[Qemu-devel] [PATCH v3 0/6] trace: Generic event state description

[Qemu-devel] [PATCH v3 0/6] trace: Generic event state description

[Lluís Vilanova]

NOTE: Applies on top of the tracetool-handling trivial changes.

Provides a generic event state description and a more detailed event control and
query interface.

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

Changes in v3:

* Add some assertions.

* Remove debugging printf's.

* Improve documentation.

* Make 'trace_event_get_state_static' use run-time information, and leave
  TRACE_*_ENABLED for compile-time checks.


Changes in v2:

* Minor compilation fixes.


Lluís Vilanova (6):
      trace: Provide a generic tracing event descriptor
      trace: Provide a detailed event control interface
      trace: [monitor] Use new event control interface
      trace: [default] Use new event control interface
      trace: [simple] Port to generic event information and new control interface
      trace: [stderr] Port to generic event information and new control interface


 Makefile                 |    5 ++
 Makefile.objs            |   15 ++++-
 docs/tracing.txt         |   41 +++++--------
 monitor.c                |   15 ++++-
 scripts/tracetool.py     |  149 ++++++++++++++++++++++++++++++++--------------
 trace/control-internal.h |   60 +++++++++++++++++++
 trace/control.c          |   92 ++++++++++++++++++++++++++--
 trace/control.h          |  148 ++++++++++++++++++++++++++++++++++++++++++----
 trace/default.c          |    3 -
 trace/event-internal.h   |   28 +++++++++
 trace/simple.c           |   33 ++--------
 trace/simple.h           |    6 --
 trace/stderr.c           |   35 ++---------
 trace/stderr.h           |   11 ---
 14 files changed, 475 insertions(+), 166 deletions(-)
 create mode 100644 trace/control-internal.h
 create mode 100644 trace/event-internal.h
 delete mode 100644 trace/stderr.h


To: qemu-devel@nongnu.org
Cc: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Blue Swirl <blauwirbel@gmail.com>

[Qemu-devel] [PATCH v3 1/6] trace: Provide a generic tracing event descriptor

[Lluís Vilanova]

Uses tracetool to generate a backend-independent tracing event description.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 Makefile               |    5 +++
 Makefile.objs          |   15 +++++++-
 scripts/tracetool.py   |   94 ++++++++++++++++++++++++++++++++++++++++++++----
 trace/event-internal.h |   28 ++++++++++++++
 4 files changed, 134 insertions(+), 8 deletions(-)
 create mode 100644 trace/event-internal.h

diff --git a/Makefile b/Makefile
index a9f3c7e..13e603c 100644
--- a/Makefile
+++ b/Makefile
@@ -4,9 +4,14 @@
 BUILD_DIR=$(CURDIR)
 
 GENERATED_HEADERS = config-host.h trace.h qemu-options.def
+
+GENERATED_HEADERS += trace-events.h
+GENERATED_SOURCES += trace-events.c
+
 ifeq ($(TRACE_BACKEND),dtrace)
 GENERATED_HEADERS += trace-dtrace.h
 endif
+
 GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h
 GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c trace.c
 
diff --git a/Makefile.objs b/Makefile.objs
index e6644c6..31abd21 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -348,6 +348,19 @@ libdis-$(CONFIG_SPARC_DIS) += sparc-dis.o
 ######################################################################
 # trace
 
+trace-events.h: trace-events.h-timestamp
+trace-events.h-timestamp: $(SRC_PATH)/trace-events $(TRACETOOL)
+	$(call tracetool-gen,events-h,events)
+	$(call tracetool-ci)
+
+trace-events.c: trace-events.c-timestamp
+trace-events.c-timestamp: $(SRC_PATH)/trace-events $(TRACETOOL)
+	$(call tracetool-gen,events-c,events)
+	$(call tracetool-ci)
+
+trace-obj-y += trace-events.o
+
+
 ifeq ($(TRACE_BACKEND),dtrace)
 TRACE_H_EXTRA_DEPS=trace-dtrace.h
 endif
@@ -389,7 +402,7 @@ trace/simple.o: trace/simple.c $(GENERATED_HEADERS)
 
 trace-obj-$(CONFIG_TRACE_DTRACE) += trace-dtrace.o
 ifneq ($(TRACE_BACKEND),dtrace)
-trace-obj-y = trace.o
+trace-obj-y += trace.o
 endif
 
 trace-nested-$(CONFIG_TRACE_DEFAULT) += default.o
diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index 7053a74..724b595 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -118,6 +118,73 @@ def get_backend_descr(backend):
 # formats
 
