/*
- silcschedule.c
+ silcschedule.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1998 - 2000 Pekka Riikonen
+ Copyright (C) 1998 - 2002 Pekka Riikonen
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; either version 2 of the License, or
- (at your option) any later version.
-
+ the Free Software Foundation; version 2 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.
*/
-/*
- * $Id$
- * $Log$
- * Revision 1.1 2000/09/13 17:45:16 priikone
- * Splitted SILC core library. Core library includes now only
- * SILC protocol specific stuff. New utility library includes the
- * old stuff from core library that is more generic purpose stuff.
- *
- * Revision 1.3 2000/07/18 06:51:58 priikone
- * Debug version bug fixes.
- *
- * Revision 1.2 2000/07/05 06:06:35 priikone
- * Global cosmetic change.
- *
- * Revision 1.1.1.1 2000/06/27 11:36:55 priikone
- * Imported from internal CVS/Added Log headers.
- *
- *
- */
+/* $Id$ */
#include "silcincludes.h"
+#include "silcschedule_i.h"
+
+/* Forward declarations */
+typedef struct SilcTaskQueueStruct *SilcTaskQueue;
+
+/* System specific routines. Implemented under unix/, win32/ and such. */
+
+/* System specific select(). Returns same values as normal select(). */
+int silc_select(SilcScheduleFd fds, SilcUInt32 fds_count,
+ struct timeval *timeout);
+
+/* Initializes the platform specific scheduler. This for example initializes
+ the wakeup mechanism of the scheduler. In multi-threaded environment
+ the scheduler needs to be wakenup when tasks are added or removed from
+ the task queues. Returns context to the platform specific scheduler. */
+void *silc_schedule_internal_init(SilcSchedule schedule, void *context);
+
+/* Uninitializes the platform specific scheduler context. */
+void silc_schedule_internal_uninit(void *context);
+
+/* Wakes up the scheduler. This is platform specific routine */
+void silc_schedule_internal_wakeup(void *context);
+
+/* Register signal */
+void silc_schedule_internal_signal_register(void *context,
+ SilcUInt32 signal,
+ SilcTaskCallback callback,
+ void *callback_context);
+
+/* Unregister signal */
+void silc_schedule_internal_signal_unregister(void *context,
+ SilcUInt32 signal,
+ SilcTaskCallback callback,
+ void *callback_context);
+
+/* Mark signal to be called later. */
+void silc_schedule_internal_signal_call(void *context, SilcUInt32 signal);
+
+/* Call all signals */
+void silc_schedule_internal_signals_call(void *context,
+ SilcSchedule schedule);
+
+/* Block registered signals in scheduler. */
+void silc_schedule_internal_signals_block(void *context);
+
+/* Unblock registered signals in schedule. */
+void silc_schedule_internal_signals_unblock(void *context);
+
+/* Internal task management routines. */
+
+static void silc_schedule_dispatch_timeout(SilcSchedule schedule,
+ bool dispatch_all);
+static void silc_task_queue_alloc(SilcTaskQueue *queue);
+static void silc_task_queue_free(SilcTaskQueue queue);
+static SilcTask silc_task_find(SilcTaskQueue queue, SilcUInt32 fd);
+static SilcTask silc_task_add(SilcTaskQueue queue, SilcTask newtask,
+ SilcTaskPriority priority);
+static SilcTask silc_task_get_first(SilcTaskQueue queue, SilcTask first);
+static SilcTask silc_task_add_timeout(SilcTaskQueue queue, SilcTask newtask,
+ SilcTaskPriority priority);
+static int silc_schedule_task_remove(SilcTaskQueue queue, SilcTask task);
+static void silc_task_del_by_context(SilcTaskQueue queue, void *context);
+static void silc_task_del_by_callback(SilcTaskQueue queue,
+ SilcTaskCallback callback);
+static void silc_task_del_by_fd(SilcTaskQueue queue, SilcUInt32 fd);
+
+/* Returns the task queue by task type */
+#define SILC_SCHEDULE_GET_QUEUE(type) \
+ (type == SILC_TASK_FD ? schedule->fd_queue : \
+ type == SILC_TASK_TIMEOUT ? schedule->timeout_queue : \
+ schedule->generic_queue)
+
+/* Locks. These also blocks signals that we care about and thus guarantee
+ that while we are in scheduler no signals can happen. This way we can
+ synchronise signals with SILC Scheduler. */
+#define SILC_SCHEDULE_LOCK(schedule) \
+do { \
+ silc_schedule_internal_signals_block(schedule->internal); \
+ silc_mutex_lock(schedule->lock); \
+} while (0)
+#define SILC_SCHEDULE_UNLOCK(schedule) \
+do { \
+ silc_mutex_unlock(schedule->lock); \
+ silc_schedule_internal_signals_unblock(schedule->internal); \
+} while (0)
+
+/* SILC Task object. Represents one task in the scheduler. */
+struct SilcTaskStruct {
+ SilcUInt32 fd;
+ SilcTaskCallback callback; /* Task callback */
+ void *context; /* Task callback context */
+ struct timeval timeout; /* Set for timeout tasks */
+ unsigned int valid : 1; /* Set when task is valid */
+ unsigned int priority : 2; /* Priority of the task */
+ unsigned int type : 5; /* Type of the task */
+
+ /* Pointers forming doubly linked circular list */
+ struct SilcTaskStruct *next;
+ struct SilcTaskStruct *prev;
+};
+
+/* SILC Task Queue object. The queue holds all the tasks in the scheduler.
+ There are always three task queues in the scheduler. One for non-timeout
+ tasks (fd tasks performing tasks over specified file descriptor),
+ one for timeout tasks and one for generic tasks. */
+struct SilcTaskQueueStruct {
+ SilcTask task; /* Pointer to all tasks */
+ struct timeval timeout; /* Current timeout */
+ SILC_MUTEX_DEFINE(lock); /* Queue's lock */
+};
+
+/*
+ SILC Scheduler structure.
+
+ This is the actual schedule object in SILC. Both SILC client and server
+ uses this same scheduler. Actually, this scheduler could be used by any
+ program needing scheduling.
+
+ Following short description of the fields:
+
+ SilcTaskQueue fd_queue
+
+ Task queue hook for non-timeout tasks. Usually this means that these
+ tasks perform different kind of I/O on file descriptors. File
+ descriptors are usually network sockets but they actually can be
+ any file descriptors. This hook is initialized in silc_schedule_init
+ function. Timeout tasks should not be added to this queue because
+ they will never expire.
+
+ SilcTaskQueue timeout_queue
+
+ Task queue hook for timeout tasks. This hook is reserved specificly
+ for tasks with timeout. Non-timeout tasks should not be added to this
+ queue because they will never get scheduled. This hook is also
+ initialized in silc_schedule_init function.
+
+ SilcTaskQueue generic_queue
+
+ Task queue hook for generic tasks. This hook is reserved specificly
+ for generic tasks, tasks that apply to all file descriptors, except
+ to those that have specificly registered a non-timeout task. This hook
+ is also initialized in silc_schedule_init function.
+
+ SilcScheduleFd fd_list
+
+ List of file descriptors the scheduler is supposed to be listenning.
+ This is updated internally.
+
+ SilcUInt32 max_fd
+ SilcUInt32 last_fd
+
+ Size of the fd_list list. There can be `max_fd' many tasks in
+ the scheduler at once. The `last_fd' is the last valid entry
+ in the fd_list.
