/*
This file is part of GNUnet
Copyright (C) 2009-2017 GNUnet e.V.
GNUnet 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 3, or (at your
option) any later version.
GNUnet 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 GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
/**
* @file util/scheduler.c
* @brief schedule computations using continuation passing style
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "disk.h"
#define LOG(kind,...) GNUNET_log_from (kind, "util-scheduler", __VA_ARGS__)
#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util-scheduler", syscall)
#if HAVE_EXECINFO_H
#include "execinfo.h"
/**
* Use lsof to generate file descriptor reports on select error?
* (turn off for stable releases).
*/
#define USE_LSOF GNUNET_NO
/**
* Obtain trace information for all scheduler calls that schedule tasks.
*/
#define EXECINFO GNUNET_NO
/**
* Check each file descriptor before adding
*/
#define DEBUG_FDS GNUNET_NO
/**
* Depth of the traces collected via EXECINFO.
*/
#define MAX_TRACE_DEPTH 50
#endif
/**
* Should we figure out which tasks are delayed for a while
* before they are run? (Consider using in combination with EXECINFO).
*/
#define PROFILE_DELAYS GNUNET_NO
/**
* Task that were in the queue for longer than this are reported if
* PROFILE_DELAYS is active.
*/
#define DELAY_THRESHOLD GNUNET_TIME_UNIT_SECONDS
/**
* Argument to be passed from the driver to
* #GNUNET_SCHEDULER_run_from_driver(). Contains the
* scheduler's internal state.
*/
struct GNUNET_SCHEDULER_Handle
{
/**
* Passed here to avoid constantly allocating/deallocating
* this element, but generally we want to get rid of this.
* @deprecated
*/
struct GNUNET_NETWORK_FDSet *rs;
/**
* Passed here to avoid constantly allocating/deallocating
* this element, but generally we want to get rid of this.
* @deprecated
*/
struct GNUNET_NETWORK_FDSet *ws;
/**
* Driver we used for the event loop.
*/
const struct GNUNET_SCHEDULER_Driver *driver;
};
/**
* Entry in list of pending tasks.
*/
struct GNUNET_SCHEDULER_Task
{
/**
* This is a linked list.
*/
struct GNUNET_SCHEDULER_Task *next;
/**
* This is a linked list.
*/
struct GNUNET_SCHEDULER_Task *prev;
/**
* Function to run when ready.
*/
GNUNET_SCHEDULER_TaskCallback callback;
/**
* Closure for the @e callback.
*/
void *callback_cls;
/**
* Handle to the scheduler's state.
*/
const struct GNUNET_SCHEDULER_Handle *sh;
/**
* Set of file descriptors this task is waiting
* for for reading. Once ready, this is updated
* to reflect the set of file descriptors ready
* for operation.
*/
struct GNUNET_NETWORK_FDSet *read_set;
/**
* Set of file descriptors this task is waiting for for writing.
* Once ready, this is updated to reflect the set of file
* descriptors ready for operation.
*/
struct GNUNET_NETWORK_FDSet *write_set;
/**
* Information about which FDs are ready for this task (and why).
*/
const struct GNUNET_SCHEDULER_FdInfo *fds;
/**
* Storage location used for @e fds if we want to avoid
* a separate malloc() call in the common case that this
* task is only about a single FD.
*/
struct GNUNET_SCHEDULER_FdInfo fdx;
/**
* Absolute timeout value for the task, or
* #GNUNET_TIME_UNIT_FOREVER_ABS for "no timeout".
*/
struct GNUNET_TIME_Absolute timeout;
#if PROFILE_DELAYS
/**
* When was the task scheduled?
*/
struct GNUNET_TIME_Absolute start_time;
#endif
/**
* Size of the @e fds array.
*/
unsigned int fds_len;
/**
* Why is the task ready? Set after task is added to ready queue.
* Initially set to zero. All reasons that have already been
* satisfied (i.e. read or write ready) will be set over time.
*/
enum GNUNET_SCHEDULER_Reason reason;
/**
* Task priority.
*/
enum GNUNET_SCHEDULER_Priority priority;
/**
* Set if we only wait for reading from a single FD, otherwise -1.
*/
int read_fd;
/**
* Set if we only wait for writing to a single FD, otherwise -1.
*/
int write_fd;
/**
* Should the existence of this task in the queue be counted as
* reason to not shutdown the scheduler?
*/
int lifeness;
/**
* Is this task run on shutdown?
*/
int on_shutdown;
/**
* Is this task in the ready list?
*/
int in_ready_list;
#if EXECINFO
/**
* Array of strings which make up a backtrace from the point when this
* task was scheduled (essentially, who scheduled the task?)
*/
char **backtrace_strings;
/**
* Size of the backtrace_strings array
*/
int num_backtrace_strings;
#endif
};
/**
* Head of list of tasks waiting for an event.
*/
static struct GNUNET_SCHEDULER_Task *pending_head;
/**
* Tail of list of tasks waiting for an event.
*/
static struct GNUNET_SCHEDULER_Task *pending_tail;
/**
* Head of list of tasks waiting for shutdown.
*/
static struct GNUNET_SCHEDULER_Task *shutdown_head;
/**
* Tail of list of tasks waiting for shutdown.
*/
static struct GNUNET_SCHEDULER_Task *shutdown_tail;
/**
* List of tasks waiting ONLY for a timeout event.
* Sorted by timeout (earliest first). Used so that
* we do not traverse the list of these tasks when
* building select sets (we just look at the head
* to determine the respective timeout ONCE).
*/
static struct GNUNET_SCHEDULER_Task *pending_timeout_head;
/**
* List of tasks waiting ONLY for a timeout event.
* Sorted by timeout (earliest first). Used so that
* we do not traverse the list of these tasks when
* building select sets (we just look at the head
* to determine the respective timeout ONCE).
*/
static struct GNUNET_SCHEDULER_Task *pending_timeout_tail;
/**
* Last inserted task waiting ONLY for a timeout event.
* Used to (heuristically) speed up insertion.
*/
static struct GNUNET_SCHEDULER_Task *pending_timeout_last;
/**
* ID of the task that is running right now.
*/
static struct GNUNET_SCHEDULER_Task *active_task;
/**
* Head of list of tasks ready to run right now, grouped by importance.
*/
static struct GNUNET_SCHEDULER_Task *ready_head[GNUNET_SCHEDULER_PRIORITY_COUNT];
/**
* Tail of list of tasks ready to run right now, grouped by importance.
