srv0srv.c

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

	srv_mysql_table = mem_alloc(OS_THREAD_MAX_N * sizeof(srv_slot_t));

	for (i = 0; i < OS_THREAD_MAX_N; i++) {
		slot = srv_mysql_table + i;
		slot->in_use = FALSE;
		slot->type = 0;
		slot->event = os_event_create(NULL);
		ut_a(slot->event);
	}

	srv_lock_timeout_thread_event = os_event_create(NULL);
	
	for (i = 0; i < SRV_MASTER + 1; i++) {
		srv_n_threads_active[i] = 0;
		srv_n_threads[i] = 0;
		srv_meter[i] = 30;
		srv_meter_low_water[i] = 50;
		srv_meter_high_water[i] = 100;
		srv_meter_high_water2[i] = 200;
		srv_meter_foreground[i] = 250;
	}
	
	srv_sys->operational = os_event_create(NULL);

	ut_a(srv_sys->operational);

	UT_LIST_INIT(srv_sys->tasks);

	/* create dummy table and index for old-style infimum and supremum */
	table = dict_mem_table_create("SYS_DUMMY1",
						DICT_HDR_SPACE, 1, FALSE);
	dict_mem_table_add_col(table, "DUMMY", DATA_CHAR,
					DATA_ENGLISH | DATA_NOT_NULL, 8, 0);

	srv_sys->dummy_ind1 = dict_mem_index_create("SYS_DUMMY1",
					"SYS_DUMMY1", DICT_HDR_SPACE, 0, 1);
	dict_index_add_col(srv_sys->dummy_ind1,
			dict_table_get_nth_col(table, 0), 0, 0);
	srv_sys->dummy_ind1->table = table;
	/* create dummy table and index for new-style infimum and supremum */
	table = dict_mem_table_create("SYS_DUMMY2",
						DICT_HDR_SPACE, 1, TRUE);
	dict_mem_table_add_col(table, "DUMMY", DATA_CHAR,
					DATA_ENGLISH | DATA_NOT_NULL, 8, 0);
	srv_sys->dummy_ind2 = dict_mem_index_create("SYS_DUMMY2",
					"SYS_DUMMY2", DICT_HDR_SPACE, 0, 1);
	dict_index_add_col(srv_sys->dummy_ind2,
			dict_table_get_nth_col(table, 0), 0, 0);
	srv_sys->dummy_ind2->table = table;

	/* avoid ut_ad(index->cached) in dict_index_get_n_unique_in_tree */
	srv_sys->dummy_ind1->cached = srv_sys->dummy_ind2->cached = TRUE;

	/* Init the server concurrency restriction data structures */

	os_fast_mutex_init(&srv_conc_mutex);
	
	UT_LIST_INIT(srv_conc_queue);

	srv_conc_slots = mem_alloc(OS_THREAD_MAX_N * sizeof(srv_conc_slot_t));

	for (i = 0; i < OS_THREAD_MAX_N; i++) {
		conc_slot = srv_conc_slots + i;
		conc_slot->reserved = FALSE;
		conc_slot->event = os_event_create(NULL);
		ut_a(conc_slot->event);
	}
}	

/*************************************************************************
Frees the OS fast mutex created in srv_init(). */

void
srv_free(void)
/*==========*/
{
	os_fast_mutex_free(&srv_conc_mutex);
}

/*************************************************************************
Initializes the synchronization primitives, memory system, and the thread
local storage. */

void
srv_general_init(void)
/*==================*/
{
	os_sync_init();
	sync_init();
	mem_init(srv_mem_pool_size);
	thr_local_init();
}

/*======================= InnoDB Server FIFO queue =======================*/

/* Maximum allowable purge history length.  <=0 means 'infinite'. */
ulong	srv_max_purge_lag		= 0;

/*************************************************************************
Puts an OS thread to wait if there are too many concurrent threads
(>= srv_thread_concurrency) inside InnoDB. The threads wait in a FIFO queue. */

void
srv_conc_enter_innodb(
/*==================*/
	trx_t*	trx)	/* in: transaction object associated with the
			thread */
{
	ibool			has_slept = FALSE;
	srv_conc_slot_t*	slot	  = NULL;
	ulint			i;