+
+ struct timeval *timeout;
+
+ Pointer to the schedules next timeout. Value of this timeout is
+ automatically updated in the silc_schedule function.
+
+ bool valid
+
+ Marks validity of the scheduler. This is a boolean value. When this
+ is false the scheduler is terminated and the program will end. This
+ set to true when the scheduler is initialized with silc_schedule_init
+ function.
+
+ fd_set in
+ fd_set out
+
+ File descriptor sets for select(). These are automatically managed
+ by the scheduler and should not be touched otherwise.
+
+ void *internal
+
+ System specific scheduler context.
+
+ SILC_MUTEX_DEFINE(lock)
+
+ Scheduler lock.
+
+ bool signal_tasks
-/* The actual schedule object. */
-static SilcSchedule schedule;
+ TRUE when tasks has been registered from signals. Next round in
+ scheduler will call the callbacks when this is TRUE.
-/* Initializes the schedule. Sets the non-timeout task queue hook and
- the timeout task queue hook. This must be called before the schedule
- is able to work. */
+*/
+struct SilcScheduleStruct {
+ void *app_context; /* Application specific context */
+ SilcTaskQueue fd_queue;
+ SilcTaskQueue timeout_queue;
+ SilcTaskQueue generic_queue;
+ SilcScheduleFd fd_list;
+ SilcUInt32 max_fd;
+ SilcUInt32 last_fd;
+ struct timeval *timeout;
+ bool valid;
+ void *internal;
+ SILC_MUTEX_DEFINE(lock);
+ bool is_locked;
+ bool signal_tasks;
+};
+
+/* Initializes the scheduler. This returns the scheduler context that
+ is given as arugment usually to all silc_schedule_* functions.
+ The `max_tasks' indicates the number of maximum tasks that the
+ scheduler can handle. The `app_context' is application specific
+ context that is delivered to task callbacks. */
-void silc_schedule_init(SilcTaskQueue *fd_queue,
- SilcTaskQueue *timeout_queue,
- SilcTaskQueue *generic_queue,
- int max_fd)
+SilcSchedule silc_schedule_init(int max_tasks, void *app_context)
{
- int i;
+ SilcSchedule schedule;
SILC_LOG_DEBUG(("Initializing scheduler"));
- /* Register the task queues if they are not registered already. In SILC
- we have by default three task queues. One task queue for non-timeout
- tasks which perform different kind of I/O on file descriptors, timeout
- task queue for timeout tasks, and, generic non-timeout task queue whose
- tasks apply to all connections. */
- if (!*fd_queue)
- silc_task_queue_alloc(fd_queue, TRUE);
- if (!*timeout_queue)
- silc_task_queue_alloc(timeout_queue, TRUE);
- if (!*generic_queue)
- silc_task_queue_alloc(generic_queue, TRUE);
-
- /* Initialize the schedule */
- memset(&schedule, 0, sizeof(schedule));
- schedule.fd_queue = *fd_queue;
- schedule.timeout_queue = *timeout_queue;
- schedule.generic_queue = *generic_queue;
- schedule.fd_list.fd = silc_calloc(max_fd, sizeof(int));
- schedule.fd_list.last_fd = 0;
- schedule.fd_list.max_fd = max_fd;
- schedule.timeout = NULL;
- schedule.valid = TRUE;
- FD_ZERO(&schedule.in);
- FD_ZERO(&schedule.out);
- schedule.max_fd = -1;
- for (i = 0; i < max_fd; i++)
- schedule.fd_list.fd[i] = -1;
+ schedule = silc_calloc(1, sizeof(*schedule));
+
+ /* Allocate three task queues, one for file descriptor based tasks,
+ one for timeout tasks and one for generic tasks. */
+ silc_task_queue_alloc(&schedule->fd_queue);
+ silc_task_queue_alloc(&schedule->timeout_queue);
+ silc_task_queue_alloc(&schedule->generic_queue);
+
+ if (!max_tasks)
+ max_tasks = 200;
+
+ /* Initialize the scheduler */
+ schedule->fd_list = silc_calloc(max_tasks, sizeof(*schedule->fd_list));
+ schedule->max_fd = max_tasks;
+ schedule->timeout = NULL;
+ schedule->valid = TRUE;
+ schedule->app_context = app_context;
+
+ /* Allocate scheduler lock */
+ silc_mutex_alloc(&schedule->lock);
+
+ /* Initialize the platform specific scheduler. */
+ schedule->internal = silc_schedule_internal_init(schedule, app_context);
+
+ return schedule;
}
/* Uninitializes the schedule. This is called when the program is ready
- to end. This removes all tasks and task queues. */
+ to end. This removes all tasks and task queues. Returns FALSE if the
+ scheduler could not be uninitialized. This happens when the scheduler
+ is still valid and silc_schedule_stop has not been called. */
-int silc_schedule_uninit()
+bool silc_schedule_uninit(SilcSchedule schedule)
{
-
SILC_LOG_DEBUG(("Uninitializing scheduler"));
- if (schedule.valid == TRUE)
+ if (schedule->valid == TRUE)
return FALSE;
+ /* Dispatch all timeouts before going away */
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(schedule->timeout_queue->lock);
+ silc_schedule_dispatch_timeout(schedule, TRUE);
+ silc_mutex_unlock(schedule->timeout_queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+
+ /* Deliver signals before going away */
+ if (schedule->signal_tasks) {
+ silc_schedule_internal_signals_call(schedule->internal, schedule);
+ schedule->signal_tasks = FALSE;
+ }
+
/* Unregister all tasks */
- if (schedule.fd_queue)
- silc_task_remove(schedule.fd_queue, SILC_ALL_TASKS);
- if (schedule.timeout_queue)
- silc_task_remove(schedule.timeout_queue, SILC_ALL_TASKS);
- if (schedule.generic_queue)
- silc_task_remove(schedule.generic_queue, SILC_ALL_TASKS);
+ silc_schedule_task_remove(schedule->fd_queue, SILC_ALL_TASKS);
+ silc_schedule_task_remove(schedule->timeout_queue, SILC_ALL_TASKS);
+ silc_schedule_task_remove(schedule->generic_queue, SILC_ALL_TASKS);
/* Unregister all task queues */
- if (schedule.fd_queue)
- silc_task_queue_free(schedule.fd_queue);
- if (schedule.timeout_queue)
- silc_task_queue_free(schedule.timeout_queue);
- if (schedule.generic_queue)
- silc_task_queue_free(schedule.generic_queue);
-
- /* Clear the fd list */
- if (schedule.fd_list.fd) {
- memset(schedule.fd_list.fd, -1, schedule.fd_list.max_fd);
- silc_free(schedule.fd_list.fd);
- }
+ silc_task_queue_free(schedule->fd_queue);
+ silc_task_queue_free(schedule->timeout_queue);
+ silc_task_queue_free(schedule->generic_queue);
+
+ silc_free(schedule->fd_list);
+
+ /* Uninit the platform specific scheduler. */
+ silc_schedule_internal_uninit(schedule->internal);
+
+ silc_mutex_free(schedule->lock);
+ silc_free(schedule);
+
+ return TRUE;
+}
+
+/* Enlarge the capabilities of the scheduler to handle tasks to `max_tasks'. */
- memset(&schedule, 'F', sizeof(schedule));
+bool silc_schedule_reinit(SilcSchedule schedule, int max_tasks)
+{
+ SILC_SCHEDULE_LOCK(schedule);
+ if (schedule->max_fd <= max_tasks)
