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-rw-r--r--src/providers/dp_ptask.c354
-rw-r--r--src/providers/dp_ptask.h93
2 files changed, 447 insertions, 0 deletions
diff --git a/src/providers/dp_ptask.c b/src/providers/dp_ptask.c
new file mode 100644
index 00000000..d3580981
--- /dev/null
+++ b/src/providers/dp_ptask.c
@@ -0,0 +1,354 @@
+/*
+ Authors:
+ Pavel Březina <pbrezina@redhat.com>
+
+ Copyright (C) 2013 Red Hat
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <tevent.h>
+#include <talloc.h>
+#include <time.h>
+#include <string.h>
+
+#include "util/util.h"
+#include "providers/dp_backend.h"
+#include "providers/dp_ptask.h"
+
+enum be_ptask_schedule {
+ BE_PTASK_SCHEDULE_FROM_NOW,
+ BE_PTASK_SCHEDULE_FROM_LAST
+};
+
+struct be_ptask {
+ struct tevent_context *ev;
+ struct be_ctx *be_ctx;
+ time_t period;
+ time_t enabled_delay;
+ time_t timeout;
+ enum be_ptask_offline offline;
+ be_ptask_send_t send;
+ be_ptask_recv_t recv;
+ void *pvt;
+ const char *name;
+
+ time_t last_execution; /* last time when send was called */
+ struct tevent_req *req; /* active tevent request */
+ struct tevent_timer *timer; /* active tevent timer */
+ bool enabled;
+};
+
+static void be_ptask_schedule(struct be_ptask *task,
+ time_t delay,
+ enum be_ptask_schedule from);
+
+static int be_ptask_destructor(void *pvt)
+{
+ struct be_ptask *task;
+
+ task = talloc_get_type(pvt, struct be_ptask);
+ if (task == NULL) {
+ DEBUG(SSSDBG_FATAL_FAILURE, ("BUG: task is NULL\n"));
+ return 0;
+ }
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Terminating periodic task [%s]\n", task->name));
+
+ return 0;
+}
+
+static void be_ptask_online_cb(void *pvt)
+{
+ struct be_ptask *task = NULL;
+
+ task = talloc_get_type(pvt, struct be_ptask);
+ if (task == NULL) {
+ DEBUG(SSSDBG_FATAL_FAILURE, ("BUG: task is NULL\n"));
+ return;
+ }
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Back end is online\n"));
+ be_ptask_enable(task);
+}
+
+static void be_ptask_offline_cb(void *pvt)
+{
+ struct be_ptask *task = NULL;
+ task = talloc_get_type(pvt, struct be_ptask);
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Back end is offline\n"));
+ be_ptask_disable(task);
+}
+
+static void be_ptask_timeout(struct tevent_context *ev,
+ struct tevent_timer *tt,
+ struct timeval tv,
+ void *pvt)
+{
+ struct be_ptask *task = NULL;
+ task = talloc_get_type(pvt, struct be_ptask);
+
+ DEBUG(SSSDBG_OP_FAILURE, ("Task [%s]: timed out\n", task->name));
+
+ talloc_zfree(task->req);
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_NOW);
+}
+
+static void be_ptask_done(struct tevent_req *req);
+
+static void be_ptask_execute(struct tevent_context *ev,
+ struct tevent_timer *tt,
+ struct timeval tv,
+ void *pvt)
+{
+ struct be_ptask *task = NULL;
+ struct tevent_timer *timeout = NULL;
+
+ task = talloc_get_type(pvt, struct be_ptask);
+ task->timer = NULL; /* timer is freed by tevent */
+
+ if (be_is_offline(task->be_ctx)) {
+ DEBUG(SSSDBG_TRACE_FUNC, ("Back end is offline\n"));
+ switch (task->offline) {
+ case BE_PTASK_OFFLINE_SKIP:
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_NOW);
+ return;
+ case BE_PTASK_OFFLINE_DISABLE:
+ /* This case is handled by offline callback. */
+ return;
+ case BE_PTASK_OFFLINE_EXECUTE:
+ /* continue */
+ break;
+ }
+ }
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: executing task, timeout %lu "
+ "seconds\n", task->name, task->timeout));
+
+ task->last_execution = time(NULL);
+
+ task->req = task->send(task, task->ev, task->be_ctx, task, task->pvt);
+ if (task->req == NULL) {
+ /* skip this iteration and try again later */
+ DEBUG(SSSDBG_OP_FAILURE, ("Task [%s]: failed to execute task, "
+ "will try again later\n", task->name));
+
