system_cmds-643.30.1.tar.gz

[apple/system_cmds.git] / msa / WriteTraceFileAction.cpp

diff --git a/msa/WriteTraceFileAction.cpp b/msa/WriteTraceFileAction.cpp
new file mode 100644 (file)
index 0000000..65c63c8
--- /dev/null
+++ b/msa/WriteTraceFileAction.cpp
@@ -0,0 +1,74 @@
+//
+//  WriteTraceFileAction.cpp
+//  system_cmds
+//
+//  Created by James McIlree on 4/29/14.
+//
+//
+
+#include "global.h"
+
+static bool shouldProcessEvents;
+static uint32_t sigintCount;
+
+static bool start_tracing(Globals& globals)
+{
+       if (!KDBG::reset()) return false;
+       if (!KDBG::set_buffer_capacity(globals.trace_buffer_size())) return false;
+       if (!KDBG::set_nowrap(false)) return false;
+       if (!KDBG::initialize_buffers()) return false;
+       if (!KDBG::set_enabled(KDEBUG_ENABLE_TRACE)) return false;
+
+       return true;
+}
+
+static void end_tracing(void)
+{
+       KDBG::reset();
+}
+
+static void signal_handler_ctrl_C(int sig)
+{
+       shouldProcessEvents = false;
+       if (++sigintCount >= 5) {
+               // Not responding, nuke it from orbit.
+               exit(1);
+       }
+}
+
+void WriteTraceFileAction::execute(Globals& globals) {
+       FileDescriptor fd(open(_path.c_str(), O_TRUNC|O_WRONLY|O_CREAT, 0777));
+       if (!fd.is_open()) {
+               log_msg(ASL_LEVEL_ERR, "Unable to write to %s\n", _path.c_str());
+               return;
+       }
+
+       shouldProcessEvents = true;
+       sigintCount = 0;
+
+       VoucherContentSysctl contents(globals.should_trace_voucher_contents());
+
+       AbsTime t1 = AbsTime::now();
+       if (start_tracing(globals)) {
+               // We cannot write the "maps" until after tracing has started.
+               if (KDBG::write_maps(fd)) {
+                       signal(SIGINT, signal_handler_ctrl_C);
+
+                       while (shouldProcessEvents) {
+                               int events_written = KDBG::write_events(fd);
+                               AbsTime t2 = AbsTime::now();
+                               if (events_written != -1) {
+                                       printf("wrote %d events - elapsed time = %.1f secs\n", events_written, (double)(t2 - t1).nano_time().value() / (double)NANOSECONDS_PER_SECOND);
+                               } else {
+                                       log_msg(ASL_LEVEL_WARNING, "write events returned -1\n");
+                                       break;
+                               }
+                               t1 = t2;
+                       }
+
+                       signal(SIGINT, SIG_DFL);
+               }
+       }
+
+       end_tracing();
+}