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authorajs <ajs>2004-11-04 19:26:16 +0000
committerajs <ajs>2004-11-04 19:26:16 +0000
commit49ff6d9d7a9ef9419dd7aab58ac9f7806e3e1040 (patch)
treebb9e1d36b5bef56d2e47c69b6bab1ef54cf9696e
parent62d8e96a06e664c929a164bfb66b515d1c6877a8 (diff)
2004-11-04 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
* vty.c: Vtysh connections to daemons should use buffering. (vty_out) Remove exception for vty_shell_serv, just use buffer_write. (vty_new) Increase output buffer size to 4096 rounded up to a multiple of pagesize. (vtysh_read) After command has been executed and all output buffered, call buffer_flush_available and schedule further writes if the buffers are not yet empty. (vtysh_write) New function to flush output to vtysh when the socket is writeable. (vty_event) Added new VTYSH_WRITE event for flushing buffers to vtysh clients. Also, should save read thread in vty->t_read so the thread can be cancelled in vty_close. * buffer.h: In struct buffer_data, remove unused "parent" field. Convert "unsigned char *data" to "unsigned char data[0]" to save a malloc. Declare new function buffer_flush_available that works with non-blocking sockets. * buffer.c: (buffer_data_new) Use a single malloc now that data is a variable-size array at end of structure. (buffer_data_free) Just a single free now that data is part of the structure. (buffer_write) Simplify the logic to make behavior more transparent. (buffer_flush) Decrease b->length as data is written out. (buffer_flush_vty_all) Decrease b->length as buffers are freed. (buffer_flush_vty) Decrease b->length as data is written out. (buffer_flush_available) New function to flush non-blocking sockets.
-rw-r--r--lib/ChangeLog28
-rw-r--r--lib/buffer.c112
-rw-r--r--lib/buffer.h16
-rw-r--r--lib/vty.c34
4 files changed, 152 insertions, 38 deletions
diff --git a/lib/ChangeLog b/lib/ChangeLog
index 0e4a2233..75ff444b 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,31 @@
+2004-11-04 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+ * vty.c: Vtysh connections to daemons should use buffering.
+ (vty_out) Remove exception for vty_shell_serv, just use buffer_write.
+ (vty_new) Increase output buffer size to 4096 rounded up to a
+ multiple of pagesize.
+ (vtysh_read) After command has been executed and all output buffered,
+ call buffer_flush_available and schedule further writes if the
+ buffers are not yet empty.
+ (vtysh_write) New function to flush output to vtysh when the socket
+ is writeable.
+ (vty_event) Added new VTYSH_WRITE event for flushing buffers to vtysh
+ clients. Also, should save read thread in vty->t_read so the
+ thread can be cancelled in vty_close.
+ * buffer.h: In struct buffer_data, remove unused "parent" field.
+ Convert "unsigned char *data" to "unsigned char data[0]" to save
+ a malloc. Declare new function buffer_flush_available that works
+ with non-blocking sockets.
+ * buffer.c: (buffer_data_new) Use a single malloc now that data is
+ a variable-size array at end of structure.
+ (buffer_data_free) Just a single free now that data is part of the
+ structure.
+ (buffer_write) Simplify the logic to make behavior more transparent.
+ (buffer_flush) Decrease b->length as data is written out.
+ (buffer_flush_vty_all) Decrease b->length as buffers are freed.
+ (buffer_flush_vty) Decrease b->length as data is written out.
+ (buffer_flush_available) New function to flush non-blocking sockets.
+
2004-11-01 Paul Jakma <paul@dishone.st>
* sockopt.c: (setsockopt_pktinfo) remove, its unused.
