diff options
| -rw-r--r-- | compat/mingw.c | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/compat/mingw.c b/compat/mingw.c index 7f89a6cb8..2677e7862 100644 --- a/compat/mingw.c +++ b/compat/mingw.c @@ -101,7 +101,62 @@ int pipe(int filedes[2]) int poll(struct pollfd *ufds, unsigned int nfds, int timeout) { - return -1; + int i, pending; + + if (timeout != -1) + return errno = EINVAL, error("poll timeout not supported"); + + /* When there is only one fd to wait for, then we pretend that + * input is available and let the actual wait happen when the + * caller invokes read(). + */ + if (nfds == 1) { + if (!(ufds[0].events & POLLIN)) + return errno = EINVAL, error("POLLIN not set"); + ufds[0].revents = POLLIN; + return 0; + } + +repeat: + pending = 0; + for (i = 0; i < nfds; i++) { + DWORD avail = 0; + HANDLE h = (HANDLE) _get_osfhandle(ufds[i].fd); + if (h == INVALID_HANDLE_VALUE) + return -1; /* errno was set */ + + if (!(ufds[i].events & POLLIN)) + return errno = EINVAL, error("POLLIN not set"); + + /* this emulation works only for pipes */ + if (!PeekNamedPipe(h, NULL, 0, NULL, &avail, NULL)) { + int err = GetLastError(); + if (err == ERROR_BROKEN_PIPE) { + ufds[i].revents = POLLHUP; + pending++; + } else { + errno = EINVAL; + return error("PeekNamedPipe failed," + " GetLastError: %u", err); + } + } else if (avail) { + ufds[i].revents = POLLIN; + pending++; + } else + ufds[i].revents = 0; + } + if (!pending) { + /* The only times that we spin here is when the process + * that is connected through the pipes is waiting for + * its own input data to become available. But since + * the process (pack-objects) is itself CPU intensive, + * it will happily pick up the time slice that we are + * relinguishing here. + */ + Sleep(0); + goto repeat; + } + return 0; } struct tm *gmtime_r(const time_t *timep, struct tm *result) |