*/
static struct GNUNET_SCHEDULER_Task *ready_tail[GNUNET_SCHEDULER_PRIORITY_COUNT];
/**
* Number of tasks on the ready list.
*/
static unsigned int ready_count;
/**
* How many tasks have we run so far?
*/
static unsigned long long tasks_run;
/**
* Priority of the task running right now. Only
* valid while a task is running.
*/
static enum GNUNET_SCHEDULER_Priority current_priority;
/**
* Priority of the highest task added in the current select
* iteration.
*/
static enum GNUNET_SCHEDULER_Priority max_priority_added;
/**
* Value of the 'lifeness' flag for the current task.
*/
static int current_lifeness;
/**
* Function to use as a select() in the scheduler.
* If NULL, we use GNUNET_NETWORK_socket_select().
*/
static GNUNET_SCHEDULER_select scheduler_select;
/**
* Task context of the current task.
*/
static struct GNUNET_SCHEDULER_TaskContext tc;
/**
* Closure for #scheduler_select.
*/
static void *scheduler_select_cls;
/**
* Sets the select function to use in the scheduler (scheduler_select).
*
* @param new_select new select function to use
* @param new_select_cls closure for @a new_select
* @return previously used select function, NULL for default
*/
void
GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
void *new_select_cls)
{
scheduler_select = new_select;
scheduler_select_cls = new_select_cls;
}
/**
* Check that the given priority is legal (and return it).
*
* @param p priority value to check
* @return p on success, 0 on error
*/
static enum GNUNET_SCHEDULER_Priority
check_priority (enum GNUNET_SCHEDULER_Priority p)
{
if ((p >= 0) && (p < GNUNET_SCHEDULER_PRIORITY_COUNT))
return p;
GNUNET_assert (0);
return 0; /* make compiler happy */
}
/**
* Update all sets and timeout for select.
*
* @param rs read-set, set to all FDs we would like to read (updated)
* @param ws write-set, set to all FDs we would like to write (updated)
* @param timeout next timeout (updated)
*/
static void
update_sets (struct GNUNET_NETWORK_FDSet *rs,
struct GNUNET_NETWORK_FDSet *ws,
struct GNUNET_TIME_Relative *timeout)
{
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_TIME_Absolute now;
struct GNUNET_TIME_Relative to;
now = GNUNET_TIME_absolute_get ();
pos = pending_timeout_head;
if (NULL != pos)
{
to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
if (timeout->rel_value_us > to.rel_value_us)
*timeout = to;
if (0 != pos->reason)
*timeout = GNUNET_TIME_UNIT_ZERO;
}
for (pos = pending_head; NULL != pos; pos = pos->next)
{
if (pos->timeout.abs_value_us != GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us)
{
to = GNUNET_TIME_absolute_get_difference (now, pos->timeout);
if (timeout->rel_value_us > to.rel_value_us)
*timeout = to;
}
if (-1 != pos->read_fd)
GNUNET_NETWORK_fdset_set_native (rs, pos->read_fd);
if (-1 != pos->write_fd)
GNUNET_NETWORK_fdset_set_native (ws, pos->write_fd);
if (NULL != pos->read_set)
GNUNET_NETWORK_fdset_add (rs, pos->read_set);
if (NULL != pos->write_set)
GNUNET_NETWORK_fdset_add (ws, pos->write_set);
if (0 != pos->reason)
*timeout = GNUNET_TIME_UNIT_ZERO;
}
}
/**
* Check if the ready set overlaps with the set we want to have ready.
* If so, update the want set (set all FDs that are ready). If not,
* return #GNUNET_NO.
*
* @param ready set that is ready
* @param want set that we want to be ready
* @return #GNUNET_YES if there was some overlap
*/
static int
set_overlaps (const struct GNUNET_NETWORK_FDSet *ready,
struct GNUNET_NETWORK_FDSet *want)
{
if ((NULL == want) || (NULL == ready))
return GNUNET_NO;
if (GNUNET_NETWORK_fdset_overlap (ready, want))
{
/* copy all over (yes, there maybe unrelated bits,
* but this should not hurt well-written clients) */
GNUNET_NETWORK_fdset_copy (want, ready);
return GNUNET_YES;
}
return GNUNET_NO;
}
/**
* Check if the given task is eligible to run now.
* Also set the reason why it is eligible.
*
* @param task task to check if it is ready
* @param now the current time
* @param rs set of FDs ready for reading
* @param ws set of FDs ready for writing
* @return #GNUNET_YES if we can run it, #GNUNET_NO if not.
*/
static int
is_ready (struct GNUNET_SCHEDULER_Task *task,
struct GNUNET_TIME_Absolute now,
const struct GNUNET_NETWORK_FDSet *rs,
const struct GNUNET_NETWORK_FDSet *ws)
{
enum GNUNET_SCHEDULER_Reason reason;
reason = task->reason;
if (now.abs_value_us >= task->timeout.abs_value_us)
reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
if ((0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
(((task->read_fd != -1) &&
(GNUNET_YES == GNUNET_NETWORK_fdset_test_native (rs, task->read_fd))) ||
(set_overlaps (rs, task->read_set))))
reason |= GNUNET_SCHEDULER_REASON_READ_READY;
if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
(((task->write_fd != -1) &&
(GNUNET_YES == GNUNET_NETWORK_fdset_test_native (ws, task->write_fd)))
|| (set_overlaps (ws, task->write_set))))
reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
if (0 == reason)
return GNUNET_NO; /* not ready */
reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
task->reason = reason;
return GNUNET_YES;
}
/**
* Put a task that is ready for execution into the ready queue.
*
* @param task task ready for execution
*/
static void
queue_ready_task (struct GNUNET_SCHEDULER_Task *task)
{
enum GNUNET_SCHEDULER_Priority p = check_priority (task->priority);
GNUNET_CONTAINER_DLL_insert (ready_head[p],
ready_tail[p],
task);
task->in_ready_list = GNUNET_YES;
ready_count++;
}
/**
* Check which tasks are ready and move them
* to the respective ready queue.