 ##################################################
+# format: events-h
+
+@for_format("events-h", BEGIN, "Generate .h for event description")
+def process(events):
+    print """\
+/* This file is autogenerated by tracetool, do not edit. */
+
+#ifndef TRACE_EVENTS_H
+#define TRACE_EVENTS_H
+
+#include <stdbool.h>
+"""
+
+    # event identifiers
+    print """
+typedef enum {\
+"""
+    for event in events:
+        print "    TRACE_%s," % event.name.upper()
+    print """\
+    TRACE_EVENT_COUNT
+} TraceEventID;
+"""
+
+    # static state
+    for e in events:
+        if 'disable' in e.properties:
+            enabled = 0
+        else:
+            enabled = 1
+        print "#define TRACE_%s_ENABLED %d" % (e.name.upper(), enabled)
+
+    print """\
+#include "trace/event-internal.h"
+
+#endif  /* TRACE_EVENTS_H */\
+"""
+
+
+##################################################
+# format: events-c
+
+@for_format("events-c", BEGIN, "Generate .h for event description")
+def process(events):
+    print """\
+/* This file is autogenerated by tracetool, do not edit. */
+
+#include "trace.h"
+#include "trace-events.h"
+#include "trace/control.h"
+
+
+TraceEvent trace_events[TRACE_EVENT_COUNT] = {\
+"""
+    for e in events:
+        print """\
+    { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s, .dstate = 0 },\
+""" % { "id": "TRACE_" + e.name.upper(),
+        "name": e.name,
+        "sstate": "TRACE_%s_ENABLED" % e.name.upper(),
+        }
+    print """\
+};
+"""
+
+
+##################################################
 # format: h
 
 @for_format("h", BEGIN, "Generate .h file")
@@ -131,13 +198,6 @@ def trace_h_begin(events):
 
 @for_format("h", END)
 def trace_h_end(events):
-    for e in events:
-        if 'disable' in e.properties:
-            enabled = 0
-        else:
-            enabled = 1
-        print "#define TRACE_%s_ENABLED %d" % (e.name.upper(), enabled)
-    print
     print '#endif /* TRACE_H */'
 
 
@@ -154,6 +214,26 @@ def trace_c_begin(events):
 # backends
 
 ##################################################
+# backend: events
+
+@for_backend("events", "events-h", "Generic event description")
+def process(events):
+    pass
+
+@for_backend("nop", "events-h")
+def process(events):
+    pass
+
+@for_backend("events", "events-c")
+def process(events):
+    pass
+
+@for_backend("nop", "events-c")
+def process(events):
+    pass
+
+
+##################################################
 # backend: nop
 
 @for_backend("nop", "h", "Tracing disabled")
diff --git a/trace/event-internal.h b/trace/event-internal.h
new file mode 100644
index 0000000..d62e82f
--- /dev/null
+++ b/trace/event-internal.h
@@ -0,0 +1,28 @@
+/*
+ * Interface for configuring and controlling the state of tracing events.
+ *
+ * Copyright (C) 2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef TRACE__EVENT_H
+#define TRACE__EVENT_H
+
+#include "trace-events.h"
+
+
+typedef struct TraceEvent {
+    /** Unique event identifier. */
+    TraceEventID id;
+    /** Event name. */
+    const char * name;
+    /** Static instrumentation state. */
+    const bool sstate;
+    /** Dynamic instrumentation state. */
+    bool dstate;
+} TraceEvent;
+
+
+#endif  /* TRACE__EVENT_H */

[Qemu-devel] [PATCH v3 2/6] trace: Provide a detailed event control interface

[Lluís Vilanova]

This interface decouples event obtention from interaction.

Event can be obtained through three different methods:

* identifier
* name
* simple wildcard pattern

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 docs/tracing.txt         |   41 +++++--------
 trace/control-internal.h |   60 +++++++++++++++++++
 trace/control.c          |   92 ++++++++++++++++++++++++++---
 trace/control.h          |  148 ++++++++++++++++++++++++++++++++++++++++++----
 4 files changed, 296 insertions(+), 45 deletions(-)
 create mode 100644 trace/control-internal.h

diff --git a/docs/tracing.txt b/docs/tracing.txt
index a92716f..17690f1 100644
--- a/docs/tracing.txt
+++ b/docs/tracing.txt
@@ -100,44 +100,32 @@ respectively.  This ensures portability between 32- and 64-bit platforms.
 
