Further server optimizations:
- merged request and reply structures
- build requests directly into the buffer to avoid a copy
diff --git a/server/socket.c b/server/socket.c
index 9b78e07..5628c1e 100644
--- a/server/socket.c
+++ b/server/socket.c
@@ -30,139 +30,102 @@
struct client
{
struct select_user select; /* select user */
- unsigned int seq; /* current sequence number */
+ unsigned int res; /* current result to send */
int pass_fd; /* fd to pass to and from the client */
struct thread *self; /* client thread (opaque pointer) */
struct timeout_user *timeout; /* current timeout (opaque pointer) */
};
-/* exit code passed to remove_client */
-#define OUT_OF_MEMORY -1
-#define BROKEN_PIPE -2
-#define PROTOCOL_ERROR -3
-
-
-/* signal a client protocol error */
-static void protocol_error( struct client *client, const char *err, ... )
+/* socket communication static structures */
+static struct iovec iovec;
+static struct msghdr msghdr = { NULL, 0, &iovec, 1, };
+#ifndef HAVE_MSGHDR_ACCRIGHTS
+struct cmsg_fd
{
- va_list args;
+ int len; /* sizeof structure */
+ int level; /* SOL_SOCKET */
+ int type; /* SCM_RIGHTS */
+ int fd; /* fd to pass */
+};
+static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
+#endif /* HAVE_MSGHDR_ACCRIGHTS */
- va_start( args, err );
- fprintf( stderr, "Protocol error:%p: ", client->self );
- vfprintf( stderr, err, args );
- va_end( args );
- remove_client( client, PROTOCOL_ERROR );
-}
/* send a message to a client that is ready to receive something */
-static void do_write( struct client *client )
+static int do_write( struct client *client )
{
int ret;
if (client->pass_fd == -1)
{
- ret = write( client->select.fd, &client->seq, sizeof(client->seq) );
+ ret = write( client->select.fd, &client->res, sizeof(client->res) );
+ if (ret == sizeof(client->res)) goto ok;
}
else /* we have an fd to send */
{
- struct iovec vec;
- struct msghdr msghdr;
-
#ifdef HAVE_MSGHDR_ACCRIGHTS
+ msghdr.msg_accrightslen = sizeof(int);
msghdr.msg_accrights = (void *)&client->pass_fd;
- msghdr.msg_accrightslen = sizeof(client->pass_fd);
#else /* HAVE_MSGHDR_ACCRIGHTS */
- struct cmsg_fd cmsg;
-
- cmsg.len = sizeof(cmsg);
- cmsg.level = SOL_SOCKET;
- cmsg.type = SCM_RIGHTS;
- cmsg.fd = client->pass_fd;
msghdr.msg_control = &cmsg;
msghdr.msg_controllen = sizeof(cmsg);
- msghdr.msg_flags = 0;
+ cmsg.fd = client->pass_fd;
#endif /* HAVE_MSGHDR_ACCRIGHTS */
- msghdr.msg_name = NULL;
- msghdr.msg_namelen = 0;
- msghdr.msg_iov = &vec;
- msghdr.msg_iovlen = 1;
- vec.iov_base = (char *)&client->seq;
- vec.iov_len = sizeof(client->seq);
+ iovec.iov_base = (char *)&client->res;
+ iovec.iov_len = sizeof(client->res);
ret = sendmsg( client->select.fd, &msghdr, 0 );
close( client->pass_fd );
client->pass_fd = -1;
- }
- if (ret == sizeof(client->seq))
- {
- /* everything OK */
- client->seq++;
- set_select_events( &client->select, READ_EVENT );
- return;
+ if (ret == sizeof(client->res)) goto ok;
}
if (ret == -1)
{
+ if (errno == EWOULDBLOCK) return 0; /* not a fatal error */
if (errno != EPIPE) perror("sendmsg");
- remove_client( client, BROKEN_PIPE );
- return;
}
- fprintf( stderr, "Partial sequence sent (%d)\n", ret );
+ else fprintf( stderr, "Partial message sent %d/%d\n", ret, sizeof(client->res) );
remove_client( client, BROKEN_PIPE );
+ return 0;
+
+ ok:
+ set_select_events( &client->select, READ_EVENT );
+ return 1;
}
/* read a message from a client that has something to say */
static void do_read( struct client *client )
{
- struct iovec vec;
- int ret, seq;
+ int ret;
+ enum request req;
#ifdef HAVE_MSGHDR_ACCRIGHTS
- struct msghdr msghdr;
-
- msghdr.msg_accrights = (void *)&client->pass_fd;
- msghdr.msg_accrightslen = sizeof(client->pass_fd);
+ msghdr.msg_accrightslen = sizeof(int);
+ msghdr.msg_accrights = (void *)&client->pass_fd;
#else /* HAVE_MSGHDR_ACCRIGHTS */
- struct msghdr msghdr;
- struct cmsg_fd cmsg;
-
- cmsg.len = sizeof(cmsg);
- cmsg.level = SOL_SOCKET;
- cmsg.type = SCM_RIGHTS;
- cmsg.fd = -1;
msghdr.msg_control = &cmsg;
msghdr.msg_controllen = sizeof(cmsg);
- msghdr.msg_flags = 0;
+ cmsg.fd = -1;
#endif /* HAVE_MSGHDR_ACCRIGHTS */
assert( client->pass_fd == -1 );
- msghdr.msg_name = NULL;
- msghdr.msg_namelen = 0;
- msghdr.msg_iov = &vec;
- msghdr.msg_iovlen = 1;
-
- vec.iov_base = &seq;
- vec.iov_len = sizeof(seq);
+ iovec.iov_base = &req;
+ iovec.iov_len = sizeof(req);
ret = recvmsg( client->select.fd, &msghdr, 0 );
#ifndef HAVE_MSGHDR_ACCRIGHTS
client->pass_fd = cmsg.fd;
#endif
- if (ret == sizeof(seq))
+ if (ret == sizeof(req))
{
int pass_fd = client->pass_fd;
- if (seq != client->seq++)
- {
- protocol_error( client, "bad sequence %08x instead of %08x\n",
- seq, client->seq - 1 );
- return;
- }
client->pass_fd = -1;
- call_req_handler( client->self, pass_fd );
+ call_req_handler( client->self, req, pass_fd );
if (pass_fd != -1) close( pass_fd );
return;
}
@@ -177,7 +140,7 @@
remove_client( client, BROKEN_PIPE );
return;
}
- protocol_error( client, "partial sequence received %d/%d\n", ret, sizeof(seq) );
+ fatal_protocol_error( client->self, "partial message received %d/%d\n", ret, sizeof(req) );
}
/* handle a client event */
@@ -204,7 +167,6 @@
client->select.fd = fd;
client->select.func = client_event;
client->select.private = client;
- client->seq = 0;
client->self = self;
client->timeout = NULL;
client->pass_fd = -1;
@@ -237,8 +199,9 @@
}
/* send a reply to a client */
-void client_reply( struct client *client )
+void client_reply( struct client *client, unsigned int res )
{
- if (debug_level) trace_reply( client->self, client->pass_fd );
- set_select_events( &client->select, WRITE_EVENT );
+ if (debug_level) trace_reply( client->self, res, client->pass_fd );
+ client->res = res;
+ if (!do_write( client )) set_select_events( &client->select, WRITE_EVENT );
}