*
* @param rs FDs ready for reading
* @param ws FDs ready for writing
*/
static void
check_ready (const struct GNUNET_NETWORK_FDSet *rs,
const struct GNUNET_NETWORK_FDSet *ws)
{
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_SCHEDULER_Task *next;
struct GNUNET_TIME_Absolute now;
now = GNUNET_TIME_absolute_get ();
while (NULL != (pos = pending_timeout_head))
{
if (now.abs_value_us >= pos->timeout.abs_value_us)
pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
if (0 == pos->reason)
break;
GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
pending_timeout_tail,
pos);
if (pending_timeout_last == pos)
pending_timeout_last = NULL;
queue_ready_task (pos);
}
pos = pending_head;
while (NULL != pos)
{
next = pos->next;
if (GNUNET_YES == is_ready (pos, now, rs, ws))
{
GNUNET_CONTAINER_DLL_remove (pending_head,
pending_tail,
pos);
queue_ready_task (pos);
}
pos = next;
}
}
/**
* Request the shutdown of a scheduler. Marks all tasks
* awaiting shutdown as ready. Note that tasks
* scheduled with #GNUNET_SCHEDULER_add_shutdown() AFTER this call
* will be delayed until the next shutdown signal.
*/
void
GNUNET_SCHEDULER_shutdown ()
{
struct GNUNET_SCHEDULER_Task *pos;
while (NULL != (pos = shutdown_head))
{
GNUNET_CONTAINER_DLL_remove (shutdown_head,
shutdown_tail,
pos);
pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
queue_ready_task (pos);
}
}
/**
* Destroy a task (release associated resources)
*
* @param t task to destroy
*/
static void
destroy_task (struct GNUNET_SCHEDULER_Task *t)
{
if (NULL != t->read_set)
GNUNET_NETWORK_fdset_destroy (t->read_set);
if (NULL != t->write_set)
GNUNET_NETWORK_fdset_destroy (t->write_set);
#if EXECINFO
GNUNET_free (t->backtrace_strings);
#endif
GNUNET_free (t);
}
/**
* Output stack trace of task @a t.
*
* @param t task to dump stack trace of
*/
static void
dump_backtrace (struct GNUNET_SCHEDULER_Task *t)
{
#if EXECINFO
unsigned int i;
for (i = 0; i < t->num_backtrace_strings; i++)
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Task %p trace %u: %s\n",
t,
i,
t->backtrace_strings[i]);
#endif
}
/**
* Run at least one task in the highest-priority queue that is not
* empty. Keep running tasks until we are either no longer running
* "URGENT" tasks or until we have at least one "pending" task (which
* may become ready, hence we should select on it). Naturally, if
* there are no more ready tasks, we also return.
*
* @param rs FDs ready for reading
* @param ws FDs ready for writing
*/
static void
run_ready (struct GNUNET_NETWORK_FDSet *rs,
struct GNUNET_NETWORK_FDSet *ws)
{
enum GNUNET_SCHEDULER_Priority p;
struct GNUNET_SCHEDULER_Task *pos;
max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
do
{
if (0 == ready_count)
return;
GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
/* yes, p>0 is correct, 0 is "KEEP" which should
* always be an empty queue (see assertion)! */
for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
{
pos = ready_head[p];
if (NULL != pos)
break;
}
GNUNET_assert (NULL != pos); /* ready_count wrong? */
GNUNET_CONTAINER_DLL_remove (ready_head[p],
ready_tail[p],
pos);
ready_count--;
current_priority = pos->priority;
current_lifeness = pos->lifeness;
active_task = pos;
#if PROFILE_DELAYS
if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
DELAY_THRESHOLD.rel_value_us)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Task %p took %s to be scheduled\n",
pos,
GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->start_time),
GNUNET_YES));
}
#endif
tc.reason = pos->reason;
tc.read_ready = (NULL == pos->read_set) ? rs : pos->read_set;
if ((-1 != pos->read_fd) &&
(0 != (pos->reason & GNUNET_SCHEDULER_REASON_READ_READY)))
GNUNET_NETWORK_fdset_set_native (rs, pos->read_fd);
tc.write_ready = (NULL == pos->write_set) ? ws : pos->write_set;
if ((-1 != pos->write_fd) &&
(0 != (pos->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)))
GNUNET_NETWORK_fdset_set_native (ws, pos->write_fd);
if ((0 != (tc.reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
(-1 != pos->write_fd) &&
(!GNUNET_NETWORK_fdset_test_native (ws, pos->write_fd)))
GNUNET_assert (0); // added to ready in previous select loop!
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Running task: %p\n",
pos);
pos->callback (pos->callback_cls);
dump_backtrace (pos);
active_task = NULL;
destroy_task (pos);
tasks_run++;
}
while ((NULL == pending_head) || (p >= max_priority_added));
}
/**
* Pipe used to communicate shutdown via signal.
*/
static struct GNUNET_DISK_PipeHandle *shutdown_pipe_handle;
/**
* Process ID of this process at the time we installed the various
* signal handlers.
*/
static pid_t my_pid;
/**
* Signal handler called for SIGPIPE.
*/
#ifndef MINGW
static void
sighandler_pipe ()
{
return;
}
#endif
/**
* Wait for a short time.
* Sleeps for @a ms ms (as that should be long enough for virtually all
* modern systems to context switch and allow another process to do
* some 'real' work).
*
* @param ms how many ms to wait
*/
static void
short_wait (unsigned int ms)
{
struct GNUNET_TIME_Relative timeout;
timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, ms);
(void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
}
/**
* Signal handler called for signals that should cause us to shutdown.
*/
static void
sighandler_shutdown ()
{
static char c;
int old_errno = errno; /* backup errno */
if (getpid () != my_pid)
exit (1); /* we have fork'ed since the signal handler was created,
* ignore the signal, see https://gnunet.org/vfork discussion */
GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
(shutdown_pipe_handle, GNUNET_DISK_PIPE_END_WRITE),
&c, sizeof (c));
errno = old_errno;
}
/**
* Check if the system is still alive. Trigger shutdown if we
* have tasks, but none of them give us lifeness.
*
* @return #GNUNET_OK to continue the main loop,
* #GNUNET_NO to exit
*/
static int
check_lifeness ()
{
struct GNUNET_SCHEDULER_Task *t;
if (ready_count > 0)
return GNUNET_OK;
for (t = pending_head; NULL != t; t = t->next)
if (t->lifeness == GNUNET_YES)
return GNUNET_OK;
for (t = shutdown_head; NULL != t; t = t->next)
if (t->lifeness == GNUNET_YES)
return GNUNET_OK;
for (t = pending_timeout_head; NULL != t; t = t->next)
if (t->lifeness == GNUNET_YES)
return GNUNET_OK;
if (NULL != shutdown_head)
{
GNUNET_SCHEDULER_shutdown ();
return GNUNET_OK;
}
return GNUNET_NO;
}
/**
* Initialize and run scheduler. This function will return when all
* tasks have completed. On systems with signals, receiving a SIGTERM
* (and other similar signals) will cause #GNUNET_SCHEDULER_shutdown()
* to be run after the active task is complete. As a result, SIGTERM
* causes all active tasks to be scheduled with reason
* #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added
* afterwards will execute normally!). Note that any particular signal
* will only shut down one scheduler; applications should always only
* create a single scheduler.
