lib: Introduced a portable abstraction layer for custom stdio streams.

[ashd.git] / lib / mtio.c

diff --git a/lib/mtio.c b/lib/mtio.c
index 3bb7b86..1f4a579 100644 (file)
--- a/lib/mtio.c
+++ b/lib/mtio.c
@@ -16,109 +16,120 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 #include <stdlib.h>
+#include <stdio.h>
 #include <unistd.h>
+#include <fcntl.h>
 #include <string.h>
-#include <time.h>
 #include <errno.h>
-#include <sys/select.h>
+#include <sys/socket.h>
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
 #include <log.h>
 #include <utils.h>
 #include <mt.h>
 #include <mtio.h>
 
-struct blocker {
-    struct blocker *n, *p;
+struct stdiofd {
     int fd;
-    int ev;
-    time_t to;
-    struct muth *th;
+    int sock;
+    int timeout;
 };
 
-static struct blocker *blockers;
-
-int block(int fd, int ev, time_t to)
+static ssize_t mtread(void *cookie, void *buf, size_t len)
 {
-    struct blocker *bl;
-    int rv;
+    struct stdiofd *d = cookie;
+    int ev;
+    ssize_t ret;
     
-    omalloc(bl);
-    bl->fd = fd;
-    bl->ev = ev;
-    if(to > 0)
-       bl->to = time(NULL) + to;
-    bl->th = current;
-    bl->n = blockers;
-    if(blockers)
-       blockers->p = bl;
-    blockers = bl;
-    rv = yield();
-    if(bl->n)
-       bl->n->p = bl->p;
-    if(bl->p)
-       bl->p->n = bl->n;
-    if(bl == blockers)
-       blockers = bl->n;
-    return(rv);
+    while(1) {
+       ret = read(d->fd, buf, len);
+       if((ret < 0) && (errno == EAGAIN)) {
+           ev = block(d->fd, EV_READ, d->timeout);
+           if(ev < 0) {
+               /* If we just go on, we should get the real error. */
+               continue;
+           } else if(ev == 0) {
+               errno = ETIMEDOUT;
+               return(-1);
+           } else {
+               continue;
+           }
+       } else {
+           return(ret);
+       }
+    }
 }
 
-void ioloop(void)
+static ssize_t mtwrite(void *cookie, const void *buf, size_t len)
 {
-    int ret;
-    fd_set rfds, wfds, efds;
-    struct blocker *bl, *nbl;
-    struct timeval toval;
-    time_t now, timeout;
-    int maxfd;
+    struct stdiofd *d = cookie;
     int ev;
+    size_t off;
+    ssize_t ret;
     
-    while(blockers != NULL) {
-       FD_ZERO(&rfds);
-       FD_ZERO(&wfds);
-       FD_ZERO(&efds);
-       maxfd = 0;
-       now = time(NULL);
-       timeout = 0;
-       for(bl = blockers; bl; bl = bl->n) {
-           if(bl->ev & EV_READ)
-               FD_SET(bl->fd, &rfds);
-           if(bl->ev & EV_WRITE)
-               FD_SET(bl->fd, &wfds);
-           FD_SET(bl->fd, &efds);
-           if(bl->fd > maxfd)
-               maxfd = bl->fd;
-           if((bl->to != 0) && ((timeout == 0) || (timeout > bl->to)))
-               timeout = bl->to;
-       }
-       toval.tv_sec = timeout - now;
-       toval.tv_usec = 0;
-       ret = select(maxfd + 1, &rfds, &wfds, &efds, timeout?(&toval):NULL);
+    off = 0;
+    while(off < len) {
+       if(d->sock)
+           ret = send(d->fd, buf + off, len - off, MSG_DONTWAIT | MSG_NOSIGNAL);
+       else
+           ret = write(d->fd, buf + off, len - off);
        if(ret < 0) {
-           if(errno != EINTR) {
-               flog(LOG_CRIT, "ioloop: select errored out: %s", strerror(errno));
-               /* To avoid CPU hogging in case it's bad, which it
-                * probably is. */
-               sleep(1);
+           if(errno == EAGAIN) {
+               ev = block(d->fd, EV_WRITE, d->timeout);
+               if(ev < 0) {
+                   /* If we just go on, we should get the real error. */
+                   continue;
+               } else if(ev == 0) {
+                   errno = ETIMEDOUT;
+                   return(off);
+               } else {
+                   continue;
+               }
+           } else {
+               return(off);
            }
+       } else {
+           off += ret;
        }
-       now = time(NULL);
-       for(bl = blockers; bl; bl = nbl) {
-           nbl = bl->n;
-           ev = 0;
-           if(FD_ISSET(bl->fd, &rfds))
-               ev |= EV_READ;
-           if(FD_ISSET(bl->fd, &wfds))
-               ev |= EV_WRITE;
-           if(FD_ISSET(bl->fd, &efds))
-               ev = -1;
-           if((ev < 0) || (ev & bl->ev))
-               resume(bl->th, ev);
-           else if((bl->to != 0) && (bl->to <= now))
-               resume(bl->th, 0);
-       }
     }
+    return(off);
+}
+
+static int mtclose(void *cookie)
+{
+    struct stdiofd *d = cookie;
+    
+    close(d->fd);
+    free(d);
+    return(0);
+}
+
+FILE *mtstdopen(int fd, int issock, int timeout, char *mode)
+{
+    struct stdiofd *d;
+    FILE *ret;
+    int r, w;
+    
+    if(!strcmp(mode, "r")) {
+       r = 1; w = 0;
+    } else if(!strcmp(mode, "w")) {
+       r = 0; w = 1;
+    } else if(!strcmp(mode, "r+")) {
+       r = w = 1;
+    } else {
+       return(NULL);
+    }
+    omalloc(d);
+    d->fd = fd;
+    d->sock = issock;
+    d->timeout = timeout;
+    ret = funstdio(d, r?mtread:NULL, w?mtwrite:NULL, NULL, mtclose);
+    if(!ret)
+       free(d);
+    else
+       fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_NONBLOCK);
+    return(ret);
 }