| 1 | /* Host support routines for MinGW, for GDB, the GNU debugger. |
| 2 | |
| 3 | Copyright (C) 2006 |
| 4 | Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| 21 | Boston, MA 02110-1301, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "serial.h" |
| 25 | |
| 26 | #include "gdb_assert.h" |
| 27 | #include "gdb_select.h" |
| 28 | #include "gdb_string.h" |
| 29 | |
| 30 | #include <windows.h> |
| 31 | |
| 32 | /* The strerror() function can return NULL for errno values that are |
| 33 | out of range. Provide a "safe" version that always returns a |
| 34 | printable string. |
| 35 | |
| 36 | The Windows runtime implementation of strerror never returns NULL, |
| 37 | but does return a useless string for anything above sys_nerr; |
| 38 | unfortunately this includes all socket-related error codes. |
| 39 | This replacement tries to find a system-provided error message. */ |
| 40 | |
| 41 | char * |
| 42 | safe_strerror (int errnum) |
| 43 | { |
| 44 | static char *buffer; |
| 45 | int len; |
| 46 | |
| 47 | if (errnum >= 0 && errnum < sys_nerr) |
| 48 | return strerror (errnum); |
| 49 | |
| 50 | if (buffer) |
| 51 | { |
| 52 | LocalFree (buffer); |
| 53 | buffer = NULL; |
| 54 | } |
| 55 | |
| 56 | if (FormatMessage (FORMAT_MESSAGE_ALLOCATE_BUFFER |
| 57 | | FORMAT_MESSAGE_FROM_SYSTEM, |
| 58 | NULL, errnum, |
| 59 | MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT), |
| 60 | (LPTSTR) &buffer, 0, NULL) == 0) |
| 61 | { |
| 62 | static char buf[32]; |
| 63 | xsnprintf (buf, sizeof buf, "(undocumented errno %d)", errnum); |
| 64 | return buf; |
| 65 | } |
| 66 | |
| 67 | /* Windows error messages end with a period and a CR-LF; strip that |
| 68 | out. */ |
| 69 | len = strlen (buffer); |
| 70 | if (len > 3 && strcmp (buffer + len - 3, ".\r\n") == 0) |
| 71 | buffer[len - 3] = '\0'; |
| 72 | |
| 73 | return buffer; |
| 74 | } |
| 75 | |
| 76 | /* Wrapper for select. On Windows systems, where the select interface |
| 77 | only works for sockets, this uses the GDB serial abstraction to |
| 78 | handle sockets, consoles, pipes, and serial ports. |
| 79 | |
| 80 | The arguments to this function are the same as the traditional |
| 81 | arguments to select on POSIX platforms. */ |
| 82 | |
| 83 | int |
| 84 | gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, |
| 85 | struct timeval *timeout) |
| 86 | { |
| 87 | static HANDLE never_handle; |
| 88 | HANDLE handles[MAXIMUM_WAIT_OBJECTS]; |
| 89 | HANDLE h; |
| 90 | DWORD event; |
| 91 | DWORD num_handles; |
| 92 | int fd; |
| 93 | int num_ready; |
| 94 | int indx; |
| 95 | |
| 96 | num_ready = 0; |
| 97 | num_handles = 0; |
| 98 | for (fd = 0; fd < n; ++fd) |
| 99 | { |
| 100 | HANDLE read = NULL, except = NULL; |
| 101 | struct serial *scb; |
| 102 | |
| 103 | /* There is no support yet for WRITEFDS. At present, this isn't |
| 104 | used by GDB -- but we do not want to silently ignore WRITEFDS |
| 105 | if something starts using it. */ |
| 106 | gdb_assert (!writefds || !FD_ISSET (fd, writefds)); |
| 107 | |
| 108 | if (!FD_ISSET (fd, readfds) |
| 109 | && !FD_ISSET (fd, exceptfds)) |
| 110 | continue; |
| 111 | h = (HANDLE) _get_osfhandle (fd); |
| 112 | |
| 113 | scb = serial_for_fd (fd); |
| 114 | if (scb) |
| 115 | serial_wait_handle (scb, &read, &except); |
| 116 | |
| 117 | if (read == NULL) |
| 118 | read = h; |
| 119 | if (except == NULL) |
| 120 | { |
| 121 | if (!never_handle) |
| 122 | never_handle = CreateEvent (0, FALSE, FALSE, 0); |
| 123 | |
| 124 | except = never_handle; |
| 125 | } |
| 126 | |
| 127 | if (FD_ISSET (fd, readfds)) |
| 128 | { |
| 129 | gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS); |
| 130 | handles[num_handles++] = read; |
| 131 | } |
| 132 | |
| 133 | if (FD_ISSET (fd, exceptfds)) |
| 134 | { |
| 135 | gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS); |
| 136 | handles[num_handles++] = except; |
| 137 | } |
| 138 | } |
| 139 | /* If we don't need to wait for any handles, we are done. */ |
| 140 | if (!num_handles) |
| 141 | { |
| 142 | if (timeout) |
| 143 | Sleep (timeout->tv_sec * 1000 + timeout->tv_usec / 1000); |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | event = WaitForMultipleObjects (num_handles, |
| 149 | handles, |
| 150 | FALSE, |
| 151 | timeout |
| 152 | ? (timeout->tv_sec * 1000 |
| 153 | + timeout->tv_usec / 1000) |
| 154 | : INFINITE); |
| 155 | /* EVENT can only be a value in the WAIT_ABANDONED_0 range if the |
| 156 | HANDLES included an abandoned mutex. Since GDB doesn't use |
| 157 | mutexes, that should never occur. */ |
| 158 | gdb_assert (!(WAIT_ABANDONED_0 <= event |
| 159 | && event < WAIT_ABANDONED_0 + num_handles)); |
| 160 | if (event == WAIT_FAILED) |
| 161 | return -1; |
| 162 | if (event == WAIT_TIMEOUT) |
| 163 | return 0; |
| 164 | /* Run through the READFDS, clearing bits corresponding to descriptors |
| 165 | for which input is unavailable. */ |
| 166 | h = handles[event - WAIT_OBJECT_0]; |
| 167 | for (fd = 0, indx = 0; fd < n; ++fd) |
| 168 | { |
| 169 | HANDLE fd_h; |
| 170 | |
| 171 | if (FD_ISSET (fd, readfds)) |
| 172 | { |
| 173 | fd_h = handles[indx++]; |
| 174 | /* This handle might be ready, even though it wasn't the handle |
| 175 | returned by WaitForMultipleObjects. */ |
| 176 | if (fd_h != h && WaitForSingleObject (fd_h, 0) != WAIT_OBJECT_0) |
| 177 | FD_CLR (fd, readfds); |
| 178 | else |
| 179 | num_ready++; |
| 180 | } |
| 181 | |
| 182 | if (FD_ISSET (fd, exceptfds)) |
| 183 | { |
| 184 | fd_h = handles[indx++]; |
| 185 | /* This handle might be ready, even though it wasn't the handle |
| 186 | returned by WaitForMultipleObjects. */ |
| 187 | if (fd_h != h && WaitForSingleObject (fd_h, 0) != WAIT_OBJECT_0) |
| 188 | FD_CLR (fd, exceptfds); |
| 189 | else |
| 190 | num_ready++; |
| 191 | } |
| 192 | } |
| 193 | |
| 194 | return num_ready; |
| 195 | } |