 == Generic interface and monitor commands ==
 
-You can programmatically query and control the dynamic state of trace events
-through a backend-agnostic interface:
+You can programmatically query and control the state of trace events through a
+backend-agnostic interface provided by the file "trace/control.h".
 
-* trace_print_events
+Note that some of the backends do not provide an implementation for some parts
+of this interface, in which case QEMU will just print a warning (please refer to
+header "trace/control.h" to see which routines are backend-dependant).
 
-* trace_event_set_state
-  Enables or disables trace events at runtime inside QEMU.
-  The function returns "true" if the state of the event has been successfully
-  changed, or "false" otherwise:
-
-    #include "trace/control.h"
-    
-    trace_event_set_state("virtio_irq", true); /* enable */
-    [...]
-    trace_event_set_state("virtio_irq", false); /* disable */
-
-Note that some of the backends do not provide an implementation for this
-interface, in which case QEMU will just print a warning.
-
-This functionality is also provided through monitor commands:
+The state of events can also be queried and modified through monitor commands:
 
 * info trace-events
   View available trace events and their state.  State 1 means enabled, state 0
   means disabled.
 
 * trace-event NAME on|off
-  Enable/disable a given trace event or a group of events having common prefix
-  through wildcard.
+  Enable/disable a given trace event or a group of events (using wildcards).
 
 The "-trace events=<file>" command line argument can be used to enable the
 events listed in <file> from the very beginning of the program. This file must
 contain one event name per line.
 
-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
+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 the following monitor command:
+
+    trace-event virtio_blk_* on
 
 == Trace backends ==
 
@@ -268,3 +256,6 @@ guard such computations and avoid its compilation when the event is disabled:
         }
         return ptr;
     }
+
+You can check both if the event has been disabled and is dynamically enabled at
+the same time using the 'trace_event_get_state' routine.
diff --git a/trace/control-internal.h b/trace/control-internal.h
new file mode 100644
index 0000000..81db761
--- /dev/null
+++ b/trace/control-internal.h
@@ -0,0 +1,60 @@
+/*
+ * Interface for configuring and controlling the state of tracing events.
+ *
+ * Copyright (C) 2011, 2012 Lluís Vilanova <vilanova@ac.upc.edu>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+
+extern TraceEvent trace_events[];
+
+
+static inline TraceEvent *trace_event_id(TraceEventID id)
+{
+    assert(id < trace_event_count());
+    return &trace_events[id];
+}
+
+static inline TraceEventID trace_event_count(void)
+{
+    return TRACE_EVENT_COUNT;
+}
+
+static inline bool trace_event_is_pattern(const char *str)
+{
+    assert(str != NULL);
+
+    while (*str != '\0') {
+        if (*str == '*') {
+            return true;
+        }
+        str++;
+    }
+    return false;
+}
+
+static inline TraceEventID trace_event_get_id(TraceEvent *ev)
+{
+    assert(ev != NULL);
+    return ev->id;
+}
+
+static inline const char * trace_event_get_name(TraceEvent *ev)
+{
+    assert(ev != NULL);
+    return ev->name;
+}
+
+static inline bool trace_event_get_state_static(TraceEvent *ev)
+{
+    assert(ev != NULL);
+    return ev->sstate;
+}
+
+static inline bool trace_event_get_state_dynamic(TraceEvent *ev)
+{
+    assert(ev != NULL);
+    return ev->dstate;
+}
diff --git a/trace/control.c b/trace/control.c
index 4c5527d..7fbe854 100644
--- a/trace/control.c
+++ b/trace/control.c
@@ -1,15 +1,84 @@
 /*
  * Interface for configuring and controlling the state of tracing events.
  *
- * Copyright (C) 2011 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011, 2012 Lluís Vilanova <vilanova@ac.upc.edu>
  *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
  */
 
 #include "trace/control.h"
 