+ return FALSE;
+ schedule->fd_list = silc_realloc(schedule->fd_list,
+ (sizeof(*schedule->fd_list) * max_tasks));
+ schedule->max_fd = max_tasks;
+ SILC_SCHEDULE_UNLOCK(schedule);
return TRUE;
}
After calling this, one should call silc_schedule_uninit (after the
silc_schedule has returned). */
-void silc_schedule_stop()
+void silc_schedule_stop(SilcSchedule schedule)
{
SILC_LOG_DEBUG(("Stopping scheduler"));
+ SILC_SCHEDULE_LOCK(schedule);
+ schedule->valid = FALSE;
+ SILC_SCHEDULE_UNLOCK(schedule);
+}
- if (schedule.valid == TRUE)
- schedule.valid = FALSE;
+/* Executes nontimeout tasks. It then checks whether any of ther fd tasks
+ was signaled by the silc_select. If some task was not signaled then
+ all generic tasks are executed for that task. The generic tasks are
+ never executed for task that has explicit fd task set. */
+/* This holds the schedule->lock and the queue locks. */
+
+static void silc_schedule_dispatch_nontimeout(SilcSchedule schedule)
+{
+ SilcTask task;
+ int i;
+ SilcUInt32 fd, last_fd = schedule->last_fd;
+
+ for (i = 0; i <= last_fd; i++) {
+ if (schedule->fd_list[i].events == 0)
+ continue;
+
+ fd = schedule->fd_list[i].fd;
+
+ /* First check whether this fd has task in the fd queue */
+ silc_mutex_lock(schedule->fd_queue->lock);
+ task = silc_task_find(schedule->fd_queue, fd);
+
+ /* If the task was found then execute its callbacks. If not then
+ execute all generic tasks for that fd. */
+ if (task) {
+ /* Validity of the task is checked always before and after
+ execution beacuse the task might have been unregistered
+ in the callback function, ie. it is not valid anymore. */
+
+ /* Is the task ready for reading */
+ if (task->valid && schedule->fd_list[i].revents & SILC_TASK_READ) {
+ silc_mutex_unlock(schedule->fd_queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+ task->callback(schedule, schedule->app_context,
+ SILC_TASK_READ, task->fd, task->context);
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(schedule->fd_queue->lock);
+ }
+
+ /* Is the task ready for writing */
+ if (task->valid && schedule->fd_list[i].revents & SILC_TASK_WRITE) {
+ silc_mutex_unlock(schedule->fd_queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+ task->callback(schedule, schedule->app_context,
+ SILC_TASK_WRITE, task->fd, task->context);
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(schedule->fd_queue->lock);
+ }
+
+ if (!task->valid)
+ silc_schedule_task_remove(schedule->fd_queue, task);
+
+ silc_mutex_unlock(schedule->fd_queue->lock);
+ } else {
+ /* Run generic tasks for this fd. */
+
+ silc_mutex_unlock(schedule->fd_queue->lock);
+
+ silc_mutex_lock(schedule->generic_queue->lock);
+ if (!schedule->generic_queue->task) {
+ silc_mutex_unlock(schedule->generic_queue->lock);
+ continue;
+ }
+
+ task = schedule->generic_queue->task;
+ while(1) {
+ /* Validity of the task is checked always before and after
+ execution beacuse the task might have been unregistered
+ in the callback function, ie. it is not valid anymore. */
+
+ /* Is the task ready for reading */
+ if (task->valid && schedule->fd_list[i].revents & SILC_TASK_READ) {
+ silc_mutex_unlock(schedule->generic_queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+ task->callback(schedule, schedule->app_context,
+ SILC_TASK_READ, fd, task->context);
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(schedule->generic_queue->lock);
+ }
+
+ /* Is the task ready for writing */
+ if (task->valid && schedule->fd_list[i].revents & SILC_TASK_WRITE) {
+ silc_mutex_unlock(schedule->generic_queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+ task->callback(schedule, schedule->app_context,
+ SILC_TASK_WRITE, fd, task->context);
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(schedule->generic_queue->lock);
+ }
+
+ if (!task->valid) {
+ /* Invalid (unregistered) tasks are removed from the
+ task queue. */
+ if (schedule->generic_queue->task == task->next) {
+ silc_schedule_task_remove(schedule->generic_queue, task);
+ silc_mutex_unlock(schedule->generic_queue->lock);
+ break;
+ }
+
+ task = task->next;
+ silc_schedule_task_remove(schedule->generic_queue, task);
+ continue;
+ }
+
+ /* Break if there isn't more tasks in the queue */
+ if (schedule->generic_queue->task == task->next)
+ break;
+
+ task = task->next;
+ }
+
+ silc_mutex_unlock(schedule->generic_queue->lock);
+ }
+ }
}
-/* Sets a file descriptor to be listened by select() in scheduler. One can
- call this directly if wanted. This can be called multiple times for
- one file descriptor to set different iomasks. */
+/* Executes all tasks whose timeout has expired. The task is removed from
+ the task queue after the callback function has returned. Also, invalid
+ tasks are removed here. We don't have to care about priorities because
+ tasks are already sorted in their priority order at the registration
+ phase. */
+/* This holds the schedule->lock and the schedule->timeout_queue->lock */
-void silc_schedule_set_listen_fd(int fd, unsigned int iomask)
+static void silc_schedule_dispatch_timeout(SilcSchedule schedule,
+ bool dispatch_all)
{
- assert(schedule.valid != FALSE);
- assert(fd < schedule.fd_list.max_fd);
+ SilcTaskQueue queue = schedule->timeout_queue;
+ SilcTask task;
+ struct timeval curtime;
- schedule.fd_list.fd[fd] = iomask;
-
- if (fd > schedule.fd_list.last_fd)
- schedule.fd_list.last_fd = fd;
+ SILC_LOG_DEBUG(("Running timeout tasks"));
+
+ silc_gettimeofday(&curtime);
+
+ queue = schedule->timeout_queue;
+ if (queue && queue->task) {
+ task = queue->task;
+
+ /* Walk thorugh all tasks in the particular task queue and run all
+ the expired tasks. */
+ while(1) {
+ /* Execute the task if the timeout has expired */
+ if (dispatch_all ||
+ silc_compare_timeval(&task->timeout, &curtime)) {
+ if (task->valid) {
+ silc_mutex_unlock(queue->lock);
+ SILC_SCHEDULE_UNLOCK(schedule);
+ task->callback(schedule, schedule->app_context,
+ SILC_TASK_EXPIRE, task->fd, task->context);
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_mutex_lock(queue->lock);
+ }
+
+ /* Break if there isn't more tasks in the queue */
+ if (queue->task == task->next) {
+ silc_schedule_task_remove(queue, task);
+ break;
+ }
+
+ task = task->next;
+
+ /* Remove the task from queue */
+ silc_schedule_task_remove(queue, task->prev);
+ } else {
+ /* The timeout hasn't expired, check for next one */
+
