- Teach pmcstat(8) to log over the network; the -O option now

takes a host:port specification.
- Update the manual page and add an example showing how log
  over the network using pmcstat(8) and nc(1).  Document the
  current inability to process logs in cross-platform manner.
- Have pmcstat_open_log() call err(3) directly in case
  of an error; this simplifies error handling in its caller.

MFC after:	1 week

usr.sbin/pmcstat/pmcstat.8

@@ -23,7 +23,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 26, 2006
+.Dd April 2, 2006
 .Os
 .Dt PMCSTAT 8
 .Sh NAME
@@ -138,8 +138,27 @@ option.
 .It Fl O Ar logfilename
 Send logging output to file
 .Ar logfilename .
-If this option is not specified and one of the logging options
-is requested, then
+If
+.Ar logfilename
+is of the form
+.Ar hostname Ns : Ns Ar port ,
+where
+.Ar hostname
+does not start with a
+.Sq \&.
+or a
+.Sq / ,
+then
+.Nm
+will open a network socket to host
+.Ar hostname 
+on port
+.Ar port .
+.Pp
+If the
+.Fl O
+option is not specified and one of the logging options is requested,
+then
 .Nm
 will print a textual form of the logged events to the configured
 output file.
@@ -249,10 +268,16 @@ and measure the number of data cache misses suffered
 by it and its children every 12 seconds on an AMD Athlon, use:
 .Dl "pmcstat -d -w 12 -p k7-dc-misses mozilla"
 .Pp
-To collect a system-wide samples driven by processor instructions executed
-use:
+To perform system-wide sampling based on processor instructions
+retired use:
 .Dl "pmcstat -S instructions -O /tmp/sample.out"
 .Pp
+To send the generated event log to a remote machine use:
+.Dl "pmcstat -S instructions -O remotehost:port"
+On the remote machine, the sample log can be collected using
+.Xr nc 1 :
+.Dl "nc -l remotehost port > /tmp/sample.out"
+.Pp
 To generate
 .Xr gprof 1
 compatible flat profiles from a sample file use:
@@ -261,6 +286,7 @@ compatible flat profiles from a sample file use:
 .Ex -std
 .Sh SEE ALSO
 .Xr gprof 1 ,
+.Xr nc 1 ,
 .Xr execvp 3 ,
 .Xr pmc 3 ,
 .Xr pmclog 3 ,
@@ -277,6 +303,7 @@ It is
 .Sh AUTHORS
 .An Joseph Koshy Aq jkoshy@FreeBSD.org
 .Sh BUGS
-On AMD64 platforms
 .Nm
-does not yet handle profiles with samples from 32 bit executables.
+cannot yet analyse 
+.Xr hwpmc 4
+logs generated by non-native architectures.

usr.sbin/pmcstat/pmcstat.c

@@ -751,10 +751,8 @@ main(int argc, char **argv)
 			args.pa_flags |= FLAG_DO_PRINT;
 
 		pmcstat_initialize_logging(&args);
-		if ((args.pa_logfd = pmcstat_open_log(args.pa_inputpath,
-		    PMCSTAT_OPEN_FOR_READ)) < 0)
-			err(EX_OSERR, "ERROR: Cannot open \"%s\" for "
-			    "reading", args.pa_inputpath);
+		args.pa_logfd = pmcstat_open_log(args.pa_inputpath,
+		    PMCSTAT_OPEN_FOR_READ);
 		if ((args.pa_logparser = pmclog_open(args.pa_logfd)) == NULL)
 			err(EX_OSERR, "ERROR: Cannot create parser");
 		pmcstat_process_log(&args);
@@ -784,13 +782,10 @@ main(int argc, char **argv)
 	 * consumer via a pipe.
 	 */
 	if (args.pa_required & FLAG_HAS_OUTPUT_LOGFILE) {
-		if (args.pa_outputpath) {
-			if ((args.pa_logfd =
-			    pmcstat_open_log(args.pa_outputpath,
-			    PMCSTAT_OPEN_FOR_WRITE)) < 0)
-				err(EX_OSERR, "ERROR: Cannot open \"%s\" for "
-				    "writing", args.pa_outputpath);
-		} else {
+		if (args.pa_outputpath)
+			args.pa_logfd = pmcstat_open_log(args.pa_outputpath,
+			    PMCSTAT_OPEN_FOR_WRITE);
+		else {
 			/*
 			 * process the log on the fly by reading it in
 			 * through a pipe.