 
+TraceEvent *trace_event_name(const char *name)
+{
+    assert(name != NULL);
+
+    TraceEventID i;
+    for (i = 0; i < trace_event_count(); i++) {
+        TraceEvent *ev = trace_event_id(i);
+        if (strcmp(trace_event_get_name(ev), name) == 0) {
+            return ev;
+        }
+    }
+    return NULL;
+}
+
+static inline bool glob(const char *pat, const char *ev)
+{
+    while (*pat != '\0' && *ev != '\0') {
+        if (*pat == *ev) {
+            pat++;
+            ev++;
+        }
+        else if (*pat == '*') {
+            if (glob(pat, ev+1)) {
+                return true;
+            } else if (glob(pat+1, ev)) {
+                return true;
+            } else {
+                return false;
+            }
+        } else {
+            return false;
+        }
+    }
+
+    while (*pat == '*') {
+        pat++;
+    }
+
+    if (*pat == '\0' && *ev == '\0') {
+        return true;
+    } else {
+        return false;
+    }
+}
+
+TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev)
+{
+    assert(pat != NULL);
+
+    TraceEventID i;
+
+    if (ev == NULL) {
+        i = -1;
+    } else {
+        i = trace_event_get_id(ev);
+    }
+    i++;
+
+    while (i < trace_event_count()) {
+        TraceEvent *res = trace_event_id(i);
+        if (glob(pat, trace_event_get_name(res))) {
+            return res;
+        }
+        i++;
+    }
+
+    return NULL;
+}
+
 void trace_backend_init_events(const char *fname)
 {
     if (fname == NULL) {
@@ -27,10 +96,19 @@ void trace_backend_init_events(const char *fname)
         size_t len = strlen(line_buf);
         if (len > 1) {              /* skip empty lines */
             line_buf[len - 1] = '\0';
-            if (!trace_event_set_state(line_buf, true)) {
-                fprintf(stderr,
-                        "error: trace event '%s' does not exist\n", line_buf);
-                exit(1);
+            if (trace_event_is_pattern(line_buf)) {
+                TraceEvent *ev;
+                while ((ev = trace_event_pattern(line_buf, ev)) != NULL) {
+                    trace_event_set_state_dynamic(ev, true);
+                }
+            } else {
+                TraceEvent *ev = trace_event_name(line_buf);
+                if (ev == NULL) {
+                    fprintf(stderr,
+                            "error: trace event '%s' does not exist\n", line_buf);
+                    exit(1);
+                }
+                trace_event_set_state_dynamic(ev, true);
             }
         }
     }
diff --git a/trace/control.h b/trace/control.h
index 2acaa42..3b9c6f5 100644
--- a/trace/control.h
+++ b/trace/control.h
@@ -1,41 +1,163 @@
 /*
  * Interface for configuring and controlling the state of tracing events.
  *
- * Copyright (C) 2011 Lluís Vilanova <vilanova@ac.upc.edu>
+ * Copyright (C) 2011, 2012 Lluís Vilanova <vilanova@ac.upc.edu>
  *
- * This work is licensed under the terms of the GNU GPL, version 2.  See
- * the COPYING file in the top-level directory.
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
  */
 
-#ifndef TRACE_CONTROL_H
-#define TRACE_CONTROL_H
+#ifndef TRACE__CONTROL_H
+#define TRACE__CONTROL_H
 
 #include "qemu-common.h"
+#include "trace-events.h"
 
