--- /dev/null
+/*
+ Create and remove pidfile
+
+ Copyright (C) Amitay Isaacs 2016
+
+ 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 "replace.h"
+#include "system/filesys.h"
+
+#include <talloc.h>
+
+#include "common/pidfile.h"
+
+struct pidfile_context {
+ const char *pidfile;
+ int fd;
+ pid_t pid;
+};
+
+static int pidfile_context_destructor(struct pidfile_context *pid_ctx);
+
+int pidfile_create(TALLOC_CTX *mem_ctx, const char *pidfile,
+ struct pidfile_context **result)
+{
+ struct pidfile_context *pid_ctx;
+ struct flock lck;
+ char tmp[64];
+ int fd, ret = 0;
+ int len;
+ ssize_t nwritten;
+
+ pid_ctx = talloc_zero(mem_ctx, struct pidfile_context);
+ if (pid_ctx == NULL) {
+ return ENOMEM;
+ }
+
+ pid_ctx->pidfile = talloc_strdup(pid_ctx, pidfile);
+ if (pid_ctx->pidfile == NULL) {
+ ret = ENOMEM;
+ goto fail;
+ }
+
+ pid_ctx->pid = getpid();
+
+ fd = open(pidfile, O_CREAT|O_WRONLY|O_NONBLOCK, 0644);
+ if (fd == -1) {
+ ret = errno;
+ goto fail;
+ }
+
+ pid_ctx->fd = fd;
+
+ lck = (struct flock) {
+ .l_type = F_WRLCK,
+ .l_whence = SEEK_SET,
+ };
+
+ do {
+ ret = fcntl(fd, F_SETLK, &lck);
+ } while ((ret == -1) && (errno == EINTR));
+
+ if (ret != 0) {
+ ret = errno;
+ goto fail;
+ }
+
+ do {
+ ret = ftruncate(fd, 0);
+ } while ((ret == -1) && (errno == EINTR));
+
+ if (ret == -1) {
+ ret = EIO;
+ goto fail_unlink;
+ }
+
+ len = snprintf(tmp, sizeof(tmp), "%u\n", pid_ctx->pid);
+ if (len < 0) {
+ ret = EIO;
+ goto fail_unlink;
+ }
+
+ do {
+ nwritten = write(fd, tmp, len);
+ } while ((nwritten == -1) && (errno == EINTR));
+
+ if ((nwritten == -1) || (nwritten != len)) {
+ ret = EIO;
+ goto fail_unlink;
+ }
+
+ talloc_set_destructor(pid_ctx, pidfile_context_destructor);
+
+ *result = pid_ctx;
+ return 0;
+
+fail_unlink:
+ unlink(pidfile);
+ close(fd);
+
+fail:
+ talloc_free(pid_ctx);
+ return ret;
+}
+
+static int pidfile_context_destructor(struct pidfile_context *pid_ctx)
+{
+ struct flock lck;
+ int ret;
+
+ if (getpid() != pid_ctx->pid) {
+ return 0;
+ }
+
+ lck = (struct flock) {
+ .l_type = F_UNLCK,
+ .l_whence = SEEK_SET,
+ };
+
+ (void) unlink(pid_ctx->pidfile);
+
+ do {
+ ret = fcntl(pid_ctx->fd, F_SETLK, &lck);
+ } while ((ret == -1) && (errno == EINTR));
+
+ do {
+ ret = close(pid_ctx->fd);
+ } while ((ret == -1) && (errno == EINTR));
+
+ return 0;
+}
--- /dev/null
+/*
+ Create and remove pidfile
+
+ Copyright (C) Amitay Isaacs 2016
+
+ 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 __CTDB_PIDFILE_H__
+#define __CTDB_PIDFILE_H__
+
+#include <talloc.h>
+
+/**
+ * @file pidfile.h
+ *
+ * @brief Routines to manage PID file
+ */
+
+/**
+ * @brief Abstract struct to store pidfile details
+ */
+struct pidfile_context;
+
+/**
+ * @brief Create a PID file
+ *
+ * This creates a PID file, locks it, and writes PID.
+ *
+ * @param[in] mem_ctx Talloc memory context
+ * @param[in] pidfile Path of PID file
+ * @param[out] result Pidfile context
+ * @return 0 on success, errno on failure
+ *
+ * Freeing the pidfile_context, will delete the pidfile.
