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Commit 57b6cb39 authored by Vladislav Vaintroub's avatar Vladislav Vaintroub
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Further review points and simplify Windows implementation

parent 7ed6530a
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Showing with 123 additions and 147 deletions
mysql-test/r/mysqld--help-notwin.result
View file @ 57b6cb39
......@@ -934,7 +934,7 @@ lower-case-table-names 1
master-info-file master.info
master-retry-count 86400
master-verify-checksum FALSE
max-allowed-packet 8388608
max-allowed-packet 1048576
max-binlog-cache-size 18446744073709547520
max-binlog-size 1073741824
max-binlog-stmt-cache-size 18446744073709547520
......@@ -945,7 +945,7 @@ max-error-count 64
max-heap-table-size 16777216
max-join-size 18446744073709551615
max-length-for-sort-data 1024
max-long-data-size 8388608
max-long-data-size 1048576
max-prepared-stmt-count 16382
max-relay-log-size 0
max-seeks-for-key 18446744073709551615
......
sql/sql_class.cc
View file @ 57b6cb39
......@@ -3918,6 +3918,7 @@ extern "C" bool thd_sqlcom_can_generate_row_events(const MYSQL_THD thd)
SYNOPSIS
thd_wait_begin()
thd Thread object
Can be NULL, in this case current THD is used.
wait_type Type of wait
1 -- short wait (e.g. for mutex)
2 -- medium wait (e.g. for disk io)
......@@ -3945,6 +3946,7 @@ extern "C" void thd_wait_begin(MYSQL_THD thd, int wait_type)
when they waking up from a sleep/stall.
@param thd Thread handle
Can be NULL, in this case current THD is used.
*/
extern "C" void thd_wait_end(MYSQL_THD thd)
{
......
sql/sys_vars.cc
View file @ 57b6cb39
......@@ -2245,7 +2245,7 @@ static bool fix_threadpool_stall_limit(sys_var*, THD*, enum_var_type)
#ifdef _WIN32
static Sys_var_uint Sys_threadpool_min_threads(
"thread_pool_min_threads",
"Minimuim number of threads in the thread pool.",
"Minimum number of threads in the thread pool.",
GLOBAL_VAR(threadpool_min_threads), CMD_LINE(REQUIRED_ARG),
VALID_RANGE(1, 256), DEFAULT(1), BLOCK_SIZE(1),
NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
......@@ -2267,8 +2267,9 @@ static Sys_var_uint Sys_threadpool_oversubscribe(
);
static Sys_var_uint Sys_threadpool_size(
"thread_pool_size",
"Number of concurrently executing threads in the pool. "
"Leaving value default (0) sets it to the number of processors.",
"Number of thread groups in the pool. "
"This parameter is roughly equivalent to maximum number of concurrently "
"executing threads (threads in a waiting state do not count as executing).",
GLOBAL_VAR(threadpool_size), CMD_LINE(REQUIRED_ARG),
VALID_RANGE(1, MAX_THREAD_GROUPS), DEFAULT(my_getncpus()), BLOCK_SIZE(1),
NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0),
......
sql/threadpool_unix.cc
View file @ 57b6cb39
......@@ -207,6 +207,7 @@ static void print_pool_blocked_message(bool);
descriptors can be retrieved from native_events array, using
native_event_get_userdata() function.
On Linux: epoll_wait()
*/
......@@ -248,6 +249,11 @@ int io_poll_disassociate_fd(int pollfd, int fd)
}
/*
Wrapper around epoll_wait.
NOTE - in case of EINTR, it restarts with original timeout. Since we use
either infinite or 0 timeouts, this is not critical
*/
int io_poll_wait(int pollfd, native_event *native_events, int maxevents,
int timeout_ms)
{
......@@ -260,6 +266,7 @@ int io_poll_wait(int pollfd, native_event *native_events, int maxevents,
return ret;
}
static void *native_event_get_userdata(native_event *event)
{
return event->data.ptr;
......@@ -364,8 +371,10 @@ int io_poll_wait(int pollfd, native_event *events, int maxevents, int timeout_ms
(timeout_ms >= 0)?&ts:NULL);
}
while (ret == -1 && errno == EINTR);
return nget;
DBUG_ASSERT(nget < INT_MAX);
return (int)nget;
}
static void* native_event_get_userdata(native_event *event)
{
return event->portev_user;
......@@ -375,9 +384,8 @@ static void* native_event_get_userdata(native_event *event)
#endif
/* Dequeue element from a workqueue */
static connection_t *queue_get(thread_group_t *thread_group)
{
DBUG_ENTER("queue_get");
......@@ -391,12 +399,12 @@ static connection_t *queue_get(thread_group_t *thread_group)
}
/*
Handle wait timeout :
Find connections that have been idle for too long and kill them.