*
* @param task task to run immediately
* @param task_cls closure of @a task
*/
void
GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_NETWORK_FDSet *rs;
struct GNUNET_NETWORK_FDSet *ws;
struct GNUNET_TIME_Relative timeout;
int ret;
struct GNUNET_SIGNAL_Context *shc_int;
struct GNUNET_SIGNAL_Context *shc_term;
#if (SIGTERM != GNUNET_TERM_SIG)
struct GNUNET_SIGNAL_Context *shc_gterm;
#endif
#ifndef MINGW
struct GNUNET_SIGNAL_Context *shc_quit;
struct GNUNET_SIGNAL_Context *shc_hup;
struct GNUNET_SIGNAL_Context *shc_pipe;
#endif
unsigned long long last_tr;
unsigned int busy_wait_warning;
const struct GNUNET_DISK_FileHandle *pr;
char c;
GNUNET_assert (NULL == active_task);
rs = GNUNET_NETWORK_fdset_create ();
ws = GNUNET_NETWORK_fdset_create ();
GNUNET_assert (NULL == shutdown_pipe_handle);
shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO,
GNUNET_NO,
GNUNET_NO,
GNUNET_NO);
GNUNET_assert (NULL != shutdown_pipe_handle);
pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
GNUNET_DISK_PIPE_END_READ);
GNUNET_assert (NULL != pr);
my_pid = getpid ();
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Registering signal handlers\n");
shc_int = GNUNET_SIGNAL_handler_install (SIGINT,
&sighandler_shutdown);
shc_term = GNUNET_SIGNAL_handler_install (SIGTERM,
&sighandler_shutdown);
#if (SIGTERM != GNUNET_TERM_SIG)
shc_gterm = GNUNET_SIGNAL_handler_install (GNUNET_TERM_SIG,
&sighandler_shutdown);
#endif
#ifndef MINGW
shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE,
&sighandler_pipe);
shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT,
&sighandler_shutdown);
shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP,
&sighandler_shutdown);
#endif
current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
current_lifeness = GNUNET_YES;
GNUNET_SCHEDULER_add_with_reason_and_priority (task,
task_cls,
GNUNET_SCHEDULER_REASON_STARTUP,
GNUNET_SCHEDULER_PRIORITY_DEFAULT);
active_task = (void *) (long) -1; /* force passing of sanity check */
GNUNET_SCHEDULER_add_now_with_lifeness (GNUNET_NO,
&GNUNET_OS_install_parent_control_handler,
NULL);
active_task = NULL;
last_tr = 0;
busy_wait_warning = 0;
while (GNUNET_OK == check_lifeness ())
{
GNUNET_NETWORK_fdset_zero (rs);
GNUNET_NETWORK_fdset_zero (ws);
timeout = GNUNET_TIME_UNIT_FOREVER_REL;
update_sets (rs, ws, &timeout);
GNUNET_NETWORK_fdset_handle_set (rs, pr);
if (ready_count > 0)
{
/* no blocking, more work already ready! */
timeout = GNUNET_TIME_UNIT_ZERO;
}
if (NULL == scheduler_select)
ret = GNUNET_NETWORK_socket_select (rs,
ws,
NULL,
timeout);
else
ret = scheduler_select (scheduler_select_cls,
rs,
ws,
NULL,
timeout);
if (ret == GNUNET_SYSERR)
{
if (errno == EINTR)
continue;
LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "select");
#ifndef MINGW
#if USE_LSOF
char lsof[512];
snprintf (lsof, sizeof (lsof), "lsof -p %d", getpid ());
(void) close (1);
(void) dup2 (2, 1);
if (0 != system (lsof))
LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING,
"system");
#endif
#endif
#if DEBUG_FDS
struct GNUNET_SCHEDULER_Task *t;
for (t = pending_head; NULL != t; t = t->next)
{
if (-1 != t->read_fd)
{
int flags = fcntl (t->read_fd, F_GETFD);
if ((flags == -1) && (errno == EBADF))
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
t->read_fd);
dump_backtrace (t);
}
}
if (-1 != t->write_fd)
{
int flags = fcntl (t->write_fd, F_GETFD);
if ((flags == -1) && (errno == EBADF))
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
t->write_fd);
dump_backtrace (t);
}
}
}
#endif
GNUNET_assert (0);
break;
}
if ( (0 == ret) &&
(0 == timeout.rel_value_us) &&
(busy_wait_warning > 16) )
{
LOG (GNUNET_ERROR_TYPE_WARNING,
"Looks like we're busy waiting...\n");
short_wait (100); /* mitigate */
}
check_ready (rs, ws);
run_ready (rs, ws);
if (GNUNET_NETWORK_fdset_handle_isset (rs, pr))
{
/* consume the signal */
GNUNET_DISK_file_read (pr, &c, sizeof (c));
/* mark all active tasks as ready due to shutdown */
GNUNET_SCHEDULER_shutdown ();
}
if (last_tr == tasks_run)
{
short_wait (1);
busy_wait_warning++;
}
else
{
last_tr = tasks_run;
busy_wait_warning = 0;
}
}
GNUNET_SIGNAL_handler_uninstall (shc_int);
GNUNET_SIGNAL_handler_uninstall (shc_term);
#if (SIGTERM != GNUNET_TERM_SIG)
GNUNET_SIGNAL_handler_uninstall (shc_gterm);
#endif
#ifndef MINGW
GNUNET_SIGNAL_handler_uninstall (shc_pipe);
GNUNET_SIGNAL_handler_uninstall (shc_quit);
GNUNET_SIGNAL_handler_uninstall (shc_hup);
#endif
GNUNET_DISK_pipe_close (shutdown_pipe_handle);
shutdown_pipe_handle = NULL;
GNUNET_NETWORK_fdset_destroy (rs);
GNUNET_NETWORK_fdset_destroy (ws);
}
/**
* Obtain the task context, giving the reason why the current task was
* started.