diff --git a/lib/buffer.c b/lib/buffer.c
index 904b4aa9..9d931a9b 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -24,25 +24,22 @@
#include "memory.h"
#include "buffer.h"
+#include <stddef.h>
/* Make buffer data. */
-struct buffer_data *
+static struct buffer_data *
buffer_data_new (size_t size)
{
struct buffer_data *d;
- d = XMALLOC (MTYPE_BUFFER_DATA, sizeof (struct buffer_data));
- memset (d, 0, sizeof (struct buffer_data));
- d->data = XMALLOC (MTYPE_BUFFER_DATA, size);
-
+ d = XMALLOC (MTYPE_BUFFER_DATA, offsetof(struct buffer_data,data[size]));
+ d->cp = d->sp = 0;
return d;
}
-void
+static void
buffer_data_free (struct buffer_data *d)
{
- if (d->data)
- XFREE (MTYPE_BUFFER_DATA, d->data);
XFREE (MTYPE_BUFFER_DATA, d);
}
@@ -159,6 +156,8 @@ buffer_write (struct buffer *b, const void *p, size_t size)
/* We use even last one byte of data buffer. */
while (size)
{
+ size_t chunk;
+
/* If there is no data buffer add it. */
if (data == NULL || data->cp == b->size)
{
@@ -166,23 +165,11 @@ buffer_write (struct buffer *b, const void *p, size_t size)
data = b->tail;
}
- /* Last data. */
- if (size <= (b->size - data->cp))
- {
- memcpy ((data->data + data->cp), ptr, size);
-
- data->cp += size;
- size = 0;
- }
- else
- {
- memcpy ((data->data + data->cp), ptr, (b->size - data->cp));
-
- size -= (b->size - data->cp);
- ptr += (b->size - data->cp);
-
- data->cp = b->size;
- }
+ chunk = ((size <= (b->size - data->cp)) ? size : (b->size - data->cp));
+ memcpy ((data->data + data->cp), ptr, chunk);
+ size -= chunk;
+ ptr += chunk;
+ data->cp += chunk;
}
return 1;
}
@@ -235,6 +222,7 @@ buffer_flush (struct buffer *b, int fd, size_t size)
{
iovec[iov_index++].iov_len = size;
data->sp += size;
+ b->length -= size;
if (data->sp == data->cp)
data = data->next;
break;
@@ -242,6 +230,7 @@ buffer_flush (struct buffer *b, int fd, size_t size)
else
{
iovec[iov_index++].iov_len = data->cp - data->sp;
+ b->length -= (data->cp - data->sp);
size -= data->cp - data->sp;
data->sp = data->cp;
}
@@ -369,6 +358,7 @@ buffer_flush_vty_all (struct buffer *b, int fd, int erase_flag,
b->tail = next;
b->head = next;
+ b->length -= (out->cp-out->sp);
buffer_data_free (out);
b->alloc--;
}
@@ -430,6 +420,7 @@ buffer_flush_vty (struct buffer *b, int fd, unsigned int size,
{
iov[iov_index++].iov_len = size;
data->sp += size;
+ b->length -= size;
if (data->sp == data->cp)
data = data->next;
break;
@@ -438,6 +429,7 @@ buffer_flush_vty (struct buffer *b, int fd, unsigned int size,
{
iov[iov_index++].iov_len = data->cp - data->sp;
size -= (data->cp - data->sp);
+ b->length -= (data->cp - data->sp);
data->sp = data->cp;
}
}
@@ -566,3 +558,73 @@ buffer_flush_window (struct buffer *b, int fd, int width, int height,
return buffer_flush_vty (b, fd, size, erase, no_more);
}
+
+/* This function (unlike other buffer_flush* functions above) is designed
+to work with non-blocking sockets. It does not attempt to write out
+all of the queued data, just a "big" chunk. It returns 0 if it was
+able to empty out the buffers completely, or 1 if more flushing is
+required later. */
+int
+buffer_flush_available(struct buffer *b, int fd)
+{
+
+/* These are just reasonable values to make sure a significant amount of
+data is written. There's no need to go crazy and try to write it all
+in one shot. */
+#ifdef IOV_MAX
+#define MAX_CHUNKS ((IOV_MAX >= 16) ? 16 : IOV_MAX)
+#else
+#define MAX_CHUNKS 16
+#endif
+#define MAX_FLUSH 131072
+
+ struct buffer_data *d;
+ struct buffer_data *next;
+ ssize_t written;
+ struct iovec iov[MAX_CHUNKS];
+ int iovcnt = 0;
+ size_t nbyte = 0;
+
+ for (d = b->head; d && (iovcnt < MAX_CHUNKS) && (nbyte < MAX_FLUSH);
+ d = d->next, iovcnt++)
+ {
+ iov[iovcnt].iov_base = d->data+d->sp;
+ nbyte += (iov[iovcnt].iov_len = d->cp-d->sp);
+ }
+
+ if ((written = writev(fd,iov,iovcnt)) < 0)
+ {
+ if ((errno != EAGAIN) && (errno != EINTR))
+ zlog_warn("buffer_flush_available write error on fd %d: %s",
+ fd,strerror(errno));
+ return 1;
+ }
+
