Changed client <-> server interface to make less system calls.

1998-06-18  Martin Baulig  <baulig@taurus.uni-trier.de>

	* lib/{command, write, read}.c: Changed client <-> server
	interface to make less system calls.

	* src/daemon/main.c: Changed server side of interface.

	* include/glibtop/command.h (struct _glibtop_response): New
	structure to return data from the server to the client.

ChangeLog

@@ -1,3 +1,13 @@
+1998-06-18  Martin Baulig  <baulig@taurus.uni-trier.de>
+
+	* lib/{command, write, read}.c: Changed client <-> server
+	interface to make less system calls.
+
+	* src/daemon/main.c: Changed server side of interface.
+	
+	* include/glibtop/command.h (struct _glibtop_response): New
+	structure to return data from the server to the client.
+
 1998-06-14  Martin Baulig  <martin@home-of-linux.org>
 
 	* glibtop.h (struct _glibtop): Added `socket' field.

include/glibtop/command.h

@@ -50,13 +50,29 @@ __BEGIN_DECLS
 
 #define GLIBTOP_MAX_CMND		18
 
+#define _GLIBTOP_PARAM_SIZE		16
+
 typedef struct _glibtop_command		glibtop_command;
+typedef struct _glibtop_response	glibtop_response;
 
 struct _glibtop_command
 {
 	glibtop		server;
 	unsigned	command;
-  size_t	size;
+	size_t		size, data_size;
+	char		parameter [_GLIBTOP_PARAM_SIZE];
+};
+
+union _glibtop_response_union
+{
+	glibtop_union	data;
+	glibtop_sysdeps	sysdeps;
+};
+
+struct _glibtop_response
+{
+	size_t data_size;
+	union _glibtop_response_union u;
 };
 
 #define glibtop_call(p1, p2, p3, p4)	glibtop_call_r(glibtop_global_server, p1, p2, p3, p4)

lib/Makefile.am

@@ -4,7 +4,7 @@ INCLUDES			= -I$(top_builddir) -I$(top_srcdir) @machine_incs@ \
 				  -I$(top_srcdir)/include -I$(top_srcdir)/intl @GUILE_INCS@ \
 				  -DGTOPLOCALEDIR=\"$(datadir)/locale\" -D_GNU_SOURCE
 
-CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\"
+CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\" -DDEBUG
 
 lib_LTLIBRARIES			= libgtop.la
 

lib/command.c

@@ -30,25 +30,41 @@ void *
 glibtop_call_l (glibtop *server, unsigned command, size_t send_size, void *send_buf,
 		size_t recv_size, void *recv_buf)
 {
-	glibtop_command *cmnd;
+	glibtop_command cmnd;
+	glibtop_response response;
 	void *ptr;
 
 	glibtop_init_r (&server, 0, 0);
 
-	cmnd = glibtop_calloc_r (server, 1, sizeof (glibtop_command));
+	memset (&cmnd, 0, sizeof (glibtop_command));
 
-	memcpy (&cmnd->server, server, sizeof (glibtop));
+	memcpy (&cmnd.server, server, sizeof (glibtop));
 	
-	cmnd->command = command;
+	cmnd.command = command;
-	cmnd->size = send_size;
 
-	glibtop_write_l (server, sizeof (glibtop_command), cmnd);
+	/* If send_size is less than _GLIBTOP_PARAM_SIZE (normally 16 Bytes), we
+	 * send it together with command, so we only need one system call instead
+	 * of two. */
+
+#ifdef DEBUG
+	fprintf (stderr, "COMMAND: send_size = %d; command = %d; sizeof (cmnd) = %d\n",
+		 send_size, command, sizeof (glibtop_command));
+#endif
+
+
+	if (send_size <= _GLIBTOP_PARAM_SIZE)
+		memcpy (cmnd.parameter, send_buf, send_size);
+	else
+		cmnd.size = send_size;
+	
+	glibtop_write_l (server, sizeof (glibtop_command), &cmnd);
 	glibtop_write_l (server, send_size, send_buf);
-	glibtop_read_l  (server, recv_size, recv_buf);
 
