1 // Copyright 2010 The Kyua Authors. 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 session; 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 "utils/process/child_fwd.hpp" 50 51 #include <istream> 52 #include <memory> 53 #include <stdexcept> 54 55 #include "utils/defs.hpp" 56 #include "utils/fs/path_fwd.hpp" 57 #include "utils/noncopyable.hpp" 58 #include "utils/process/operations_fwd.hpp" 59 #include "utils/process/status_fwd.hpp" 60 61 namespace utils { 62 namespace process { 63 64 65 namespace detail { 66 67 void report_error_and_abort(void) UTILS_NORETURN; 68 void report_error_and_abort(const std::runtime_error&) UTILS_NORETURN; 69 70 71 } // namespace detail 72 73 74 /// Child process spawner and controller. 75 class child : noncopyable { 76 struct impl; 77 78 /// Pointer to the shared internal implementation. 79 std::auto_ptr< impl > _pimpl; 80 81 static std::auto_ptr< child > fork_capture_aux(void); 82 83 static std::auto_ptr< child > fork_files_aux(const fs::path&, 84 const fs::path&); 85 86 explicit child(impl *); 87 88 public: 89 ~child(void); 90 91 template< typename Hook > 92 static std::auto_ptr< child > fork_capture(Hook); 93 std::istream& output(void); 94 95 template< typename Hook > 96 static std::auto_ptr< child > fork_files(Hook, const fs::path&, 97 const fs::path&); 98 99 static std::auto_ptr< child > spawn_capture( 100 const fs::path&, const args_vector&); 101 static std::auto_ptr< child > spawn_files( 102 const fs::path&, const args_vector&, const fs::path&, const fs::path&); 103 104 int pid(void) const; 105 106 status wait(void); 107 }; 108 109 110 } // namespace process 111 } // namespace utils 112 113 #endif // !defined(UTILS_PROCESS_CHILD_HPP) 114