that + // have embedded spaces. + + // First, determine the length of the command line. + unsigned len = 0; + for (unsigned i = 0; args[i]; i++) { + len += strlen(args[i]) + 1; + if (strchr(args[i], ' ')) + len += 2; + } + + // Now build the command line. + char *command = reinterpret_cast(_alloca(len+1)); + char *p = command; + + for (unsigned i = 0; args[i]; i++) { + const char *arg = args[i]; + size_t len = strlen(arg); + bool needsQuoting = strchr(arg, ' ') != 0; + if (needsQuoting) + *p++ = '"'; + memcpy(p, arg, len); + p += len; + if (needsQuoting) + *p++ = '"'; + *p++ = ' '; + } + + *p = 0; + + // The pointer to the environment block for the new process. + char *envblock = 0; + + if (envp) { + // An environment block consists of a null-terminated block of + // null-terminated strings. Convert the array of environment variables to + // an environment block by concatenating them. + + // First, determine the length of the environment block. + len = 0; + for (unsigned i = 0; envp[i]; i++) + len += strlen(envp[i]) + 1; + + // Now build the environment block. + envblock = reinterpret_cast(_alloca(len+1)); + p = envblock; + + for (unsigned i = 0; envp[i]; i++) { + const char *ev = envp[i]; + size_t len = strlen(ev) + 1; + memcpy(p, ev, len); + p += len; + } + + *p = 0; + } + + // Create a child process. + STARTUPINFO si; + memset(&si, 0, sizeof(si)); + si.cb = sizeof(si); + si.hStdInput = INVALID_HANDLE_VALUE; + si.hStdOutput = INVALID_HANDLE_VALUE; + si.hStdError = INVALID_HANDLE_VALUE; + + if (redirects) { + si.dwFlags = STARTF_USESTDHANDLES; + + si.hStdInput = RedirectIO(redirects[0], 0, ErrMsg); + if (si.hStdInput == INVALID_HANDLE_VALUE) { + MakeErrMsg(ErrMsg, "can't redirect stdin"); + return; + } + si.hStdOutput = RedirectIO(redirects[1], 1, ErrMsg); + if (si.hStdOutput == INVALID_HANDLE_VALUE) { + CloseHandle(si.hStdInput); + MakeErrMsg(ErrMsg, "can't redirect stdout"); + return; + } + if (redirects[1] && redirects[2] && *(redirects[1]) == *(redirects[2])) { + // If stdout and stderr should go to the same place, redirect stderr + // to the handle already open for stdout. + DuplicateHandle(GetCurrentProcess(), si.hStdOutput, + GetCurrentProcess(), &si.hStdError, + 0, TRUE, DUPLICATE_SAME_ACCESS); + } else { + // Just redirect stderr + si.hStdError = RedirectIO(redirects[2], 2, ErrMsg); + if (si.hStdError == INVALID_HANDLE_VALUE) { + CloseHandle(si.hStdInput); + CloseHandle(si.hStdOutput); + MakeErrMsg(ErrMsg, "can't redirect stderr"); + return; + } + } + } + + PROCESS_INFORMATION pi; + memset(&pi, 0, sizeof(pi)); + + fflush(stdout); + fflush(stderr); + BOOL rc = CreateProcess(path.c_str(), command, NULL, NULL, TRUE, 0, + envblock, NULL, &si, &pi); + DWORD err = GetLastError(); + + // Regardless of whether the process got created or not, we are done with + // the handles we created for it to inherit. + CloseHandle(si.hStdInput); + CloseHandle(si.hStdOutput); + CloseHandle(si.hStdError); + + // Now return an error if the process didn't get created. + if (!rc) + { + SetLastError(err); + MakeErrMsg(ErrMsg, std::string("Couldn't execute program '") + + path.toString() + "'"); + return; + } + + // Make sure these get closed no matter what. + AutoHandle hProcess(pi.hProcess); + AutoHandle hThread(pi.hThread); + + // Assign the process to a job if a memory limit is defined. + AutoHandle hJob(0); + if (memoryLimit != 0) { + hJob = CreateJobObject(0, 0); + bool success = false; + if (hJob != 0) { + JOBOBJECT_EXTENDED_LIMIT_INFORMATION jeli; + memset(&jeli, 0, sizeof(jeli)); + jeli.BasicLimitInformation.LimitFlags = JOB_OBJECT_LIMIT_PROCESS_MEMORY; + jeli.ProcessMemoryLimit = uintptr_t(memoryLimit) * 1048576; + if (SetInformationJobObject(hJob, JobObjectExtendedLimitInformation, + &jeli, sizeof(jeli))) { + if (AssignProcessToJobObject(hJob, pi.hProcess)) + success = true; + } + } + if (!success) { + SetLastError(GetLastError()); + MakeErrMsg(ErrMsg, std::string("Unable to set memory limit")); + TerminateProcess(pi.hProcess, 1); + WaitForSingleObject(pi.hProcess, INFINITE); + return; + } + } +} + bool Program::ChangeStdinToBinary(){ int result = _setmode( _fileno(stdin), _O_BINARY ); return result == -1; -- 2.34.1