 
-/** Print the state of all events. */
-void trace_print_events(FILE *stream, fprintf_function stream_printf);
-/** Set the state of an event.
+/**
+ * Opaque generic description of a tracing event.
+ */
+struct TraceEvent;
+typedef struct TraceEvent TraceEvent;
+
+/**
+ * TraceEventID - Unique tracing event identifier.
+ *
+ * These are named as 'TRACE_${EVENT_NAME}'.
+ *
+ * See also: trace-events.h
+ */
+
+/**
+ * Get an event by its identifier.
+ *
+ * @id Event identifier.
+ *
+ * @return Pointer to event.
+ *
+ * @pre The identifier is valid.
+ */
+static TraceEvent *trace_event_id(TraceEventID id);
+
+/**
+ * Search an event by its name.
+ *
+ * @id Event name.
+ *
+ * @return Pointer to Event or NULL if not found.
+ */
+TraceEvent *trace_event_name(const char *name);
+
+/**
+ * Get all events with a given name pattern.
+ *
+ * @pat Event name pattern.
+ * @ev  Event to start searching from.
+ *
+ * @return Pointer to Event or NULL if not found.
+ */
+TraceEvent *trace_event_pattern(const char *pat, TraceEvent *ev);
+
+/**
+ * Whether the given string is an event name pattern.
+ */
+static bool trace_event_is_pattern(const char *str);
+
+/**
+ * Return the number of events.
+ */
+static TraceEventID trace_event_count(void);
+
+
+
+/**
+ * Get the identifier of an event.
+ */
+static TraceEventID trace_event_get_id(TraceEvent *ev);
+
+/**
+ * Get the name of an event.
+ */
+static const char * trace_event_get_name(TraceEvent *ev);
+
+/**
+ * Get the tracing state of an event (both static and dynamic).
+ *
+ * @id Event identifier.
+ *
+ * If the event has the disabled property, the check will have no performance
+ * impact.
+ *
+ * As a down side, you must always use an immediate TraceEventID value.
+ */
+#define trace_event_get_state(id)                       \
+    ((id ##_ENABLED) && trace_event_get_state_dynamic(trace_event_id(id)))
+
+/**
+ * Get the static tracing state of an event.
+ *
+ * @id Event identifier.
+ *
+ * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
+ * be set to 1 or 0 according to the presence of the disabled property).
+ */
+static bool trace_event_get_state_static(TraceEvent *ev);
+
+/**
+ * Get the dynamic tracing state of an event.
+ */
+static bool trace_event_get_state_dynamic(TraceEvent *ev);
+
+/**
+ * Set the tracing state of an event.
+ */
+#define trace_event_set_state(id, state)                \
+    do {                                                \
+        if ((id ##_ENABLED)) {                          \
+            TraceEvent *_e = trace_event_id(id);        \
+            trace_event_set_state_dynamic(_e, state);   \
+        }                                               \
+    } while (0)
+
+/**
+ * Set the dynamic tracing state of an event.
  *
- * @return Whether the state changed.
+ * @warning This function must be implemented by each tracing backend.
  */
-bool trace_event_set_state(const char *name, bool state);
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 
 
-/** Initialize the tracing backend.
+
+/**
+ * Print the state of all events.
+ *
+ * @warning This function must be implemented by each tracing backend.
+ *
+ * @todo Should this be moved to generic code?
+ */
+void trace_print_events(FILE *stream, fprintf_function stream_printf);
+
+/**
+ * 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.
+ *
+ * @warning This function must be implemented by each tracing backend.
  */
 bool trace_backend_init(const char *events, const char *file);
 
-/** Generic function to initialize the state of events.
+/**
+ * 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 */
+
+#include "trace/control-internal.h"
+
+#endif  /* TRACE__CONTROL_H */

[Qemu-devel] [PATCH v3 3/6] trace: [monitor] Use new event control interface

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 monitor.c |   15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/monitor.c b/monitor.c
index 5e099bd..010f659 100644
--- a/monitor.c
+++ b/monitor.c
@@ -617,10 +617,19 @@ static void do_trace_event_set_state(Monitor *mon, const QDict *qdict)
 {
     const char *tp_name = qdict_get_str(qdict, "name");
     bool new_state = qdict_get_bool(qdict, "option");
-    int ret = trace_event_set_state(tp_name, new_state);
 
-    if (!ret) {
-        monitor_printf(mon, "unknown event name \"%s\"\n", tp_name);
+    if (trace_event_is_pattern(tp_name)) {
+        TraceEvent *ev = NULL;
+        while ((ev = trace_event_pattern(tp_name, ev)) != NULL) {
+            trace_event_set_state_dynamic(ev, new_state);
+        }
+    } else {
+        TraceEvent *ev = trace_event_name(tp_name);
+        if (ev == NULL) {
+            monitor_printf(mon, "unknown event name \"%s\"\n", tp_name);
+        } else {
+            trace_event_set_state_dynamic(ev, new_state);
+        }
     }
 }
 

[Qemu-devel] [PATCH v3 4/6] trace: [default] Use new event control interface

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 trace/default.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/trace/default.c b/trace/default.c
index c9b27a2..12db18d 100644
--- a/trace/default.c
+++ b/trace/default.c
@@ -18,11 +18,10 @@ void trace_print_events(FILE *stream, fprintf_function stream_printf)
                   "operation not supported with the current backend\n");
 }
 
-bool trace_event_set_state(const char *name, bool state)
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
 {
     fprintf(stderr, "warning: "
             "cannot set the state of a trace event with the current backend\n");
-    return false;
 }
 
 bool trace_backend_init(const char *events, const char *file)

