diff options
Diffstat (limited to 'mysys/thr_timer.c')
| -rw-r--r-- | mysys/thr_timer.c | 599 |
1 files changed, 599 insertions, 0 deletions
diff --git a/mysys/thr_timer.c b/mysys/thr_timer.c new file mode 100644 index 00000000..f87c1f75 --- /dev/null +++ b/mysys/thr_timer.c @@ -0,0 +1,599 @@ +/* + Copyright (c) 2012 Monty Program Ab + + This program 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; version 2 or later of the License. + + This program 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 this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ + +/* + Implementation if OS independent timers. + This is done based on pthread primitives, especially pthread_cond_timedwait() +*/ + +#include "mysys_priv.h" +#include "thr_timer.h" +#include <m_string.h> +#include <queues.h> +#ifdef HAVE_TIMER_CREATE +#include <sys/syscall.h> +#endif + +struct timespec next_timer_expire_time; + +static my_bool thr_timer_inited= 0; +static mysql_mutex_t LOCK_timer; +static mysql_cond_t COND_timer; +static QUEUE timer_queue; +pthread_t timer_thread; + +#define set_max_time(abs_time) \ + { (abs_time)->MY_tv_sec= INT_MAX32; (abs_time)->MY_tv_nsec= 0; } + + +static void *timer_handler(void *arg __attribute__((unused))); + +/* + Compare two timespecs +*/ + +static int compare_timespec(void *not_used __attribute__((unused)), + uchar *a_ptr, uchar *b_ptr) +{ + return cmp_timespec((*(struct timespec*) a_ptr), + (*(struct timespec*) b_ptr)); +} + + +/** + Initialize timer variables and create timer thread + + @param alloc_timers Init allocation of timers. Will be autoextended + if needed + @return 0 ok + @return 1 error; Can't create thread +*/ + +static thr_timer_t max_timer_data; + +my_bool init_thr_timer(uint alloc_timers) +{ + pthread_attr_t thr_attr; + my_bool res= 0; + DBUG_ENTER("init_thr_timer"); + + init_queue(&timer_queue, alloc_timers+2, offsetof(thr_timer_t,expire_time), + 0, compare_timespec, NullS, + offsetof(thr_timer_t, index_in_queue)+1, 1); + mysql_mutex_init(key_LOCK_timer, &LOCK_timer, MY_MUTEX_INIT_FAST); + mysql_cond_init(key_COND_timer, &COND_timer, NULL); + + /* Set dummy element with max time into the queue to simplify usage */ + bzero(&max_timer_data, sizeof(max_timer_data)); + set_max_time(&max_timer_data.expire_time); + queue_insert(&timer_queue, (uchar*) &max_timer_data); + next_timer_expire_time= max_timer_data.expire_time; + + /* Create a thread to handle timers */ + pthread_attr_init(&thr_attr); + pthread_attr_setscope(&thr_attr,PTHREAD_SCOPE_PROCESS); + pthread_attr_setstacksize(&thr_attr,64*1024); + thr_timer_inited= 1; + if (mysql_thread_create(key_thread_timer, &timer_thread, &thr_attr, + timer_handler, NULL)) + { + thr_timer_inited= 0; + res= 1; + mysql_mutex_destroy(&LOCK_timer); + mysql_cond_destroy(&COND_timer); + delete_queue(&timer_queue); + } + pthread_attr_destroy(&thr_attr); + + DBUG_RETURN(res); +} + + +void end_thr_timer(void) +{ + DBUG_ENTER("end_thr_timer"); + + if (!thr_timer_inited) + DBUG_VOID_RETURN; + + mysql_mutex_lock(&LOCK_timer); + thr_timer_inited= 0; /* Signal abort */ + mysql_cond_signal(&COND_timer); + mysql_mutex_unlock(&LOCK_timer); + pthread_join(timer_thread, NULL); + + mysql_mutex_destroy(&LOCK_timer); + mysql_cond_destroy(&COND_timer); + delete_queue(&timer_queue); + DBUG_VOID_RETURN; +} + + +/* + Initialize a timer object + + @param timer_data Timer structure + @param function Function to be called when getting timeout + @param argument Argument for function +*/ + +void thr_timer_init(thr_timer_t *timer_data, void(*function)(void*), + void *arg) +{ + DBUG_ENTER("thr_timer_init"); + bzero(timer_data, sizeof(*timer_data)); + timer_data->func= function; + timer_data->func_arg= arg; + timer_data->expired= 1; /* Not active */ + DBUG_VOID_RETURN; +} + +/* + Make timer periodic + + @param timer_data Timer structure + @param micro_seconds Period +*/ +void thr_timer_set_period(thr_timer_t* timer_data, ulonglong micro_seconds) +{ + DBUG_ENTER("thr_timer_set_period"); + timer_data->period= micro_seconds; + DBUG_VOID_RETURN; +} + +/* + Request timer after X milliseconds + + SYNOPSIS + thr_timer() + timer_data Pointer to timer structure + micro_seconds; Number of microseconds until timer + + RETURN VALUES + 0 ok + 1 If no more timers are allowed (aborted by process) + + Stores in first argument a pointer to a non-zero int which is set to 0 + when the timer has been given +*/ + +my_bool thr_timer_settime(thr_timer_t *timer_data, ulonglong micro_seconds) +{ + int reschedule; + DBUG_ENTER("thr_timer_settime"); + DBUG_PRINT("enter",("thread: %s micro_seconds: %llu",my_thread_name(), + micro_seconds)); + + DBUG_ASSERT(timer_data->expired == 1); + + set_timespec_nsec(timer_data->expire_time, micro_seconds*1000); + timer_data->expired= 0; + + mysql_mutex_lock(&LOCK_timer); /* Lock from threads & timers */ + if (queue_insert_safe(&timer_queue,(uchar*) timer_data)) + { + DBUG_PRINT("info", ("timer queue full")); + fprintf(stderr,"Warning: thr_timer queue is full\n"); + timer_data->expired= 1; + mysql_mutex_unlock(&LOCK_timer); + DBUG_RETURN(1); + } + + /* Reschedule timer if the current one has more time left than new one */ + reschedule= cmp_timespec(next_timer_expire_time, timer_data->expire_time); + mysql_mutex_unlock(&LOCK_timer); + if (reschedule > 0) + { +#if defined(MAIN) + printf("reschedule\n"); fflush(stdout); +#endif + DBUG_PRINT("info", ("reschedule")); + mysql_cond_signal(&COND_timer); + } + + DBUG_RETURN(0); +} + + +/* + Remove timer from list of timers + + notes: Timer will be marked as expired +*/ + +void thr_timer_end(thr_timer_t *timer_data) +{ + DBUG_ENTER("thr_timer_end"); + + mysql_mutex_lock(&LOCK_timer); + if (!timer_data->expired) + { + DBUG_ASSERT(timer_data->index_in_queue != 0); + DBUG_ASSERT(queue_element(&timer_queue, timer_data->index_in_queue) == + (uchar*) timer_data); + queue_remove(&timer_queue, timer_data->index_in_queue); + /* Mark as expired for asserts to work */ + timer_data->expired= 1; + } + mysql_mutex_unlock(&LOCK_timer); + DBUG_VOID_RETURN; +} + + +/* + Come here when some timer in queue is due. +*/ + +static sig_handler process_timers(struct timespec *now) +{ + thr_timer_t *timer_data; + DBUG_ENTER("process_timers"); + DBUG_PRINT("info",("active timers: %d", timer_queue.elements - 1)); + +#if defined(MAIN) + printf("process_timer\n"); fflush(stdout); +#endif + + /* We can safely remove the first one as it has already expired */ + for (;;) + { + void (*function)(void*); + void *func_arg; + my_bool is_periodic; + + timer_data= (thr_timer_t*) queue_top(&timer_queue); + function= timer_data->func; + func_arg= timer_data->func_arg; + is_periodic= timer_data->period != 0; + timer_data->expired= 1; /* Mark expired */ + /* + We remove timer before calling timer function to allow thread to + delete it's timer data any time. + + Deleting timer inside the callback would not work + for periodic timers, they need to be removed from + queue prior to destroying timer_data. + */ + queue_remove_top(&timer_queue); /* Remove timer */ + (*function)(func_arg); /* Inform thread of timeout */ + + /* + If timer is periodic, recalculate next expiration time, and + reinsert it into the queue. + */ + if (is_periodic && timer_data->period) + { + set_timespec_nsec(timer_data->expire_time, timer_data->period * 1000); + timer_data->expired= 0; + queue_insert(&timer_queue, (uchar*)timer_data); + } + + /* Check if next one has also expired */ + timer_data= (thr_timer_t*) queue_top(&timer_queue); + if (cmp_timespec(timer_data->expire_time, (*now)) > 0) + break; /* All data processed */ + } + DBUG_VOID_RETURN; +} + + +/* + set up a timer thread to handle timeouts + This will be killed when thr_timer_inited is set to false. +*/ + +static void *timer_handler(void *arg __attribute__((unused))) +{ + my_thread_init(); + + mysql_mutex_lock(&LOCK_timer); + while (likely(thr_timer_inited)) + { + int error; + struct timespec *top_time; + struct timespec now, abstime; + + set_timespec(now, 0); + + top_time= &(((thr_timer_t*) queue_top(&timer_queue))->expire_time); + + if (cmp_timespec((*top_time), now) <= 0) + { + process_timers(&now); + top_time= &(((thr_timer_t*) queue_top(&timer_queue))->expire_time); + } + + abstime= *top_time; + next_timer_expire_time= *top_time; + if ((error= mysql_cond_timedwait(&COND_timer, &LOCK_timer, &abstime)) && + error != ETIME && error != ETIMEDOUT) + { +#ifdef MAIN + printf("Got error: %d from ptread_cond_timedwait (errno: %d)\n", + error,errno); +#endif + } + } + mysql_mutex_unlock(&LOCK_timer); + my_thread_end(); + pthread_exit(0); + return 0; /* Impossible */ +} + + +/**************************************************************************** + Testing of thr_timer (when compiled with -DMAIN) +***************************************************************************/ + +#ifdef MAIN + +static mysql_cond_t COND_thread_count; +static mysql_mutex_t LOCK_thread_count; +static uint thread_count, benchmark_runs, test_to_run= 1; + +static void send_signal(void *arg) +{ + struct st_my_thread_var *current_my_thread_var= arg; +#if defined(MAIN) + printf("sending signal\n"); fflush(stdout); +#endif + mysql_mutex_lock(¤t_my_thread_var->mutex); + mysql_cond_signal(¤t_my_thread_var->suspend); + mysql_mutex_unlock(¤t_my_thread_var->mutex); +} + + +static void run_thread_test(int param) +{ + int i,wait_time,retry; + my_hrtime_t start_time; + thr_timer_t timer_data; + struct st_my_thread_var *current_my_thread_var; + DBUG_ENTER("run_thread_test"); + + current_my_thread_var= my_thread_var; + thr_timer_init(&timer_data, send_signal, current_my_thread_var); + + for (i=1 ; i <= 10 ; i++) + { + wait_time=param ? 11-i : i; + start_time= my_hrtime(); + + mysql_mutex_lock(¤t_my_thread_var->mutex); + if (thr_timer_settime(&timer_data, wait_time * 1000000)) + { + printf("Thread: %s timers aborted\n",my_thread_name()); + break; + } + if (wait_time == 3) + { + printf("Thread: %s Simulation of no timer needed\n",my_thread_name()); + fflush(stdout); + } + else + { + for (retry=0 ; !timer_data.expired && retry < 10 ; retry++) + { + printf("Thread: %s Waiting %d sec\n",my_thread_name(),wait_time); + mysql_cond_wait(¤t_my_thread_var->suspend, + ¤t_my_thread_var->mutex); + + } + if (!timer_data.expired) + { + printf("Thread: %s didn't get an timer. Aborting!\n", + my_thread_name()); + break; + } + } + mysql_mutex_unlock(¤t_my_thread_var->mutex); + printf("Thread: %s Slept for %g (%d) sec\n",my_thread_name(), + (int) (my_hrtime().val-start_time.val)/1000000.0, wait_time); + fflush(stdout); + thr_timer_end(&timer_data); + fflush(stdout); + } + DBUG_VOID_RETURN; +} + + +static void run_thread_benchmark(int param) +{ + int i; + struct st_my_thread_var *current_my_thread_var; + thr_timer_t timer_data; + DBUG_ENTER("run_thread_benchmark"); + + current_my_thread_var= my_thread_var; + thr_timer_init(&timer_data, send_signal, current_my_thread_var); + + for (i=1 ; i <= param ; i++) + { + if (thr_timer_settime(&timer_data, 1000000)) + { + printf("Thread: %s timers