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_NOW);
+ return;
+ }
+
+ tevent_req_set_callback(task->req, be_ptask_done, task);
+
+ /* schedule timeout */
+ if (task->timeout > 0) {
+ tv = tevent_timeval_current_ofs(task->timeout, 0);
+ timeout = tevent_add_timer(task->ev, task->req, tv,
+ be_ptask_timeout, task);
+ if (timeout == NULL) {
+ /* If we can't guarantee a timeout,
+ * we need to cancel the request. */
+ talloc_zfree(task->req);
+
+ DEBUG(SSSDBG_OP_FAILURE, ("Task [%s]: failed to set timeout, "
+ "the task will be rescheduled\n", task->name));
+
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_NOW);
+ }
+ }
+
+ return;
+}
+
+static void be_ptask_done(struct tevent_req *req)
+{
+ struct be_ptask *task = NULL;
+ errno_t ret;
+
+ task = tevent_req_callback_data(req, struct be_ptask);
+
+ ret = task->recv(req);
+ talloc_zfree(req);
+ task->req = NULL;
+ switch (ret) {
+ case EOK:
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: finished successfully\n",
+ task->name));
+
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_LAST);
+ break;
+ default:
+ DEBUG(SSSDBG_OP_FAILURE, ("Task [%s]: failed with [%d]: %s\n",
+ task->name, ret, sss_strerror(ret)));
+
+ be_ptask_schedule(task, task->period, BE_PTASK_SCHEDULE_FROM_NOW);
+ break;
+ }
+}
+
+static void be_ptask_schedule(struct be_ptask *task,
+ time_t delay,
+ enum be_ptask_schedule from)
+{
+ struct timeval tv;
+
+ if (!task->enabled) {
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: disabled\n", task->name));
+ return;
+ }
+
+ switch (from) {
+ case BE_PTASK_SCHEDULE_FROM_NOW:
+ tv = tevent_timeval_current_ofs(delay, 0);
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: scheduling task %lu seconds "
+ "from now [%lu]\n", task->name, delay, tv.tv_sec));
+ break;
+ case BE_PTASK_SCHEDULE_FROM_LAST:
+ tv = tevent_timeval_set(task->last_execution + delay, 0);
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: scheduling task %lu seconds "
+ "from last execution time [%lu]\n",
+ task->name, delay, tv.tv_sec));
+ break;
+ }
+
+ if (task->timer != NULL) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("Task [%s]: another timer is already "
+ "active?\n", task->name));
+ talloc_zfree(task->timer);
+ }
+
+ task->timer = tevent_add_timer(task->ev, task, tv, be_ptask_execute, task);
+ if (task->timer == NULL) {
+ /* nothing we can do about it */
+ DEBUG(SSSDBG_CRIT_FAILURE, ("FATAL: Unable to schedule task [%s]\n",
+ task->name));
+ be_ptask_disable(task);
+ }
+}
+
+errno_t be_ptask_create(TALLOC_CTX *mem_ctx,
+ struct be_ctx *be_ctx,
+ time_t period,
+ time_t first_delay,
+ time_t enabled_delay,
+ time_t timeout,
+ enum be_ptask_offline offline,
+ be_ptask_send_t send,
+ be_ptask_recv_t recv,
+ void *pvt,
+ const char *name,
+ struct be_ptask **_task)
+{
+ struct be_ptask *task = NULL;
+ errno_t ret;
+
+ if (be_ctx == NULL || period == 0 || send == NULL || recv == NULL
+ || name == NULL) {
+ return EINVAL;
+ }
+
+ task = talloc_zero(mem_ctx, struct be_ptask);
+ if (task == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ task->ev = be_ctx->ev;
+ task->be_ctx = be_ctx;
+ task->period = period;
+ task->enabled_delay = enabled_delay;
+ task->timeout = timeout;
+ task->offline = offline;
+ task->send = send;
+ task->recv = recv;
+ task->pvt = pvt;
+ task->name = talloc_strdup(task, name);
+ if (task->name == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ task->enabled = true;
+
+ talloc_set_destructor((TALLOC_CTX*)task, be_ptask_destructor);
+
+ if (offline == BE_PTASK_OFFLINE_DISABLE) {
+ /* install offline and online callbacks */
+ ret = be_add_online_cb(task, be_ctx, be_ptask_online_cb, task, NULL);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_OP_FAILURE, ("Unable to install online callback "
