diff options
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/ser-base.c | 190 | ||||
| -rw-r--r-- | gdb/ser-base.h | 4 |
2 files changed, 188 insertions, 6 deletions
diff --git a/gdb/ser-base.c b/gdb/ser-base.c index b17b11a..30cf7ea 100644 --- a/gdb/ser-base.c +++ b/gdb/ser-base.c @@ -24,6 +24,9 @@ #include "serial.h" #include "ser-unix.h" #include "event-loop.h" +#ifdef WINAPI +#include <winsock2.h> +#endif static timer_handler_func push_event; static handler_func fd_event; @@ -136,11 +139,7 @@ fd_event (int error, void *context) pull characters out of the buffer. See also generic_readchar(). */ int nr; - do - { - nr = read (scb->fd, scb->buf, BUFSIZ); - } - while (nr == -1 && errno == EINTR); + nr = scb->ops->read_prim (scb, BUFSIZ); if (nr == 0) { scb->bufcnt = SERIAL_EOF; @@ -174,6 +173,185 @@ push_event (void *context) reschedule (scb); } +/* Wait for input on scb, with timeout seconds. Returns 0 on success, + otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */ + +static int +ser_base_wait_for (struct serial *scb, int timeout) +{ + while (1) + { + int numfds; + struct timeval tv; + fd_set readfds, exceptfds; + + /* NOTE: Some OS's can scramble the READFDS when the select() + call fails (ex the kernel with Red Hat 5.2). Initialize all + arguments before each call. */ + + tv.tv_sec = timeout; + tv.tv_usec = 0; + + FD_ZERO (&readfds); + FD_ZERO (&exceptfds); + FD_SET (scb->fd, &readfds); + FD_SET (scb->fd, &exceptfds); + + if (timeout >= 0) + numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, &tv); + else + numfds = select (scb->fd + 1, &readfds, 0, &exceptfds, 0); + + if (numfds <= 0) + { + if (numfds == 0) + return SERIAL_TIMEOUT; + else if (errno == EINTR) + continue; + else + return SERIAL_ERROR; /* Got an error from select or poll */ + } + + return 0; + } +} + +/* Read a character with user-specified timeout. TIMEOUT is number of seconds + to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns + char if successful. Returns -2 if timeout expired, EOF if line dropped + dead, or -3 for any other error (see errno in that case). */ + +static int +do_ser_base_readchar (struct serial *scb, int timeout) +{ + int status; + int delta; + + /* We have to be able to keep the GUI alive here, so we break the + original timeout into steps of 1 second, running the "keep the + GUI alive" hook each time through the loop. + + Also, timeout = 0 means to poll, so we just set the delta to 0, + so we will only go through the loop once. */ + + delta = (timeout == 0 ? 0 : 1); + while (1) + { + + /* N.B. The UI may destroy our world (for instance by calling + remote_stop,) in which case we want to get out of here as + quickly as possible. It is not safe to touch scb, since + someone else might have freed it. The + deprecated_ui_loop_hook signals that we should exit by + returning 1. */ + + if (deprecated_ui_loop_hook) + { + if (deprecated_ui_loop_hook (0)) + return SERIAL_TIMEOUT; + } + + status = ser_base_wait_for (scb, delta); + if (timeout > 0) + timeout -= delta; + + /* If we got a character or an error back from wait_for, then we can + break from the loop before the timeout is completed. */ + + if (status != SERIAL_TIMEOUT) + { + break; + } + + /* If we have exhausted the original timeout, then generate + a SERIAL_TIMEOUT, and pass it out of the loop. */ + + else if (timeout == 0) + { + status = SERIAL_TIMEOUT; + break; + } + } + + if (status < 0) + return status; + + status = scb->ops->read_prim (scb, BUFSIZ); + + if (status <= 0) + { + if (status == 0) + return SERIAL_TIMEOUT; /* 0 chars means timeout [may need to + distinguish between EOF & timeouts + someday] */ + else + return SERIAL_ERROR; /* Got an error from read */ + } + + scb->bufcnt = status; + scb->bufcnt--; + scb->bufp = scb->buf; + return *scb->bufp++; +} + +/* Perform operations common to both old and new readchar. */ + +/* Return the next character from the input FIFO. If the FIFO is + empty, call the SERIAL specific routine to try and read in more + characters. + + Initially data from the input FIFO is returned (fd_event() + pre-reads the input into that FIFO. Once that has been emptied, + further data is obtained by polling the input FD using the device + specific readchar() function. Note: reschedule() is called after + every read. This is because there is no guarentee that the lower + level fd_event() poll_event() code (which also calls reschedule()) + will be called. */ + +int +generic_readchar (struct serial *scb, int timeout, + int (do_readchar) (struct serial *scb, int timeout)) +{ + int ch; + if (scb->bufcnt > 0) + { + ch = *scb->bufp; + scb->bufcnt--; + scb->bufp++; + } + else if (scb->bufcnt < 0) + { + /* Some errors/eof are are sticky. */ + ch = scb->bufcnt; + } + else + { + ch = do_readchar (scb, timeout); + if (ch < 0) + { + switch ((enum serial_rc) ch) + { + case SERIAL_EOF: + case SERIAL_ERROR: + /* Make the error/eof stick. */ + scb->bufcnt = ch; + break; + case SERIAL_TIMEOUT: + scb->bufcnt = 0; + break; + } + } + } + reschedule (scb); + return ch; +} + +int +ser_base_readchar (struct serial *scb, int timeout) +{ + return generic_readchar (scb, timeout, do_ser_base_readchar); +} + int ser_base_write (struct serial *scb, const char *str, int len) { @@ -181,7 +359,7 @@ ser_base_write (struct serial *scb, const char *str, int len) while (len > 0) { - cc = write (scb->fd, str, len); + cc = scb->ops->write_prim (scb, str, len); if (cc < 0) return 1; diff --git a/gdb/ser-base.h b/gdb/ser-base.h index 5467fc8..8604629 100644 --- a/gdb/ser-base.h +++ b/gdb/ser-base.h @@ -25,6 +25,9 @@ struct serial; struct ui_file; +extern int generic_readchar (struct serial *scb, int timeout, + int (*do_readchar) (struct serial *scb, + int timeout)); extern void reschedule (struct serial *scb); extern int ser_base_flush_output (struct serial *scb); extern int ser_base_flush_input (struct serial *scb); @@ -46,5 +49,6 @@ extern int ser_base_drain_output (struct serial *scb); extern int ser_base_write (struct serial *scb, const char *str, int len); extern void ser_base_async (struct serial *scb, int async_p); +extern int ser_base_readchar (struct serial *scb, int timeout); #endif |