-	ptr = glibtop_read_data_l (server);
+	glibtop_read_l (server, sizeof (glibtop_response), &response);
 
-	glibtop_free_r (server, cmnd);
+	/*	glibtop_read_l  (server, recv_size, recv_buf); */
 	
-	return ptr;
+	/* ptr = glibtop_read_data_l (server); */
+	
+	return NULL;
 }

lib/read.c

@@ -26,27 +26,10 @@
 void
 glibtop_read_l (glibtop *server, size_t size, void *buf)
 {
-	size_t	ssize;
 	int ret;
 
 	glibtop_init_r (&server, 0, 0);
 
-#ifdef DEBUG
-	fprintf (stderr, "LIBRARY: reading %d bytes, should be %d.\n", sizeof (size_t), size);
-#endif
-
-	if (server->socket) {
-		ret = recv (server->socket, &ssize, sizeof (size_t), 0);
-	} else {
-		ret = read (server->input [0], &ssize, sizeof (size_t));
-	}
-
-	if (ret < 0)
-		glibtop_error_io_r (server, _("read size"));
-	
-	if (size != ssize)
-		glibtop_error_r (server, _("got %d bytes but requested %d (ret = %d)"), ssize, size, ret);
-
 #ifdef DEBUG
 	fprintf (stderr, "LIBRARY: really reading %d bytes.\n", size);
 #endif

lib/write.c

@@ -30,20 +30,7 @@ glibtop_write_l (glibtop *server, size_t size, void *buf)
 
 	glibtop_init_r (&server, 0, 0);
 
-#ifdef DEBUG
+	if (size == 0) return;
-	fprintf (stderr, "LIBRARY: writing %d bytes = %d.\n", sizeof (size_t), size);
-#endif
-
-	if (server->socket) {
-		ret = send (server->socket, &size, sizeof (size_t), 0);
-	} else {
-		ret = write (server->output [1], &size, sizeof (size_t));
-	}
-
-	if (ret < 0)
-		glibtop_error_io_r (server, _("write size"));
-
-	if (!size) return;
 
 #ifdef DEBUG
 	fprintf (stderr, "LIBRARY: really writing %d bytes.\n", size);

src/daemon/Makefile.am

@@ -4,7 +4,7 @@ INCLUDES			= -I$(top_builddir) -I$(top_srcdir) @machine_incs@ \
 				  -I$(top_srcdir)/include -I$(top_srcdir)/intl @GUILE_INCS@ \
 				  -DGTOPLOCALEDIR=\"$(datadir)/locale\" -D_GNU_SOURCE
 
-CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\"
+CFLAGS				= -Wall -W @CFLAGS@ -DGTOP_SERVER=\""@LIBGTOP_SERVER@"\" -DDEBUG -DREAL_DEBUG
 
 bin_PROGRAMS			= gnuserv
 

src/daemon/main.c

@@ -39,24 +39,25 @@
 #endif
 
 static void
-do_output (int s, size_t size, const void *buf)
+do_output (int s, glibtop_response *response, size_t data_size, const void *data)
 {
 #ifdef REAL_DEBUG
-  fprintf (stderr, "Writing %d bytes = %d.\n", sizeof (size_t), size);
+	fprintf (stderr, "Really writing %d bytes.\n", sizeof (glibtop_response));
 #endif
 
-  if (send (s, &size, sizeof (size_t), 0) < 0)
+	response->data_size = data_size;
+	
+	if (send (s, response, sizeof (glibtop_response), 0) < 0)
 		glibtop_warn_io ("send");
 
-  if (!size)
+	if (response->data_size) {
-    return;
-
 #ifdef REAL_DEBUG
-  fprintf (stderr, "Really writing %d bytes.\n", size);
+		fprintf (stderr, "Writing %d bytes of data.\n", response->data_size);
 #endif
 
