asprintf is not available for all hosts. g_strdup_printf is
more portable and simplifies the code because if does not
need error handling.

The static variable does not need an explicit assignment to be NULL.

Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Declaring a TraceRecord on the stack works fine.  No need for a
uint8_t array and pointer aliasing.
Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

The buffer argument is void* so it is not necessary to cast.
Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

The TraceRecordHeader is really the header for the entire trace log
file.  It's not per-record header so make this obvious by renaming it.
Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Existing simpletrace backend allows to trace at max 6 args and does not
support strings. This newer tracelog format gets rid of fixed size records
and therefore allows to trace variable number of args including strings.

Sample trace with strings:
v9fs_version 0.000 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L
v9fs_version_return 6.705 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L
Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Going forward with simpletrace v2 variable size trace records, we cannot
have a generic function to print trace event info and therefore this
interface becomes invalid.

As per Stefan Hajnoczi:

"This command is only available from the human monitor.  It's not very
useful because it historically hasn't been able to pretty-print events
or show them in the right order (we use a ringbuffer but it prints
them out from index 0).

Therefore, I don't think we're under any obligation to keep this
command around.  No one has complained about it's limitations - I
think this is a sign that no one has used it.  I'd be okay with a
patch that removes it."

Ref: http://lists.gnu.org/archive/html/qemu-devel/2012-01/msg01268.htmlSigned-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

It is convenient for debug to be able to switch on/off some events easily.
The only possibility now is to remove event name from the file completely
and type it again when we want it back.

The patch adds '#' symbol handling as a comment specifier.
Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Signed-off-by: NHarsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

This patch makes trace_thread_create() to use its function arg to
initialize thread.  The other choice is to make this a function to use
void arg, but i prefer this way.
Signed-off-by: NJun Koi <junkoi2004@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

since commit f9b29ca03 included in release 2.31 (docs below say 2.32 but
that is not correct) and onwards g_thread_init is deprecated and calling
it is not required:

 http://developer.gnome.org/glib/unstable/glib-Deprecated-Thread-APIs.html#g-thread-init

 g_thread_init has been deprecated since version 2.32 and should not be
 used in newly-written code. This function is no longer necessary. The
 GLib threading system is automatically initialized at the start of your
 program.

Fixes bulid failure when warnings are treated as errors on fedora 17.

I only tested the change to vl.c, and copy pasted to the two other
locations (couldn't decide if a wrapper for calling g_thread_init is
uglier).
Signed-off-by: NAlon Levy <alevy@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

A basic wildcard matching is supported in both the monitor command
"trace-event" and the events list file. That means you can enable/disable
the events having a common prefix in a batch. For example, virtio-blk trace
events could be enabled using:
    trace-event virtio_blk_* on
Signed-off-by: NMark Wu <wudxw@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

For Windows portability the simple trace backend must use the 'b' file
open mode.  This prevents the stdio library from mangling 0x0a/0x0d
newline characters.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Convert the simple trace backend to glib so that it works under Windows.
We cannot use pthread directly but glib provides portable abstractions.
Also use glib atomics instead of newish gcc builtins which may not be
supported on Windows toolchains.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Uses the generic interface provided in "trace/control.h" in order to provide
a programmatic interface as well as command line and monitor controls.
Signed-off-by: NFabien Chouteau <chouteau@adacore.com>
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>

The "-trace events" argument can be used to provide a file with a list of trace
event names that will be enabled prior to starting execution, thus providing
early tracing.

This saves the user from manually toggling event states through the monitor
interface or whichever backend-specific interface.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>

Generalize the 'st_print_trace_events' and 'st_change_trace_event_state' into
backend-specific 'trace_print_events' and 'trace_event_set_state' (respectively)
in the "trace/control.h" file.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>

A default implementation for backend-specific routines is provided in
"trace/default.c", which backends can override by setting "trace_default=no" in
"configure".
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>

Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>