/*
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 Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
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
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @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"
// DEBUG
#include
#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_do_work(). 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;
/**
* context of the SIGINT handler
*/
struct GNUNET_SIGNAL_Context *shc_int;
/**
* context of the SIGTERM handler
*/
struct GNUNET_SIGNAL_Context *shc_term;
#if (SIGTERM != GNUNET_TERM_SIG)
/**
* context of the TERM_SIG handler
*/
struct GNUNET_SIGNAL_Context *shc_gterm;
#endif
/**
* context of the SIGQUIT handler
*/
struct GNUNET_SIGNAL_Context *shc_quit;
/**
* context of the SIGHUP handler
*/
struct GNUNET_SIGNAL_Context *shc_hup;
/**
* context of hte SIGPIPE handler
*/
struct GNUNET_SIGNAL_Context *shc_pipe;
};
/**
* 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;
/**
* Information about which FDs are ready for this task (and why).
*/
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;
/**
* Size of the @e fds array.
*/
unsigned int fds_len;
/**
* Do we own the network and file handles referenced by the FdInfo
* structs in the fds array. This will only be GNUNET_YES if the
* task was created by the #GNUNET_SCHEDULER_add_select function.
*/
int own_handles;
/**
* 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
/**
* 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
/**
* Asynchronous scope of the task that scheduled this scope,
*/
struct GNUNET_AsyncScopeSave scope;
};
/**
* A struct representing an event the select driver is waiting for
*/
struct Scheduled
{
struct Scheduled *prev;
struct Scheduled *next;
/**
* the task, the event is related to
*/
struct GNUNET_SCHEDULER_Task *task;
/**
* information about the network socket / file descriptor where
* the event is expected to occur
*/
struct GNUNET_SCHEDULER_FdInfo *fdi;
/**
* the event types (multiple event types can be ORed) the select
* driver is expected to wait for
*/
enum GNUNET_SCHEDULER_EventType et;
};
/**
* Driver context used by GNUNET_SCHEDULER_run
*/
struct DriverContext
{
/**
* the head of a DLL containing information about the events the
* select driver is waiting for
*/
struct Scheduled *scheduled_head;
/**
* the tail of a DLL containing information about the events the
* select driver is waiting for
*/
struct Scheduled *scheduled_tail;
/**
* the time when the select driver will wake up again (after
* calling select)
*/
struct GNUNET_TIME_Absolute timeout;
};
/**
* The driver used for the event loop. Will be handed over to
* the scheduler in #GNUNET_SCHEDULER_do_work(), persisted
* there in this variable for later use in functions like
* #GNUNET_SCHEDULER_add_select(), #add_without_sets() and
* #GNUNET_SCHEDULER_cancel().
*/
static const struct GNUNET_SCHEDULER_Driver *scheduler_driver;
/**
* 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];
/**
* Task for installing parent control handlers (it might happen that the
* scheduler is shutdown before this task is executed, so
* GNUNET_SCHEDULER_shutdown must cancel it in that case)
*/
static struct GNUNET_SCHEDULER_Task *install_parent_control_task;
/**
* Task for reading from a pipe that signal handlers will use to initiate
* shutdown
*/
static struct GNUNET_SCHEDULER_Task *shutdown_pipe_task;
/**
* Number of tasks on the ready list.
*/
static unsigned int ready_count;
/**
* 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;
/**
* Priority used currently in #GNUNET_SCHEDULER_do_work().
*/
static enum GNUNET_SCHEDULER_Priority work_priority;
/**
* 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 */
}
/**
* chooses the nearest timeout from all pending tasks, to be used
* to tell the driver the next wakeup time (using its set_wakeup
* callback)
*/
struct GNUNET_TIME_Absolute
get_timeout ()
{
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_TIME_Absolute now;
struct GNUNET_TIME_Absolute timeout;
pos = pending_timeout_head;
now = GNUNET_TIME_absolute_get ();
timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
if (NULL != pos)
{
if (0 != pos->reason)
{
return now;
}
else
{
timeout = pos->timeout;
}
}
for (pos = pending_head; NULL != pos; pos = pos->next)
{
if (0 != pos->reason)
{
return now;
}
else if ((pos->timeout.abs_value_us !=
GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us) &&
(timeout.abs_value_us > pos->timeout.abs_value_us))
{
timeout = pos->timeout;
}
}
return timeout;
}
/**
* 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_tail (ready_head[p],
ready_tail[p],
task);
task->in_ready_list = GNUNET_YES;
ready_count++;
}
/**
* 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;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SCHEDULER_shutdown\n");
if (NULL != install_parent_control_task)
{
GNUNET_SCHEDULER_cancel (install_parent_control_task);
install_parent_control_task = NULL;
}
if (NULL != shutdown_pipe_task)
{
GNUNET_SCHEDULER_cancel (shutdown_pipe_task);
shutdown_pipe_task = NULL;
}
while (NULL != (pos = shutdown_head))
{
GNUNET_CONTAINER_DLL_remove (shutdown_head,
shutdown_tail,
pos);
pos->reason |= GNUNET_SCHEDULER_REASON_SHUTDOWN;
queue_ready_task (pos);
}
}
/**
* 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
for (unsigned int i = 0; i < t->num_backtrace_strings; i++)
LOG (GNUNET_ERROR_TYPE_WARNING,
"Task %p trace %u: %s\n",
t,
i,
t->backtrace_strings[i]);
#else
(void) t;
#endif
}
/**
* Destroy a task (release associated resources)
*
* @param t task to destroy
*/
static void
destroy_task (struct GNUNET_SCHEDULER_Task *t)
{
unsigned int i;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"destroying task %p\n",
t);
if (GNUNET_YES == t->own_handles)
{
for (i = 0; i != t->fds_len; ++i)
{
const struct GNUNET_NETWORK_Handle *fd = t->fds[i].fd;
const struct GNUNET_DISK_FileHandle *fh = t->fds[i].fh;
if (fd)
{
GNUNET_NETWORK_socket_free_memory_only_ ((struct
GNUNET_NETWORK_Handle *) fd);
}
if (fh)
{
// FIXME: on WIN32 this is not enough! A function
// GNUNET_DISK_file_free_memory_only would be nice
GNUNET_free ((void *) fh);
}
}
}
if (t->fds_len > 1)
{
GNUNET_array_grow (t->fds, t->fds_len, 0);
}
#if EXECINFO
GNUNET_free (t->backtrace_strings);
#endif
GNUNET_free (t);
}
/**
* 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.
