1 // Copyright 2010 Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright 11 // notice, this list of conditions and the following disclaimer in the 12 // documentation and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors 14 // may be used to endorse or promote products derived from this software 15 // without specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29 /// \file utils/process/child.hpp 30 /// Spawning and manipulation of children processes. 31 /// 32 /// The child module provides a set of functions to spawn subprocesses with 33 /// different settings, and the corresponding set of classes to interact with 34 /// said subprocesses. The interfaces to fork subprocesses are very simplified 35 /// and only provide the minimum functionality required by the rest of the 36 /// project. 37 /// 38 /// Be aware that the semantics of the fork and wait methods exposed by this 39 /// module are slightly different from that of the native calls. Any process 40 /// spawned by fork here will be isolated in its own process group; once any of 41 /// such children processes is awaited for, its whole process group will be 42 /// terminated. This is the semantics we want in the above layers to ensure 43 /// that test programs (and, for that matter, external utilities) do not leak 44 /// subprocesses on the system. 45 46 #if !defined(UTILS_PROCESS_CHILD_HPP) 47 #define UTILS_PROCESS_CHILD_HPP 48 49 #include <istream> 50 #include <memory> 51 #include <string> 52 #include <vector> 53 54 #include "utils/fs/path.hpp" 55 #include "utils/noncopyable.hpp" 56 #include "utils/process/status.hpp" 57 58 namespace utils { 59 namespace process { 60 61 62 /// Arguments to a program, without the program name. 63 typedef std::vector< std::string > args_vector; 64 65 66 /// Child process spawner and controller. 67 class child : noncopyable { 68 struct impl; 69 70 /// Pointer to the shared internal implementation. 71 std::auto_ptr< impl > _pimpl; 72 73 static std::auto_ptr< child > fork_capture_aux(void); 74 75 static std::auto_ptr< child > fork_files_aux(const fs::path&, 76 const fs::path&); 77 78 explicit child(impl *); 79 80 public: 81 ~child(void); 82 83 template< typename Hook > 84 static std::auto_ptr< child > fork_capture(Hook); 85 std::istream& output(void); 86 87 template< typename Hook > 88 static std::auto_ptr< child > fork_files(Hook, const fs::path&, 89 const fs::path&); 90 91 static std::auto_ptr< child > spawn_capture( 92 const fs::path&, const args_vector&); 93 static std::auto_ptr< child > spawn_files( 94 const fs::path&, const args_vector&, const fs::path&, const fs::path&); 95 96 int pid(void) const; 97 98 status wait(void); 99 }; 100 101 102 } // namespace process 103 } // namespace utils 104 105 #endif // !defined(UTILS_PROCESS_CHILD_HPP) 106