block/cow: Return real error code

[qemu.git] / trace / control.h

/*
 * Interface for configuring and controlling the state of tracing events.
 *
 * Copyright (C) 2011 Lluís Vilanova <[email protected]>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 */

#ifndef TRACE_CONTROL_H
#define TRACE_CONTROL_H

#include "qemu-common.h"


/** Print the state of all events. */
void trace_print_events(FILE *stream, fprintf_function stream_printf);
/** Set the state of an event.
 *
 * @return Whether the state changed.
 */
bool trace_event_set_state(const char *name, bool state);


/** Initialize the tracing backend.
 *
 * @events Name of file with events to be enabled at startup; may be NULL.
 *         Corresponds to commandline option "-trace events=...".
 * @file   Name of trace output file; may be NULL.
 *         Corresponds to commandline option "-trace file=...".
 * @return Whether the backend could be successfully initialized.
 */
bool trace_backend_init(const char *events, const char *file);

/** Generic function to initialize the state of events.
 *
 * @fname Name of file with events to enable; may be NULL.
 */
void trace_backend_init_events(const char *fname);

#endif  /* TRACE_CONTROL_H */