sync0sync.h

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

Synchronization object			Notes
----------------------			-----
		
Dictionary mutex			If we have a pointer to a dictionary
|					object, e.g., a table, it can be
|					accessed without reserving the
|					dictionary mutex. We must have a
|					reservation, a memoryfix, to the
|					appropriate table object in this case,
|					and the table must be explicitly
|					released later.
V
Dictionary header
|
V					
Secondary index tree latch		The tree latch protects also all
|					the B-tree non-leaf pages. These
V					can be read with the page only
Secondary index non-leaf		bufferfixed to save CPU time,
|					no s-latch is needed on the page.
|					Modification of a page requires an
|					x-latch on the page, however. If a
|					thread owns an x-latch to the tree,
|					it is allowed to latch non-leaf pages
|					even after it has acquired the fsp
|					latch.
V					
Secondary index leaf			The latch on the secondary index leaf
|					can be kept while accessing the
|					clustered index, to save CPU time.
V
Clustered index tree latch		To increase concurrency, the tree
|					latch is usually released when the
|					leaf page latch has been acquired.
V					
Clustered index non-leaf
|
V
Clustered index leaf
|
V
Transaction system header
|
V
Transaction undo mutex			The undo log entry must be written
|					before any index page is modified.
|					Transaction undo mutex is for the undo
|					logs the analogue of the tree latch
|					for a B-tree. If a thread has the
|					trx undo mutex reserved, it is allowed
|					to latch the undo log pages in any
|					order, and also after it has acquired
|					the fsp latch. 
V
Rollback segment mutex			The rollback segment mutex must be
|					reserved, if, e.g., a new page must
|					be added to an undo log. The rollback
|					segment and the undo logs in its
|					history list can be seen as an
|					analogue of a B-tree, and the latches
|					reserved similarly, using a version of
|					lock-coupling. If an undo log must be
|					extended by a page when inserting an
|					undo log record, this corresponds to
|					a pessimistic insert in a B-tree.
V
Rollback segment header
|
V
Purge system latch
|
V
Undo log pages				If a thread owns the trx undo mutex,
|					or for a log in the history list, the
|					rseg mutex, it is allowed to latch
|					undo log pages in any order, and even
|					after it has acquired the fsp latch.
|					If a thread does not have the
|					appropriate mutex, it is allowed to
|					latch only a single undo log page in
|					a mini-transaction.
V
File space management latch		If a mini-transaction must allocate
|					several file pages, it can do that,
|					because it keeps the x-latch to the
|					file space management in its memo.
V
File system pages
|
V
Kernel mutex				If a kernel operation needs a file
|					page allocation, it must reserve the
|					fsp x-latch before acquiring the kernel
|					mutex.
V
Search system mutex
|
V
Buffer pool mutex
|
V
Log mutex
|
Any other latch
|
V
Memory pool mutex */

/* Latching order levels */

/* User transaction locks are higher than any of the latch levels below:
no latches are allowed when a thread goes to wait for a normal table
or row lock! */
#define SYNC_USER_TRX_LOCK	9999
#define SYNC_NO_ORDER_CHECK	3000	/* this can be used to suppress
					latching order checking */
#define	SYNC_LEVEL_NONE		2000	/* default: level not defined */
#define	SYNC_DICT_OPERATION	1001	/* table create, drop, etc. reserve
					this in X-mode, implicit or backround
					operations purge, rollback, foreign
					key checks reserve this in S-mode */
#define SYNC_DICT		1000
#define SYNC_DICT_AUTOINC_MUTEX	999
#define SYNC_DICT_HEADER	995
#define SYNC_IBUF_HEADER	914
#define SYNC_IBUF_PESS_INSERT_MUTEX 912
#define SYNC_IBUF_MUTEX		910	/* ibuf mutex is really below
					SYNC_FSP_PAGE: we assign a value this
					high only to make the program to pass
					the debug checks */
/*-------------------------------*/
#define	SYNC_INDEX_TREE		900
#define SYNC_TREE_NODE_NEW	892
#define SYNC_TREE_NODE_FROM_HASH 891
#define SYNC_TREE_NODE		890
#define	SYNC_PURGE_SYS		810
#define	SYNC_PURGE_LATCH	800
#define	SYNC_TRX_UNDO		700
#define SYNC_RSEG		600
#define SYNC_RSEG_HEADER_NEW	591
#define SYNC_RSEG_HEADER	590
#define SYNC_TRX_UNDO_PAGE	570
#define SYNC_EXTERN_STORAGE	500
#define	SYNC_FSP		400
#define	SYNC_FSP_PAGE		395
/*------------------------------------- Insert buffer headers */ 
/*------------------------------------- ibuf_mutex */
/*------------------------------------- Insert buffer tree */
#define	SYNC_IBUF_BITMAP_MUTEX	351
#define	SYNC_IBUF_BITMAP	350
/*------------------------------------- MySQL query cache mutex */
/*------------------------------------- MySQL binlog mutex */
/*-------------------------------*/
#define	SYNC_KERNEL		300
#define SYNC_REC_LOCK		299
#define	SYNC_TRX_LOCK_HEAP	298
#define SYNC_TRX_SYS_HEADER	290
#define SYNC_LOG		170
#define SYNC_RECV		168
#define	SYNC_SEARCH_SYS		160	/* NOTE that if we have a memory
					heap that can be extended to the
					buffer pool, its logical level is
					SYNC_SEARCH_SYS, as memory allocation
					can call routines there! Otherwise
					the level is SYNC_MEM_HASH. */
#define	SYNC_BUF_POOL		150
#define	SYNC_BUF_BLOCK		149
#define SYNC_DOUBLEWRITE	140
#define	SYNC_ANY_LATCH		135
#define SYNC_THR_LOCAL		133
#define	SYNC_MEM_HASH		131
#define	SYNC_MEM_POOL		130