+ */
+int pidfile_create(TALLOC_CTX *mem_ctx, const char *pidfile,
+ struct pidfile_context **result);
+
+#endif /* __CTDB_PIDFILE_H__ */
--- /dev/null
+/*
+ pidfile tests
+
+ Copyright (C) Amitay Isaacs 2016
+
+ 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 "replace.h"
+#include "system/wait.h"
+
+#include <assert.h>
+
+#include "common/pidfile.c"
+
+
+/* create pid file, check pid file exists, check pid and remove pid file */
+static void test1(const char *pidfile)
+{
+ struct pidfile_context *pid_ctx;
+ int ret;
+ struct stat st;
+ FILE *fp;
+ pid_t pid;
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret == 0);
+ assert(pid_ctx != NULL);
+
+ ret = stat(pidfile, &st);
+ assert(ret == 0);
+ assert(S_ISREG(st.st_mode));
+
+ fp = fopen(pidfile, "r");
+ ret = fscanf(fp, "%d", &pid);
+ assert(ret == 1);
+ assert(pid == getpid());
+ fclose(fp);
+
+ TALLOC_FREE(pid_ctx);
+
+ ret = stat(pidfile, &st);
+ assert(ret == -1);
+}
+
+/* create pid file in two processes */
+static void test2(const char *pidfile)
+{
+ struct pidfile_context *pid_ctx;
+ pid_t pid, pid2;
+ int fd[2];
+ int ret;
+ size_t nread;
+ FILE *fp;
+ struct stat st;
+
+ ret = pipe(fd);
+ assert(ret == 0);
+
+ pid = fork();
+ assert(pid != -1);
+
+ if (pid == 0) {
+ ssize_t nwritten;
+
+ close(fd[0]);
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret == 0);
+ assert(pid_ctx != NULL);
+
+ nwritten = write(fd[1], &ret, sizeof(ret));
+ assert(nwritten == sizeof(ret));
+
+ sleep(10);
+
+ TALLOC_FREE(pid_ctx);
+
+ nwritten = write(fd[1], &ret, sizeof(ret));
+ assert(nwritten == sizeof(ret));
+
+ exit(1);
+ }
+
+ close(fd[1]);
+
+ nread = read(fd[0], &ret, sizeof(ret));
+ assert(nread == sizeof(ret));
+ assert(ret == 0);
+
+ fp = fopen(pidfile, "r");
+ assert(fp != NULL);
+ ret = fscanf(fp, "%d", &pid2);
+ assert(ret == 1);
+ assert(pid == pid2);
+ fclose(fp);
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret != 0);
+
+ nread = read(fd[0], &ret, sizeof(ret));
+ assert(nread == sizeof(ret));
+ assert(ret == 0);
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret == 0);
+ assert(pid_ctx != NULL);
+
+ TALLOC_FREE(pid_ctx);
+
+ ret = stat(pidfile, &st);
+ assert(ret == -1);
+}
+
+/* create pid file, fork, try to remove pid file in separate process */
+static void test3(const char *pidfile)
+{
+ struct pidfile_context *pid_ctx;
+ pid_t pid;
+ int fd[2];
+ int ret;
+ size_t nread;
+ struct stat st;
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret == 0);
+ assert(pid_ctx != NULL);
+
+ ret = pipe(fd);
+ assert(ret == 0);
+
+ pid = fork();
+ assert(pid != -1);
+
+ if (pid == 0) {
+ ssize_t nwritten;
+
+ close(fd[0]);
+
+ TALLOC_FREE(pid_ctx);
+
+ nwritten = write(fd[1], &ret, sizeof(ret));
+ assert(nwritten == sizeof(ret));
+
+ exit(1);
+ }
+
+ close(fd[1]);
+
+ nread = read(fd[0], &ret, sizeof(ret));
+ assert(nread == sizeof(ret));
+
+ ret = stat(pidfile, &st);
+ assert(ret == 0);
+
+ TALLOC_FREE(pid_ctx);
+
+ ret = stat(pidfile, &st);
+ assert(ret == -1);
+}
+
+/* create pid file, kill process, overwrite pid file in different process */
+static void test4(const char *pidfile)
+{
+ struct pidfile_context *pid_ctx;
+ pid_t pid, pid2;
+ int fd[2];
+ int ret;
+ size_t nread;
+ struct stat st;
+
+ ret = pipe(fd);
+ assert(ret == 0);
+
+ pid = fork();
+ assert(pid != -1);
+
+ if (pid == 0) {
+ ssize_t nwritten;
+
+ close(fd[0]);
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+
+ nwritten = write(fd[1], &ret, sizeof(ret));
+ assert(nwritten == sizeof(ret));
+
+ sleep(99);
+ exit(1);
+ }
+
+ close(fd[1]);
+
+ nread = read(fd[0], &ret, sizeof(ret));
+ assert(nread == sizeof(ret));
+ assert(ret == 0);
+
+ ret = stat(pidfile, &st);
+ assert(ret == 0);
+
+ ret = kill(pid, SIGKILL);
+ assert(ret == 0);
+
+ pid2 = waitpid(pid, &ret, 0);
+ assert(pid2 == pid);
+
+ ret = pidfile_create(NULL, pidfile, &pid_ctx);
+ assert(ret == 0);
+ assert(pid_ctx != NULL);
+
+ ret = stat(pidfile, &st);
+ assert(ret == 0);
+
+ TALLOC_FREE(pid_ctx);
+}
+
+int main(int argc, const char **argv)
+{
+ if (argc != 2) {
+ fprintf(stderr, "Usage: %s <pidfile>\n", argv[0]);
+ exit(1);
+ }
+
+ test1(argv[1]);
+ test2(argv[1]);
+ test3(argv[1]);
+ test4(argv[1]);
+
+ return 0;
+}
git.samba.org / metze / samba / wip.git / commitdiff