[Qemu-devel] [PATCH v3 5/6] trace: [simple] Port to generic event information and new control interface

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool.py |   29 ++++++++++-------------------
 trace/simple.c       |   33 ++++++---------------------------
 trace/simple.h       |    6 +-----
 trace/stderr.h       |   11 -----------
 4 files changed, 17 insertions(+), 62 deletions(-)
 delete mode 100644 trace/stderr.h

diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index 724b595..98a8ca8 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -265,28 +265,18 @@ def simple_h(events):
     'name': event.name,
     'args': event.args
 }
-    print
-    print '#define NR_TRACE_EVENTS %d' % len(events)
-    print 'extern TraceEvent trace_list[NR_TRACE_EVENTS];'
 
 @for_backend("simple", "c")
 def simple_c(events):
     rec_off = 0
-    print '#include "trace.h"'
-    print '#include "trace/simple.h"'
-    print
-    print 'TraceEvent trace_list[] = {'
-    print
-    for event in events:
-        print '{.tp_name = "%(name)s", .state=0},' % {
-    'name': event.name
-}
-        print
-    print '};'
-    print
+    print """\
+#include "trace.h"
+#include "trace/control.h"
+#include "trace/simple.h"
+"""
 
-    for num, event in enumerate(events):
-        sizes = []
+    for event in events:
+        sizes = ["0"]
         for type_, name in event.args:
             if type_is_string(type_):
                 sizes.append("4 + strlen(%s)" % name)
@@ -301,7 +291,8 @@ def simple_c(events):
     uint64_t pvar64 __attribute__ ((unused));
     uint32_t slen __attribute__ ((unused));
 
-    if (!trace_list[%(event_id)s].state) {
+    bool _state = trace_event_get_state(%(event_id)s);
+    if (!_state) {
         return;
     }
 
@@ -310,7 +301,7 @@ def simple_c(events):
 ''' % {
     'name': event.name,
     'args': event.args,
-    'event_id': num,
+    'event_id': "TRACE_" + event.name.upper(),
     'sizestr' : sizestr,
 }
 
diff --git a/trace/simple.c b/trace/simple.c
index f5aa3bd..3c99923 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -263,38 +263,17 @@ void trace_print_events(FILE *stream, fprintf_function stream_printf)
 {
     unsigned int i;
 
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+    for (i = 0; i < trace_event_count(); i++) {
+        TraceEvent *ev = trace_event_id(i);
         stream_printf(stream, "%s [Event ID %u] : state %u\n",
-                      trace_list[i].tp_name, i, trace_list[i].state);
+                      trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
     }
 }
 
-bool trace_event_set_state(const char *name, bool state)
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
 {
-    unsigned int i;
-    unsigned int len;
-    bool wildcard = false;
-    bool matched = false;
-
-    len = strlen(name);
-    if (len > 0 && name[len - 1] == '*') {
-        wildcard = true;
-        len -= 1;
-    }
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
-        if (wildcard) {
-            if (!strncmp(trace_list[i].tp_name, name, len)) {
-                trace_list[i].state = state;
-                matched = true;
-            }
-            continue;
-        }
-        if (!strcmp(trace_list[i].tp_name, name)) {
-            trace_list[i].state = state;
-            return true;
-        }
-    }
-    return matched;
+    assert(ev != NULL);
+    ev->dstate = state;
 }
 
 /* Helper function to create a thread with signals blocked.  Use glib's
diff --git a/trace/simple.h b/trace/simple.h
index 671cbeb..6850ac5 100644
--- a/trace/simple.h
+++ b/trace/simple.h
@@ -15,12 +15,8 @@
 #include <stdbool.h>
 #include <stdio.h>
 
-typedef uint64_t TraceEventID;
+#include "trace-events.h"
 
-typedef struct {
-    const char *tp_name;
-    bool state;
-} TraceEvent;
 
 void st_print_trace(FILE *stream, fprintf_function stream_printf);
 void st_print_trace_file_status(FILE *stream, fprintf_function stream_printf);
diff --git a/trace/stderr.h b/trace/stderr.h
deleted file mode 100644
index d575b61..0000000
--- a/trace/stderr.h
+++ /dev/null
@@ -1,11 +0,0 @@
-#ifndef TRACE_STDERR_H
-#define TRACE_STDERR_H
-
-typedef uint64_t TraceEventID;
-
-typedef struct {
-    const char *tp_name;
-    bool state;
-} TraceEvent;
-
-#endif /* ! TRACE_STDERR_H */