Also, recalculate time when next timeout check should run.
*/
static void timeout_check(pool_timer_t *timer)
{
DBUG_ENTER("timeout_check");
......@@ -418,7 +426,7 @@ static void timeout_check(pool_timer_t *timer)
{
/*
Connection does not have scheduler data. This happens for example
if THD belongs to another scheduler, that is listening to extra_port.
if THD belongs to a different scheduler, that is listening to extra_port.
*/
continue;
}
......@@ -458,18 +466,18 @@ static void timeout_check(pool_timer_t *timer)
static void* timer_thread(void *param)
{
uint i;
pool_timer_t* timer=(pool_timer_t *)param;
timer->next_timeout_check= ULONGLONG_MAX;
timer->current_microtime= microsecond_interval_timer();
my_thread_init();
DBUG_ENTER("timer_thread");
timer->next_timeout_check= ULONGLONG_MAX;
timer->current_microtime= microsecond_interval_timer();
for(;;)
{
struct timespec ts;
int err;
set_timespec_nsec(ts,timer->tick_interval*1000000);
mysql_mutex_lock(&timer->mutex);
err= mysql_cond_timedwait(&timer->cond, &timer->mutex, &ts);
......@@ -543,7 +551,6 @@ void check_stall(thread_group_t *thread_group)
}
static void start_timer(pool_timer_t* timer)
{
pthread_t thread_id;
......@@ -555,6 +562,7 @@ static void start_timer(pool_timer_t* timer)
DBUG_VOID_RETURN;
}
static void stop_timer(pool_timer_t *timer)
{
DBUG_ENTER("stop_timer");
......@@ -664,42 +672,42 @@ static connection_t * listener(worker_thread_t *current_thread,
thread_group->queue.push_back(c);
}
if (listener_picks_event)
{
/* Handle the first event. */
retval= (connection_t *)native_event_get_userdata(&ev[0]);
mysql_mutex_unlock(&thread_group->mutex);
break;
}
if(thread_group->active_thread_count==0 && !listener_picks_event)
if(thread_group->active_thread_count==0)
{
/* Wake one worker thread */
/* We added some work items to queue, now wake a worker. */
if(wake_thread(thread_group))
{
/*
Wake failed, groups has no idle threads.
Now check if the group has at least one worker.
Wake failed, hence groups has no idle threads. Now check if there are
any threads in the group except listener.
*/
if(thread_group->thread_count == 1 &&
thread_group->pending_thread_start_count == 0)
{
/*
Currently there is no worker thread in the group, as indicated by
thread_count == 1 (means listener is the only one thread in the
group).
Rhe queue is not empty, and listener is not going to handle
thread_count == 1 (this means listener is the only one thread in
the group).
The queue is not empty, and listener is not going to handle
events. In order to drain the queue, we create a worker here.
Alternatively, we could just rely on timer to detect stall, but
this would be an inefficient, pointless delay.
Alternatively, we could just rely on timer to detect stall, and
create thread, but waiting for timer would be an inefficient and
pointless delay.
*/
create_worker(thread_group);
}
}
}
mysql_mutex_unlock(&thread_group->mutex);
if (listener_picks_event)
{
retval= (connection_t *)native_event_get_userdata(&ev[0]);
break;
}
}
DBUG_RETURN(retval);
}
......@@ -707,7 +715,7 @@ static connection_t * listener(worker_thread_t *current_thread,
/*
/**
Creates a new worker thread.
thread_mutex must be held when calling this function
......@@ -806,10 +814,10 @@ static int wake_or_create_thread(thread_group_t *thread_group)
if (thread_group->active_thread_count == 0)
{
/*
We're better off creating a new thread here with no delay,
either there is no workers at all, or they all are all blocking
and there was no sleeping thread to wakeup. It smells like deadlock
or very slowly executing requests, e.g sleeps or user locks.
We're better off creating a new thread here with no delay, either there
are no workers at all, or they all are all blocking and there was no
idle thread to wakeup. Smells like a potential deadlock or very slowly
executing requests, e.g sleeps or user locks.
