mirror_zfs/include/spl-debug.h
Brian Behlendorf 9fe45dc1ac Add Thread Specific Data (TSD) Implementation
Thread specific data has implemented using a hash table, this avoids
the need to add a member to the task structure and allows maximum
portability between kernels.  This implementation has been optimized
to keep the tsd_set() and tsd_get() times as small as possible.

The majority of the entries in the hash table are for specific tsd
entries.  These entries are hashed by the product of their key and
pid because by design the key and pid are guaranteed to be unique.
Their product also has the desirable properly that it will be uniformly
distributed over the hash bins providing neither the pid nor key is zero.
Under linux the zero pid is always the init process and thus won't be
used, and this implementation is careful to never to assign a zero key.
By default the hash table is sized to 512 bins which is expected to
be sufficient for light to moderate usage of thread specific data.

The hash table contains two additional type of entries.  They first
type is entry is called a 'key' entry and it is added to the hash during
tsd_create().  It is used to store the address of the destructor function
and it is used as an anchor point.  All tsd entries which use the same
key will be linked to this entry.  This is used during tsd_destory() to
quickly call the destructor function for all tsd associated with the key.
The 'key' entry may be looked up with tsd_hash_search() by passing the
key you wish to lookup and DTOR_PID constant as the pid.

The second type of entry is called a 'pid' entry and it is added to the
hash the first time a process set a key.  The 'pid' entry is also used
as an anchor and all tsd for the process will be linked to it.  This
list is using during tsd_exit() to ensure all registered destructors
are run for the process.  The 'pid' entry may be looked up with
tsd_hash_search() by passing the PID_KEY constant as the key, and
the process pid.  Note that tsd_exit() is called by thread_exit()
so if your using the Solaris thread API you should not need to call
tsd_exit() directly.
2010-12-07 10:02:32 -08:00