[Qemu-devel] [PATCH v3 6/6] trace: [stderr] Port to generic event information and new control interface

[Lluís Vilanova]

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
---
 scripts/tracetool.py |   26 ++++++++------------------
 trace/stderr.c       |   35 +++++++----------------------------
 2 files changed, 15 insertions(+), 46 deletions(-)

diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index 98a8ca8..a3135b8 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -348,10 +348,10 @@ def simple_c(events):
 
 @for_backend("stderr", "h", "Stderr built-in backend")
 def stderr_h(events):
-    print '''#include <stdio.h>
-#include "trace/stderr.h"
-
-extern TraceEvent trace_list[];'''
+    print """\
+#include <stdio.h>
+#include "trace/control.h"
+"""
 
     for num, event in enumerate(events):
         argnames = ", ".join(event.args.names())
@@ -360,31 +360,21 @@ extern TraceEvent trace_list[];'''
         print '''
 static inline void trace_%(name)s(%(args)s)
 {
-    if (trace_list[%(event_num)s].state != 0) {
+    bool _state = trace_event_get_state(%(event_id)s);
+    if (_state) {
         fprintf(stderr, "%(name)s " %(fmt)s "\\n" %(argnames)s);
     }
 }''' % {
     'name': event.name,
     'args': event.args,
-    'event_num': num,
+    'event_id': "TRACE_" + event.name.upper(),
     'fmt': event.fmt.rstrip('\n'),
     'argnames': argnames
 }
-    print
-    print '#define NR_TRACE_EVENTS %d' % len(events)
 
 @for_backend("stderr", "c")
 def stderr_c(events):
-    print '''#include "trace.h"
-
-TraceEvent trace_list[] = {
-'''
-    for event in events:
-        print '{.tp_name = "%(name)s", .state=0},' % {
-    'name': event.name
-}
-        print
-    print '};'
+    pass
 
 
 ##################################################
diff --git a/trace/stderr.c b/trace/stderr.c
index 0810d6f..3d5f313 100644
--- a/trace/stderr.c
+++ b/trace/stderr.c
@@ -4,40 +4,19 @@
 
 void trace_print_events(FILE *stream, fprintf_function stream_printf)
 {
-    unsigned int i;
+    TraceEventID i;
 
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
+    for (i = 0; i < trace_event_count(); i++) {
+        TraceEvent *ev = trace_event_id(i);
         stream_printf(stream, "%s [Event ID %u] : state %u\n",
-                      trace_list[i].tp_name, i, trace_list[i].state);
+                      trace_event_get_name(ev), i, trace_event_get_state_dynamic(ev));
     }
 }
 
-bool trace_event_set_state(const char *name, bool state)
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
 {
-    unsigned int i;
-    unsigned int len;
-    bool wildcard = false;
-    bool matched = false;
-
-    len = strlen(name);
-    if (len > 0 && name[len - 1] == '*') {
-        wildcard = true;
-        len -= 1;
-    }
-    for (i = 0; i < NR_TRACE_EVENTS; i++) {
-        if (wildcard) {
-            if (!strncmp(trace_list[i].tp_name, name, len)) {
-                trace_list[i].state = state;
-                matched = true;
-            }
-            continue;
-        }
-        if (!strcmp(trace_list[i].tp_name, name)) {
-            trace_list[i].state = state;
-            return true;
-        }
-    }
-    return matched;
+    assert(ev != NULL);
+    ev->dstate = state;
 }
 
 bool trace_backend_init(const char *events, const char *file)

Re: [Qemu-devel] [PATCH v3 0/6] trace: Generic event state description

[Lluís Vilanova]

Lluís Vilanova writes:

> NOTE: Applies on top of the tracetool-handling trivial changes.
> Provides a generic event state description and a more detailed event control and
> query interface.

Please disregard this series; it will be resent after acceptance of the
tracetool rewrite.


Thanks,
    Lluis

-- 
 "And it's much the same thing with knowledge, for whenever you learn
 something new, the whole world becomes that much richer."
 -- The Princess of Pure Reason, as told by Norton Juster in The Phantom
 Tollbooth