From fe4db84d49545e669806d0cce12b3aa384e04ac3 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Tue, 4 Oct 2016 14:35:52 +0100 Subject: trace: provide mechanism for registering trace events MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Remove the notion of there being a single global array of trace events, by introducing a method for registering groups of events. The module_call_init() needs to be invoked at the start of any program that wants to make use of the trace support. Currently this covers system emulators qemu-nbd, qemu-img and qemu-io. [Squashed the following fix from Daniel P. Berrange : linux-user/bsd-user: initialize trace events subsystem The bsd-user/linux-user programs make use of the CPU emulation code and this now requires that the trace events subsystem is enabled, otherwise it'll crash trying to allocate an empty trace events bitmap for the CPU object. --Stefan] Reviewed-by: Stefan Hajnoczi Reviewed-by: Lluís Vilanova Signed-off-by: Daniel P. Berrange Message-id: 1475588159-30598-14-git-send-email-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- trace/control.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) (limited to 'trace/control.c') diff --git a/trace/control.c b/trace/control.c index 6b32511d60..a2313273d8 100644 --- a/trace/control.c +++ b/trace/control.c @@ -29,6 +29,13 @@ int trace_events_enabled_count; +typedef struct TraceEventGroup { + TraceEvent **events; +} TraceEventGroup; + +static TraceEventGroup *event_groups; +static size_t nevent_groups; + QemuOptsList qemu_trace_opts = { .name = "trace", .implied_opt_name = "enable", @@ -50,6 +57,14 @@ QemuOptsList qemu_trace_opts = { }; +void trace_event_register_group(TraceEvent **events) +{ + event_groups = g_renew(TraceEventGroup, event_groups, nevent_groups + 1); + event_groups[nevent_groups].events = events; + nevent_groups++; +} + + TraceEvent *trace_event_name(const char *name) { assert(name != NULL); @@ -100,14 +115,20 @@ static bool pattern_glob(const char *pat, const char *ev) void trace_event_iter_init(TraceEventIter *iter, const char *pattern) { iter->event = 0; + iter->group = 0; iter->pattern = pattern; } TraceEvent *trace_event_iter_next(TraceEventIter *iter) { - while (trace_events[iter->event] != NULL) { - TraceEvent *ev = trace_events[iter->event]; + while (iter->group < nevent_groups && + event_groups[iter->group].events[iter->event] != NULL) { + TraceEvent *ev = event_groups[iter->group].events[iter->event]; iter->event++; + if (event_groups[iter->group].events[iter->event] == NULL) { + iter->event = 0; + iter->group++; + } if (!iter->pattern || pattern_glob(iter->pattern, trace_event_get_name(ev))) { -- cgit v1.2.3