+ /* Break if there isn't more tasks in the queue */
+ if (queue->task == task->next)
+ break;
+
+ task = task->next;
+ }
+ }
+ }
}
-/* Removes a file descriptor from listen list. */
+/* Calculates next timeout for select(). This is the timeout value
+ when at earliest some of the timeout tasks expire. If this is in the
+ past, they will be run now. */
+/* This holds the schedule->lock and the schedule->timeout_queue->lock */
-void silc_schedule_unset_listen_fd(int fd)
+static void silc_schedule_select_timeout(SilcSchedule schedule)
{
- assert(schedule.valid != FALSE);
- assert(fd < schedule.fd_list.max_fd);
+ SilcTaskQueue queue = schedule->timeout_queue;
+ SilcTask task;
+ struct timeval curtime;
- schedule.fd_list.fd[fd] = -1;
-
- if (fd == schedule.fd_list.last_fd) {
- int i;
+ /* Get the current time */
+ silc_gettimeofday(&curtime);
+ schedule->timeout = NULL;
- for (i = fd; i >= 0; i--)
- if (schedule.fd_list.fd[i] != -1)
+ /* First task in the task queue has always the smallest timeout. */
+ task = queue->task;
+ while(1) {
+ if (task && task->valid == TRUE) {
+ /* If the timeout is in past, we will run the task and all other
+ timeout tasks from the past. */
+ if (silc_compare_timeval(&task->timeout, &curtime)) {
+ silc_schedule_dispatch_timeout(schedule, FALSE);
+
+ /* The task(s) has expired and doesn't exist on the task queue
+ anymore. We continue with new timeout. */
+ queue = schedule->timeout_queue;
+ task = queue->task;
+ if (task == NULL || task->valid == FALSE)
+ break;
+ }
+
+ /* Calculate the next timeout for select() */
+ queue->timeout.tv_sec = task->timeout.tv_sec - curtime.tv_sec;
+ queue->timeout.tv_usec = task->timeout.tv_usec - curtime.tv_usec;
+ if (queue->timeout.tv_sec < 0)
+ queue->timeout.tv_sec = 0;
+
+ /* We wouldn't want to go under zero, check for it. */
+ if (queue->timeout.tv_usec < 0) {
+ queue->timeout.tv_sec -= 1;
+ if (queue->timeout.tv_sec < 0)
+ queue->timeout.tv_sec = 0;
+ queue->timeout.tv_usec += 1000000L;
+ }
+
+ /* We've got the timeout value */
+ break;
+ } else {
+ /* Task is not valid, remove it and try next one. */
+ silc_schedule_task_remove(queue, task);
+ task = queue->task;
+ if (queue->task == NULL)
break;
+ }
+ }
- schedule.fd_list.last_fd = i;
+ /* Save the timeout */
+ if (task) {
+ schedule->timeout = &queue->timeout;
+ SILC_LOG_DEBUG(("timeout: sec=%d, usec=%d", schedule->timeout->tv_sec,
+ schedule->timeout->tv_usec));
}
}
-/* Executes tasks matching the file descriptor set by select(). The task
- remains on the task queue after execution. Invalid tasks are removed
- here from the task queue. This macro is used by silc_schedule function.
- We don't have to care about the tasks priority here because the tasks
- are sorted in their priority order already at the registration phase. */
-
-#define SILC_SCHEDULE_RUN_TASKS \
-do { \
- queue = schedule.fd_queue; \
- if (queue && queue->valid == TRUE && queue->task) { \
- task = queue->task; \
- \
- /* Walk thorugh all tasks in the particular task queue and \
- execute the callback functions of those tasks matching the \
- fd set by select(). */ \
- while(1) { \
- /* Validity of the task is checked always before and after \
- execution beacuse the task might have been unregistered \
- in the callback function, ie. it is not valid anymore. */ \
- \
- if (task->valid) { \
- /* Task ready for reading */ \
- if ((FD_ISSET(task->fd, &schedule.in)) && \
- (task->iomask & (1L << SILC_TASK_READ))) { \
- task->callback(queue, SILC_TASK_READ, task->context, task->fd); \
- is_run = TRUE; \
- } \
- } \
- \
- if (task->valid) { \
- /* Task ready for writing */ \
- if ((FD_ISSET(task->fd, &schedule.out)) && \
- (task->iomask & (1L << SILC_TASK_WRITE))) { \
- task->callback(queue, SILC_TASK_WRITE, task->context, task->fd); \
- is_run = TRUE; \
- } \
- } \
- \
- if (!task->valid) { \
- /* Invalid (unregistered) tasks are removed from the \
- task queue. */ \
- if (queue->task == task->next) { \
- silc_task_remove(queue, task); \
- break; \
- } \
- \
- task = task->next; \
- silc_task_remove(queue, task->prev); \
- continue; \
- } \
- \
- /* Break if there isn't more tasks in the queue */ \
- if (queue->task == task->next) \
- break; \
- \
- task = task->next; \
- } \
- } \
-} while(0)
-
-/* Selects tasks to be listened by select(). These are the non-timeout
- tasks. This checks the scheduler's fd list. This macro is used by
- silc_schedule function. */
-
-#define SILC_SCHEDULE_SELECT_TASKS \
-do { \
- for (i = 0; i <= schedule.fd_list.last_fd; i++) { \
- if (schedule.fd_list.fd[i] != -1) { \
- \
- /* Set the max fd value for select() to listen */ \
- if (i > schedule.max_fd) \
- schedule.max_fd = i; \
- \
- /* Add tasks for reading */ \
- if ((schedule.fd_list.fd[i] & (1L << SILC_TASK_READ))) \
- FD_SET(i, &schedule.in); \
- \
- /* Add tasks for writing */ \
- if ((schedule.fd_list.fd[i] & (1L << SILC_TASK_WRITE))) \
- FD_SET(i, &schedule.out); \
- } \
- } \
-} while(0)
+/* Runs the scheduler once and then returns. */
-/* Executes all tasks whose timeout has expired. The task is removed from
- the task queue after the callback function has returned. Also, invalid
- tasks are removed here. The current time must be get before calling this
- macro. This macro is used by silc_schedule function. We don't have to
- care about priorities because tasks are already sorted in their priority
- order at the registration phase. */
-
-#define SILC_SCHEDULE_RUN_TIMEOUT_TASKS \
-do { \
- queue = schedule.timeout_queue; \
- if (queue && queue->valid == TRUE && queue->task) { \
- task = queue->task; \
- \
- /* Walk thorugh all tasks in the particular task queue \
- and run all the expired tasks. */ \
- while(1) { \
- /* Execute the task if the timeout has expired */ \
- if (silc_task_timeout_compare(&task->timeout, &curtime)) { \
- \
- /* Task ready for reading */ \
- if (task->valid) { \
- if ((task->iomask & (1L << SILC_TASK_READ))) \
- task->callback(queue, SILC_TASK_READ, \
- task->context, task->fd); \
- } \
- \
- /* Task ready for writing */ \
- if (task->valid) { \
- if ((task->iomask & (1L << SILC_TASK_WRITE))) \
- task->callback(queue, SILC_TASK_WRITE, \
- task->context, task->fd); \
- } \
- \
- /* Break if there isn't more tasks in the queue */ \
- if (queue->task == task->next) { \
- /* Remove the task from queue */ \
- silc_task_remove(queue, task); \
- break; \
- } \
- \
- task = task->next; \
- \
- /* Remove the task from queue */ \
- silc_task_remove(queue, task->prev); \
- } else { \
- /* The timeout hasn't expired, check for next one */ \
- \
- /* Break if there isn't more tasks in the queue */ \
- if (queue->task == task->next) \
- break; \
- \
- task = task->next; \
- } \
- } \
- } \
-} while(0)
+bool silc_schedule_one(SilcSchedule schedule, int timeout_usecs)
+{
+ struct timeval timeout;
+ int ret;
-/* Calculates next timeout for select(). This is the timeout value
- when at earliest some of the timeout tasks expire. If this is in the
- past, they will be run now. This macro is used by the silc_schedule
- function. */
-
-#define SILC_SCHEDULE_SELECT_TIMEOUT \
-do { \
- if (schedule.timeout_queue && schedule.timeout_queue->valid == TRUE) { \
- queue = schedule.timeout_queue; \
- task = NULL; \
- \
- /* Get the current time */ \
- gettimeofday(&curtime, NULL); \
- schedule.timeout = NULL; \
- \
- /* First task in the task queue has always the smallest timeout. */ \
- task = queue->task; \
- while(1) { \
- if (task && task->valid == TRUE) { \
- \
- /* If the timeout is in past, we will run the task and all other \
- timeout tasks from the past. */ \
- if (silc_task_timeout_compare(&task->timeout, &curtime)) { \
- SILC_SCHEDULE_RUN_TIMEOUT_TASKS; \
- \
- /* The task(s) has expired and doesn't exist on the task queue \
- anymore. We continue with new timeout. */ \
- queue = schedule.timeout_queue; \
- task = queue->task; \
- if (task == NULL || task->valid == FALSE) \
- break; \
- goto cont; \
- } else { \
- cont: \
- /* Calculate the next timeout for select() */ \
- queue->timeout.tv_sec = task->timeout.tv_sec - curtime.tv_sec; \
- queue->timeout.tv_usec = task->timeout.tv_usec - curtime.tv_usec; \
- \
- /* We wouldn't want to go under zero, check for it. */ \
- if (queue->timeout.tv_usec < 0) { \
- queue->timeout.tv_sec -= 1; \
- queue->timeout.tv_usec += 1000000L; \
- } \
- } \
- /* We've got the timeout value */ \
- break; \
- } else { \
- /* Task is not valid, remove it and try next one. */ \
- silc_task_remove(queue, task); \
- task = queue->task; \
- if (queue->task == NULL) \
- break; \
- } \
- } \
- /* Save the timeout */ \
- if (task) \
- schedule.timeout = &queue->timeout; \
- } \
-} while(0)
-
-/* Execute generic tasks. These are executed only and only if for the
- specific fd there wasn't other non-timeout tasks. This checks the earlier
- set fd list, thus the generic tasks apply to all specified fd's. All the
- generic tasks are executed at once. */
-
-#define SILC_SCHEDULE_RUN_GENERIC_TASKS \
-do { \
- if (is_run == FALSE) { \
- SILC_LOG_DEBUG(("Running generic tasks")); \
- for (i = 0; i <= schedule.fd_list.last_fd; i++) \
- if (schedule.fd_list.fd[i] != -1) { \
- \
- /* Check whether this fd is select()ed. */ \
- if ((FD_ISSET(i, &schedule.in)) || (FD_ISSET(i, &schedule.out))) { \
- \
- /* It was selected. Now find the tasks from task queue and execute \
- all generic tasks. */ \
- if (schedule.generic_queue && schedule.generic_queue->valid) { \
- queue = schedule.generic_queue; \
- \
- if (!queue->task) \
- break; \
- \
- task = queue->task; \
- \
- while(1) { \
- /* Validity of the task is checked always before and after \
- execution beacuse the task might have been unregistered \
- in the callback function, ie. it is not valid anymore. */ \
- \
- if (task->valid && schedule.fd_list.fd[i] != -1) { \
- /* Task ready for reading */ \
- if ((schedule.fd_list.fd[i] & (1L << SILC_TASK_READ))) \
- task->callback(queue, SILC_TASK_READ, \
- task->context, i); \
- } \
- \
- if (task->valid && schedule.fd_list.fd[i] != -1) { \
- /* Task ready for writing */ \
- if ((schedule.fd_list.fd[i] & (1L << SILC_TASK_WRITE))) \
- task->callback(queue, SILC_TASK_WRITE, \
- task->context, i); \
- } \
- \
- if (!task->valid) { \
- /* Invalid (unregistered) tasks are removed from the \
- task queue. */ \
- if (queue->task == task->next) { \
- silc_task_remove(queue, task); \
- break; \
- } \
- \
- task = task->next; \
- silc_task_remove(queue, task->prev); \
- continue; \
- } \
- \
- /* Break if there isn't more tasks in the queue */ \
- if (queue->task == task->next) \
- break; \
- \
- task = task->next; \
- } \
- } \
- } \
- } \
- } \
-} while(0)
+ SILC_LOG_DEBUG(("In scheduler loop"));
+
+ if (!schedule->is_locked)
+ SILC_SCHEDULE_LOCK(schedule);
+
+ /* Deliver signals if any has been set to be called */
+ if (schedule->signal_tasks) {
+ SILC_SCHEDULE_UNLOCK(schedule);
+ silc_schedule_internal_signals_call(schedule->internal, schedule);
+ schedule->signal_tasks = FALSE;
+ SILC_SCHEDULE_LOCK(schedule);
+ }
+
+ /* If the task queues aren't initialized or we aren't valid anymore
+ we will return */
+ if ((!schedule->fd_queue && !schedule->timeout_queue
+ && !schedule->generic_queue) || schedule->valid == FALSE) {
+ SILC_LOG_DEBUG(("Scheduler not valid anymore, exiting"));
+ if (!schedule->is_locked)
+ SILC_SCHEDULE_UNLOCK(schedule);
+ return FALSE;
+ }
+
+ /* Calculate next timeout for silc_select(). This is the timeout value
+ when at earliest some of the timeout tasks expire. */
+ silc_mutex_lock(schedule->timeout_queue->lock);
+ silc_schedule_select_timeout(schedule);
+ silc_mutex_unlock(schedule->timeout_queue->lock);
+
+ if (timeout_usecs >= 0) {
+ timeout.tv_sec = 0;
+ timeout.tv_usec = timeout_usecs;
+ schedule->timeout = &timeout;
+ }
+
+ SILC_SCHEDULE_UNLOCK(schedule);
+
+ /* This is the main select(). The program blocks here until some
+ of the selected file descriptors change status or the selected
+ timeout expires. */
+ SILC_LOG_DEBUG(("Select"));
+ ret = silc_select(schedule->fd_list, schedule->last_fd + 1,
+ schedule->timeout);
+
+ SILC_SCHEDULE_LOCK(schedule);
+
+ switch (ret) {
+ case -1:
+ /* Error */
+ if (errno == EINTR)
+ break;
+ SILC_LOG_ERROR(("Error in select(): %s", strerror(errno)));
+ break;
+ case 0:
+ /* Timeout */
+ silc_mutex_lock(schedule->timeout_queue->lock);
+ silc_schedule_dispatch_timeout(schedule, FALSE);
+ silc_mutex_unlock(schedule->timeout_queue->lock);
+ break;
+ default:
+ /* There is some data available now */
+ SILC_LOG_DEBUG(("Running non-timeout tasks"));
+ silc_schedule_dispatch_nontimeout(schedule);
+ break;
+ }
+
+ if (!schedule->is_locked)
+ SILC_SCHEDULE_UNLOCK(schedule);
+
+ return TRUE;
+}
/* The SILC scheduler. This is actually the main routine in SILC programs.
When this returns the program is to be ended. Before this function can
be called, one must call silc_schedule_init function. */
-void silc_schedule()
+void silc_schedule(SilcSchedule schedule)
{
- int is_run, i;
- SilcTask task;
- SilcTaskQueue queue;
- struct timeval curtime;
-
SILC_LOG_DEBUG(("Running scheduler"));
- if (schedule.valid == FALSE) {
+ if (schedule->valid == FALSE) {
SILC_LOG_ERROR(("Scheduler is not valid, stopping"));
return;
}
+ SILC_SCHEDULE_LOCK(schedule);
+ schedule->is_locked = TRUE;
+
/* Start the scheduler loop */
- while(1) {
+ while (silc_schedule_one(schedule, -1))
+ ;
+
+ SILC_SCHEDULE_UNLOCK(schedule);
+}
+
+/* Wakes up the scheduler. This is used only in multi-threaded
+ environments where threads may add new tasks or remove old tasks
+ from task queues. This is called to wake up the scheduler in the
+ main thread so that it detects the changes in the task queues.
+ If threads support is not compiled in this function has no effect.
+ Implementation of this function is platform specific. */
- SILC_LOG_DEBUG(("In scheduler loop"));
+void silc_schedule_wakeup(SilcSchedule schedule)
+{
+#ifdef SILC_THREADS
+ SILC_LOG_DEBUG(("Wakeup scheduler"));
+ SILC_SCHEDULE_LOCK(schedule);
+ silc_schedule_internal_wakeup(schedule->internal);
+ SILC_SCHEDULE_UNLOCK(schedule);
+#endif
+}
+
+/* Returns the application specific context that was saved into the
+ scheduler in silc_schedule_init function. The context is also
+ returned to application in task callback functions, but this function
+ may be used to get it as well if needed. */
+
+void *silc_schedule_get_context(SilcSchedule schedule)
+{
+ return schedule->app_context;
+}
- /* If the task queues aren't initialized or we aren't valid anymore
- we will return */
- if ((!schedule.fd_queue && !schedule.timeout_queue
- && !schedule.generic_queue) || schedule.valid == FALSE) {
- SILC_LOG_DEBUG(("Scheduler not valid anymore, exiting"));
+/* Add new task to the scheduler */
+
+SilcTask silc_schedule_task_add(SilcSchedule schedule, SilcUInt32 fd,
+ SilcTaskCallback callback, void *context,
+ long seconds, long useconds,
+ SilcTaskType type,
+ SilcTaskPriority priority)
+{
+ SilcTask newtask;
+ SilcTaskQueue queue;
+ int timeout = FALSE;
+
+ if (!schedule->valid)
+ return NULL;
+
+ SILC_LOG_DEBUG(("Registering new task, fd=%d type=%d priority=%d", fd,
+ type, priority));
+
+ queue = SILC_SCHEDULE_GET_QUEUE(type);
+
+ /* If the task is generic task, we check whether this task has already
+ been registered. Generic tasks are registered only once and after that
+ the same task applies to all file descriptors to be registered. */
+ if (type == SILC_TASK_GENERIC) {
+ silc_mutex_lock(queue->lock);
+
+ if (queue->task) {
+ SilcTask task = queue->task;
+ while(1) {
+ if ((task->callback == callback) && (task->context == context)) {
+ SILC_LOG_DEBUG(("Found matching generic task, using the match"));
+
+ silc_mutex_unlock(queue->lock);
+
+ /* Add the fd to be listened, the task found now applies to this
+ fd as well. */
+ silc_schedule_set_listen_fd(schedule, fd, SILC_TASK_READ, FALSE);
+ return task;
+ }
+
+ if (queue->task == task->next)
+ break;
+
+ task = task->next;
+ }
+ }
+
+ silc_mutex_unlock(queue->lock);
+ }
+
+ newtask = silc_calloc(1, sizeof(*newtask));
+ newtask->fd = fd;
+ newtask->context = context;
+ newtask->callback = callback;
+ newtask->valid = TRUE;
+ newtask->priority = priority;
+ newtask->type = type;
+ newtask->next = newtask;
+ newtask->prev = newtask;
+
+ /* Create timeout if marked to be timeout task */
+ if (((seconds + useconds) > 0) && (type == SILC_TASK_TIMEOUT)) {
+ silc_gettimeofday(&newtask->timeout);
+ newtask->timeout.tv_sec += seconds + (useconds / 1000000L);
+ newtask->timeout.tv_usec += (useconds % 1000000L);
+ if (newtask->timeout.tv_usec > 999999L) {
+ newtask->timeout.tv_sec += 1;
+ newtask->timeout.tv_usec -= 1000000L;
+ }
+ timeout = TRUE;
+ }
+
+ /* If the task is non-timeout task we have to tell the scheduler that we
+ would like to have these tasks scheduled at some odd distant future. */
+ if (type != SILC_TASK_TIMEOUT)
+ silc_schedule_set_listen_fd(schedule, fd, SILC_TASK_READ, FALSE);
+
+ silc_mutex_lock(queue->lock);
+
+ /* Is this first task of the queue? */
+ if (queue->task == NULL) {
+ queue->task = newtask;
+ silc_mutex_unlock(queue->lock);
+ return newtask;
+ }
+
+ if (timeout)
+ newtask = silc_task_add_timeout(queue, newtask, priority);
+ else
+ newtask = silc_task_add(queue, newtask, priority);
+
+ silc_mutex_unlock(queue->lock);
+
+ return newtask;
+}
+
+/* Removes a task from the scheduler */
+
+void silc_schedule_task_del(SilcSchedule schedule, SilcTask task)
+{
+ SilcTaskQueue queue = SILC_SCHEDULE_GET_QUEUE(task->type);
+
+ /* Unregister all tasks */
+ if (task == SILC_ALL_TASKS) {
+ SilcTask next;
+ SILC_LOG_DEBUG(("Unregistering all tasks at once"));
+
+ silc_mutex_lock(queue->lock);
+
+ if (!queue->task) {
+ silc_mutex_unlock(queue->lock);
+ return;
+ }
+
+ next = queue->task;
+
+ while(1) {
+ if (next->valid)
+ next->valid = FALSE;
+ if (queue->task == next->next)
+ break;
+ next = next->next;
+ }
+
+ silc_mutex_unlock(queue->lock);
+ return;
+ }
+
+ SILC_LOG_DEBUG(("Unregistering task"));
+
+ silc_mutex_lock(queue->lock);
+
+ /* Unregister the specific task */
+ if (task->valid)
+ task->valid = FALSE;
+
+ silc_mutex_unlock(queue->lock);
+}
+
+/* Remove task by fd */
+
+void silc_schedule_task_del_by_fd(SilcSchedule schedule, SilcUInt32 fd)
+{
+ SILC_LOG_DEBUG(("Unregister task by fd %d", fd));
+
+ silc_task_del_by_fd(schedule->timeout_queue, fd);
+ silc_task_del_by_fd(schedule->fd_queue, fd);
+}
+
+/* Remove task by task callback. */
+
+void silc_schedule_task_del_by_callback(SilcSchedule schedule,
+ SilcTaskCallback callback)
+{
+ SILC_LOG_DEBUG(("Unregister task by callback"));
+
+ silc_task_del_by_callback(schedule->timeout_queue, callback);
+ silc_task_del_by_callback(schedule->fd_queue, callback);