*/
DBUG_RETURN(create_worker(thread_group));
}
......@@ -862,7 +870,8 @@ void thread_group_destroy(thread_group_t *thread_group)
/**
Wake sleeping thread from waiting list
*/
*/
static int wake_thread(thread_group_t *thread_group)
{
DBUG_ENTER("wake_thread");
......@@ -879,16 +888,14 @@ static int wake_thread(thread_group_t *thread_group)
}
/*
/**
Initiate shutdown for thread group.
The shutdown is asynchronous, we only care to wake all threads
in here, so they can finish. We do not wait here until threads
terminate,
Final cleanup of the group (thread_group_destroy) will be done by
the last exiting threads.
The shutdown is asynchronous, we only care to wake all threads in here, so
they can finish. We do not wait here until threads terminate. Final cleanup
of the group (thread_group_destroy) will be done by the last exiting threads.
*/
static void thread_group_close(thread_group_t *thread_group)
{
DBUG_ENTER("thread_group_close");
......@@ -938,6 +945,7 @@ static void thread_group_close(thread_group_t *thread_group)
perform login (this is done in worker threads).
*/
static void queue_put(thread_group_t *thread_group, connection_t *connection)
{
DBUG_ENTER("queue_put");
......@@ -949,14 +957,16 @@ static void queue_put(thread_group_t *thread_group, connection_t *connection)
wake_or_create_thread(thread_group);
}
mysql_mutex_unlock(&thread_group->mutex);
DBUG_VOID_RETURN;
}
/*
This is used to prevent too many threads executing at the same time,
if the workload is not CPU bound.
Prevent too many threads executing at the same time,if the workload is
not CPU bound.
*/
static bool too_many_threads(thread_group_t *thread_group)
{
return (thread_group->active_thread_count >= 1+(int)threadpool_oversubscribe
......@@ -964,7 +974,6 @@ static bool too_many_threads(thread_group_t *thread_group)
}
/**
Retrieve a connection with pending event.
......@@ -981,17 +990,15 @@ static bool too_many_threads(thread_group_t *thread_group)
@return
connection with pending event. NULL is returned if timeout has expired,or on shutdown.
*/
connection_t *get_event(worker_thread_t *current_thread,
thread_group_t *thread_group, struct timespec *abstime)
{
DBUG_ENTER("get_event");
connection_t *connection = NULL;
int err=0;
mysql_mutex_lock(&thread_group->mutex);
DBUG_ASSERT(thread_group->active_thread_count >= 0);
do
......@@ -1083,6 +1090,7 @@ connection_t *get_event(worker_thread_t *current_thread,
Tells the pool that worker starts waiting on IO, lock, condition,
sleep() or similar.
*/
void wait_begin(thread_group_t *thread_group)
{
DBUG_ENTER("wait_begin");
......@@ -1273,7 +1281,6 @@ static void set_next_timeout_check(ulonglong abstime)
/**
Set wait timeout for connection.
*/
static void set_wait_timeout(connection_t *c)
{
DBUG_ENTER("set_wait_timeout");
......@@ -1402,6 +1409,7 @@ static void handle_event(connection_t *connection)
/**
Worker thread's main
*/
static void *worker_main(void *param)
{
......@@ -1543,7 +1551,8 @@ void tp_set_threadpool_stall_limit(uint limit)
Calculate number of idle/waiting threads in the pool.
Sum idle threads over all groups.
Don't do any locking, it is not required for stats.
D
on't do any locking, it is not required for stats.
*/
int tp_get_idle_thread_count()
{
......@@ -1601,7 +1610,8 @@ static void print_pool_blocked_message(bool max_threads_reached)
else
sql_print_error(create_thread_error_msg, my_errno);
sql_print_information("Threadpool has been blocked for %u seconds\n",(uint)(now- pool_block_start));
sql_print_information("Threadpool has been blocked for %u seconds\n",
(uint)(now- pool_block_start));
/* avoid reperated messages for the same blocking situation */
msg_written= true;
}
......
sql/threadpool_win.cc
View file @ 57b6cb39
......@@ -17,6 +17,30 @@
#include <windows.h>
/*
Threadpool API is not available on XP. We still want to compile a single
version on Windows, but use the latest functionality if available.
We cannot use threadpool functionality directly, since executable won't
start on XP and loader will complain about missing symbols.
We solve using the usual way it is done on Windows, i.e with dynamic loading.