*/
static void
sighandler_pipe ()
{
return;
}
///**
// * 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;
}
static void
shutdown_if_no_lifeness ()
{
struct GNUNET_SCHEDULER_Task *t;
if (ready_count > 0)
return;
for (t = pending_head; NULL != t; t = t->next)
if (GNUNET_YES == t->lifeness)
return;
for (t = shutdown_head; NULL != t; t = t->next)
if (GNUNET_YES == t->lifeness)
return;
for (t = pending_timeout_head; NULL != t; t = t->next)
if (GNUNET_YES == t->lifeness)
return;
/* No lifeness! */
GNUNET_SCHEDULER_shutdown ();
}
static int
select_loop (struct GNUNET_SCHEDULER_Handle *sh,
struct DriverContext *context);
/**
* 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_SCHEDULER_Handle *sh;
struct GNUNET_SCHEDULER_Driver *driver;
struct DriverContext context = {
.scheduled_head = NULL,
.scheduled_tail = NULL,
.timeout = GNUNET_TIME_absolute_get ()
};
driver = GNUNET_SCHEDULER_driver_select ();
driver->cls = &context;
sh = GNUNET_SCHEDULER_driver_init (driver);
GNUNET_SCHEDULER_add_with_reason_and_priority (task,
task_cls,
GNUNET_SCHEDULER_REASON_STARTUP,
GNUNET_SCHEDULER_PRIORITY_DEFAULT);
select_loop (sh,
&context);
GNUNET_SCHEDULER_driver_done (sh);
GNUNET_free (driver);
}
/**
* 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)
{
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 (struct GNUNET_SCHEDULER_Task *pos = ready_head[check_priority (p)];
NULL != pos;
pos = pos->next)
ret++;
return ret;
}
void
init_fd_info (struct GNUNET_SCHEDULER_Task *t,
const struct GNUNET_NETWORK_Handle *const *read_nh,
unsigned int read_nh_len,
const struct GNUNET_NETWORK_Handle *const *write_nh,
unsigned int write_nh_len,
const struct GNUNET_DISK_FileHandle *const *read_fh,
unsigned int read_fh_len,
const struct GNUNET_DISK_FileHandle *const *write_fh,
unsigned int write_fh_len)
{
// FIXME: if we have exactly two network handles / exactly two file handles
// and they are equal, we can make one FdInfo with both
// GNUNET_SCHEDULER_ET_IN and GNUNET_SCHEDULER_ET_OUT set.