*
* @return current tasks' scheduler context
*/
const struct GNUNET_SCHEDULER_TaskContext *
GNUNET_SCHEDULER_get_task_context ()
{
GNUNET_assert (NULL != active_task);
return &tc;
}
/**
* Get information about the current load of this scheduler. Use this
* function to determine if an elective task should be added or simply
* dropped (if the decision should be made based on the number of
* tasks ready to run).
*
* @param p priority level to look at
* @return number of tasks pending right now
*/
unsigned int
GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p)
{
struct GNUNET_SCHEDULER_Task *pos;
unsigned int ret;
GNUNET_assert (NULL != active_task);
if (p == GNUNET_SCHEDULER_PRIORITY_COUNT)
return ready_count;
if (p == GNUNET_SCHEDULER_PRIORITY_KEEP)
p = current_priority;
ret = 0;
for (pos = ready_head[check_priority (p)]; NULL != pos; pos = pos->next)
ret++;
return ret;
}
/**
* Cancel the task with the specified identifier.
* The task must not yet have run.
*
* @param task id of the task to cancel
* @return original closure of the task
*/
void *
GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Task *task)
{
enum GNUNET_SCHEDULER_Priority p;
void *ret;
GNUNET_assert ( (NULL != active_task) ||
(GNUNET_NO == task->lifeness) );
if (! task->in_ready_list)
{
if ( (-1 == task->read_fd) &&
(-1 == task->write_fd) &&
(NULL == task->read_set) &&
(NULL == task->write_set) )
{
if (GNUNET_YES == task->on_shutdown)
GNUNET_CONTAINER_DLL_remove (shutdown_head,
shutdown_tail,
task);
else
GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
pending_timeout_tail,
task);
if (task == pending_timeout_last)
pending_timeout_last = NULL;
}
else
{
GNUNET_CONTAINER_DLL_remove (pending_head,
pending_tail,
task);
}
}
else
{
p = check_priority (task->priority);
GNUNET_CONTAINER_DLL_remove (ready_head[p],
ready_tail[p],
task);
ready_count--;
}
ret = task->callback_cls;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Canceling task %p\n",
task);
destroy_task (task);
return ret;
}
/**
* Initialize backtrace data for task @a t
*
* @param t task to initialize
*/
static void
init_backtrace (struct GNUNET_SCHEDULER_Task *t)
{
#if EXECINFO
void *backtrace_array[MAX_TRACE_DEPTH];
t->num_backtrace_strings
= backtrace (backtrace_array, MAX_TRACE_DEPTH);
t->backtrace_strings =
backtrace_symbols (backtrace_array,
t->num_backtrace_strings);
dump_backtrace (t);
#endif
}
/**
* Continue the current execution with the given function. This is
* similar to the other "add" functions except that there is no delay
* and the reason code can be specified.
*
* @param task main function of the task
* @param task_cls closure for @a task
* @param reason reason for task invocation
* @param priority priority to use for the task
*/
void
GNUNET_SCHEDULER_add_with_reason_and_priority (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls,
enum GNUNET_SCHEDULER_Reason reason,
enum GNUNET_SCHEDULER_Priority priority)
{
struct GNUNET_SCHEDULER_Task *t;
GNUNET_assert (NULL != task);
GNUNET_assert ((NULL != active_task) ||
(GNUNET_SCHEDULER_REASON_STARTUP == reason));
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
t->read_fd = -1;
t->write_fd = -1;
t->callback = task;
t->callback_cls = task_cls;
#if PROFILE_DELAYS
t->start_time = GNUNET_TIME_absolute_get ();
#endif
t->reason = reason;
t->priority = priority;
t->lifeness = current_lifeness;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding continuation task %p\n",
t);
init_backtrace (t);
queue_ready_task (t);
}
/**
* Schedule a new task to be run at the specified time. The task
* will be scheduled for execution at time @a at.
*
* @param at time when the operation should run
* @param priority priority to use for the task
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_at_with_priority (struct GNUNET_TIME_Absolute at,
enum GNUNET_SCHEDULER_Priority priority,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *t;
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_SCHEDULER_Task *prev;
GNUNET_assert (NULL != active_task);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
t->callback = task;
t->callback_cls = task_cls;
t->read_fd = -1;
t->write_fd = -1;
#if PROFILE_DELAYS
t->start_time = GNUNET_TIME_absolute_get ();
#endif
t->timeout = at;
t->priority = priority;
t->lifeness = current_lifeness;
/* try tail first (optimization in case we are
* appending to a long list of tasks with timeouts) */
if ( (NULL == pending_timeout_head) ||
(at.abs_value_us < pending_timeout_head->timeout.abs_value_us) )
{
GNUNET_CONTAINER_DLL_insert (pending_timeout_head,
pending_timeout_tail,
t);
}
else
{
/* first move from heuristic start backwards to before start time */
prev = pending_timeout_last;
while ( (NULL != prev) &&
(prev->timeout.abs_value_us > t->timeout.abs_value_us) )
prev = prev->prev;
/* now, move from heuristic start (or head of list) forward to insertion point */
if (NULL == prev)
pos = pending_timeout_head;
else
pos = prev->next;
while ( (NULL != pos) &&
( (pos->timeout.abs_value_us <= t->timeout.abs_value_us) ||
(0 != pos->reason) ) )
{
prev = pos;
pos = pos->next;
}
GNUNET_CONTAINER_DLL_insert_after (pending_timeout_head,
pending_timeout_tail,
prev,
t);
}
/* finally, update heuristic insertion point to last insertion... */
pending_timeout_last = t;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding task: %p\n",
t);
init_backtrace (t);
return t;
}
/**
* Schedule a new task to be run with a specified delay. The task
* will be scheduled for execution once the delay has expired.
*
* @param delay when should this operation time out?
* @param priority priority to use for the task
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_delayed_with_priority (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_at_with_priority (GNUNET_TIME_relative_to_absolute (delay),
priority,
task,
task_cls);
}
/**
* Schedule a new task to be run with a specified priority.
*
* @param prio how important is the new task?
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_delayed_with_priority (GNUNET_TIME_UNIT_ZERO,
prio,
task,
task_cls);
}
/**
* Schedule a new task to be run at the specified time. The task
* will be scheduled for execution once specified time has been
* reached. It will be run with the DEFAULT priority.
*
* @param at time at which this operation should run
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_at (struct GNUNET_TIME_Absolute at,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_at_with_priority (at,
GNUNET_SCHEDULER_PRIORITY_DEFAULT,
task,
task_cls);
}
/**
* Schedule a new task to be run with a specified delay. The task
* will be scheduled for execution once the delay has expired. It
* will be run with the DEFAULT priority.