We'll need to load a lot of function, and make this less painful with the
WEAK_SYMBOL macro below
*/
/*
WEAK_SYMBOL(return_type, function_name, argument_type1,..,argument_typeN)
Declare and load function pointer from kernel32. The name of the static
variable that holds the function pointer is my_<original function name>
This should be combined with
#define <original function name> my_<original function name>
so that one could use Widows APIs transparently, without worrying whether
they are present in a particular version or not.
Of course, prior to use of any function there should be a check for correct
Windows version, or check whether function pointer is not NULL.
*/
#define WEAK_SYMBOL(return_type, function, ...) \
typedef return_type (WINAPI *pFN_##function)(__VA_ARGS__); \
static pFN_##function my_##function = (pFN_##function) \
......@@ -110,9 +134,7 @@ WEAK_SYMBOL(VOID, CloseThreadpoolWork, PTP_WORK pwk);
WEAK_SYMBOL(BOOL, SetThreadpoolStackInformation, PTP_POOL,
PTP_POOL_STACK_INFORMATION);
#define SetThreadpoolStackInformation my_SetThreadpoolStackInformation
#endif
#if _MSC_VER < 1600
#else /* _MSC_VER < 1600 */
#define SetThreadpoolCallbackPriority(env,prio)
typedef enum _TP_CALLBACK_PRIORITY {
TP_CALLBACK_PRIORITY_HIGH,
......@@ -158,8 +180,6 @@ static void CALLBACK shm_read_callback(PTP_CALLBACK_INSTANCE instance,
static void CALLBACK shm_close_callback(PTP_CALLBACK_INSTANCE instance,
PVOID Context, PTP_WAIT wait,TP_WAIT_RESULT wait_result);
#define CONNECTION_SIGNATURE 0xAFFEAFFE
static void check_thread_init();
/* Get current time as Windows time */
......@@ -178,21 +198,19 @@ static ulonglong now()
struct connection_t
{
THD *thd;
bool logged_in;
HANDLE handle;
OVERLAPPED overlapped;
/* absolute time for wait timeout (as Windows time) */
volatile ulonglong timeout;
PTP_CLEANUP_GROUP cleanup_group;
TP_CALLBACK_ENVIRON callback_environ;
PTP_IO io;
PTP_TIMER timer;
PTP_WAIT shm_read;
bool logged_in;
};
void init_connection(connection_t *connection)
{
connection->logged_in = false;
......@@ -208,6 +226,7 @@ void init_connection(connection_t *connection)
connection->thd = 0;
}
int init_io(connection_t *connection, THD *thd)
{
connection->thd= thd;
......@@ -237,7 +256,7 @@ int init_io(connection_t *connection, THD *thd)
if (connection->handle)
{
/* Performance tweaks (s. MSDN documentation)*/
UCHAR flags = FILE_SKIP_SET_EVENT_ON_HANDLE;
UCHAR flags= FILE_SKIP_SET_EVENT_ON_HANDLE;
if (skip_completion_port_on_success)
{
flags |= FILE_SKIP_COMPLETION_PORT_ON_SUCCESS;
......@@ -245,7 +264,7 @@ int init_io(connection_t *connection, THD *thd)
(void)SetFileCompletionNotificationModes(connection->handle, flags);
/* Assign io completion callback */
connection->io = CreateThreadpoolIo(connection->handle,
connection->io= CreateThreadpoolIo(connection->handle,
io_completion_callback, connection, &connection->callback_environ);
if(!connection->io)
{
......@@ -253,7 +272,7 @@ int init_io(connection_t *connection, THD *thd)
return -1;
}
}
connection->timer = CreateThreadpoolTimer(timer_callback, connection,
connection->timer= CreateThreadpoolTimer(timer_callback, connection,
&connection->callback_environ);
if (!connection->timer)
{
......@@ -354,6 +373,7 @@ int start_io(connection_t *connection, PTP_CALLBACK_INSTANCE instance)
return -1;
}
int login(connection_t *connection, PTP_CALLBACK_INSTANCE instance)
{
if (threadpool_add_connection(connection->thd) == 0
......@@ -380,21 +400,6 @@ void set_wait_timeout(connection_t *connection, ulonglong old_timeout)
connection->timeout = new_timeout;
}
/*
Terminates (idle) connection by closing the socket.