struct GNUNET_SCHEDULER_FdInfo *fdi;
t->fds_len = read_nh_len + write_nh_len + read_fh_len + write_fh_len;
if (1 == t->fds_len)
{
fdi = &t->fdx;
t->fds = fdi;
if (1 == read_nh_len)
{
GNUNET_assert (NULL != read_nh);
GNUNET_assert (NULL != *read_nh);
fdi->fd = *read_nh;
fdi->et = GNUNET_SCHEDULER_ET_IN;
fdi->sock = GNUNET_NETWORK_get_fd (*read_nh);
t->read_fd = fdi->sock;
t->write_fd = -1;
}
else if (1 == write_nh_len)
{
GNUNET_assert (NULL != write_nh);
GNUNET_assert (NULL != *write_nh);
fdi->fd = *write_nh;
fdi->et = GNUNET_SCHEDULER_ET_OUT;
fdi->sock = GNUNET_NETWORK_get_fd (*write_nh);
t->read_fd = -1;
t->write_fd = fdi->sock;
}
else if (1 == read_fh_len)
{
GNUNET_assert (NULL != read_fh);
GNUNET_assert (NULL != *read_fh);
fdi->fh = *read_fh;
fdi->et = GNUNET_SCHEDULER_ET_IN;
fdi->sock = (*read_fh)->fd; // FIXME: does not work under WIN32
t->read_fd = fdi->sock;
t->write_fd = -1;
}
else
{
GNUNET_assert (NULL != write_fh);
GNUNET_assert (NULL != *write_fh);
fdi->fh = *write_fh;
fdi->et = GNUNET_SCHEDULER_ET_OUT;
fdi->sock = (*write_fh)->fd; // FIXME: does not work under WIN32
t->read_fd = -1;
t->write_fd = fdi->sock;
}
}
else
{
fdi = GNUNET_new_array (t->fds_len, struct GNUNET_SCHEDULER_FdInfo);
t->fds = fdi;
t->read_fd = -1;
t->write_fd = -1;
unsigned int i;
for (i = 0; i != read_nh_len; ++i)
{
fdi->fd = read_nh[i];
GNUNET_assert (NULL != fdi->fd);
fdi->et = GNUNET_SCHEDULER_ET_IN;
fdi->sock = GNUNET_NETWORK_get_fd (read_nh[i]);
++fdi;
}
for (i = 0; i != write_nh_len; ++i)
{
fdi->fd = write_nh[i];
GNUNET_assert (NULL != fdi->fd);
fdi->et = GNUNET_SCHEDULER_ET_OUT;
fdi->sock = GNUNET_NETWORK_get_fd (write_nh[i]);
++fdi;
}
for (i = 0; i != read_fh_len; ++i)
{
fdi->fh = read_fh[i];
GNUNET_assert (NULL != fdi->fh);
fdi->et = GNUNET_SCHEDULER_ET_IN;
fdi->sock = (read_fh[i])->fd; // FIXME: does not work under WIN32
++fdi;
}
for (i = 0; i != write_fh_len; ++i)
{
fdi->fh = write_fh[i];
GNUNET_assert (NULL != fdi->fh);
fdi->et = GNUNET_SCHEDULER_ET_OUT;
fdi->sock = (write_fh[i])->fd; // FIXME: does not work under WIN32
++fdi;
}
}
}
/**
* calls the given function @a func on each FdInfo related to @a t.
* Optionally updates the event type field in each FdInfo after calling
* @a func.
*
* @param t the task
* @param driver_func the function to call with each FdInfo contained in
* in @a t
* @param if_not_ready only call @a driver_func on FdInfos that are not
* ready
* @param et the event type to be set in each FdInfo after calling
* @a driver_func on it, or -1 if no updating not desired.
*/
static void
driver_add_multiple (struct GNUNET_SCHEDULER_Task *t)
{
struct GNUNET_SCHEDULER_FdInfo *fdi;
int success = GNUNET_YES;
for (unsigned int i = 0; i != t->fds_len; ++i)
{
fdi = &t->fds[i];
success = scheduler_driver->add (scheduler_driver->cls,
t,
fdi) && success;
fdi->et = GNUNET_SCHEDULER_ET_NONE;
}
if (GNUNET_YES != success)
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"driver could not add task\n");
}
}
static void
install_parent_control_handler (void *cls)
{
(void) cls;
install_parent_control_task = NULL;
GNUNET_OS_install_parent_control_handler (NULL);
}
static void
shutdown_pipe_cb (void *cls)
{
char c;
const struct GNUNET_DISK_FileHandle *pr;
(void) cls;
shutdown_pipe_task = NULL;
pr = GNUNET_DISK_pipe_handle (shutdown_pipe_handle,
GNUNET_DISK_PIPE_END_READ);
GNUNET_assert (! GNUNET_DISK_handle_invalid (pr));
/* consume the signal */
GNUNET_DISK_file_read (pr, &c, sizeof(c));
/* mark all active tasks as ready due to shutdown */
GNUNET_SCHEDULER_shutdown ();
shutdown_pipe_task =
GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
pr,
&shutdown_pipe_cb,
NULL);
}
/**
* Cancel the task with the specified identifier.
* The task must not yet have run. Only allowed to be called as long as the
* scheduler is running, that is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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;
int is_fd_task;
void *ret;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"canceling task %p\n",
task);
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
is_fd_task = (NULL != task->fds);
if (is_fd_task)
{
int del_result = scheduler_driver->del (scheduler_driver->cls, task);
if (GNUNET_OK != del_result)
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"driver could not delete task\n");
GNUNET_assert (0);
}
}
if (! task->in_ready_list)
{
if (is_fd_task)
{
GNUNET_CONTAINER_DLL_remove (pending_head,
pending_tail,
task);
}
else 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 (pending_timeout_last == task)
pending_timeout_last = NULL;
}
}
else
{
p = check_priority (task->priority);
GNUNET_CONTAINER_DLL_remove (ready_head[p],
ready_tail[p],
task);
ready_count--;
}
ret = task->callback_cls;
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);
#else
(void) 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;
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (NULL != task);
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 = check_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;
struct GNUNET_TIME_Relative left;
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
GNUNET_async_scope_get (&t->scope);
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 = check_priority (priority);
t->lifeness = current_lifeness;
init_backtrace (t);
left = GNUNET_TIME_absolute_get_remaining (at);
if (0 == left.rel_value_us)
{
queue_ready_task (t);
if (priority > work_priority)
work_priority = priority;
return t;
}
/* 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))
{
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);
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)
{
struct GNUNET_SCHEDULER_Task *t;
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
GNUNET_async_scope_get (&t->scope);
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_ZERO_ABS;
t->priority = current_priority;
t->on_shutdown = GNUNET_YES;
t->lifeness = current_lifeness;
queue_ready_task (t);
init_backtrace (t);
return t;
}
/**
* 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;
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
GNUNET_async_scope_get (&t->scope);
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_NO;
GNUNET_CONTAINER_DLL_insert (shutdown_head,
shutdown_tail,
t);
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Adding shutdown 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;
}
#if DEBUG_FDS
/**
* check a raw file descriptor and abort if it is bad (for debugging purposes)
*
* @param t the task related to the file descriptor
* @param raw_fd the raw file descriptor to check
*/
void
check_fd (struct GNUNET_SCHEDULER_Task *t, int raw_fd)
{
if (-1 != raw_fd)
{
int flags = fcntl (raw_fd, F_GETFD);
if ((flags == -1) && (errno == EBADF))
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
raw_fd);
init_backtrace (t);
GNUNET_assert (0);
}
}
}
#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 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!