*
* @param delay when should this operation time out?
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
GNUNET_SCHEDULER_PRIORITY_DEFAULT,
task,
task_cls);
}
/**
* Schedule a new task to be run as soon as possible. Note that this
* does not guarantee that this will be the next task that is being
* run, as other tasks with higher priority (or that are already ready
* to run) might get to run first. Just as with delays, clients must
* not rely on any particular order of execution between tasks
* scheduled concurrently.
*
* The task will be run with the DEFAULT priority.
*
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_ZERO,
task,
task_cls);
}
/**
* Schedule a new task to be run on shutdown, that is when a CTRL-C
* signal is received, or when #GNUNET_SCHEDULER_shutdown() is being
* invoked.
*
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_shutdown (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *t;
GNUNET_assert (NULL != active_task);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
t->callback = task;
t->callback_cls = task_cls;
t->read_fd = -1;
t->write_fd = -1;
#if PROFILE_DELAYS
t->start_time = GNUNET_TIME_absolute_get ();
#endif
t->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
t->priority = GNUNET_SCHEDULER_PRIORITY_SHUTDOWN;
t->on_shutdown = GNUNET_YES;
t->lifeness = GNUNET_YES;
GNUNET_CONTAINER_DLL_insert (shutdown_head,
shutdown_tail,
t);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding task: %p\n",
t);
init_backtrace (t);
return t;
}
/**
* Schedule a new task to be run as soon as possible with the
* (transitive) ignore-shutdown flag either explicitly set or
* explicitly enabled. This task (and all tasks created from it,
* other than by another call to this function) will either count or
* not count for the "lifeness" of the process. This API is only
* useful in a few special cases.
*
* @param lifeness #GNUNET_YES if the task counts for lifeness, #GNUNET_NO if not.
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *ret;
ret = GNUNET_SCHEDULER_add_now (task, task_cls);
ret->lifeness = lifeness;
return ret;
}
/**
* Schedule a new task to be run with a specified delay or when any of
* the specified file descriptor sets is ready. The delay can be used
* as a timeout on the socket(s) being ready. The task will be
* scheduled for execution once either the delay has expired or any of
* the socket operations is ready. This is the most general
* function of the "add" family. Note that the "prerequisite_task"
* must be satisfied in addition to any of the other conditions. In
* other words, the task will be started when
*
* (prerequisite-run)
* && (delay-ready
* || any-rs-ready
* || any-ws-ready)
*
*
* @param delay how long should we wait?
* @param priority priority to use
* @param rfd file descriptor we want to read (can be -1)
* @param wfd file descriptors we want to write (can be -1)
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
#ifndef MINGW
static struct GNUNET_SCHEDULER_Task *
add_without_sets (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
int rfd,
int wfd,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *t;
GNUNET_assert (NULL != active_task);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
t->callback = task;
t->callback_cls = task_cls;
#if DEBUG_FDS
if (-1 != rfd)
{
int flags = fcntl (rfd, F_GETFD);
if ((flags == -1) && (errno == EBADF))
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
rfd);
init_backtrace (t);
GNUNET_assert (0);
}
}
if (-1 != wfd)
{
int flags = fcntl (wfd, F_GETFD);
if (flags == -1 && errno == EBADF)
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
wfd);
init_backtrace (t);
GNUNET_assert (0);
}
}
#endif
t->read_fd = rfd;
GNUNET_assert (wfd >= -1);
t->write_fd = wfd;
#if PROFILE_DELAYS
t->start_time = GNUNET_TIME_absolute_get ();
#endif
t->timeout = GNUNET_TIME_relative_to_absolute (delay);
t->priority = check_priority ((priority == GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority : priority);
t->lifeness = current_lifeness;
GNUNET_CONTAINER_DLL_insert (pending_head,
pending_tail,
t);
max_priority_added = GNUNET_MAX (max_priority_added,
t->priority);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding task %p\n",
t);
init_backtrace (t);
return t;
}
#endif
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for reading. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
*
* @param delay when should this operation time out?
* @param rfd read file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
struct GNUNET_NETWORK_Handle *rfd,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_read_net_with_priority (delay,
GNUNET_SCHEDULER_PRIORITY_DEFAULT,
rfd, task, task_cls);
}
/**
* Schedule a new task to be run with a specified priority and to be
* run after the specified delay or when the specified file descriptor
* is ready for reading. The delay can be used as a timeout on the
* socket being ready. The task will be scheduled for execution once
* either the delay has expired or the socket operation is ready. It
* will be run with the DEFAULT priority.
*
* @param delay when should this operation time out?
* @param priority priority to use for the task
* @param rfd read file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_net_with_priority (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
struct GNUNET_NETWORK_Handle *rfd,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_net_with_priority (delay, priority,
rfd,
GNUNET_YES,
GNUNET_NO,
task, task_cls);
}
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for writing. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the priority of
* the calling task.
*
* @param delay when should this operation time out?
* @param wfd write file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
struct GNUNET_NETWORK_Handle *wfd,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
return GNUNET_SCHEDULER_add_net_with_priority (delay,
GNUNET_SCHEDULER_PRIORITY_DEFAULT,
wfd,
GNUNET_NO, GNUNET_YES,
task, task_cls);
}
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready.
*
* @param delay when should this operation time out?
* @param priority priority of the task
* @param fd file-descriptor
* @param on_read whether to poll the file-descriptor for readability
* @param on_write whether to poll the file-descriptor for writability
* @param task main function of the task
* @param task_cls closure of task
* @return unique task identifier for the job
* only valid until "task" is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_net_with_priority (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
struct GNUNET_NETWORK_Handle *fd,
int on_read,
int on_write,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
#if MINGW
struct GNUNET_NETWORK_FDSet *s;
struct GNUNET_SCHEDULER_Task * ret;
GNUNET_assert (NULL != fd);
s = GNUNET_NETWORK_fdset_create ();
GNUNET_NETWORK_fdset_set (s, fd);
ret = GNUNET_SCHEDULER_add_select (
priority, delay,
on_read ? s : NULL,
on_write ? s : NULL,
task, task_cls);
GNUNET_NETWORK_fdset_destroy (s);
return ret;
#else
GNUNET_assert (GNUNET_NETWORK_get_fd (fd) >= 0);
return add_without_sets (delay, priority,
on_read ? GNUNET_NETWORK_get_fd (fd) : -1,
on_write ? GNUNET_NETWORK_get_fd (fd) : -1,
task, task_cls);
#endif
}
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for reading. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
*
* @param delay when should this operation time out?
* @param rfd read file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
const struct GNUNET_DISK_FileHandle *rfd,
GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
{
return GNUNET_SCHEDULER_add_file_with_priority (
delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
rfd, GNUNET_YES, GNUNET_NO,
task, task_cls);
}
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for writing. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
*
* @param delay when should this operation time out?
* @param wfd write file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
const struct GNUNET_DISK_FileHandle *wfd,
GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
{
return GNUNET_SCHEDULER_add_file_with_priority (
delay, GNUNET_SCHEDULER_PRIORITY_DEFAULT,
wfd, GNUNET_NO, GNUNET_YES,
task, task_cls);
}
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready.
*
* @param delay when should this operation time out?
* @param priority priority of the task
* @param fd file-descriptor
* @param on_read whether to poll the file-descriptor for readability
* @param on_write whether to poll the file-descriptor for writability
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_file_with_priority (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
const struct GNUNET_DISK_FileHandle *fd,
int on_read, int on_write,
GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
{
#if MINGW
struct GNUNET_NETWORK_FDSet *s;
struct GNUNET_SCHEDULER_Task * ret;
GNUNET_assert (NULL != fd);
s = GNUNET_NETWORK_fdset_create ();
GNUNET_NETWORK_fdset_handle_set (s, fd);
ret = GNUNET_SCHEDULER_add_select (
priority, delay,
on_read ? s : NULL,
on_write ? s : NULL,
task, task_cls);
GNUNET_NETWORK_fdset_destroy (s);
return ret;
#else
int real_fd;
GNUNET_DISK_internal_file_handle_ (fd, &real_fd, sizeof (int));
GNUNET_assert (real_fd >= 0);
return add_without_sets (
delay, priority,
on_read ? real_fd : -1,
on_write ? real_fd : -1,
task, task_cls);
#endif
}
/**
* Schedule a new task to be run with a specified delay or when any of
* the specified file descriptor sets is ready. The delay can be used
* as a timeout on the socket(s) being ready. The task will be
* scheduled for execution once either the delay has expired or any of
* the socket operations is ready. This is the most general
* function of the "add" family. Note that the "prerequisite_task"
* must be satisfied in addition to any of the other conditions. In
* other words, the task will be started when
*
* (prerequisite-run)
* && (delay-ready
* || any-rs-ready
* || any-ws-ready) )
*
*
* @param prio how important is this task?
* @param delay how long should we wait?
* @param rs set of file descriptors we want to read (can be NULL)
* @param ws set of file descriptors we want to write (can be NULL)
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
struct GNUNET_TIME_Relative delay,
const struct GNUNET_NETWORK_FDSet *rs,
const struct GNUNET_NETWORK_FDSet *ws,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *t;
if ( (NULL == rs) &&
(NULL == ws) )
return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
prio,
task,
task_cls);
GNUNET_assert (NULL != active_task);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
t->callback = task;
t->callback_cls = task_cls;
t->read_fd = -1;
t->write_fd = -1;
if (NULL != rs)
{
t->read_set = GNUNET_NETWORK_fdset_create ();
GNUNET_NETWORK_fdset_copy (t->read_set, rs);
}
if (NULL != ws)
{
t->write_set = GNUNET_NETWORK_fdset_create ();
GNUNET_NETWORK_fdset_copy (t->write_set, ws);
}
#if PROFILE_DELAYS
t->start_time = GNUNET_TIME_absolute_get ();
#endif
t->timeout = GNUNET_TIME_relative_to_absolute (delay);
t->priority =
check_priority ((prio ==
GNUNET_SCHEDULER_PRIORITY_KEEP) ? current_priority :
prio);
t->lifeness = current_lifeness;
GNUNET_CONTAINER_DLL_insert (pending_head,
pending_tail,
t);
max_priority_added = GNUNET_MAX (max_priority_added,
t->priority);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding task %p\n",
t);
init_backtrace (t);
return t;
}
/**
* Function used by event-loop implementations to signal the scheduler
* that a particular @a task is ready due to an event of type @a et.
*
* This function will then queue the task to notify the application
* that the task is ready (with the respective priority).
*
* @param task the task that is ready, NULL for wake up calls
* @param et information about why the task is ready
*/
void
GNUNET_SCHEDULER_task_ready (struct GNUNET_SCHEDULER_Task *task,
enum GNUNET_SCHEDULER_EventType et)
{
enum GNUNET_SCHEDULER_Reason reason;
struct GNUNET_TIME_Absolute now;
now = GNUNET_TIME_absolute_get ();
reason = task->reason;
if (now.abs_value_us >= task->timeout.abs_value_us)
reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
if ( (0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
(0 != (GNUNET_SCHEDULER_ET_IN & et)) )
reason |= GNUNET_SCHEDULER_REASON_READ_READY;
if ( (0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
(0 != (GNUNET_SCHEDULER_ET_OUT & et)) )
reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
task->reason = reason;
task->fds = &task->fdx;
task->fdx.et = et;
task->fds_len = 1;
queue_ready_task (task);
}
/**
* Function called by the driver to tell the scheduler to run some of
* the tasks that are ready. This function may return even though
* there are tasks left to run just to give other tasks a chance as
* well. If we return #GNUNET_YES, the driver should call this
* function again as soon as possible, while if we return #GNUNET_NO
* it must block until the operating system has more work as the
* scheduler has no more work to do right now.