aborted\n",my_thread_name()); + break; + } + thr_timer_end(&timer_data); + } + DBUG_VOID_RETURN; +} + + +#ifdef HAVE_TIMER_CREATE + +/* Test for benchmarking posix timers against thr_timer */ + +#ifndef sigev_notify_thread_id +#define sigev_notify_thread_id _sigev_un._tid +#endif + +static void run_timer_benchmark(int param) +{ + int i; + timer_t timerid; + struct sigevent sigev; + pid_t thread_id= (pid_t) syscall(SYS_gettid); + DBUG_ENTER("run_timer_benchmark"); + + /* Setup a signal that will never be signaled */ + sigev.sigev_value.sival_ptr= 0; + sigev.sigev_signo= SIGRTMIN; /* First free signal */ + sigev.sigev_notify= SIGEV_SIGNAL | SIGEV_THREAD_ID; + sigev.sigev_notify_thread_id= thread_id; + + if (timer_create(CLOCK_MONOTONIC, &sigev, &timerid)) + { + printf("Could not create timer\n"); + exit(1); + } + + for (i=1 ; i <= param ; i++) + { + struct itimerspec abstime; + abstime.it_interval.tv_sec= 0; + abstime.it_interval.tv_nsec= 0; + abstime.it_value.tv_sec= 1; + abstime.it_value.tv_nsec= 0; + + if (timer_settime(timerid, 0, &abstime, NULL)) + { + printf("Thread: %s timers aborted\n",my_thread_name()); + break; + } + abstime.it_interval.tv_sec= 0; + abstime.it_interval.tv_nsec= 0; + abstime.it_value.tv_sec= 0; + abstime.it_value.tv_nsec= 0; + timer_settime(timerid, 0, &abstime, NULL); + } + timer_delete(timerid); + DBUG_VOID_RETURN; +} +#endif /* HAVE_TIMER_CREATE */ + + +static void *start_thread(void *arg) +{ + my_thread_init(); + printf("Thread %d (%s) started\n",*((int*) arg),my_thread_name()); + fflush(stdout); + + switch (test_to_run) { + case 1: + run_thread_test(*((int*) arg)); + break; + case 2: + run_thread_benchmark(benchmark_runs); + break; + case 3: +#ifdef HAVE_TIMER_CREATE + run_timer_benchmark(benchmark_runs); +#endif + break; + } + free((uchar*) arg); + mysql_mutex_lock(&LOCK_thread_count); + thread_count--; + mysql_cond_signal(&COND_thread_count); /* Tell main we are ready */ + mysql_mutex_unlock(&LOCK_thread_count); + my_thread_end(); + return 0; +} + + +/* Start a lot of threads that will run with timers */ + +static void run_test() +{ + pthread_t tid; + pthread_attr_t thr_attr; + int i,*param,error; + DBUG_ENTER("run_test"); + + if (init_thr_timer(5)) + { + printf("Can't initialize timers\n"); + exit(1); + } + + mysql_mutex_init(0, &LOCK_thread_count, MY_MUTEX_INIT_FAST); + mysql_cond_init(0, &COND_thread_count, NULL); + + thr_setconcurrency(3); + pthread_attr_init(&thr_attr); + pthread_attr_setscope(&thr_attr,PTHREAD_SCOPE_PROCESS); + printf("Main thread: %s\n",my_thread_name()); + for (i=0 ; i < 2 ; i++) + { + param=(int*) malloc(sizeof(int)); + *param= i; + mysql_mutex_lock(&LOCK_thread_count); + if ((error= mysql_thread_create(0, + &tid, &thr_attr, start_thread, + (void*) param))) + { + printf("Can't create thread %d, error: %d\n",i,error); + exit(1); + } + thread_count++; + mysql_mutex_unlock(&LOCK_thread_count); + } + + pthread_attr_destroy(&thr_attr); + mysql_mutex_lock(&LOCK_thread_count); + while (thread_count) + { + mysql_cond_wait(&COND_thread_count, &LOCK_thread_count); + } + mysql_mutex_unlock(&LOCK_thread_count); + DBUG_ASSERT(timer_queue.elements == 1); + end_thr_timer(); + printf("Test succeeded\n"); + DBUG_VOID_RETURN; +} + + +int main(int argc __attribute__((unused)),char **argv __attribute__((unused))) +{ + MY_INIT(argv[0]); + + if (argc > 1 && argv[1][0] == '-') + { + switch (argv[1][1]) { + case '#': + test_to_run= 1; + DBUG_PUSH(argv[1]+2); + break; + case 'b': + test_to_run= 2; + benchmark_runs= atoi(argv[1]+2); + break; + case 't': + test_to_run= 3; + benchmark_runs= atoi(argv[1]+2); + break; + } + } + if (!benchmark_runs) + benchmark_runs= 1000000; + + run_test(); + my_end(1); + return 0; +} + +#endif /* MAIN */ |