+ "[%d]: %s", ret, sss_strerror(ret)));
+ goto done;
+ }
+
+ ret = be_add_offline_cb(task, be_ctx, be_ptask_offline_cb, task, NULL);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_OP_FAILURE, ("Unable to install offline callback "
+ "[%d]: %s", ret, sss_strerror(ret)));
+ goto done;
+ }
+ }
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Periodic task [%s] was created\n", task->name));
+
+ be_ptask_schedule(task, first_delay, BE_PTASK_SCHEDULE_FROM_NOW);
+
+ if (_task != NULL) {
+ *_task = task;
+ }
+
+ ret = EOK;
+
+done:
+ if (ret != EOK) {
+ talloc_free(task);
+ }
+
+ return ret;
+}
+
+void be_ptask_enable(struct be_ptask *task)
+{
+ if (task->enabled) {
+ DEBUG(SSSDBG_MINOR_FAILURE, ("Task [%s]: already enabled\n",
+ task->name));
+ return;
+ }
+
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: enabling task\n", task->name));
+
+ task->enabled = true;
+ be_ptask_schedule(task, task->enabled_delay, BE_PTASK_SCHEDULE_FROM_NOW);
+}
+
+/* Disable the task, but if a request already in progress, let it finish. */
+void be_ptask_disable(struct be_ptask *task)
+{
+ DEBUG(SSSDBG_TRACE_FUNC, ("Task [%s]: disabling task\n", task->name));
+
+ talloc_zfree(task->timer);
+ task->enabled = false;
+}
+
+void be_ptask_destroy(struct be_ptask **task)
+{
+ talloc_zfree(*task);
+}
+
+time_t be_ptask_get_period(struct be_ptask *task)
+{
+ return task->period;
+}
diff --git a/src/providers/dp_ptask.h b/src/providers/dp_ptask.h
new file mode 100644
index 00000000..5a1d62c8
--- /dev/null
+++ b/src/providers/dp_ptask.h
@@ -0,0 +1,93 @@
+/*
+ Authors:
+ Pavel Březina <pbrezina@redhat.com>
+
+ Copyright (C) 2013 Red Hat
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _DP_PTASK_H_
+#define _DP_PTASK_H_
+
+#include <tevent.h>
+#include <talloc.h>
+#include <time.h>
+
+#include "providers/dp_backend.h"
+
+struct be_ptask;
+
+/**
+ * Defines how should task behave when back end is offline.
+ */
+enum be_ptask_offline {
+ /* current request will be skipped and rescheduled to 'now + period' */
+ BE_PTASK_OFFLINE_SKIP,
+
+ /* An offline and online callback is registered. The task is disabled
+ * immediately when back end goes offline and then enabled again
+ * when back end goes back online */
+ BE_PTASK_OFFLINE_DISABLE,
+
+ /* current request will be executed as planned */
+ BE_PTASK_OFFLINE_EXECUTE
+};
+
+typedef struct tevent_req *
+(*be_ptask_send_t)(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct be_ctx *be_ctx,
+ struct be_ptask *be_ptask,
+ void *pvt);
+
+/**
+ * If EOK, task will be scheduled again to 'last_execution_time + period'.
+ * If other error code, task will be rescheduled to 'now + period'.
+ */
+typedef errno_t
+(*be_ptask_recv_t)(struct tevent_req *req);
+
+/**
+ * The first execution is scheduled first_delay seconds after the task is
+ * created.
+ *
+ * If request does not complete in timeout seconds, it will be
+ * cancelled and rescheduled to 'now + period'.
+ *
+ * If the task is reenabled, it will be scheduled again to
+ * 'now + enabled_delay'.
+ *
+ * If an internal error occurred, the task is automatically disabled.
+ */
+errno_t be_ptask_create(TALLOC_CTX *mem_ctx,
+ struct be_ctx *be_ctx,
+ time_t period,
+ time_t first_delay,
+ time_t enabled_delay,
+ time_t timeout,
+ enum be_ptask_offline offline,
+ be_ptask_send_t send,
+ be_ptask_recv_t recv,
+ void *pvt,
+ const char *name,
+ struct be_ptask **_task);
+
+void be_ptask_enable(struct be_ptask *task);
+void be_ptask_disable(struct be_ptask *task);
+void be_ptask_destroy(struct be_ptask **task);
+
+time_t be_ptask_get_period(struct be_ptask *task);
+
+#endif /* _DP_PTASK_H_ */
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