+ /* Free printed buffer data. */
+ for (d = b->head; (written > 0) && d; d = next)
+ {
+ if (written < d->cp-d->sp)
+ {
+ d->sp += written;
+ b->length -= written;
+ return 1;
+ }
+
+ written -= (d->cp-d->sp);
+ next = d->next;
+ if (next)
+ next->prev = NULL;
+ else
+ b->tail = next;
+ b->head = next;
+
+ b->length -= (d->cp-d->sp);
+ buffer_data_free (d);
+ b->alloc--;
+ }
+
+ return (b->head != NULL);
+
+#undef MAX_CHUNKS
+#undef MAX_FLUSH
+}
diff --git a/lib/buffer.h b/lib/buffer.h
index 9d453b1d..2acd571f 100644
--- a/lib/buffer.h
+++ b/lib/buffer.h
@@ -33,7 +33,7 @@ struct buffer
/* Current allocated data. */
unsigned long alloc;
- /* Total length of buffer. */
+ /* Size of each buffer_data chunk. */
unsigned long size;
/* For allocation. */
@@ -47,18 +47,17 @@ struct buffer
/* Data container. */
struct buffer_data
{
- struct buffer *parent;
struct buffer_data *next;
struct buffer_data *prev;
- /* Acctual data stream. */
- unsigned char *data;
-
/* Current pointer. */
unsigned long cp;
/* Start pointer. */
unsigned long sp;
+
+ /* Actual data stream (variable length). */
+ unsigned char data[0]; /* real dimension is buffer->size */
};
/* Buffer prototypes. */
@@ -74,4 +73,11 @@ int buffer_flush_vty_all (struct buffer *, int, int, int);
int buffer_flush_window (struct buffer *, int, int, int, int, int);
int buffer_empty (struct buffer *);
+/* buffer_flush_available attempts to flush the queued data to the given
+ file descriptor. It returns 0 if the buffers are now empty (after
+ flushing), or 1 if more data remains on the buffer queue (must be flushed
+ later). This function (unlike the other buffer_flush* functions) is
+ designed to work with non-blocking file descriptors. */
+int buffer_flush_available(struct buffer *, int fd);
+
#endif /* _ZEBRA_BUFFER_H */
diff --git a/lib/vty.c b/lib/vty.c
index e37c99f5..e6bcb61a 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -45,10 +45,14 @@ enum event
VTY_TIMEOUT_RESET,
#ifdef VTYSH
VTYSH_SERV,
- VTYSH_READ
+ VTYSH_READ,
+ VTYSH_WRITE
#endif /* VTYSH */
};
+/* Minimum size of output buffers; to be rounded up to multiple of pagesize. */
+#define VTY_OBUF_SIZE 4096
+
static void vty_event (enum event, int, struct vty *);
/* Extern host structure from command.c */
@@ -127,10 +131,7 @@ vty_out (struct vty *vty, const char *format, ...)
p = buf;
/* Pointer p must point out buffer. */
- if (vty_shell_serv (vty))
- write (vty->fd, (u_char *) p, len);
- else
- buffer_write (vty->obuf, (u_char *) p, len);
+ buffer_write (vty->obuf, (u_char *) p, len);
/* If p is not different with buf, it is allocated buffer. */
if (p != buf)
@@ -264,8 +265,9 @@ struct vty *
vty_new ()
{
struct vty *new = XCALLOC (MTYPE_VTY, sizeof (struct vty));
+ int pgsz = getpagesize();
- new->obuf = (struct buffer *) buffer_new (100);
+ new->obuf = (struct buffer *) buffer_new ((((VTY_OBUF_SIZE-1)/pgsz)+1)*pgsz);
new->buf = XCALLOC (MTYPE_VTY, VTY_BUFSIZ);
new->max = VTY_BUFSIZ;
new->sb_buffer = NULL;
@@ -2014,12 +2016,25 @@ vtysh_read (struct thread *thread)
#endif /* VTYSH_DEBUG */
header[3] = ret;
- write (vty->fd, header, 4);
+ buffer_write(vty->obuf, header, 4);
+ if (!vty->t_write && buffer_flush_available(vty->obuf, vty->fd))
+ vty_event (VTYSH_WRITE, vty->fd, vty);
vty_event (VTYSH_READ, sock, vty);
return 0;
}
+
+static int
+vtysh_write (struct thread *thread)
+{
+ struct vty *vty = THREAD_ARG (thread);
+
+ vty->t_write = NULL;
+ if (buffer_flush_available(vty->obuf, vty->fd))
+ vty_event (VTYSH_WRITE, vty->fd, vty);
+}
+
#endif /* VTYSH */
/* Determine address family to bind. */
@@ -2364,7 +2379,10 @@ vty_event (enum event event, int sock, struct vty *vty)
thread_add_read (master, vtysh_accept, vty, sock);
break;
case VTYSH_READ:
- thread_add_read (master, vtysh_read, vty, sock);
+ vty->t_read = thread_add_read (master, vtysh_read, vty, sock);
+ break;
+ case VTYSH_WRITE:
+ vty->t_write = thread_add_write (master, vtysh_write, vty, sock);
break;
#endif /* VTYSH */
case VTY_READ: