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-rw-r--r--src/shared/eventfd-util.c169
-rw-r--r--src/shared/eventfd-util.h43
2 files changed, 0 insertions, 212 deletions
diff --git a/src/shared/eventfd-util.c b/src/shared/eventfd-util.c
deleted file mode 100644
index 27b7cf788f..0000000000
--- a/src/shared/eventfd-util.c
+++ /dev/null
@@ -1,169 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2014 Djalal Harouni
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <assert.h>
-#include <errno.h>
-#include <unistd.h>
-#include <sys/eventfd.h>
-#include <sys/syscall.h>
-
-#include "eventfd-util.h"
-#include "util.h"
-
-
-/*
- * Use this to create processes that need to setup a full context
- * and sync it with their parents using cheap mechanisms.
- *
- * This will create two blocking eventfd(s). A pair for the parent and
- * the other for the child so they can be used as a notify mechanism.
- * Each process will gets its copy of the parent and child eventfds.
- *
- * This is useful in case:
- * 1) If the parent fails or dies, the child must die.
- * 2) Child will install PR_SET_PDEATHSIG as soon as possible.
- * 3) Parent and child need to sync using less resources.
- * 4) If parent is not able to install a SIGCHLD handler:
- * parent will wait using a blocking eventfd_read() or
- * eventfd_child_succeeded() call on the child eventfd.
- *
- * * If the child setup succeeded, child should notify with an
- * EVENTFD_CHILD_SUCCEEDED, parent will continue.
- * * If the child setup failed, child should notify with an
- * EVENTFD_CHILD_FAILED before any _exit(). This avoids blocking
- * the parent.
- *
- * 5) If parent is able to install a SIGCHLD handler:
- * An empty signal handler without SA_RESTART will do it, since the
- * blocking eventfd_read() or eventfd_parent_succeeded() of the
- * parent will be interrupted by SIGCHLD and the call will fail with
- * EINTR. This is useful in case the child dies abnormaly and did
- * not have a chance to notify its parent using EVENTFD_CHILD_FAILED.
- *
- * 6) Call wait*() in the main instead of the signal handler in order
- * to: 1) reduce side effects and 2) have a better handling for
- * child termination in order to reduce various race conditions.
- *
- *
- * The return value of clone_with_eventfd() is the same of clone().
- * On success the eventfds[] will contain the two eventfd(s). These
- * file descriptors can be closed later with safe_close(). On failure,
- * a negative value is returned in the caller's context, and errno will
- * be set appropriately.
- *
- * Extra preliminary work:
- * 1) Child can wait before starting its setup by using the
- * eventfd_recv_start() call on the parent eventfd, in that case the
- * parent must notify with EVENTFD_START, after doing any preliminary
- * work.
- *
- * Note: this function depends on systemd internal functions
- * safe_close() and it should be used only by direct binaries, no
- * libraries.
- */
-pid_t clone_with_eventfd(int flags, int eventfds[2]) {
- pid_t pid;
-
- assert(eventfds);
-
- eventfds[0] = eventfd(EVENTFD_INIT, EFD_CLOEXEC);
- if (eventfds[0] < 0)
- return -1;
-
- eventfds[1] = eventfd(EVENTFD_INIT, EFD_CLOEXEC);
- if (eventfds[1] < 0)
- goto err_eventfd0;
-
- pid = syscall(__NR_clone, flags, NULL);
- if (pid < 0)
- goto err_eventfd1;
-
- return pid;
-
-err_eventfd1:
- eventfds[1] = safe_close(eventfds[1]);
-err_eventfd0:
- eventfds[0] = safe_close(eventfds[0]);
- return -1;
-}
-
-int eventfd_send_state(int efd, eventfd_t s) {
- return eventfd_write(efd, s);
-}
-
-/*
- * Receive an eventfd state on the eventfd file descriptor.
- *
- * If the third argument is set to a value other than zero, then this
- * function will compare the received value with this argument and set
- * the return value.
- *
- * On success return 0. On error, -1 will be returned, and errno will
- * be set appropriately.
- */
-int eventfd_recv_state(int efd, eventfd_t *e, eventfd_t s) {
- int ret;
-
- ret = eventfd_read(efd, e);
- if (ret < 0)
- return ret;
- else if (s != 0 && *e != s) {
- errno = EINVAL;
- return -1;
- }
-
- return 0;
-}
-
-/*
- * Receive the EVENTFD_START state on the eventfd file descriptor.
- *
- * On Success return 0. On error, -1 will be returned, and errno will
- * be set appropriately.
- */
-int eventfd_recv_start(int efd) {
- eventfd_t e = EVENTFD_INIT;
- return eventfd_recv_state(efd, &e, EVENTFD_START);
-}
-
-/*
- * Receive the EVENTFD_PARENT_SUCCEEDED state on the eventfd file
- * descriptor.
- *
- * On Success return 0. On error, -1 will be returned, and errno will
- * be set appropriately.
- */
-int eventfd_parent_succeeded(int efd) {
- eventfd_t e = EVENTFD_INIT;
- return eventfd_recv_state(efd, &e, EVENTFD_PARENT_SUCCEEDED);
-}
-
-/*
- * Receive the EVENTFD_CHILD_SUCCEEDED state on the eventfd file
- * descriptor.
- *
- * On Success return 0. On error, -1 will be returned, and errno will
- * be set appropriately.
- */
-int eventfd_child_succeeded(int efd) {
- eventfd_t e = EVENTFD_INIT;
- return eventfd_recv_state(efd, &e, EVENTFD_CHILD_SUCCEEDED);
-}
diff --git a/src/shared/eventfd-util.h b/src/shared/eventfd-util.h
deleted file mode 100644
index 0120f0409e..0000000000
--- a/src/shared/eventfd-util.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-#pragma once
-
-/***
- This file is part of systemd.
-
- Copyright 2014 Djalal Harouni
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd 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
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <sys/types.h>
-#include <sys/eventfd.h>
-
-enum {
- EVENTFD_INIT,
- EVENTFD_START,
- EVENTFD_PARENT_SUCCEEDED,
- EVENTFD_PARENT_FAILED,
- EVENTFD_CHILD_SUCCEEDED,
- EVENTFD_CHILD_FAILED,
-};
-
-pid_t clone_with_eventfd(int flags, int eventfds[2]);
-
-int eventfd_send_state(int efd, eventfd_t s);
-int eventfd_recv_state(int efd, eventfd_t *e, eventfd_t s);
-
-int eventfd_recv_start(int efd);
-int eventfd_parent_succeeded(int efd);
-int eventfd_child_succeeded(int efd);