*/
static struct GNUNET_SCHEDULER_Task *
add_without_sets (struct GNUNET_TIME_Relative delay,
enum GNUNET_SCHEDULER_Priority priority,
const struct GNUNET_NETWORK_Handle *read_nh,
const struct GNUNET_NETWORK_Handle *write_nh,
const struct GNUNET_DISK_FileHandle *read_fh,
const struct GNUNET_DISK_FileHandle *write_fh,
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls)
{
struct GNUNET_SCHEDULER_Task *t;
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (NULL != task);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
GNUNET_async_scope_get (&t->scope);
init_fd_info (t,
&read_nh,
read_nh ? 1 : 0,
&write_nh,
write_nh ? 1 : 0,
&read_fh,
read_fh ? 1 : 0,
&write_fh,
write_fh ? 1 : 0);
t->callback = task;
t->callback_cls = task_cls;
#if DEBUG_FDS
check_fd (t, NULL != read_nh ? GNUNET_NETWORK_get_fd (read_nh) : -1);
check_fd (t, NULL != write_nh ? GNUNET_NETWORK_get_fd (write_nh) : -1);
check_fd (t, NULL != read_fh ? read_fh->fd : -1);
check_fd (t, NULL != write_fh ? write_fh->fd : -1);
#endif
#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);
driver_add_multiple (t);
max_priority_added = GNUNET_MAX (max_priority_added,
t->priority);
init_backtrace (t);
return t;
}
/**
* 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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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)
{
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (on_read || on_write);
GNUNET_assert (GNUNET_NETWORK_get_fd (fd) >= 0);
return add_without_sets (delay, priority,
on_read ? fd : NULL,
on_write ? fd : NULL,
NULL,
NULL,
task, task_cls);
}
/**
* 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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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.
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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)
{
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (on_read || on_write);
GNUNET_assert (fd->fd >= 0);
return add_without_sets (delay, priority,
NULL,
NULL,
on_read ? fd : NULL,
on_write ? fd : NULL,
task, task_cls);
}
void
extract_handles (const struct GNUNET_NETWORK_FDSet *fdset,
const struct GNUNET_NETWORK_Handle ***ntarget,
unsigned int *extracted_nhandles,
const struct GNUNET_DISK_FileHandle ***ftarget,
unsigned int *extracted_fhandles)
{
// FIXME: this implementation only works for unix, for WIN32 the file handles
// in fdset must be handled separately
const struct GNUNET_NETWORK_Handle **nhandles;
const struct GNUNET_DISK_FileHandle **fhandles;
unsigned int nhandles_len;
unsigned int fhandles_len;
nhandles = NULL;
fhandles = NULL;
nhandles_len = 0;
fhandles_len = 0;
for (int sock = 0; sock != fdset->nsds; ++sock)
{
if (GNUNET_YES == GNUNET_NETWORK_fdset_test_native (fdset, sock))
{
struct GNUNET_NETWORK_Handle *nhandle;
struct GNUNET_DISK_FileHandle *fhandle;
nhandle = GNUNET_NETWORK_socket_box_native (sock);
if (NULL != nhandle)
{
GNUNET_array_append (nhandles, nhandles_len, nhandle);
}
else
{
fhandle = GNUNET_DISK_get_handle_from_int_fd (sock);
if (NULL != fhandle)
{
GNUNET_array_append (fhandles, fhandles_len, fhandle);
}
else
{
GNUNET_assert (0);
}
}
}
}
*ntarget = nhandles_len > 0 ? nhandles : NULL;
*ftarget = fhandles_len > 0 ? fhandles : NULL;
*extracted_nhandles = nhandles_len;
*extracted_fhandles = fhandles_len;
}
/**
* 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) )
*
* Only allowed to be called as long as the scheduler is running, that
* is one of the following conditions is met:
*
* - #GNUNET_SCHEDULER_run has been called and has not returned yet
* - #GNUNET_SCHEDULER_driver_init has been run and
* #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @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;
const struct GNUNET_NETWORK_Handle **read_nhandles = NULL;
const struct GNUNET_NETWORK_Handle **write_nhandles = NULL;
const struct GNUNET_DISK_FileHandle **read_fhandles = NULL;
const struct GNUNET_DISK_FileHandle **write_fhandles = NULL;
unsigned int read_nhandles_len = 0;
unsigned int write_nhandles_len = 0;
unsigned int read_fhandles_len = 0;
unsigned int write_fhandles_len = 0;
/* scheduler must be running */
GNUNET_assert (NULL != scheduler_driver);
GNUNET_assert (NULL != task);
int no_rs = (NULL == rs);
int no_ws = (NULL == ws);
int empty_rs = (NULL != rs) && (0 == rs->nsds);
int empty_ws = (NULL != ws) && (0 == ws->nsds);
int no_fds = (no_rs && no_ws) ||
(empty_rs && empty_ws) ||
(no_rs && empty_ws) ||
(no_ws && empty_rs);
if (! no_fds)
{
if (NULL != rs)
