The log filters have supported the use of a "+" before the source match
string to request that a stack trace be emitted for every log message:
commit
548563956e484e0e43e9a66a89bdda0f95930108
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Wed May 9 15:18:56 2012 +0100
Allow stack traces to be included with log messages
Sometimes it is useful to see the callpath for log messages.
This change enhances the log filter syntax so that stack traces
can be show by setting '1:+NAME' instead of '1:NAME'.
With the huge & ever increasing number of logging statements per file,
this will be incredibly verbose and have a major performance penalty.
This makes the feature impractical to use widely and as such it is not
worth the code maint cost.
Removing this seldom used feature allows us to drop the 'execinfo'
module in gnulib which provides the backtrace() function which doesn't
exist on non-Linux.
Users who want to get stack traces of parts of libvirt can use GDB,
or systemtap for live tracing with minimal perf impact.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
configmake
dirname-lgpl
environ
-execinfo
fclose
fcntl
fcntl-h
</h2>
<p>The syntax for filters and outputs is the same for both types of
variables.</p>
- <p>The format for a filter is one of:</p>
+ <p>The format for a filter is:</p>
<pre>
-x:name (log message only)
-x:+name (log message + stack trace)</pre>
+x:name</pre>
<p>where <code>name</code> is a string which is matched against
the category given in the VIR_LOG_INIT() at the top of each
libvirt source file, e.g., <code>remote</code>, <code>qemu</code>,
or <code>util.json</code> (the name in the filter can be a
substring of the full category name, in order to match multiple
- similar categories), the optional <code>+</code> prefix tells
- libvirt to log stack trace for each message
- matching <code>name</code>, and <code>x</code> is the minimal
+ similar categories), and <code>x</code> is the minimal
level where matching messages should be logged:</p>
<ul>
<li>1: DEBUG</li>
# Logging filters:
# A filter allows to select a different logging level for a given category
-# of logs. The format for a filter is one of:
+# of logs. The format for a filter is:
#
# level:match
-# level:+match
#
# where 'match' is a string which is matched against the category
# given in the VIR_LOG_INIT() at the top of each libvirt source
# The 'match' is always treated as a substring match. IOW a match
# string 'foo' is equivalent to '*foo*'.
#
-# If 'match' contains the optional "+" prefix, it tells libvirt
-# to log stack trace for each message matching name.
-#
# 'level' is the minimal level where matching messages should
# be logged:
#
# Logging filters:
# A filter allows to select a different logging level for a given category
-# of logs. The format for a filter is one of:
+# of logs. The format for a filter is:
#
# level:match
-# level:+match
#
# where 'match' is a string which is matched against the category
# given in the VIR_LOG_INIT() at the top of each libvirt source
# The 'match' is always treated as a substring match. IOW a match
# string 'foo' is equivalent to '*foo*'.
#
-# If 'match' contains the optional "+" prefix, it tells libvirt
-# to log stack trace for each message matching name.
-#
# 'level' is the minimal level where matching messages should
# be logged:
#
# Logging filters:
# A filter allows to select a different logging level for a given category
-# of logs. The format for a filter is one of:
+# of logs. The format for a filter is:
#
# level:match
-# level:+match
#
# where 'match' is a string which is matched against the category
# given in the VIR_LOG_INIT() at the top of each libvirt source
# The 'match' is always treated as a substring match. IOW a match
# string 'foo' is equivalent to '*foo*'.
#
-# If 'match' contains the optional "+" prefix, it tells libvirt
-# to log stack trace for each message matching name.
-#
# 'level' is the minimal level where matching messages should
# be logged:
#
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
-#include <execinfo.h>
#include <regex.h>
#include <sys/uio.h>
#if HAVE_SYSLOG_H
}
-static void
-virLogStackTraceToFd(int fd)
-{
- void *array[100];
- int size;
- static bool doneWarning;
- const char *msg = "Stack trace not available on this platform\n";
-
-#define STRIP_DEPTH 3
- size = backtrace(array, G_N_ELEMENTS(array));
- if (size) {
- backtrace_symbols_fd(array + STRIP_DEPTH, size - STRIP_DEPTH, fd);
- ignore_value(safewrite(fd, "\n", 1));
- } else if (!doneWarning) {
- ignore_value(safewrite(fd, msg, strlen(msg)));
- doneWarning = true;
- }
-#undef STRIP_DEPTH
-}
-
static void
virLogOutputToFd(virLogSourcePtr source G_GNUC_UNUSED,
virLogPriority priority G_GNUC_UNUSED,
int fd = (intptr_t) data;
char *msg;
+ virCheckFlags(0,);
+
if (fd < 0)
return;
ignore_value(safewrite(fd, msg, strlen(msg)));
VIR_FREE(msg);
-
- if (flags & VIR_LOG_STACK_TRACE)
- virLogStackTraceToFd(fd);
}
const char *str,
void *data G_GNUC_UNUSED)
{
- virCheckFlags(VIR_LOG_STACK_TRACE,);
+ virCheckFlags(0,);
syslog(virLogPrioritySyslog(priority), "%s", str);
}
const char *str G_GNUC_UNUSED,
void *data)
{
- virCheckFlags(VIR_LOG_STACK_TRACE,);
+ virCheckFlags(0,);
int buffd = -1;
int journalfd = (intptr_t) data;
struct msghdr mh;
virLogLock();
for (i = 0; i < virLogNbFilters; i++) {
const char *sep = ":";
- if (virLogFilters[i]->flags & VIR_LOG_STACK_TRACE)
- sep = ":+";
virBufferAsprintf(&filterbuf, "%d%s%s ",
virLogFilters[i]->priority,
sep,
char *mdup = NULL;
size_t mlen = strlen(match);
- virCheckFlags(VIR_LOG_STACK_TRACE, NULL);
+ virCheckFlags(0, NULL);
if (priority < VIR_LOG_DEBUG || priority > VIR_LOG_ERROR) {
virReportError(VIR_ERR_INVALID_ARG, _("Invalid log priority %d"),
* virLogParseFilter:
* @src: string defining a single filter
*
- * The format of @src should be one of the following:
+ * The format of @src should be:
* x:name - filter affecting all modules which match 'name'
- * x:+name
- *
- * '+' - hints the logger to also include a stack trace for every message
* 'name' - match string which either matches a name of a directory in
* libvirt's source tree which in turn affects all modules in
* that directory or it can matches a specific module within a
match = tokens[1];
if (match[0] == '+') {
- flags |= VIR_LOG_STACK_TRACE;
+ /* '+' used to indicate printing a stack trace,
+ * but we dropped that feature, so just chomp
+ * that leading '+' */
match++;
}
void *data)
{
struct virtTestLogData *log = data;
- virCheckFlags(VIR_LOG_STACK_TRACE,);
+ virCheckFlags(0,);
virBufferAsprintf(&log->buf, "%s: %s", timestamp, str);
}
#include <unistd.h>
#include <sys/types.h>
#include <fcntl.h>
-#include <execinfo.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/socket.h>
projects / libvirt.git / commitdiff