t/cli: Add trace piping support

src/xrt/targets/cli/CMakeLists.txt

@@ -13,6 +13,13 @@ set(SOURCE_FILES
 	cli_main.c
 	)
 
+if(NOT WIN32)
+	# Lots of linux assumptions in this file.
+	list(APPEND SOURCE_FILES
+		cli_cmd_trace.c
+		)
+endif()
+
 if(NOT WIN32)
 	# No getline on Windows, so until we have a portable impl
 	list(APPEND SOURCE_FILES

src/xrt/targets/cli/cli_cmd_trace.c

@@ -0,0 +1,334 @@
+// Copyright 2021, Collabora, Ltd.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief  Trace marker parsing and coversion code.
+ * @author Jakob Bornecrantz <jakob@collabora.com>
+ */
+
+#include "xrt/xrt_compiler.h"
+
+#include "util/u_misc.h"
+#include "util/u_trace_marker.h"
+
+#include "cli_common.h"
+
+#include <stdio.h>
+#include <signal.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <inttypes.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#define P(...) fprintf(stderr, __VA_ARGS__)
+
+#define TRACE_PIPE_FILENAME "/sys/kernel/tracing/trace_pipe"
+#define TRACE_MARKER_FILENAME "/sys/kernel/tracing/trace_marker"
+#define BUF_SIZE (1024 * 8)
+
+
+struct trace
+{
+	int fd;
+	FILE *file;
+
+	bool running;
+
+	char buffer[BUF_SIZE];
+};
+
+static struct trace t = {0};
+
+
+/*
+ *
+ * JSON writing.
+ *
+ */
+
+static void
+json_w_header()
+{
+	fprintf(t.file,
+	        "{\n"
+	        "\t\"displayTimeUnit\": \"ms\",\n"
+	        "\t\"traceEvents\": [\n"
+	        "\t\t{\n"
+	        "\t\t\t\"#\": \"This is to avoid having to deal with ',' all over the code.\"\n"
+	        "\t\t}");
+}
+
+static void
+json_w_end()
+{
+	fprintf(t.file,
+	        "\n"
+	        "\t]\n"
+	        "}\n");
+}
+
+
+/*
+ *
+ * Functions.
+ *
+ */
+
+static int
+open_file_fd(const char *filename, int flags)
+{
+	int fd = open(filename, flags);
+	if (fd < 0) {
+		fprintf(stderr, " :: Failed to open the file: '%s'\n", filename);
+		fprintf(stderr, "    See command help!\n");
+	}
+
+	return fd;
+}
+
+static int
+open_fd()
+{
+	int check_fd = open_file_fd(TRACE_MARKER_FILENAME, O_WRONLY);
+	if (check_fd < 0) {
+		return -1;
+	}
+	close(check_fd);
+
+	fprintf(stderr, " :: Checked '%s'\n", TRACE_MARKER_FILENAME);
+
+	t.fd = open_file_fd(TRACE_PIPE_FILENAME, O_RDONLY);
+
+	fprintf(stderr, " :: Opened '%s'\n", TRACE_PIPE_FILENAME);
+
+	return 0;
+}
+
+static void
+handle_data(const char *rest_of_line, size_t len)
+{
+	int type = 0;
+	int data_length = 0;
+	int consumed = 0;
+	int scan = sscanf(rest_of_line, "%i %i %n", &type, &data_length, &consumed);
+	char data[1024];
+
+	if ((int)data_length * 2 != (int)len - (int)consumed) {
+		return;
+	}
+
+	if ((size_t)data_length > sizeof(data)) {
+		return;
+	}
+
+	rest_of_line = rest_of_line + consumed;
+	len = len - (size_t)consumed;
+
+
+	for (int i = 0; i < data_length; i++) {
+		int tmp = 0;
+		scan = sscanf(rest_of_line + (i * 2), "%2x", &tmp);
+		if (scan < 1) {
+			return;
+		}
+
+		data[i] = tmp;
+	}
+
+	switch (type) {
+	case U_TRACE_DATA_TYPE_TIMING_FRAME: u_timing_frame_write_json(t.file, (void *)data); break;
+	default: fprintf(stderr, "%.*s\n", (int)len, rest_of_line); break;
+	}
+}
+
+static void
+handle_line(const char *line, size_t len)
+{
+	int pid = 0, tid = 0;
+	int secs = 0, usecs = 0;
+	char cmd = '\0';
+	int consumed = 0;
+	char function[256] = {0};
+
+	int scan = sscanf(                                                      //
+	    line,                                                               //
+	    "           <...>-%i %*s %*s %d.%d: tracing_mark_write: %1s %i %n", //
+	    &tid,                                                               //
+	    &secs,                                                              //
+	    &usecs,                                                             //
+	    &cmd,                                                               //
+	    &pid,                                                               //
+	    &consumed);                                                         //
+
+	if (scan < 5) {
+		fprintf(stderr, "%.*s\n", (int)len, line);
+		return;
+	}
+
+	switch (cmd) {
+	case 'E':
+	case 'B':
+		scan = sscanf(line + consumed, "%256s", function);
+		if (scan < 1) {
+			fprintf(stderr, "%.*s\n", (int)len, line);
+			return;
+		}
+
+		fprintf(t.file,
+		        ",\n"
+		        "\t\t{\n"
+		        "\t\t\t\"ph\": \"%.1s\",\n"
+		        "\t\t\t\"name\": \"%s\",\n"
+		        "\t\t\t\"cat\": \"%s\",\n"
+		        "\t\t\t\"ts\": %u%06u,\n"
+		        "\t\t\t\"pid\": %u,\n"
+		        "\t\t\t\"tid\": %u\n"
+		        "\t\t}",
+		        &cmd, function, "func", secs, usecs, pid, tid);
+		break;
+	case 'r': handle_data(line + consumed, len - (size_t)consumed); break;
+	default: fprintf(stderr, "%.*s\n", (int)len, line); break;
+	}
+}
+
+static int
+loop()
+{
+	while (t.running) {
+		ssize_t ret = read(t.fd, t.buffer, BUF_SIZE);
+		if (ret < 0) {
+			return 1;
+		}
+		if (ret == 0) {
+			continue;
+		}
+
+		size_t pos = 0;
+		size_t count = 0;
+		while (count < (size_t)ret) {
+			if (t.buffer[count] != '\n') {
+				count++;
+				continue;
+			}
+
+			assert(t.buffer[pos] != '\n');
+
+			size_t length = count - pos;
+			handle_line(t.buffer + pos, length);
+
+			// Point *after* the newline.
+			count++;
+			pos = count;
+		}
+
+		fflush(t.file);
+	}
+
+	return 0;
+}
+
+void
+signal_handler(int signum, siginfo_t *info, void *ptr)
+{
+	t.running = false;
+
+	// Since we are doing a clean shutdown ^C be on it's own line.
+	write(STDERR_FILENO, "\n", 1);
+}
+
+void
+catch_sigterm()
+{
+	static struct sigaction _sigact;
+
+	memset(&_sigact, 0, sizeof(_sigact));
+	_sigact.sa_sigaction = signal_handler;
+	_sigact.sa_flags = SA_SIGINFO;
+
+	sigaction(SIGTERM, &_sigact, NULL);
+	sigaction(SIGINT, &_sigact, NULL);
+}
+
+static int
+trace_pipe(int argc, const char **argv)
+{
+	catch_sigterm();
+
+	t.file = stdout;
+	t.running = true;
+
+	int ret = open_fd();
+	if (ret < 0) {
+		return 1;
+	}
+
+	json_w_header();
+
+	u_timing_frame_write_json_metadata(t.file);
+
+	P(" :: Looping\n");
+
+	ret = loop();
+	if (ret < 0) {
+		return 1;
+	}
+
+	json_w_end();
+
+	P(" :: Clean shutdown\n");
+
+	return 0;
+}
+
+static void
+print_help(int argc, const char **argv)
+{
+	if (argc >= 3) {
+		P("Unknown trace command '%s'\n\n", argv[2]);
+	}
+
+	P("Usage %s trace <cmd>\n", argv[0]);
+	P("\n");
+	P("Commands:\n");
+	P("  pipe - Read the trace_pipe stream and convert into json outputted to stdout.\n");
+	P("\n");
+	P("Example:\n");
+	P("  $ %s trace pipe 1> /tmp/chrome_tracing.json\n", argv[0]);
+	P("\n");
+	P("Make sure your user has access to the files:\n");
+	P("  '%s'.\n", TRACE_PIPE_FILENAME);
+	P("  '%s'.\n", TRACE_MARKER_FILENAME);
+	P("\n");
+	P("The reference clocks needs to be the same in Monado and the tracing framework.\n");
+	P("  $ echo mono | sudo dd of=/sys/kernel/tracing/trace_clock\n");
+	P("This command is very unsecure but will make things work.\n");
+	P("  $ sudo chown -R <user>:<user> /sys/kernel/tracing\n");
+	P("\n");
+	P("See https://lwn.net/Articles/366796/\n");
+}
+
+int
+cli_cmd_trace(int argc, const char **argv)
+{
+	if (argc <= 2) {
+		print_help(argc, argv);
+		return 1;
+	}
+
+	if (strcmp(argv[2], "help") == 0) {
+		print_help(2, argv);
+		return 0;
+	}
+
+	if (strcmp(argv[2], "pipe") == 0) {
+		return trace_pipe(argc, argv);
+	}
+
+	print_help(argc, argv);
+
+	return 1;
+}