This will activate io_completion_callback() in a different thread
*/
void post_kill_notification(connection_t *connection)
{
check_thread_init();
THD *thd=connection->thd;
mysql_mutex_lock(&thd->LOCK_thd_data);
thd->killed = KILL_CONNECTION;
vio_shutdown(thd->net.vio, SHUT_RDWR);
thd->mysys_var= NULL;
mysql_mutex_unlock(&thd->LOCK_thd_data);
}
/* Connection destructor */
void destroy_connection(connection_t *connection)
......@@ -438,7 +443,6 @@ static void check_thread_init()
if (FlsGetValue(fls) == NULL)
{
FlsSetValue(fls, (void *)1);
my_thread_init();
thread_created++;
InterlockedIncrement((volatile long *)&tp_stats.num_worker_threads);
}
......@@ -446,28 +450,14 @@ static void check_thread_init()
/*
Take care of proper cleanup when threadpool threads exit.
We do not control how threads are created, thus it is our responsibility to
check that my_thread_init() is called on thread initialization and
my_thread_end() on thread destruction. On Windows, FlsAlloc() provides the
thread destruction callbacks.
Decrement number of threads when a thread exits .
On Windows, FlsAlloc() provides the thread destruction callbacks.
*/
static VOID WINAPI thread_destructor(void *data)
{
if(data)
{
if (InterlockedDecrement((volatile long *)&tp_stats.num_worker_threads) >= 0)
{
/*
The above check for number of thread >= 0 is due to shutdown code (
see tp_end()) where we forcefully set num_worker_threads to 0, even
if not all threads have shut down yet to the point they would ran Fls
destructors, even after CloseThreadpool(). See also comment in tp_end().
*/
mysql_mutex_lock(&LOCK_thread_count);
my_thread_end();
mysql_mutex_unlock(&LOCK_thread_count);
}
InterlockedDecrement((volatile long *)&tp_stats.num_worker_threads);
}
}
......@@ -507,7 +497,7 @@ bool tp_init(void)
{
TP_POOL_STACK_INFORMATION stackinfo;
stackinfo.StackCommit = 0;
stackinfo.StackReserve = my_thread_stack_size;
stackinfo.StackReserve = (SIZE_T)my_thread_stack_size;
if (!SetThreadpoolStackInformation(pool, &stackinfo))
{
tp_log_warning("Can't set threadpool stack size",
......@@ -520,45 +510,19 @@ bool tp_init(void)
}
/*
/**
Scheduler callback : Destroy the scheduler.
*/
extern "C" uint THR_thread_count;
extern "C" mysql_mutex_t THR_LOCK_threads;
extern "C" mysql_cond_t THR_COND_threads;
void tp_end(void)
{
if(pool)
{
SetThreadpoolThreadMaximum(pool, 0);
CloseThreadpool(pool);
/*
Tell my_global_thread_end() we're complete.
This would not be necessary if CloseThreadpool() would synchronously
release all threads and wait until they disappear and call all their FLS
destructors . However, threads in the pool are released asynchronously
and might spend some time in the CRT shutdown code. Thus zero
num_worker_threads, to avoid thread destructor's my_thread_end()s after
this point.
*/
LONG remaining_threads=
InterlockedExchange( (volatile long *)&tp_stats.num_worker_threads, 0);
if (remaining_threads)
{
mysql_mutex_lock(&THR_LOCK_threads);
THR_thread_count -= remaining_threads;
mysql_cond_signal(&THR_COND_threads);
mysql_mutex_unlock(&THR_LOCK_threads);
}
}
}
/*
/**
Notify pool about connection being killed.
*/
void tp_post_kill_notification(THD *thd)
......@@ -606,7 +570,7 @@ error:
DisassociateCurrentThreadFromCallback(instance);
destroy_connection(connection);
my_free(connection);
free(connection);
}
......@@ -623,7 +587,7 @@ static void CALLBACK login_callback(PTP_CALLBACK_INSTANCE instance,
if (login(connection, instance) != 0)
{
destroy_connection(connection);
my_free(connection);
free(connection);
}
}
......@@ -688,8 +652,7 @@ static void CALLBACK shm_read_callback(PTP_CALLBACK_INSTANCE instance,
*/
void tp_add_connection(THD *thd)
{
bool success = false;
connection_t *con = (connection_t *)my_malloc(sizeof(connection_t), 0);
connection_t *con = (connection_t *)malloc(sizeof(connection_t));
if (con)
threads.append(thd);
......@@ -698,6 +661,7 @@ void tp_add_connection(THD *thd)
if(!con)
{
tp_log_warning("Allocation failed", "tp_add_connection");
threadpool_remove_connection(thd);
return;
}
......@@ -718,8 +682,7 @@ void tp_add_connection(THD *thd)
}
/*
/**
Sets the number of idle threads the thread pool maintains in anticipation of new
requests.
*/
......
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