haproxy/include/common/debug.h
Willy Tarreau c7091d89ae MEDIUM: debug/threads: implement an advanced thread dump system
The current "show threads" command was too limited as it was not possible
to dump other threads' detailed states (e.g. their tasks). This patch
goes further by using thread signals so that each thread can dump its
own state in turn into a shared buffer provided by the caller. Threads
are synchronized using a mechanism very similar to the rendez-vous point
and using this method, each thread can safely dump any of its contents
and the caller can finally report the aggregated ones from the buffer.

It is important to keep in mind that the list of signal-safe functions
is limited, so we take care of only using chunk_printf() to write to a
pre-allocated buffer.

This mechanism is enabled by USE_THREAD_DUMP and is enabled by default
on Linux 2.6.28+. On other platforms it falls back to the previous
solution using the loop and the less precise dump.
2019-05-17 17:16:20 +02:00

104 lines
3.3 KiB
C

/*
include/common/debug.h
This files contains some macros to help debugging.
Copyright (C) 2000-2006 Willy Tarreau - w@1wt.eu
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation, version 2.1
exclusively.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _COMMON_DEBUG_H
#define _COMMON_DEBUG_H
#include <common/config.h>
#include <common/memory.h>
#ifdef DEBUG_FULL
#define DPRINTF(x...) fprintf(x)
#else
#define DPRINTF(x...)
#endif
#ifdef DEBUG_FSM
#define FSM_PRINTF(x...) fprintf(x)
#else
#define FSM_PRINTF(x...)
#endif
/* This abort is more efficient than abort() because it does not mangle the
* stack and stops at the exact location we need.
*/
#define ABORT_NOW() (*(volatile int*)1=0)
/* BUG_ON: complains if <cond> is true when DEBUG_STRICT or DEBUG_STRICT_NOCRASH
* are set, does nothing otherwise. With DEBUG_STRICT in addition it immediately
* crashes using ABORT_NOW() above.
*/
#if defined(DEBUG_STRICT) || defined(DEBUG_STRICT_NOCRASH)
#if defined(DEBUG_STRICT)
#define CRASH_NOW() ABORT_NOW()
#else
#define CRASH_NOW()
#endif
#define BUG_ON(cond) _BUG_ON(cond, __FILE__, __LINE__)
#define _BUG_ON(cond, file, line) __BUG_ON(cond, file, line)
#define __BUG_ON(cond, file, line) \
do { \
if (unlikely(cond)) { \
const char msg[] = "\nFATAL: bug condition \"" #cond "\" matched at " file ":" #line "\n"; \
(void)write(2, msg, strlen(msg)); \
CRASH_NOW(); \
} \
} while (0)
#else
#undef CRASH_NOW
#define BUG_ON(cond)
#endif
/* this one is provided for easy code tracing.
* Usage: TRACE(strm||0, fmt, args...);
* TRACE(strm, "");
*/
#define TRACE(strm, fmt, args...) do { \
fprintf(stderr, \
"%d.%06d [%s:%d %s] [strm %p(%x)] " fmt "\n", \
(int)now.tv_sec, (int)now.tv_usec, \
__FILE__, __LINE__, __FUNCTION__, \
strm, strm?((struct stream *)strm)->uniq_id:~0U, \
##args); \
} while (0)
struct task;
struct buffer;
void ha_task_dump(struct buffer *buf, const struct task *task, const char *pfx);
void ha_thread_dump(struct buffer *buf, int thr, int calling_tid);
void ha_thread_dump_all_to_trash();
/* This one is useful to automatically apply poisonning on an area returned
* by malloc(). Only "p_" is required to make it work, and to define a poison
* byte using -dM.
*/
static inline void *p_malloc(size_t size)
{
void *ret = malloc(size);
if (mem_poison_byte >= 0 && ret)
memset(ret, mem_poison_byte, size);
return ret;
}
#endif /* _COMMON_DEBUG_H */