	/* If trx has 'free tickets' to enter the engine left, then use one
	such ticket */

	if (trx->n_tickets_to_enter_innodb > 0) {
		trx->n_tickets_to_enter_innodb--;

		return;
	}

	os_fast_mutex_lock(&srv_conc_mutex);
retry:
	if (trx->declared_to_be_inside_innodb) {
	        ut_print_timestamp(stderr);
		fputs(
"  InnoDB: Error: trying to declare trx to enter InnoDB, but\n"
"InnoDB: it already is declared.\n", stderr);
		trx_print(stderr, trx, 0);
		putc('\n', stderr);
		os_fast_mutex_unlock(&srv_conc_mutex);

		return;
	}

	if (srv_conc_n_threads < (lint)srv_thread_concurrency) {

		srv_conc_n_threads++;
		trx->declared_to_be_inside_innodb = TRUE;
		trx->n_tickets_to_enter_innodb = SRV_FREE_TICKETS_TO_ENTER;
		
		os_fast_mutex_unlock(&srv_conc_mutex);

		return;
	}

	/* If the transaction is not holding resources, 
  let it sleep for SRV_THREAD_SLEEP_DELAY microseconds, and try again then */
 
	if (!has_slept && !trx->has_search_latch
	    && NULL == UT_LIST_GET_FIRST(trx->trx_locks)) {

	        has_slept = TRUE; /* We let is sleep only once to avoid
				  starvation */

		srv_conc_n_waiting_threads++;

		os_fast_mutex_unlock(&srv_conc_mutex);

		trx->op_info = "sleeping before joining InnoDB queue";

		/* Peter Zaitsev suggested that we take the sleep away
		altogether. But the sleep may be good in pathological
		situations of lots of thread switches. Simply put some
		threads aside for a while to reduce the number of thread
		switches. */
    if (SRV_THREAD_SLEEP_DELAY > 0)
    {
      os_thread_sleep(SRV_THREAD_SLEEP_DELAY);
    }

		trx->op_info = "";

		os_fast_mutex_lock(&srv_conc_mutex);

		srv_conc_n_waiting_threads--;

		goto retry;
	}   

	/* Too many threads inside: put the current thread to a queue */

	for (i = 0; i < OS_THREAD_MAX_N; i++) {
		slot = srv_conc_slots + i;

		if (!slot->reserved) {

			break;
		}
	}

	if (i == OS_THREAD_MAX_N) {
		/* Could not find a free wait slot, we must let the
		thread enter */

		srv_conc_n_threads++;
		trx->declared_to_be_inside_innodb = TRUE;
		trx->n_tickets_to_enter_innodb = 0;

		os_fast_mutex_unlock(&srv_conc_mutex);

		return;
	}

	/* Release possible search system latch this thread has */
	if (trx->has_search_latch) {
		trx_search_latch_release_if_reserved(trx);
	}

	/* Add to the queue */
	slot->reserved = TRUE;
	slot->wait_ended = FALSE;
	
	UT_LIST_ADD_LAST(srv_conc_queue, srv_conc_queue, slot);

	os_event_reset(slot->event);

	srv_conc_n_waiting_threads++;

	os_fast_mutex_unlock(&srv_conc_mutex);

	/* Go to wait for the event; when a thread leaves InnoDB it will
	release this thread */

	trx->op_info = "waiting in InnoDB queue";

	os_event_wait(slot->event);

	trx->op_info = "";

	os_fast_mutex_lock(&srv_conc_mutex);

	srv_conc_n_waiting_threads--;

	/* NOTE that the thread which released this thread already
	incremented the thread counter on behalf of this thread */

	slot->reserved = FALSE;

	UT_LIST_REMOVE(srv_conc_queue, srv_conc_queue, slot);

	trx->declared_to_be_inside_innodb = TRUE;
	trx->n_tickets_to_enter_innodb = SRV_FREE_TICKETS_TO_ENTER;

	os_fast_mutex_unlock(&srv_conc_mutex);
}

/*************************************************************************
This lets a thread enter InnoDB regardless of the number of threads inside
InnoDB. This must be called when a thread ends a lock wait. */

void
srv_conc_force_enter_innodb(
/*========================*/
	trx_t*	trx)	/* in: transaction object associated with the
			thread */
{
	if (UNIV_LIKELY(!srv_thread_concurrency)) {
	
		return;
	}

	os_fast_mutex_lock(&srv_conc_mutex);

	srv_conc_n_threads++;
	trx->declared_to_be_inside_innodb = TRUE;
	trx->n_tickets_to_enter_innodb = 0;

	os_fast_mutex_unlock(&srv_conc_mutex);
}

/*************************************************************************
This must be called when a thread exits InnoDB in a lock wait or at the
end of an SQL statement. */

