New file.

1998-06-07  Martin Baulig  <martin@home-of-linux.org>

	* sysdeps/linux/glibtop_machine.h: New file.

	* sysdeps/linux/*.c: Performance optimizations. We now use
	`open' and `read' instead of `fopen' and `fscanf'.

1 files changed, 53 insertions, 34 deletions

diff --git a/sysdeps/linux/procsegment.c b/sysdeps/linux/procsegment.c
index d5ce5652..1ecefa2a 100644
--- a/sysdeps/linux/procsegment.c
+++ b/sysdeps/linux/procsegment.c
@@ -20,6 +20,7 @@
    Boston, MA 02111-1307, USA.  */
 
 #include <config.h>
+#include <glibtop/error.h>
 #include <glibtop/procsegment.h>
 
 static const unsigned long _glibtop_sysdeps_proc_segment =
@@ -32,11 +33,10 @@ static const unsigned long _glibtop_sysdeps_proc_segment =
 
 void
 glibtop_get_proc_segment_s (glibtop *server, glibtop_proc_segment *buf,
-			     pid_t pid)
+			    pid_t pid)
 {
-	char input [BUFSIZ], *tmp;
-	int nread;
-	FILE *f;
+	char buffer [BUFSIZ], input [BUFSIZ], *tmp;
+	int fd = 0, nread;
 	
 	glibtop_init_r (&server, 0, 0);
 
@@ -48,24 +48,41 @@ glibtop_get_proc_segment_s (glibtop *server, glibtop_proc_segment *buf,
 		return;
 	}
 
-	sprintf (input, "/proc/%d/stat", pid);
+	if (pid != server->machine.last_pid) {
+		server->machine.last_pid = pid;
+		server->machine.no_update = 0;
+	}
 
-	f = fopen (input, "r");
-	if (!f) return;
-	
-	nread = fread (input, 1, BUFSIZ, f);
-	
-	if (nread < 0) {
-		fclose (f);
-		return;
+	if (!server->machine.no_update) {
+		server->machine.proc_status [0] = 0;
+		server->machine.proc_statm [0] = 0;
+		server->machine.proc_stat [0] = 0;
 	}
-	
-	input [nread] = 0;
-	
+
+	if (server->machine.proc_stat [0]) {
+		strcpy (buffer, server->machine.proc_stat);
+	} else {
+		sprintf (input, "/proc/%d/stat", pid);
+		
+		fd = open (input, O_RDONLY);
+		if (fd == -1)
+			glibtop_error_r (server, "open (%s): %s",
+					 input, strerror (errno));
+		
+		nread = read (fd, buffer, BUFSIZ);
+		if (nread == -1)
+			glibtop_error_r (server, "read (%s): %s",
+					 input, strerror (errno));
+		
+		buffer [nread] = 0;
+		strcpy (server->machine.proc_stat, buffer);
+		close (fd);
+	}
+
 	/* This is from guile-utils/gtop/proc/readproc.c */
 	
 	/* split into "PID (cmd" and "<rest>" */
-	tmp = strrchr (input, ')');
+	tmp = strrchr (buffer, ')');
 	*tmp = '\0';		/* replace trailing ')' with NUL */
 	/* parse these two strings separately, skipping the leading "(". */
 	sscanf(tmp + 2,		/* skip space after ')' too */
@@ -74,26 +91,28 @@ glibtop_get_proc_segment_s (glibtop *server, glibtop_proc_segment *buf,
 	       "%*u %*u %lu %lu %lu", &buf->start_code,
 	       &buf->end_code, &buf->start_stack);
 	
-	fclose (f);
-
-	sprintf (input, "/proc/%d/statm", pid);
-
-	f = fopen (input, "r");
-	if (!f) return;
-
-	nread = fread (input, 1, BUFSIZ, f);
-
-	if (nread < 0) {
-		fclose (f);
-		return;
+	if (server->machine.proc_statm [0]) {
+		strcpy (buffer, server->machine.proc_statm);
+	} else {
+		sprintf (input, "/proc/%d/statm", pid);
+		
+		fd = open (input, O_RDONLY);
+		if (fd == -1)
+			glibtop_error_r (server, "open (%s): %s",
+					 input, strerror (errno));
+		
+		nread = read (fd, buffer, BUFSIZ);
+		if (nread == -1)
+			glibtop_error_r (server, "read (%s): %s",
+					 input, strerror (errno));
+		
+		buffer [nread] = 0;
+		strcpy (server->machine.proc_statm, buffer);
+		close (fd);
 	}
 
-	input [nread] = 0;
-
-	sscanf (input, "%*d %*d %*d %ld %ld %ld %ld",
+	sscanf (buffer, "%*d %*d %*d %ld %ld %ld %ld",
 		&buf->trs, &buf->lrs, &buf->drs, &buf->dt);
 
-	fclose (f);
-
 	buf->flags = _glibtop_sysdeps_proc_segment;
 }