usr.sbin/pmcstat/pmcstat_log.c

@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mman.h>
 #include <sys/pmc.h>
 #include <sys/queue.h>
+#include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
 
@@ -47,9 +48,11 @@ __FBSDID("$FreeBSD$");
 
 #include <assert.h>
 #include <err.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <libgen.h>
 #include <limits.h>
+#include <netdb.h>
 #include <pmc.h>
 #include <pmclog.h>
 #include <sysexits.h>
@@ -1639,19 +1642,77 @@ pmcstat_close_log(struct pmcstat_args *a)
 int
 pmcstat_open_log(const char *path, int mode)
 {
-	int fd;
+	int error, fd;
+	size_t hlen;
+	const char *p, *errstr;
+	struct addrinfo hints, *res, *res0;
+	char hostname[MAXHOSTNAMELEN];
+
+	errstr = NULL;
+	fd = -1;
 
 	/*
 	 * If 'path' is "-" then open one of stdin or stdout depending
-	 * on the value of 'mode'.  Otherwise, treat 'path' as a file
-	 * name and open that.
+	 * on the value of 'mode'.
+	 * 
+	 * If 'path' contains a ':' and does not start with a '/' or '.',
+	 * and is being opened for writing, treat it as a "host:port"
+	 * specification and open a network socket.
+	 *
+	 * Otherwise, treat 'path' as a file name and open that.
 	 */
 	if (path[0] == '-' && path[1] == '\0')
 		fd = (mode == PMCSTAT_OPEN_FOR_READ) ? 0 : 1;
-	else
-		fd = open(path, mode == PMCSTAT_OPEN_FOR_READ ?
+	else if (mode == PMCSTAT_OPEN_FOR_WRITE && path[0] != '/' &&
+	    path[0] != '.' && strchr(path, ':') != NULL) {
+
+		p = strrchr(path, ':');
+		hlen = p - path;
+		if (p == path || hlen >= sizeof(hostname)) {
+			errstr = strerror(EINVAL);
+			goto done;
+		}
+
+		assert(hlen < sizeof(hostname));
+		(void) strncpy(hostname, path, hlen);
+		hostname[hlen] = '\0';
+
+		(void) memset(&hints, 0, sizeof(hints));
+		hints.ai_family = AF_UNSPEC;
+		hints.ai_socktype = SOCK_STREAM;
+		if ((error = getaddrinfo(hostname, p+1, &hints, &res0)) != 0) {
+			errstr = gai_strerror(error);
+			goto done;
+		}
+
+		fd = -1;
+		for (res = res0; res; res = res->ai_next) {
+			if ((fd = socket(res->ai_family, res->ai_socktype,
+			    res->ai_protocol)) < 0) {
+				errstr = strerror(errno);
+				continue;
+			}
+			if (connect(fd, res->ai_addr, res->ai_addrlen) < 0) {
+				errstr = strerror(errno);
+				(void) close(fd);
+				fd = -1;
+				continue;
+			}
+			errstr = NULL;
+			break;
+		}
+		freeaddrinfo(res0);
+
+	} else if ((fd = open(path, mode == PMCSTAT_OPEN_FOR_READ ?
 		    O_RDONLY : (O_WRONLY|O_CREAT|O_TRUNC),
-		    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
+		    S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) < 0)
+			errstr = strerror(errno);
+
+  done: 
+	if (errstr)
+		errx(EX_OSERR, "ERROR: Cannot open \"%s\" for %s: %s.", path,
+		    (mode == PMCSTAT_OPEN_FOR_READ ? "reading" : "writing"),
+		    errstr);
 
 	return (fd);
 }