{
extract_handles (rs,
&read_nhandles,
&read_nhandles_len,
&read_fhandles,
&read_fhandles_len);
}
if (NULL != ws)
{
extract_handles (ws,
&write_nhandles,
&write_nhandles_len,
&write_fhandles,
&write_fhandles_len);
}
}
/**
* here we consider the case that a GNUNET_NETWORK_FDSet might be empty
* although its maximum FD number (nsds) is greater than 0. We handle
* this case gracefully because some libraries such as libmicrohttpd
* only provide a hint what the maximum FD number in an FD set might be
* and not the exact FD number (see e.g. gnunet-rest-service.c)
*/int no_fds_extracted = (0 == read_nhandles_len) &&
(0 == read_fhandles_len) &&
(0 == write_nhandles_len) &&
(0 == write_fhandles_len);
if (no_fds || no_fds_extracted)
return GNUNET_SCHEDULER_add_delayed_with_priority (delay,
prio,
task,
task_cls);
t = GNUNET_new (struct GNUNET_SCHEDULER_Task);
GNUNET_async_scope_get (&t->scope);
init_fd_info (t,
read_nhandles,
read_nhandles_len,
write_nhandles,
write_nhandles_len,
read_fhandles,
read_fhandles_len,
write_fhandles,
write_fhandles_len);
t->callback = task;
t->callback_cls = task_cls;
t->own_handles = GNUNET_YES;
/* free the arrays of pointers to network / file handles, the actual
* handles will be freed in destroy_task */
GNUNET_array_grow (read_nhandles, read_nhandles_len, 0);
GNUNET_array_grow (write_nhandles, write_nhandles_len, 0);
GNUNET_array_grow (read_fhandles, read_fhandles_len, 0);
GNUNET_array_grow (write_fhandles, write_fhandles_len, 0);
#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);
driver_add_multiple (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 specified in the
* et field of @a fdi.
*
* 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
* @param fdi information about the related FD
*/
void
GNUNET_SCHEDULER_task_ready (struct GNUNET_SCHEDULER_Task *task,
struct GNUNET_SCHEDULER_FdInfo *fdi)
{
enum GNUNET_SCHEDULER_Reason reason;
reason = task->reason;
if ((0 == (reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
(0 != (GNUNET_SCHEDULER_ET_IN & fdi->et)))
reason |= GNUNET_SCHEDULER_REASON_READ_READY;
if ((0 == (reason & GNUNET_SCHEDULER_REASON_WRITE_READY)) &&
(0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et)))
reason |= GNUNET_SCHEDULER_REASON_WRITE_READY;
reason |= GNUNET_SCHEDULER_REASON_PREREQ_DONE;
task->reason = reason;
if (GNUNET_NO == task->in_ready_list)
{
GNUNET_CONTAINER_DLL_remove (pending_head,
pending_tail,
task);
queue_ready_task (task);
}
}
/**
* Function called by external event loop implementations to tell the
* scheduler to run some of the tasks that are ready. Must be called
* only after #GNUNET_SCHEDULER_driver_init has been called and before
* #GNUNET_SCHEDULER_driver_done is called.
* 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 event loop implementation should call this function again as
* soon as possible, while if we return #GNUNET_NO it must block until
* either the operating system has more work (the scheduler has no more
* work to do right now) or the timeout set by the scheduler (using the
* set_wakeup callback) is reached.
*
* @param sh scheduler handle that was returned by
* #GNUNET_SCHEDULER_driver_init
* @return #GNUNET_YES 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)
*/
int
GNUNET_SCHEDULER_do_work (struct GNUNET_SCHEDULER_Handle *sh)
{
struct GNUNET_SCHEDULER_Task *pos;
struct GNUNET_TIME_Absolute now;
/* check for tasks that reached the timeout! */
now = GNUNET_TIME_absolute_get ();
pos = pending_timeout_head;
while (NULL != pos)
{
struct GNUNET_SCHEDULER_Task *next = pos->next;
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 = next;
}
pos = pending_head;
while (NULL != pos)
{
struct GNUNET_SCHEDULER_Task *next = pos->next;
if (now.abs_value_us >= pos->timeout.abs_value_us)
{
pos->reason |= GNUNET_SCHEDULER_REASON_TIMEOUT;
GNUNET_CONTAINER_DLL_remove (pending_head,
pending_tail,
pos);
queue_ready_task (pos);
}
pos = next;
}
if (0 == ready_count)
{
struct GNUNET_TIME_Absolute timeout = get_timeout ();
if (timeout.abs_value_us > now.abs_value_us)
{
/**
* The event loop called this function before the current timeout was
* reached (and no FD tasks are ready). This is acceptable if
*
* - the system time was changed while the driver was waiting for
* the timeout
* - an external event loop called GNUnet API functions outside of
* the callbacks called in GNUNET_SCHEDULER_do_work and thus
* wasn't notified about the new timeout
*
* It might also mean we are busy-waiting because of a programming
* error in the external event loop.
