--- /dev/null
+/*
+ * Copyright (C) 2016-2019 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <signal.h>
+#include <string.h>
+#include <time.h>
+#include <sys/syscall.h>
+#include <pthread.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/eventfd.h>
+
+#include <systemd/sd-event.h>
+
+#include "evmgr.h"
+#include "verbose.h"
+#include "systemd.h"
+
+/** Description of handled event loops */
+struct evmgr
+{
+ unsigned state; /**< encoded state */
+ int efd; /**< event notification */
+ void *holder; /**< holder of the evmgr */
+ struct sd_event *sdev; /**< the systemd event loop */
+};
+
+#define EVLOOP_STATE_WAIT 1U
+#define EVLOOP_STATE_RUN 2U
+
+/**
+ * Run the event loop is set.
+ */
+void evmgr_run(struct evmgr *evmgr)
+{
+ int rc;
+ struct sd_event *se;
+
+ evmgr->state = EVLOOP_STATE_WAIT|EVLOOP_STATE_RUN;
+ se = evmgr->sdev;
+ rc = sd_event_prepare(se);
+ if (rc < 0) {
+ errno = -rc;
+ CRITICAL("sd_event_prepare returned an error (state: %d): %m", sd_event_get_state(se));
+ abort();
+ } else {
+ if (rc == 0) {
+ rc = sd_event_wait(se, (uint64_t)(int64_t)-1);
+ if (rc < 0) {
+ errno = -rc;
+ ERROR("sd_event_wait returned an error (state: %d): %m", sd_event_get_state(se));
+ }
+ }
+ evmgr->state = EVLOOP_STATE_RUN;
+ if (rc > 0) {
+ rc = sd_event_dispatch(se);
+ if (rc < 0) {
+ errno = -rc;
+ ERROR("sd_event_dispatch returned an error (state: %d): %m", sd_event_get_state(se));
+ }
+ }
+ }
+ evmgr->state = 0;
+}
+
+void evmgr_job_run(int signum, struct evmgr *evmgr)
+{
+ if (signum)
+ evmgr->state = 0;
+ else
+ evmgr_run(evmgr);
+}
+
+int evmgr_can_run(struct evmgr *evmgr)
+{
+ return !evmgr->state;
+}
+
+/**
+ * Internal callback for evmgr management.
+ * The effect of this function is hidden: it exits
+ * the waiting poll if any.
+ */
+static void evmgr_on_efd_event(struct evmgr *evmgr)
+{
+ uint64_t x;
+ read(evmgr->efd, &x, sizeof x);
+}
+
+/**
+ * wakeup the event loop if needed by sending
+ * an event.
+ */
+void evmgr_wakeup(struct evmgr *evmgr)
+{
+ uint64_t x;
+
+ if (evmgr->state & EVLOOP_STATE_WAIT) {
+ x = 1;
+ write(evmgr->efd, &x, sizeof x);
+ }
+}
+
+/**
+ */
+void *evmgr_holder(struct evmgr *evmgr)
+{
+ return evmgr->holder;
+}
+
+/**
+ */
+int evmgr_release_if(struct evmgr *evmgr, void *holder)
+{
+ if (evmgr->holder != holder)
+ return 0;
+ evmgr->holder = 0;
+ return 1;
+}
+
+/**
+ */
+int evmgr_try_hold(struct evmgr *evmgr, void *holder)
+{
+ if (!evmgr->holder)
+ evmgr->holder = holder;
+ return evmgr->holder == holder;
+}
+
+/******************************************************************************/
+/******************************************************************************/
+/****** SYSTEM D ******/
+/******************************************************************************/
+/******************************************************************************/
+
+/**
+ * Internal callback for evmgr management.
+ * The effect of this function is hidden: it exits
+ * the waiting poll if any. Then it wakes up a thread
+ * awaiting the evmgr using signal.
+ */
+static int on_evmgr_efd(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+{
+ struct evmgr *evmgr = userdata;
+ evmgr_on_efd_event(evmgr);
+ return 1;
+}
+
+/**
+ * Gets a sd_event item for the current thread.
+ * @return a sd_event or NULL in case of error
+ */
+int evmgr_create(struct evmgr **result)
+{
+ int rc;
+ struct evmgr *evmgr;
+
+ /* creates the evmgr on need */
+ evmgr = malloc(sizeof *evmgr);
+ if (!evmgr) {
+ ERROR("out of memory");
+ rc = -ENOMEM;
+ goto error;
+ }
+
+ /* creates the eventfd for waking up polls */
+ evmgr->efd = eventfd(0, EFD_CLOEXEC|EFD_SEMAPHORE);
+ if (evmgr->efd < 0) {
+ ERROR("can't make eventfd for events");
+ rc = -errno;
+ goto error1;
+ }
+ /* create the systemd event loop */
+ evmgr->sdev = systemd_get_event_loop();
+ if (!evmgr->sdev) {
+ ERROR("can't make new event loop");
+ goto error2;
+ }
+ /* put the eventfd in the event loop */
+ rc = sd_event_add_io(evmgr->sdev, NULL, evmgr->efd, EPOLLIN, on_evmgr_efd, evmgr);
+ if (rc < 0) {
+ ERROR("can't register eventfd");
+ goto error2;
+ }
+
+ /* start the creation */
+ evmgr->state = 0;
+ evmgr->holder = 0;
+ *result = evmgr;
+ return 0;
+
+
+error2:
+ close(evmgr->efd);
+error1:
+ free(evmgr);
+error:
+ *result = 0;
+ return rc;
+}
+
Code Review / src / app-framework-binder.git / blobdiff