-  if (send (s, buf, size, 0) < 0)
+		if (send (s, data, response->data_size, 0) , 0)
 			glibtop_warn_io ("send");
+	}
 }
 
 void
@@ -64,12 +65,11 @@ handle_socket_connection (int s)
 {
 	pid_t pid;
 	int nread;
-  size_t size, dsize;
+	size_t size;
 	char parameter [BUFSIZ];
 	struct timeval tv;
-  glibtop_union data;
+	glibtop_response response;
 	glibtop_command cmnd;
-  glibtop_sysdeps sysdeps;
 	glibtop server;
 	void *ptr;
 
@@ -77,7 +77,7 @@ handle_socket_connection (int s)
 	tv.tv_usec = 0;
   
 	while(1) {
-    nread = recv (s, &size, sizeof (size_t), 0);
+		nread = recv (s, &cmnd, sizeof (glibtop_command), 0);
     
 		if (nread < 0) {
 			glibtop_warn_io ("recv");
@@ -87,55 +87,27 @@ handle_socket_connection (int s)
 		if (nread == 0)
 			return;
 
-    if (nread != sizeof (size_t)) {
+		if (nread != sizeof (glibtop_command))
-      glibtop_warn ("Expected %d bytes but got %d", sizeof (size_t), nread);
+			glibtop_warn ("Received %d bytes, but expected %d\n",
-      return;
+				      nread, sizeof (glibtop_command));
-    }
-
-    if (size != sizeof (glibtop_command)) {
-      glibtop_warn ("Expected %d bytes but got %d", sizeof (size_t), nread);
-      return;
-    }
-
-    nread = recv (s, &cmnd, size, 0);
-    
-    if (nread < 0) {
-      glibtop_warn_io ("recv");
-      return;
-    }
-    
-    if (nread == 0)
-      return;
 
 #ifdef REAL_DEBUG
 		fprintf (stderr, "Received command %d from client.\n", cmnd.command);
 #endif
 
-    nread = recv (s, &dsize, sizeof (size_t), 0);
+		if (cmnd.size >= BUFSIZ) {
-    
+			glibtop_warn ("Client sent %d bytes, but buffer is %d", cmnd.size, BUFSIZ);
-    /* will return 0 if parent exits. */
-    
-    if (nread < 0) {
-      glibtop_warn_io ("recv");
-      return;
-    }
-    
-    if (nread == 0)
-      return;
-
-    if (dsize >= BUFSIZ) {
-      glibtop_warn ("Client sent %d bytes, but buffer is %d", dsize, BUFSIZ);
 			return;
 		}
 
 		memset (parameter, 0, sizeof (parameter));
     
-    if (dsize) {
+		if (cmnd.size) {
 #ifdef REAL_DEBUG
-      fprintf (stderr, "Client has %d bytes of data.\n", dsize);
+			fprintf (stderr, "Client has %d bytes of data.\n", cmnd.size);
 #endif
 
-      nread = recv (s, parameter, dsize, 0);
+			nread = recv (s, parameter, cmnd.size, 0);
       
 			/* will return 0 if parent exits. */
       
@@ -147,112 +119,96 @@ handle_socket_connection (int s)
 			if (nread == 0)
 				return;
 
-      if (nread != (int) dsize) {
+			if (nread != (int) cmnd.size) {
-	glibtop_warn ("Expected %d bytes but got %d", dsize, nread);
+				glibtop_warn ("Expected %d bytes but got %d",
+					      cmnd.size, nread);
 				return;
 			}
 		}
     