*/LOG (GNUNET_ERROR_TYPE_DEBUG,
"GNUNET_SCHEDULER_do_work did not find any ready "
"tasks and timeout has not been reached yet.\n");
}
else
{
/**
* the current timeout was reached but no ready tasks were found,
* internal scheduler error!
*/
GNUNET_assert (0);
}
}
else
{
/* 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 (work_priority = GNUNET_SCHEDULER_PRIORITY_COUNT - 1;
work_priority > 0;
work_priority--)
{
pos = ready_head[work_priority];
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[work_priority]))
{
GNUNET_CONTAINER_DLL_remove (ready_head[work_priority],
ready_tail[work_priority],
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);
// FIXME: do we have to remove FdInfos from fds if they are not ready?
tc.fds_len = pos->fds_len;
tc.fds = pos->fds;
for (unsigned int i = 0; i != pos->fds_len; ++i)
{
struct GNUNET_SCHEDULER_FdInfo *fdi = &pos->fds[i];
if (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et))
{
GNUNET_NETWORK_fdset_set_native (sh->rs,
fdi->sock);
}
if (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et))
{
GNUNET_NETWORK_fdset_set_native (sh->ws,
fdi->sock);
}
}
tc.read_ready = sh->rs;
tc.write_ready = sh->ws;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Running task %p\n",
pos);
GNUNET_assert (NULL != pos->callback);
{
struct GNUNET_AsyncScopeSave old_scope;
if (pos->scope.have_scope)
GNUNET_async_scope_enter (&pos->scope.scope_id, &old_scope);
else
GNUNET_async_scope_get (&old_scope);
pos->callback (pos->callback_cls);
GNUNET_async_scope_restore (&old_scope);
}
if (NULL != pos->fds)
{
int del_result = scheduler_driver->del (scheduler_driver->cls, pos);
if (GNUNET_OK != del_result)
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"driver could not delete task %p\n", pos);
GNUNET_assert (0);
}
}
active_task = NULL;
dump_backtrace (pos);
destroy_task (pos);
}
}
shutdown_if_no_lifeness ();
if (0 == ready_count)
{
scheduler_driver->set_wakeup (scheduler_driver->cls,
get_timeout ());
return GNUNET_NO;
}
scheduler_driver->set_wakeup (scheduler_driver->cls,
GNUNET_TIME_absolute_get ());
return GNUNET_YES;
}
/**
* Function called by external event loop implementations to initialize
* the scheduler. An external implementation has to provide @a driver
* which contains callbacks for the scheduler (see definition of struct
* #GNUNET_SCHEDULER_Driver). The callbacks are used to instruct the
* external implementation to watch for events. If it detects any of
* those events it is expected to call #GNUNET_SCHEDULER_do_work to let
* the scheduler handle it. If an event is related to a specific task
* (e.g. the scheduler gave instructions to watch a file descriptor),
* the external implementation is expected to mark that task ready
* before by calling #GNUNET_SCHEDULER_task_ready.
* This function has to be called before any tasks are scheduled and
* before GNUNET_SCHEDULER_do_work is called for the first time. It
* allocates resources that have to be freed again by calling
* #GNUNET_SCHEDULER_driver_done.
