suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

rktio: simplify Windoes 98 pipe writer

Browse Source 
This code is unlikely to get used, but make sure it runs just
in case Racket otherwise works on Windows 95/98.
This commit is contained in:
Matthew Flatt 2017-06-18 07:55:46 -06:00
parent dacdf64f59
commit 20e23902ba
1 changed files with 15 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
racket/src/rktio/rktio_fd.c
View File

@ -69,14 +69,14 @@ typedef struct Win_FD_Output_Thread {
write has ben flushed, which in turn is needed to
know whether future writes will immediately succeed. */
int flushed, needflush; /* Used for non-blocking, only. The flushed
flag communicates from the flush-testing thread
to the main thread. For efficiency, we request
flush checking only when needed (instead of
after every write); needflush indicates that
a flush check is currently needed, but hasn't
been started. */
flag communicates from the flush-testing thread
to the main thread. For efficiency, we request
flush checking only when needed (instead of
after every write); needflush indicates that
a flush check is currently needed, but hasn't
been started. */
int done, err_no, you_clean_up;
unsigned int buflen, bufstart, bufend; /* used for blocking, only */
unsigned int buflen; /* used for blocking, only */
unsigned char *buffer; /* used for blocking, only */
int *refcount;
HANDLE lock_sema, work_sema, ready_sema;
@ -1270,8 +1270,6 @@ intptr_t rktio_write(rktio_t *rktio, rktio_fd_t *rfd, const char *buffer, intptr
}
oth->buflen = 0;
oth->bufstart = 0;
oth->bufend = 0;
oth->fd = (HANDLE)rfd->fd;
oth->err_no = 0;
@ -1313,53 +1311,18 @@ intptr_t rktio_write(rktio_t *rktio, rktio_fd_t *rfd, const char *buffer, intptr
errsaved = oth->err_no;
ok = 0;
} else if (oth->buflen == RKTIO_FD_BUFFSIZE) {
/* buffer is full, so can't write */
out_len = 0;
ok = 1;
} else {
intptr_t topp;
int was_pre;
if (!oth->buflen) {
/* Avoid fragmenting in circular buffer: */
oth->bufstart = 0;
oth->bufend = 0;
}
/* Write to top part of circular buffer, then bottom part
if anything's left. */
if (oth->bufstart <= oth->bufend) {
was_pre = 1;
topp = RKTIO_FD_BUFFSIZE;
} else {
was_pre = 0;
topp = oth->bufstart;
}
winwrote = topp - oth->bufend;
winwrote = RKTIO_FD_BUFFSIZE - oth->buflen;
if ((intptr_t)winwrote > len)
winwrote = len;
memcpy(oth->buffer + oth->bufend, buffer, winwrote);
memcpy(oth->buffer + oth->buflen, buffer, winwrote);
oth->buflen += winwrote;
out_len = winwrote;
oth->bufend += winwrote;
if (oth->bufend == RKTIO_FD_BUFFSIZE)
oth->bufend = 0;
if (was_pre) {
if ((intptr_t)winwrote < len) {
/* Try continuing with a wrap-around: */
winwrote = oth->bufstart - oth->bufend;
if ((intptr_t)winwrote > len - out_len)
winwrote = len - out_len;
memcpy(oth->buffer + oth->bufend, buffer + out_len, winwrote);
oth->buflen += winwrote;
oth->bufend += winwrote;
out_len += winwrote;
}
}
/* Let the other thread know that it should start trying
to write, if it isn't already: */
ReleaseSemaphore(oth->work_sema, 1, NULL);
@ -1486,17 +1449,15 @@ static long WINAPI WindowsFDWriter(Win_FD_Output_Thread *oth)
WaitForSingleObject(oth->work_sema, INFINITE);
WaitForSingleObject(oth->lock_sema, INFINITE);
if (oth->done)
break;
towrite = oth->buflen;
if (towrite > (RKTIO_FD_BUFFSIZE - oth->bufstart))
towrite = RKTIO_FD_BUFFSIZE - oth->bufstart;
start = oth->bufstart;
ReleaseSemaphore(oth->lock_sema, 1, NULL);
ok = WriteFile(oth->fd, oth->buffer + start, towrite, &wrote, NULL);
ok = WriteFile(oth->fd, oth->buffer, towrite, &wrote, NULL);
if (!ok)
err_no = GetLastError();
else
@ -1506,10 +1467,9 @@ static long WINAPI WindowsFDWriter(Win_FD_Output_Thread *oth)
if (!ok)
oth->err_no = err_no;
else {
oth->bufstart += wrote;
oth->buflen -= wrote;
if (oth->bufstart == RKTIO_FD_BUFFSIZE)
oth->bufstart = 0;
if (oth->buflen)
memmove(oth->buffer, oth->buffer + wrote, oth->buflen);
more_work = oth->buflen > 0;
}
if ((oth->buflen < RKTIO_FD_BUFFSIZE) || oth->err_no)