 		switch (cmnd.command) {
 		case GLIBTOP_CMND_SYSDEPS:
-      sysdeps.features = GLIBTOP_SYSDEPS_ALL;
+			response.u.sysdeps.features = GLIBTOP_SYSDEPS_ALL;
-      do_output (s, sizeof (glibtop_sysdeps), &sysdeps);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_CPU:
-      glibtop_get_cpu_l (&server, &data.cpu);
+			glibtop_get_cpu_l (&server, &response.u.data.cpu);
-      do_output (s, sizeof (glibtop_cpu), &data.cpu);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_MEM:
-      glibtop_get_mem_l (&server, &data.mem);
+			glibtop_get_mem_l (&server, &response.u.data.mem);
-      do_output (s, sizeof (glibtop_mem), &data.mem);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_SWAP:
-      glibtop_get_swap_l (&server, &data.swap);
+			glibtop_get_swap_l (&server, &response.u.data.swap);
-      do_output (s, sizeof (glibtop_swap), &data.swap);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_UPTIME:
-      glibtop_get_uptime_l (&server, &data.uptime);
+			glibtop_get_uptime_l (&server, &response.u.data.uptime);
-      do_output (s, sizeof (glibtop_uptime), &data.uptime);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_LOADAVG:
-      glibtop_get_loadavg_l (&server, &data.loadavg);
+			glibtop_get_loadavg_l (&server, &response.u.data.loadavg);
-      do_output (s, sizeof (glibtop_loadavg), &data.loadavg);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_SHM_LIMITS:
-      glibtop_get_shm_limits_l (&server, &data.shm_limits);
+			glibtop_get_shm_limits_l (&server, &response.u.data.shm_limits);
-      do_output (s, sizeof (glibtop_shm_limits), &data.shm_limits);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_MSG_LIMITS:
-      glibtop_get_msg_limits_l (&server, &data.msg_limits);
+			glibtop_get_msg_limits_l (&server, &response.u.data.msg_limits);
-      do_output (s, sizeof (glibtop_msg_limits), &data.msg_limits);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_SEM_LIMITS:
-      glibtop_get_sem_limits_l (&server, &data.sem_limits);
+			glibtop_get_sem_limits_l (&server, &response.u.data.sem_limits);
-      do_output (s, sizeof (glibtop_sem_limits), &data.sem_limits);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROCLIST:
-      ptr = glibtop_get_proclist_l (&server, &data.proclist);
+			ptr = glibtop_get_proclist_l (&server, &response.u.data.proclist);
-      do_output (s, sizeof (glibtop_proclist), &data.proclist);
+			do_output (s, &response, response.u.data.proclist.total, ptr);
-      do_output (s, data.proclist.total, ptr);
 			glibtop_free_r (&server, ptr);
 			break;
 		case GLIBTOP_CMND_PROC_STATE:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_state_l
-	(&server, &data.proc_state, pid);
+				(&server, &response.u.data.proc_state, pid);
-      do_output (s, sizeof (glibtop_proc_state), &data.proc_state);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_UID:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_uid_l
-	(&server, &data.proc_uid, pid);
+				(&server, &response.u.data.proc_uid, pid);
-      do_output (s, sizeof (glibtop_proc_uid), &data.proc_uid);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_MEM:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_mem_l
-	(&server, &data.proc_mem, pid);
+				(&server, &response.u.data.proc_mem, pid);
-      do_output (s, sizeof (glibtop_proc_mem), &data.proc_mem);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_TIME:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_time_l
-	(&server, &data.proc_time, pid);
+				(&server, &response.u.data.proc_time, pid);
-      do_output (s, sizeof (glibtop_proc_time), &data.proc_time);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_SIGNAL:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_signal_l
-	(&server, &data.proc_signal, pid);
+				(&server, &response.u.data.proc_signal, pid);
-      do_output (s, sizeof (glibtop_proc_signal), &data.proc_signal);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_KERNEL:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_kernel_l
-	(&server, &data.proc_kernel, pid);
+				(&server, &response.u.data.proc_kernel, pid);
-      do_output (s, sizeof (glibtop_proc_kernel), &data.proc_kernel);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		case GLIBTOP_CMND_PROC_SEGMENT:
 			memcpy (&pid, parameter, sizeof (pid_t));
 			glibtop_get_proc_segment_l
-	(&server, &data.proc_segment, pid);
+				(&server, &response.u.data.proc_segment, pid);
-      do_output (s, sizeof (glibtop_proc_segment), &data.proc_segment);
+			do_output (s, &response, 0, NULL);
-      do_output (s, 0, NULL);
 			break;
 		}
 	}