*
* @param sh scheduler handle that was given to the `loop`
* @return #GNUNET_OK if there are more tasks that are ready,
* and thus we would like to run more (yield to avoid
* blocking other activities for too long)
* #GNUNET_NO if we are done running tasks (yield to block)
* #GNUNET_SYSERR on error
*/
int
GNUNET_SCHEDULER_run_from_driver (struct GNUNET_SCHEDULER_Handle *sh)
{
enum GNUNET_SCHEDULER_Priority p;
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_TIME_Absolute now;
/* check for tasks that reached the timeout! */
now = GNUNET_TIME_absolute_get ();
while (NULL != (pos = pending_timeout_head))
{
if (now.abs_value_us >= pos->timeout.abs_value_us)
pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
if (0 == pos->reason)
break;
GNUNET_CONTAINER_DLL_remove (pending_timeout_head,
pending_timeout_tail,
pos);
if (pending_timeout_last == pos)
pending_timeout_last = NULL;
queue_ready_task (pos);
}
if (0 == ready_count)
return GNUNET_NO;
/* find out which task priority level we are going to
process this time */
max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
/* yes, p>0 is correct, 0 is "KEEP" which should
* always be an empty queue (see assertion)! */
for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
{
pos = ready_head[p];
if (NULL != pos)
break;
}
GNUNET_assert (NULL != pos); /* ready_count wrong? */
/* process all tasks at this priority level, then yield */
while (NULL != (pos = ready_head[p]))
{
GNUNET_CONTAINER_DLL_remove (ready_head[p],
ready_tail[p],
pos);
ready_count--;
current_priority = pos->priority;
current_lifeness = pos->lifeness;
active_task = pos;
#if PROFILE_DELAYS
if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
DELAY_THRESHOLD.rel_value_us)
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Task %p took %s to be scheduled\n",
pos,
GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->start_time),
GNUNET_YES));
}
#endif
tc.reason = pos->reason;
GNUNET_NETWORK_fdset_zero (sh->rs);
GNUNET_NETWORK_fdset_zero (sh->ws);
tc.fds_len = pos->fds_len;
tc.fds = pos->fds;
tc.read_ready = (NULL == pos->read_set) ? sh->rs : pos->read_set;
if ( (-1 != pos->read_fd) &&
(0 != (pos->reason & GNUNET_SCHEDULER_REASON_READ_READY)) )
GNUNET_NETWORK_fdset_set_native (sh->rs,
pos->read_fd);
tc.write_ready = (NULL == pos->write_set) ? sh->ws : pos->write_set;
if ((-1 != pos->write_fd) &&
(0 != (pos->reason & GNUNET_SCHEDULER_REASON_WRITE_READY)))
GNUNET_NETWORK_fdset_set_native (sh->ws,
pos->write_fd);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Running task: %p\n",
pos);
pos->callback (pos->callback_cls);
active_task = NULL;
dump_backtrace (pos);
destroy_task (pos);
tasks_run++;
}
if (0 == ready_count)
return GNUNET_NO;
return GNUNET_OK;
}
/**
* Initialize and run scheduler. This function will return when all
* tasks have completed. On systems with signals, receiving a SIGTERM
* (and other similar signals) will cause #GNUNET_SCHEDULER_shutdown
* to be run after the active task is complete. As a result, SIGTERM
* causes all shutdown tasks to be scheduled with reason
* #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added
* afterwards will execute normally!). Note that any particular
* signal will only shut down one scheduler; applications should
* always only create a single scheduler.
*
* @param driver drive to use for the event loop
* @param task task to run first (and immediately)
* @param task_cls closure of @a task
* @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
*/
int
GNUNET_SCHEDULER_run_with_driver (const struct GNUNET_SCHEDULER_Driver *driver,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
int ret;
struct GNUNET_SIGNAL_Context *shc_int;
struct GNUNET_SIGNAL_Context *shc_term;
#if (SIGTERM != GNUNET_TERM_SIG)
struct GNUNET_SIGNAL_Context *shc_gterm;
#endif
#ifndef MINGW
struct GNUNET_SIGNAL_Context *shc_quit;
struct GNUNET_SIGNAL_Context *shc_hup;
struct GNUNET_SIGNAL_Context *shc_pipe;
#endif
struct GNUNET_SCHEDULER_Task tsk;
const struct GNUNET_DISK_FileHandle *pr;
struct GNUNET_SCHEDULER_Handle sh;
/* general set-up */
GNUNET_assert (NULL == active_task);
GNUNET_assert (NULL == shutdown_pipe_handle);
shutdown_pipe_handle = GNUNET_DISK_pipe (GNUNET_NO,
GNUNET_NO,
GNUNET_NO,
GNUNET_NO);
GNUNET_assert (NULL != shutdown_pipe_handle);
pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
GNUNET_DISK_PIPE_END_READ);
GNUNET_assert (NULL != pr);
my_pid = getpid ();
/* install signal handlers */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Registering signal handlers\n");
shc_int = GNUNET_SIGNAL_handler_install (SIGINT,
&sighandler_shutdown);
shc_term = GNUNET_SIGNAL_handler_install (SIGTERM,
&sighandler_shutdown);
#if (SIGTERM != GNUNET_TERM_SIG)
shc_gterm = GNUNET_SIGNAL_handler_install (GNUNET_TERM_SIG,
&sighandler_shutdown);
#endif
#ifndef MINGW
shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE,
&sighandler_pipe);
shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT,
&sighandler_shutdown);
shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP,
&sighandler_shutdown);
#endif
/* Setup initial tasks */
current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
current_lifeness = GNUNET_YES;
memset (&tsk,
0,
sizeof (tsk));
active_task = &tsk;
tsk.sh = &sh;
GNUNET_SCHEDULER_add_with_reason_and_priority (task,
task_cls,
GNUNET_SCHEDULER_REASON_STARTUP,
GNUNET_SCHEDULER_PRIORITY_DEFAULT);
GNUNET_SCHEDULER_add_now_with_lifeness (GNUNET_NO,
&GNUNET_OS_install_parent_control_handler,
NULL);
active_task = NULL;
driver->set_wakeup (driver->cls,
GNUNET_TIME_absolute_get ());
/* begin main event loop */
sh.rs = GNUNET_NETWORK_fdset_create ();
sh.ws = GNUNET_NETWORK_fdset_create ();
sh.driver = driver;
ret = driver->loop (driver->cls,
&sh);
GNUNET_NETWORK_fdset_destroy (sh.rs);
GNUNET_NETWORK_fdset_destroy (sh.ws);
/* uninstall signal handlers */
GNUNET_SIGNAL_handler_uninstall (shc_int);
GNUNET_SIGNAL_handler_uninstall (shc_term);
#if (SIGTERM != GNUNET_TERM_SIG)
GNUNET_SIGNAL_handler_uninstall (shc_gterm);
#endif
#ifndef MINGW
GNUNET_SIGNAL_handler_uninstall (shc_pipe);
GNUNET_SIGNAL_handler_uninstall (shc_quit);
GNUNET_SIGNAL_handler_uninstall (shc_hup);
#endif
GNUNET_DISK_pipe_close (shutdown_pipe_handle);
shutdown_pipe_handle = NULL;
return ret;
}
/**
* Obtain the driver for using select() as the event loop.
*
* @return NULL on error
*/
const struct GNUNET_SCHEDULER_Driver *
GNUNET_SCHEDULER_driver_select ()
{
GNUNET_break (0); // not implemented
return NULL;
}
/* end of scheduler.c */