+ silc_task_del_by_callback(schedule->generic_queue, callback);
+}
+
+/* Remove task by context. */
+
+void silc_schedule_task_del_by_context(SilcSchedule schedule, void *context)
+{
+ SILC_LOG_DEBUG(("Unregister task by context"));
+
+ silc_task_del_by_context(schedule->timeout_queue, context);
+ silc_task_del_by_context(schedule->fd_queue, context);
+ silc_task_del_by_context(schedule->generic_queue, context);
+}
+
+/* Sets a file descriptor to be listened by select() in scheduler. One can
+ call this directly if wanted. This can be called multiple times for
+ one file descriptor to set different iomasks. */
+
+void silc_schedule_set_listen_fd(SilcSchedule schedule, SilcUInt32 fd,
+ SilcTaskEvent mask, bool send_events)
+{
+ int i;
+ bool found = FALSE;
+
+ if (!schedule->valid)
+ return;
+
+ SILC_SCHEDULE_LOCK(schedule);
+
+ for (i = 0; i < schedule->max_fd; i++)
+ if (schedule->fd_list[i].fd == fd) {
+ schedule->fd_list[i].fd = fd;
+ schedule->fd_list[i].events = mask;
+ if (i > schedule->last_fd)
+ schedule->last_fd = i;
+ found = TRUE;
+ if (send_events) {
+ schedule->fd_list[i].revents = mask;
+ silc_schedule_dispatch_nontimeout(schedule);
+ }
break;
}
- /* Clear everything */
- FD_ZERO(&schedule.in);
- FD_ZERO(&schedule.out);
- schedule.max_fd = -1;
- is_run = FALSE;
+ if (!found)
+ for (i = 0; i < schedule->max_fd; i++)
+ if (schedule->fd_list[i].events == 0) {
+ schedule->fd_list[i].fd = fd;
+ schedule->fd_list[i].events = mask;
+ if (i > schedule->last_fd)
+ schedule->last_fd = i;
+ if (send_events) {
+ schedule->fd_list[i].revents = mask;
+ silc_schedule_dispatch_nontimeout(schedule);
+ }
+ break;
+ }
+
+ SILC_SCHEDULE_UNLOCK(schedule);
+}
+
+/* Removes a file descriptor from listen list. */
+
+void silc_schedule_unset_listen_fd(SilcSchedule schedule, SilcUInt32 fd)
+{
+ int i;
+
+ SILC_SCHEDULE_LOCK(schedule);
+
+ SILC_LOG_DEBUG(("Unset listen fd %d", fd));
+
+ for (i = 0; i < schedule->max_fd; i++)
+ if (schedule->fd_list[i].fd == fd) {
+ schedule->fd_list[i].fd = 0;
+ schedule->fd_list[i].events = 0;
+ if (schedule->last_fd == i)
+ schedule->last_fd = schedule->max_fd - 1;
+ break;
+ }
+
+ SILC_SCHEDULE_UNLOCK(schedule);
+}
+
+/* Register a new signal */
+
+void silc_schedule_signal_register(SilcSchedule schedule, SilcUInt32 signal,
+ SilcTaskCallback callback, void *context)
+{
+ silc_schedule_internal_signal_register(schedule->internal, signal,
+ callback, context);
+}
+
+/* Unregister a new signal */
+
+void silc_schedule_signal_unregister(SilcSchedule schedule, SilcUInt32 signal,
+ SilcTaskCallback callback, void *context)
+{
+ silc_schedule_internal_signal_unregister(schedule->internal, signal,
+ callback, context);
+}
+
+/* Call signal indicated by `signal'. */
+
+void silc_schedule_signal_call(SilcSchedule schedule, SilcUInt32 signal)
+{
+ /* Mark that signals needs to be delivered later. */
+ silc_schedule_internal_signal_call(schedule->internal, signal);
+ schedule->signal_tasks = TRUE;
+}
+
+/* Allocates a newtask task queue into the scheduler */
+
+static void silc_task_queue_alloc(SilcTaskQueue *queue)
+{
+ *queue = silc_calloc(1, sizeof(**queue));
+ silc_mutex_alloc(&(*queue)->lock);
+}
+
+/* Free's a task queue. */
+
+static void silc_task_queue_free(SilcTaskQueue queue)
+{
+ silc_mutex_free(queue->lock);
+ memset(queue, 'F', sizeof(*queue));
+ silc_free(queue);
+}
+
+/* Return task by its fd. */
+
+static SilcTask silc_task_find(SilcTaskQueue queue, SilcUInt32 fd)
+{
+ SilcTask next;
+
+ if (!queue->task)
+ return NULL;
+
+ next = queue->task;
+
+ while (1) {
+ if (next->fd == fd)
+ return next;
+ if (queue->task == next->next)
+ return NULL;
+ next = next->next;
+ }
+
+ return NULL;
+}
+
+/* Adds a non-timeout task into the task queue. This function is used
+ by silc_task_register function. Returns a pointer to the registered
+ task. */
+
+static SilcTask silc_task_add(SilcTaskQueue queue, SilcTask newtask,
+ SilcTaskPriority priority)
+{
+ SilcTask task, next, prev;
+
+ /* Take the first task in the queue */
+ task = queue->task;
+
+ switch(priority) {
+ case SILC_TASK_PRI_LOW:
+ /* Lowest priority. The task is added at the end of the list. */
+ prev = task->prev;
+ newtask->prev = prev;
+ newtask->next = task;
+ prev->next = newtask;
+ task->prev = newtask;
+ break;
+ case SILC_TASK_PRI_NORMAL:
+ /* Normal priority. The task is added before lower priority tasks
+ but after tasks with higher priority. */
+ prev = task->prev;
+ while(prev != task) {
+ if (prev->priority > SILC_TASK_PRI_LOW)
+ break;
+ prev = prev->prev;
+ }
+ if (prev == task) {
+ /* There are only lower priorities in the list, we will
+ sit before them and become the first task in the queue. */
+ prev = task->prev;
+ newtask->prev = prev;
+ newtask->next = task;
+ task->prev = newtask;
+ prev->next = newtask;
+
+ /* We are now the first task in queue */
+ queue->task = newtask;
+ } else {
+ /* Found a spot from the list, add the task to the list. */
+ next = prev->next;
+ newtask->prev = prev;
+ newtask->next = next;
+ prev->next = newtask;
+ next->prev = newtask;
+ }
+ break;
+ default:
+ silc_free(newtask);
+ return NULL;
+ }
+
+ return newtask;
+}
+
+/* Return the timeout task with smallest timeout. */
+
+static SilcTask silc_task_get_first(SilcTaskQueue queue, SilcTask first)
+{
+ SilcTask prev, task;
- /* Calculate next timeout for select(). This is the timeout value
- when at earliest some of the timeout tasks expire. */
- SILC_SCHEDULE_SELECT_TIMEOUT;
+ prev = first->prev;
- /* Add the file descriptors to the fd sets. These are the non-timeout
- tasks. The select() listens to these file descriptors. */
- SILC_SCHEDULE_SELECT_TASKS;
+ if (first == prev)
+ return first;
- if (schedule.max_fd == -1) {
- SILC_LOG_ERROR(("Nothing to listen, exiting"));
+ task = first;
+ while (1) {
+ if (first == prev)
break;
+
+ if (silc_compare_timeval(&prev->timeout, &task->timeout))
+ task = prev;
+
+ prev = prev->prev;
+ }
+
+ return task;
+}
+