192 lines
6.4 KiB
C

/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://github.com/behlendorf/spl/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL 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 General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
\*****************************************************************************/
/*
* Available debug functions. These function should be used by any
* package which needs to integrate with the SPL log infrastructure.
*
* SDEBUG() - Log debug message with specified mask.
* SDEBUG_LIMIT() - Log just 1 debug message with specified mask.
* SWARN() - Log a warning message.
* SERROR() - Log an error message.
* SEMERG() - Log an emergency error message.
* SCONSOLE() - Log a generic message to the console.
*
* SENTRY - Log entry point to a function.
* SEXIT - Log exit point from a function.
* SRETURN(x) - Log return from a function.
* SGOTO(x, y) - Log goto within a function.
*/
#ifndef _SPL_DEBUG_INTERNAL_H
#define _SPL_DEBUG_INTERNAL_H
#include <linux/limits.h>
#define SS_UNDEFINED 0x00000001
#define SS_ATOMIC 0x00000002
#define SS_KOBJ 0x00000004
#define SS_VNODE 0x00000008
#define SS_TIME 0x00000010
#define SS_RWLOCK 0x00000020
#define SS_THREAD 0x00000040
#define SS_CONDVAR 0x00000080
#define SS_MUTEX 0x00000100
#define SS_RNG 0x00000200
#define SS_TASKQ 0x00000400
#define SS_KMEM 0x00000800
#define SS_DEBUG 0x00001000
#define SS_GENERIC 0x00002000
#define SS_PROC 0x00004000
#define SS_MODULE 0x00008000
#define SS_CRED 0x00010000
#define SS_KSTAT 0x00020000
#define SS_XDR 0x00040000
#define SS_TSD 0x00080000
#define SS_USER1 0x01000000
#define SS_USER2 0x02000000
#define SS_USER3 0x04000000
#define SS_USER4 0x08000000
#define SS_USER5 0x10000000
#define SS_USER6 0x20000000
#define SS_USER7 0x40000000
#define SS_USER8 0x80000000
#define SS_DEBUG_SUBSYS SS_UNDEFINED
#define SD_TRACE 0x00000001
#define SD_INFO 0x00000002
#define SD_WARNING 0x00000004
#define SD_ERROR 0x00000008
#define SD_EMERG 0x00000010
#define SD_CONSOLE 0x00000020
#define SD_IOCTL 0x00000040
#define SD_DPRINTF 0x00000080
#define SD_OTHER 0x00000100
#define SD_CANTMASK (SD_ERROR | SD_EMERG | SD_WARNING | SD_CONSOLE)
#ifdef NDEBUG /* Debugging Disabled */
#define SDEBUG(mask, fmt, a...) ((void)0)
#define SDEBUG_LIMIT(x, y, fmt, a...) ((void)0)
#define SWARN(fmt, a...) ((void)0)
#define SERROR(fmt, a...) ((void)0)
#define SEMERG(fmt, a...) ((void)0)
#define SCONSOLE(mask, fmt, a...) ((void)0)
#define SENTRY ((void)0)
#define SEXIT ((void)0)
#define SRETURN(x) return (x)
#define SGOTO(x, y) { ((void)(y)); goto x; }
#else /* Debugging Enabled */
#define __SDEBUG(cdls, subsys, mask, format, a...) \
do { \
if (((mask) & SD_CANTMASK) != 0 || \
((spl_debug_mask & (mask)) != 0 && \
(spl_debug_subsys & (subsys)) != 0)) \
spl_debug_msg(cdls, subsys, mask, __FILE__, \
__FUNCTION__, __LINE__, format, ## a); \
} while (0)
#define SDEBUG(mask, format, a...) \
__SDEBUG(NULL, SS_DEBUG_SUBSYS, mask, format, ## a)
#define __SDEBUG_LIMIT(subsys, mask, format, a...) \
do { \
static spl_debug_limit_state_t cdls; \
\
__SDEBUG(&cdls, subsys, mask, format, ## a); \
} while (0)
#define SDEBUG_LIMIT(mask, format, a...) \
__SDEBUG_LIMIT(SS_DEBUG_SUBSYS, mask, format, ## a)
#define SWARN(fmt, a...) SDEBUG_LIMIT(SD_WARNING, fmt, ## a)
#define SERROR(fmt, a...) SDEBUG_LIMIT(SD_ERROR, fmt, ## a)
#define SEMERG(fmt, a...) SDEBUG_LIMIT(SD_EMERG, fmt, ## a)
#define SCONSOLE(mask, fmt, a...) SDEBUG(SD_CONSOLE | (mask), fmt, ## a)
#define SENTRY SDEBUG(SD_TRACE, "Process entered\n")
#define SEXIT SDEBUG(SD_TRACE, "Process leaving\n")
#define SRETURN(rc) \
do { \
typeof(rc) RETURN__ret = (rc); \
SDEBUG(SD_TRACE, "Process leaving (rc=%lu : %ld : %lx)\n", \
(long)RETURN__ret, (long)RETURN__ret, (long)RETURN__ret); \
return RETURN__ret; \
} while (0)
#define SGOTO(label, rc) \
do { \
long GOTO__ret = (long)(rc); \
SDEBUG(SD_TRACE,"Process leaving via %s (rc=%lu : %ld : %lx)\n",\
#label, (unsigned long)GOTO__ret, (signed long)GOTO__ret, \
(signed long)GOTO__ret); \
goto label; \
} while (0)
#endif /* NDEBUG */
typedef struct {
unsigned long cdls_next;
int cdls_count;
long cdls_delay;
} spl_debug_limit_state_t;
/* Global debug variables */
extern unsigned long spl_debug_subsys;
extern unsigned long spl_debug_mask;
extern unsigned long spl_debug_printk;
extern int spl_debug_mb;
extern unsigned int spl_debug_binary;
extern unsigned int spl_debug_catastrophe;
extern unsigned int spl_debug_panic_on_bug;
extern char spl_debug_file_path[PATH_MAX];
extern unsigned int spl_console_ratelimit;
extern long spl_console_max_delay;
extern long spl_console_min_delay;
extern unsigned int spl_console_backoff;
extern unsigned int spl_debug_stack;
/* Exported debug functions */
extern int spl_debug_mask2str(char *str, int size, unsigned long mask, int ss);
extern int spl_debug_str2mask(unsigned long *mask, const char *str, int ss);
extern unsigned long spl_debug_set_mask(unsigned long mask);
extern unsigned long spl_debug_get_mask(void);
extern unsigned long spl_debug_set_subsys(unsigned long mask);
extern unsigned long spl_debug_get_subsys(void);
extern int spl_debug_set_mb(int mb);
extern int spl_debug_get_mb(void);
extern int spl_debug_dumplog(int flags);
extern void spl_debug_dumpstack(struct task_struct *tsk);
extern int spl_debug_clear_buffer(void);
extern int spl_debug_mark_buffer(char *text);
int debug_init(void);
void debug_fini(void);
#endif /* SPL_DEBUG_INTERNAL_H */