src/xrt/targets/cli/cli_common.h

@@ -9,6 +9,11 @@
 #pragma once
 
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
 int
 cli_cmd_calibrate(int argc, const char **argv);
 
@@ -20,3 +25,11 @@ cli_cmd_probe(int argc, const char **argv);
 
 int
 cli_cmd_test(int argc, const char **argv);
+
+int
+cli_cmd_trace(int argc, const char **argv);
+
+
+#ifdef __cplusplus
+}
+#endif

src/xrt/targets/cli/cli_main.c

@@ -30,8 +30,8 @@ cli_print_help(int argc, const char **argv)
 	P("  test       - List found devices, for prober testing.\n");
 	P("  probe      - Just probe and then exit.\n");
 	P("  lighthouse - Control the power of lighthouses [on|off].\n");
-	P("  calibrate  - Calibrate a camera and save config (not implemented "
+	P("  calibrate  - Calibrate a camera and save config (not implemented yet).\n");
-	  "yet).\n");
+	P("  trace      - Tracing functionality.\n");
 
 	return 1;
 }
@@ -57,5 +57,10 @@ main(int argc, const char **argv)
 	if (strcmp(argv[1], "lighthouse") == 0) {
 		return cli_cmd_lighthouse(argc, argv);
 	}
+#ifndef XRT_OS_WINDOWS
+	if (strcmp(argv[1], "trace") == 0) {
+		return cli_cmd_trace(argc, argv);
+	}
+#endif // !XRT_OS_WINDOWS
 	return cli_print_help(argc, argv);
 }

src/xrt/targets/cli/meson.build

@@ -8,6 +8,7 @@ cli = executable(
 		'cli_cmd_lighthouse.c',
 		'cli_cmd_probe.c',
 		'cli_cmd_test.c',
+		'cli_cmd_trace.c',
 		'cli_common.h',
 		'cli_main.c',
 	),