*
* This function installs the same signal handlers as
* #GNUNET_SCHEDULER_run. This means SIGTERM (and other similar signals)
* will induce a call to #GNUNET_SCHEDULER_shutdown during the next
* call to #GNUNET_SCHEDULER_do_work. 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 driver to use for the event loop
* @return handle to be passed to #GNUNET_SCHEDULER_do_work and
* #GNUNET_SCHEDULER_driver_done
*/
struct GNUNET_SCHEDULER_Handle *
GNUNET_SCHEDULER_driver_init (const struct GNUNET_SCHEDULER_Driver *driver)
{
struct GNUNET_SCHEDULER_Handle *sh;
const struct GNUNET_DISK_FileHandle *pr;
/* scheduler must not be running */
GNUNET_assert (NULL == scheduler_driver);
GNUNET_assert (NULL == shutdown_pipe_handle);
/* general set-up */
sh = GNUNET_new (struct GNUNET_SCHEDULER_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);
my_pid = getpid ();
scheduler_driver = driver;
/* install signal handlers */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Registering signal handlers\n");
sh->shc_int = GNUNET_SIGNAL_handler_install (SIGINT,
&sighandler_shutdown);
sh->shc_term = GNUNET_SIGNAL_handler_install (SIGTERM,
&sighandler_shutdown);
#if (SIGTERM != GNUNET_TERM_SIG)
sh->shc_gterm = GNUNET_SIGNAL_handler_install (GNUNET_TERM_SIG,
&sighandler_shutdown);
#endif
sh->shc_pipe = GNUNET_SIGNAL_handler_install (SIGPIPE,
&sighandler_pipe);
sh->shc_quit = GNUNET_SIGNAL_handler_install (SIGQUIT,
&sighandler_shutdown);
sh->shc_hup = GNUNET_SIGNAL_handler_install (SIGHUP,
&sighandler_shutdown);
/* Setup initial tasks */
current_priority = GNUNET_SCHEDULER_PRIORITY_DEFAULT;
current_lifeness = GNUNET_NO;
/* ensure this task runs first, by using a priority level reserved for
the scheduler (not really shutdown, but start-up ;-) */
install_parent_control_task =
GNUNET_SCHEDULER_add_with_priority (GNUNET_SCHEDULER_PRIORITY_SHUTDOWN,
&install_parent_control_handler,
NULL);
shutdown_pipe_task =
GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
pr,
&shutdown_pipe_cb,
NULL);
current_lifeness = GNUNET_YES;
scheduler_driver->set_wakeup (scheduler_driver->cls,
get_timeout ());
/* begin main event loop */
sh->rs = GNUNET_NETWORK_fdset_create ();
sh->ws = GNUNET_NETWORK_fdset_create ();
GNUNET_NETWORK_fdset_handle_set (sh->rs, pr);
return sh;
}
/**
* Counter-part of #GNUNET_SCHEDULER_driver_init. Has to be called
* by external event loop implementations after the scheduler has
* shut down. This is the case if both of the following conditions
* are met:
*
* - all tasks the scheduler has added through the driver's add
* callback have been removed again through the driver's del
* callback
* - the timeout the scheduler has set through the driver's
* add_wakeup callback is FOREVER
*
* @param sh the handle returned by #GNUNET_SCHEDULER_driver_init
*/
void
GNUNET_SCHEDULER_driver_done (struct GNUNET_SCHEDULER_Handle *sh)
{
GNUNET_assert (NULL == pending_head);
GNUNET_assert (NULL == pending_timeout_head);
GNUNET_assert (NULL == shutdown_head);
for (int i = 0; i != GNUNET_SCHEDULER_PRIORITY_COUNT; ++i)
{
GNUNET_assert (NULL == ready_head[i]);
}
GNUNET_NETWORK_fdset_destroy (sh->rs);
GNUNET_NETWORK_fdset_destroy (sh->ws);
/* uninstall signal handlers */
GNUNET_SIGNAL_handler_uninstall (sh->shc_int);
GNUNET_SIGNAL_handler_uninstall (sh->shc_term);
#if (SIGTERM != GNUNET_TERM_SIG)
GNUNET_SIGNAL_handler_uninstall (sh->shc_gterm);
#endif
GNUNET_SIGNAL_handler_uninstall (sh->shc_pipe);
GNUNET_SIGNAL_handler_uninstall (sh->shc_quit);
GNUNET_SIGNAL_handler_uninstall (sh->shc_hup);
GNUNET_DISK_pipe_close (shutdown_pipe_handle);
shutdown_pipe_handle = NULL;
scheduler_driver = NULL;
GNUNET_free (sh);
}
static int
select_loop (struct GNUNET_SCHEDULER_Handle *sh,
struct DriverContext *context)
{
struct GNUNET_NETWORK_FDSet *rs;
struct GNUNET_NETWORK_FDSet *ws;
int select_result;
GNUNET_assert (NULL != context);
rs = GNUNET_NETWORK_fdset_create ();
ws = GNUNET_NETWORK_fdset_create ();
while ((NULL != context->scheduled_head) ||
(GNUNET_TIME_UNIT_FOREVER_ABS.abs_value_us !=
context->timeout.abs_value_us))
{
struct GNUNET_TIME_Relative time_remaining;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"select timeout = %s\n",
GNUNET_STRINGS_absolute_time_to_string (context->timeout));
GNUNET_NETWORK_fdset_zero (rs);
GNUNET_NETWORK_fdset_zero (ws);
for (struct Scheduled *pos = context->scheduled_head;
NULL != pos;
pos = pos->next)
{
if (0 != (GNUNET_SCHEDULER_ET_IN & pos->et))
{
GNUNET_NETWORK_fdset_set_native (rs, pos->fdi->sock);