void
srv_conc_force_exit_innodb(
/*=======================*/
	trx_t*	trx)	/* in: transaction object associated with the
			thread */
{
	srv_conc_slot_t*	slot	= NULL;

	if (UNIV_LIKELY(!srv_thread_concurrency)) {
	
		return;
	}

	if (trx->declared_to_be_inside_innodb == FALSE) {
		
		return;
	}

	os_fast_mutex_lock(&srv_conc_mutex);

	srv_conc_n_threads--;
	trx->declared_to_be_inside_innodb = FALSE;
	trx->n_tickets_to_enter_innodb = 0;

	if (srv_conc_n_threads < (lint)srv_thread_concurrency) {
		/* Look for a slot where a thread is waiting and no other
		thread has yet released the thread */
	
		slot = UT_LIST_GET_FIRST(srv_conc_queue);

		while (slot && slot->wait_ended == TRUE) {
			slot = UT_LIST_GET_NEXT(srv_conc_queue, slot);
		}

		if (slot != NULL) {
			slot->wait_ended = TRUE;

			/* We increment the count on behalf of the released
			thread */

			srv_conc_n_threads++;
		}
	}

	os_fast_mutex_unlock(&srv_conc_mutex);

	if (slot != NULL) {
		os_event_set(slot->event);
	}
}

/*************************************************************************
This must be called when a thread exits InnoDB. */

void
srv_conc_exit_innodb(
/*=================*/
	trx_t*	trx)	/* in: transaction object associated with the
			thread */
{
	if (trx->n_tickets_to_enter_innodb > 0) {
		/* We will pretend the thread is still inside InnoDB though it
		now leaves the InnoDB engine. In this way we save
		a lot of semaphore operations. srv_conc_force_exit_innodb is
		used to declare the thread definitely outside InnoDB. It
		should be called when there is a lock wait or an SQL statement
		ends. */

		return;
	}

	srv_conc_force_exit_innodb(trx);
}

/*========================================================================*/

/*************************************************************************
Normalizes init parameter values to use units we use inside InnoDB. */
static
ulint
srv_normalize_init_values(void)
/*===========================*/
				/* out: DB_SUCCESS or error code */
{
	ulint	n;
	ulint	i;

	n = srv_n_data_files;
	
	for (i = 0; i < n; i++) {
		srv_data_file_sizes[i] = srv_data_file_sizes[i]
					* ((1024 * 1024) / UNIV_PAGE_SIZE);
	}		

	srv_last_file_size_max = srv_last_file_size_max
					* ((1024 * 1024) / UNIV_PAGE_SIZE);
		
	srv_log_file_size = srv_log_file_size / UNIV_PAGE_SIZE;

	srv_log_buffer_size = srv_log_buffer_size / UNIV_PAGE_SIZE;

	srv_pool_size = srv_pool_size / (UNIV_PAGE_SIZE / 1024);

	srv_awe_window_size = srv_awe_window_size / UNIV_PAGE_SIZE;
	
	if (srv_use_awe) {
	        /* If we are using AWE we must save memory in the 32-bit
		address space of the process, and cannot bind the lock
		table size to the real buffer pool size. */

	        srv_lock_table_size = 20 * srv_awe_window_size;
	} else {
	        srv_lock_table_size = 5 * srv_pool_size;
	}

	return(DB_SUCCESS);
}

/*************************************************************************
Boots the InnoDB server. */

ulint
srv_boot(void)
/*==========*/
			/* out: DB_SUCCESS or error code */
{
	ulint	err;

	/* Transform the init parameter values given by MySQL to
	use units we use inside InnoDB: */
	
	err = srv_normalize_init_values();

	if (err != DB_SUCCESS) {
		return(err);
	}
	
	/* Initialize synchronization primitives, memory management, and thread
	local storage */
	
	srv_general_init();

	/* Initialize this module */

	srv_init();

	return(DB_SUCCESS);
}

#ifndef UNIV_HOTBACKUP
/*************************************************************************
Reserves a slot in the thread table for the current MySQL OS thread.
NOTE! The kernel mutex has to be reserved by the caller! */
static
srv_slot_t*
srv_table_reserve_slot_for_mysql(void)
/*==================================*/
			/* out: reserved slot */
{
	srv_slot_t*	slot;
	ulint		i;

#ifdef UNIV_SYNC_DEBUG
	ut_ad(mutex_own(&kernel_mutex));
#endif /* UNIV_SYNC_DEBUG */

	i = 0;