+/* Adds a timeout task into the task queue. This function is used by
+ silc_task_register function. Returns a pointer to the registered
+ task. Timeout tasks are sorted by their timeout value in ascending
+ order. The priority matters if there are more than one task with
+ same timeout. */
+
+static SilcTask silc_task_add_timeout(SilcTaskQueue queue, SilcTask newtask,
+ SilcTaskPriority priority)
+{
+ SilcTask task, prev, next;
+
+ /* Take the first task in the queue */
+ task = queue->task;
+
+ /* Take last task from the list */
+ prev = task->prev;
+
+ switch(priority) {
+ case SILC_TASK_PRI_LOW:
+ /* Lowest priority. The task is added at the end of the list. */
+ while(prev != task) {
+
+ /* If we have longer timeout than with the task head of us
+ we have found our spot. */
+ if (silc_compare_timeval(&prev->timeout, &newtask->timeout))
+ break;
+
+ /* If we are equal size of timeout we will be after it. */
+ if (!silc_compare_timeval(&newtask->timeout, &prev->timeout))
+ break;
+
+ /* We have shorter timeout, compare to next one. */
+ prev = prev->prev;
}
+ /* Found a spot from the list, add the task to the list. */
+ next = prev->next;
+ newtask->prev = prev;
+ newtask->next = next;
+ prev->next = newtask;
+ next->prev = newtask;
+
+ if (prev == task) {
+ /* Check if we are going to be the first task in the queue */
+ if (silc_compare_timeval(&prev->timeout, &newtask->timeout))
+ break;
+ if (!silc_compare_timeval(&newtask->timeout, &prev->timeout))
+ break;
+
+ /* We are now the first task in queue */
+ queue->task = newtask;
+ }
+ break;
+ case SILC_TASK_PRI_NORMAL:
+ /* Normal priority. The task is added before lower priority tasks
+ but after tasks with higher priority. */
+ while(prev != task) {
+
+ /* If we have longer timeout than with the task head of us
+ we have found our spot. */
+ if (silc_compare_timeval(&prev->timeout, &newtask->timeout))
+ break;
- if (schedule.timeout) {
- SILC_LOG_DEBUG(("timeout: sec=%d, usec=%d", schedule.timeout->tv_sec,
- schedule.timeout->tv_usec));
+ /* If we are equal size of timeout, priority kicks in place. */
+ if (!silc_compare_timeval(&newtask->timeout, &prev->timeout))
+ if (prev->priority >= SILC_TASK_PRI_NORMAL)
+ break;
+
+ /* We have shorter timeout or higher priority, compare to next one. */
+ prev = prev->prev;
+ }
+ /* Found a spot from the list, add the task to the list. */
+ next = prev->next;
+ newtask->prev = prev;
+ newtask->next = next;
+ prev->next = newtask;
+ next->prev = newtask;
+
+ if (prev == task) {
+ /* Check if we are going to be the first task in the queue */
+ if (silc_compare_timeval(&prev->timeout, &newtask->timeout))
+ break;
+ if (!silc_compare_timeval(&newtask->timeout, &prev->timeout))
+ if (prev->priority >= SILC_TASK_PRI_NORMAL)
+ break;
+
+ /* We are now the first task in queue */
+ queue->task = newtask;
}
+ break;
+ default:
+ silc_free(newtask);
+ return NULL;
+ }
+
+ return newtask;
+}
+
+/* Removes (unregisters) a task from particular task queue. This function
+ is used internally by scheduler. This must be called holding the
+ queue->lock. */
+
+static int silc_schedule_task_remove(SilcTaskQueue queue, SilcTask task)
+{
+ SilcTask first, old, next;
+
+ if (!queue || !task)
+ return FALSE;
- /* This is the main select(). The program blocks here until some
- of the selected file descriptors change status or the selected
- timeout expires. */
- SILC_LOG_DEBUG(("Select"));
- switch(select(schedule.max_fd + 1, &schedule.in,
- &schedule.out, 0, schedule.timeout)) {
- case -1:
- /* Error */
- SILC_LOG_ERROR(("Error in select(): %s", strerror(errno)));
+ if (!queue->task) {
+ return FALSE;
+ }
+
+ first = queue->task;
+
+ /* Unregister all tasks in queue */
+ if (task == SILC_ALL_TASKS) {
+ SILC_LOG_DEBUG(("Removing all tasks at once"));
+ next = first;
+
+ while(1) {
+ old = next->next;
+ silc_free(next);
+ if (old == first)
+ break;
+ next = old;
+ }
+
+ queue->task = NULL;
+ return TRUE;
+ }
+
+ SILC_LOG_DEBUG(("Removing task"));
+
+ /* Unregister the task */
+ old = first;
+ while(1) {
+ if (old == task) {
+ SilcTask prev, next;
+
+ prev = old->prev;
+ next = old->next;
+ prev->next = next;
+ next->prev = prev;
+
+ if (prev == old && next == old)
+ queue->task = NULL;
+ if (queue->task == old)
+ queue->task = silc_task_get_first(queue, next);
+
+ silc_free(old);
+ return TRUE;
+ }
+ old = old->prev;
+
+ if (old == first) {
+ return FALSE;
+ }
+ }
+}
+
+static void silc_task_del_by_fd(SilcTaskQueue queue, SilcUInt32 fd)
+{
+ SilcTask next;
+
+ silc_mutex_lock(queue->lock);
+
+ if (!queue->task) {
+ silc_mutex_unlock(queue->lock);
+ return;
+ }
+
+ next = queue->task;
+
+ while(1) {
+ if (next->fd == fd)
+ next->valid = FALSE;
+ if (queue->task == next->next)
break;
- case 0:
- /* Timeout */
- SILC_LOG_DEBUG(("Running timeout tasks"));
- gettimeofday(&curtime, NULL);
- SILC_SCHEDULE_RUN_TIMEOUT_TASKS;
+ next = next->next;
+ }
+
+ silc_mutex_unlock(queue->lock);
+}
+
+static void silc_task_del_by_callback(SilcTaskQueue queue,
+ SilcTaskCallback callback)
+{
+ SilcTask next;
+
+ silc_mutex_lock(queue->lock);
+
+ if (!queue->task) {
+ silc_mutex_unlock(queue->lock);
+ return;
+ }
+
+ next = queue->task;
+
+ while(1) {
+ if (next->callback == callback)
+ next->valid = FALSE;
+ if (queue->task == next->next)
break;
- default:
- /* There is some data available now */
- SILC_LOG_DEBUG(("Running non-timeout tasks"));
- SILC_SCHEDULE_RUN_TASKS;
+ next = next->next;
+ }
- SILC_SCHEDULE_RUN_GENERIC_TASKS;
+ silc_mutex_unlock(queue->lock);
+}
+
+static void silc_task_del_by_context(SilcTaskQueue queue, void *context)
+{
+ SilcTask next;
+
+ silc_mutex_lock(queue->lock);
+
+ if (!queue->task) {
+ silc_mutex_unlock(queue->lock);
+ return;
+ }
+
+ next = queue->task;
+
+ while(1) {
+ if (next->context == context)
+ next->valid = FALSE;
+ if (queue->task == next->next)
break;
- }
+ next = next->next;
}
+
+ silc_mutex_unlock(queue->lock);
}
projects / silc.git / blobdiff