}
if (0 != (GNUNET_SCHEDULER_ET_OUT & pos->et))
{
GNUNET_NETWORK_fdset_set_native (ws, pos->fdi->sock);
}
}
time_remaining = GNUNET_TIME_absolute_get_remaining (context->timeout);
if (0 < ready_count)
time_remaining = GNUNET_TIME_UNIT_ZERO;
if (NULL == scheduler_select)
{
select_result = GNUNET_NETWORK_socket_select (rs,
ws,
NULL,
time_remaining);
}
else
{
select_result = scheduler_select (scheduler_select_cls,
rs,
ws,
NULL,
time_remaining);
}
if (select_result == GNUNET_SYSERR)
{
if (errno == EINTR)
continue;
LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR,
"select");
#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
#if DEBUG_FDS
for (struct Scheduled *s = context->scheduled_head;
NULL != s;
s = s->next)
{
int flags = fcntl (s->fdi->sock,
F_GETFD);
if ((flags == -1) &&
(EBADF == errno))
{
LOG (GNUNET_ERROR_TYPE_ERROR,
"Got invalid file descriptor %d!\n",
s->fdi->sock);
#if EXECINFO
dump_backtrace (s->task);
#endif
}
}
#endif
GNUNET_assert (0);
GNUNET_NETWORK_fdset_destroy (rs);
GNUNET_NETWORK_fdset_destroy (ws);
return GNUNET_SYSERR;
}
if (select_result > 0)
{
for (struct Scheduled *pos = context->scheduled_head;
NULL != pos;
pos = pos->next)
{
int is_ready = GNUNET_NO;
if ((0 != (GNUNET_SCHEDULER_ET_IN & pos->et)) &&
(GNUNET_YES ==
GNUNET_NETWORK_fdset_test_native (rs,
pos->fdi->sock)) )
{
pos->fdi->et |= GNUNET_SCHEDULER_ET_IN;
is_ready = GNUNET_YES;
}
if ((0 != (GNUNET_SCHEDULER_ET_OUT & pos->et)) &&
(GNUNET_YES ==
GNUNET_NETWORK_fdset_test_native (ws,
pos->fdi->sock)) )
{
pos->fdi->et |= GNUNET_SCHEDULER_ET_OUT;
is_ready = GNUNET_YES;
}
if (GNUNET_YES == is_ready)
{
GNUNET_SCHEDULER_task_ready (pos->task,
pos->fdi);
}
}
}
if (GNUNET_YES == GNUNET_SCHEDULER_do_work (sh))
{
LOG (GNUNET_ERROR_TYPE_DEBUG,
"scheduler has more tasks ready!\n");
}
}
GNUNET_NETWORK_fdset_destroy (rs);
GNUNET_NETWORK_fdset_destroy (ws);
return GNUNET_OK;
}
static int
select_add (void *cls,
struct GNUNET_SCHEDULER_Task *task,
struct GNUNET_SCHEDULER_FdInfo *fdi)
{
struct DriverContext *context = cls;
GNUNET_assert (NULL != context);
GNUNET_assert (NULL != task);
GNUNET_assert (NULL != fdi);
GNUNET_assert (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et) ||
0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et));
if (! ((NULL != fdi->fd) ^ (NULL != fdi->fh)) || (fdi->sock < 0))
{
/* exactly one out of {fd, hf} must be != NULL and the OS handle must be valid */
return GNUNET_SYSERR;
}
struct Scheduled *scheduled = GNUNET_new (struct Scheduled);
scheduled->task = task;
scheduled->fdi = fdi;
scheduled->et = fdi->et;
GNUNET_CONTAINER_DLL_insert (context->scheduled_head,
context->scheduled_tail,
scheduled);
return GNUNET_OK;
}
static int
select_del (void *cls,
struct GNUNET_SCHEDULER_Task *task)
{
struct DriverContext *context;
struct Scheduled *pos;
int ret;
GNUNET_assert (NULL != cls);
context = cls;
ret = GNUNET_SYSERR;
pos = context->scheduled_head;
while (NULL != pos)
{
struct Scheduled *next = pos->next;
if (pos->task == task)
{
GNUNET_CONTAINER_DLL_remove (context->scheduled_head,
context->scheduled_tail,
pos);
GNUNET_free (pos);
ret = GNUNET_OK;
}
pos = next;
}
return ret;
}
static void
select_set_wakeup (void *cls,
struct GNUNET_TIME_Absolute dt)
{
struct DriverContext *context = cls;
GNUNET_assert (NULL != context);
context->timeout = dt;
}
/**
* Obtain the driver for using select() as the event loop.
*
* @return NULL on error
*/
struct GNUNET_SCHEDULER_Driver *
GNUNET_SCHEDULER_driver_select ()
{
struct GNUNET_SCHEDULER_Driver *select_driver;
select_driver = GNUNET_new (struct GNUNET_SCHEDULER_Driver);
select_driver->add = &select_add;
select_driver->del = &select_del;
select_driver->set_wakeup = &select_set_wakeup;
return select_driver;
}
/**
* Change the async scope for the currently executing task and (transitively)
* for all tasks scheduled by the current task after calling this function.
* Nested tasks can begin their own nested async scope.
*
* Once the current task is finished, the async scope ID is reset to
* its previous value.
*
* Must only be called from a running task.
*
* @param aid the asynchronous scope id to enter
*/
void
GNUNET_SCHEDULER_begin_async_scope (struct GNUNET_AsyncScopeId *aid)
{
struct GNUNET_AsyncScopeSave dummy_old_scope;
GNUNET_assert (NULL != active_task);
/* Since we're in a task, the context will be automatically
restored by the scheduler. */
GNUNET_async_scope_enter (aid, &dummy_old_scope);
}
/* end of scheduler.c */