miniposix.h (3918B)
1 // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors 2 // Licensed under the MIT License: 3 // 4 // Permission is hereby granted, free of charge, to any person obtaining a copy 5 // of this software and associated documentation files (the "Software"), to deal 6 // in the Software without restriction, including without limitation the rights 7 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 8 // copies of the Software, and to permit persons to whom the Software is 9 // furnished to do so, subject to the following conditions: 10 // 11 // The above copyright notice and this permission notice shall be included in 12 // all copies or substantial portions of the Software. 13 // 14 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 17 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 18 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 19 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 20 // THE SOFTWARE. 21 22 #pragma once 23 24 // This header provides a small subset of the POSIX API which also happens to be available on 25 // Windows under slightly-different names. 26 27 #if _WIN32 28 #include <io.h> 29 #include <direct.h> 30 #include <fcntl.h> // _O_BINARY 31 #else 32 #include <limits.h> 33 #include <errno.h> 34 #endif 35 36 #if !_WIN32 || __MINGW32__ 37 #include <unistd.h> 38 #include <sys/stat.h> 39 #include <sys/types.h> 40 #endif 41 42 #if !_WIN32 43 #include <sys/uio.h> 44 #endif 45 46 // To get KJ_BEGIN_HEADER/KJ_END_HEADER 47 #include "common.h" 48 49 KJ_BEGIN_HEADER 50 51 namespace kj { 52 namespace miniposix { 53 54 #if _WIN32 && !__MINGW32__ 55 // We're on Windows and not MinGW. So, we need to define wrappers for the POSIX API. 56 57 typedef int ssize_t; 58 59 inline ssize_t read(int fd, void* buffer, size_t size) { 60 return ::_read(fd, buffer, size); 61 } 62 inline ssize_t write(int fd, const void* buffer, size_t size) { 63 return ::_write(fd, buffer, size); 64 } 65 inline int close(int fd) { 66 return ::_close(fd); 67 } 68 69 #ifndef F_OK 70 #define F_OK 0 // access() existence test 71 #endif 72 73 #ifndef S_ISREG 74 #define S_ISREG(mode) (((mode) & S_IFMT) == S_IFREG) // stat() regular file test 75 #endif 76 #ifndef S_ISDIR 77 #define S_ISDIR(mode) (((mode) & S_IFMT) == S_IFDIR) // stat() directory test 78 #endif 79 80 #ifndef STDIN_FILENO 81 #define STDIN_FILENO 0 82 #endif 83 #ifndef STDOUT_FILENO 84 #define STDOUT_FILENO 1 85 #endif 86 #ifndef STDERR_FILENO 87 #define STDERR_FILENO 2 88 #endif 89 90 #else 91 // We're on a POSIX system or MinGW which already defines the wrappers for us. 92 93 using ::ssize_t; 94 using ::read; 95 using ::write; 96 using ::close; 97 98 #endif 99 100 #if _WIN32 101 // We're on Windows, including MinGW. pipe() and mkdir() are non-standard even on MinGW. 102 103 inline int pipe(int fds[2]) { 104 return ::_pipe(fds, 8192, _O_BINARY | _O_NOINHERIT); 105 } 106 inline int mkdir(const char* path, int mode) { 107 return ::_mkdir(path); 108 } 109 110 #else 111 // We're on real POSIX. 112 113 using ::pipe; 114 using ::mkdir; 115 116 117 // Apparently, there is a maximum number of iovecs allowed per call. I don't understand why. 118 // Most platforms define IOV_MAX but Linux defines only UIO_MAXIOV and others, like Hurd, 119 // define neither. 120 // 121 // On platforms where both IOV_MAX and UIO_MAXIOV are undefined, we poke sysconf(_SC_IOV_MAX), 122 // then try to fall back to the POSIX-mandated minimum of _XOPEN_IOV_MAX if that fails. 123 // 124 // http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html#tag_13_23_03_01 125 #if defined(IOV_MAX) 126 // Solaris, MacOS (& all other BSD-variants?) (and others?) 127 static constexpr inline size_t iovMax() { 128 return IOV_MAX; 129 } 130 #elif defined(UIO_MAX_IOV) 131 // Linux 132 static constexpr inline size_t iovMax() { 133 return UIO_MAX_IOV; 134 } 135 #else 136 #error "Please determine the appropriate constant for IOV_MAX on your system." 137 #endif 138 139 #endif 140 141 } // namespace miniposix 142 } // namespace kj 143 144 KJ_END_HEADER