/* Codes used to designate lock operations */
#define RW_LOCK_NOT_LOCKED 	350
#define RW_LOCK_EX		351
#define RW_LOCK_EXCLUSIVE	351
#define RW_LOCK_SHARED		352
#define RW_LOCK_WAIT_EX		353
#define SYNC_MUTEX		354

/* NOTE! The structure appears here only for the compiler to know its size.
Do not use its fields directly! The structure used in the spin lock
implementation of a mutual exclusion semaphore. */

struct mutex_struct {
	ulint	lock_word;	/* This ulint is the target of the atomic
				test-and-set instruction in Win32 */
#if !defined(_WIN32) || !defined(UNIV_CAN_USE_X86_ASSEMBLER)
	os_fast_mutex_t
		os_fast_mutex;	/* In other systems we use this OS mutex
				in place of lock_word */
#endif
	ulint	waiters;	/* This ulint is set to 1 if there are (or
				may be) threads waiting in the global wait
				array for this mutex to be released.
				Otherwise, this is 0. */
	UT_LIST_NODE_T(mutex_t)	list; /* All allocated mutexes are put into
				a list.	Pointers to the next and prev. */
#ifdef UNIV_SYNC_DEBUG
	const char*	file_name;	/* File where the mutex was locked */
	ulint	line;		/* Line where the mutex was locked */
	os_thread_id_t thread_id; /* Debug version: The thread id of the
				thread which locked the mutex. */
#endif /* UNIV_SYNC_DEBUG */
	ulint	level;		/* Level in the global latching
				order; default SYNC_LEVEL_NONE */
	const char*	cfile_name;/* File name where mutex created */
	ulint	cline;		/* Line where created */
	ulint	magic_n;
#ifndef UNIV_HOTBACKUP
  ulong count_using; /* count of times mutex used */
  ulong count_spin_loop; /* count of spin loops */
  ulong count_spin_rounds; /* count of spin rounds */
  ulong count_os_wait; /* count of os_wait */
  ulong count_os_yield; /* count of os_wait */
  ulonglong lspent_time; /* mutex os_wait timer msec */
  ulonglong lmax_spent_time; /* mutex os_wait timer msec */
  const char* cmutex_name;/* mutex name  */
  ulint mutex_type;/* 0 - usual mutex 1 - rw_lock mutex  */
#endif /* !UNIV_HOTBACKUP */
};

#define MUTEX_MAGIC_N	(ulint)979585

/* The global array of wait cells for implementation of the databases own
mutexes and read-write locks. Appears here for debugging purposes only! */

extern sync_array_t*	sync_primary_wait_array;

/* Constant determining how long spin wait is continued before suspending
the thread. A value 600 rounds on a 1995 100 MHz Pentium seems to correspond
to 20 microseconds. */

#define	SYNC_SPIN_ROUNDS	srv_n_spin_wait_rounds

#define SYNC_INFINITE_TIME	((ulint)(-1))

/* Means that a timeout elapsed when waiting */

#define SYNC_TIME_EXCEEDED	(ulint)1

/* The number of system calls made in this module. Intended for performance
monitoring. */

extern 	ulint	mutex_system_call_count;
extern	ulint	mutex_exit_count;

/* Latching order checks start when this is set TRUE */
extern ibool	sync_order_checks_on;

/* This variable is set to TRUE when sync_init is called */
extern ibool	sync_initialized;

/* Global list of database mutexes (not OS mutexes) created. */
typedef UT_LIST_BASE_NODE_T(mutex_t)  ut_list_base_node_t;
extern ut_list_base_node_t  mutex_list;

/* Mutex protecting the mutex_list variable */
extern mutex_t mutex_list_mutex;


#ifndef UNIV_NONINL
#include "sync0sync.ic"
#endif

#endif