diff options
Diffstat (limited to '')
-rw-r--r-- | mysys/my_win_popen.cc | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/mysys/my_win_popen.cc b/mysys/my_win_popen.cc new file mode 100644 index 00000000..cceb77e9 --- /dev/null +++ b/mysys/my_win_popen.cc @@ -0,0 +1,170 @@ +/* 2019, MariaDB Corporation. + +This program is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; version 2 of the License. + +This program 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 General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this program; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ + +/* + Replacement of the buggy implementations of popen in Windows CRT +*/ +#include <windows.h> +#include <fcntl.h> +#include <io.h> +#include <mutex> +#include <stdlib.h> +#include <unordered_map> + +enum +{ + REDIRECT_STDIN= 'w', + REDIRECT_STDOUT= 'r' +}; + +/** Map from FILE* returned by popen() to corresponding process handle.*/ +static std::unordered_map<FILE *, HANDLE> popen_map; +/* Mutex to protect the map.*/ +static std::mutex popen_mtx; + +/** +Creates a FILE* from HANDLE. +*/ +static FILE *make_fp(HANDLE *handle, const char *mode) +{ + int flags = 0; + + if (mode[0] == REDIRECT_STDOUT) + flags |= O_RDONLY; + switch (mode[1]) + { + case 't': + flags |= _O_TEXT; + break; + case 'b': + flags |= _O_BINARY; + break; + } + + int fd= _open_osfhandle((intptr_t) *handle, flags); + if (fd < 0) + return NULL; + FILE *fp= fdopen(fd, mode); + if (!fp) + { + /* Closing file descriptor also closes underlying handle.*/ + close(fd); + *handle= 0; + } + return fp; +} + +/** A home-backed version of popen(). */ +extern "C" FILE *my_win_popen(const char *cmd, const char *mode) +{ + FILE *fp(0); + char type= mode[0]; + HANDLE parent_pipe_end(0); + HANDLE child_pipe_end(0); + PROCESS_INFORMATION pi{}; + STARTUPINFO si{}; + std::string command_line; + + /* Create a pipe between this and child process.*/ + SECURITY_ATTRIBUTES sa_attr{}; + sa_attr.nLength= sizeof(SECURITY_ATTRIBUTES); + sa_attr.bInheritHandle= TRUE; + switch (type) + { + case REDIRECT_STDIN: + if (!CreatePipe(&child_pipe_end, &parent_pipe_end, &sa_attr, 0)) + goto error; + break; + case REDIRECT_STDOUT: + if (!CreatePipe(&parent_pipe_end, &child_pipe_end, &sa_attr, 0)) + goto error; + break; + default: + /* Unknown mode, expected "r", "rt", "w", "wt" */ + abort(); + } + if (!SetHandleInformation(parent_pipe_end, HANDLE_FLAG_INHERIT, 0)) + goto error; + + /* Start child process with redirected output.*/ + + si.cb= sizeof(STARTUPINFO); + si.hStdError= GetStdHandle(STD_ERROR_HANDLE); + si.hStdOutput= (type == REDIRECT_STDOUT) ? child_pipe_end + : GetStdHandle(STD_OUTPUT_HANDLE); + si.hStdInput= (type == REDIRECT_STDIN) ? child_pipe_end + : GetStdHandle(STD_INPUT_HANDLE); + + si.dwFlags|= STARTF_USESTDHANDLES; + command_line.append("cmd.exe /c ").append(cmd); + + if (!CreateProcess(0, (LPSTR) command_line.c_str(), 0, 0, TRUE, 0, 0, 0, &si, + &pi)) + goto error; + + CloseHandle(pi.hThread); + CloseHandle(child_pipe_end); + child_pipe_end= 0; + + fp= make_fp(&parent_pipe_end, mode); + if (fp) + { + std::unique_lock<std::mutex> lk(popen_mtx); + popen_map[fp]= pi.hProcess; + return fp; + } + +error: + for (auto handle : { parent_pipe_end, child_pipe_end }) + { + if (handle) + CloseHandle(handle); + } + + if (pi.hProcess) + { + TerminateProcess(pi.hProcess, 1); + CloseHandle(pi.hProcess); + } + return NULL; +} + +/** A home-backed version of pclose(). */ + +extern "C" int my_win_pclose(FILE *fp) +{ + /* Find process entry for given file pointer.*/ + std::unique_lock<std::mutex> lk(popen_mtx); + HANDLE proc= popen_map[fp]; + if (!proc) + { + errno= EINVAL; + return -1; + } + popen_map.erase(fp); + lk.unlock(); + + fclose(fp); + + /* Wait for process to complete, return its exit code.*/ + DWORD ret; + if (WaitForSingleObject(proc, INFINITE) || !GetExitCodeProcess(proc, &ret)) + { + ret= -1; + errno= EINVAL; + } + CloseHandle(proc); + return ret; +} |