s3: Add a dummy implementation for the pthreadpool API

Signed-off-by: Jeremy Allison <jra@samba.org>

source3/lib/pthreadpool/pthreadpool_sync.c

@@ -0,0 +1,174 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * sync dummy implementation of the pthreadpool API
+ * Copyright (C) Volker Lendecke 2009
+ *
+ * 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 <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+#include <signal.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <sys/time.h>
+
+#include "pthreadpool.h"
+
+struct pthreadpool {
+	/*
+	 * pipe for signalling
+	 */
+	int sig_pipe[2];
+
+	/*
+	 * Have we sent something into the pipe that has not been
+	 * retrieved yet?
+	 */
+	int pipe_busy;
+
+	/*
+	 * Jobids that we have not sent into the pipe yet
+	 */
+	size_t num_ids;
+	int *ids;
+};
+
+int pthreadpool_init(unsigned max_threads, struct pthreadpool **presult)
+{
+	struct pthreadpool *pool;
+	int ret;
+
+	pool = (struct pthreadpool *)calloc(1, sizeof(struct pthreadpool));
+	if (pool == NULL) {
+		return ENOMEM;
+	}
+	ret = pipe(pool->sig_pipe);
+	if (ret == -1) {
+		int err = errno;
+		free(pool);
+		return err;
+	}
+	*presult = pool;
+	return 0;
+}
+
+int pthreadpool_signal_fd(struct pthreadpool *pool)
+{
+	return pool->sig_pipe[0];
+}
+
+static int pthreadpool_write_to_pipe(struct pthreadpool *pool)
+{
+	ssize_t written;
+
+	if (pool->pipe_busy) {
+		return 0;
+	}
+	if (pool->num_ids == 0) {
+		return 0;
+	}
+
+	written = -1;
+	errno = EINTR;
+
+	while ((written == -1) && (errno == EINTR)) {
+		written = write(pool->sig_pipe[1], &pool->ids[0], sizeof(int));
+	}
+	if (written == -1) {
+		return errno;
+	}
+	if (written != sizeof(int)) {
+		/*
+		 * If a single int only partially fits into the pipe,
+		 * we can assume ourselves pretty broken
+		 */
+		close(pool->sig_pipe[1]);
+		pool->sig_pipe[1] = -1;
+		return EIO;
+	}
+
+	if (pool->num_ids > 1) {
+		memmove(pool->ids, pool->ids+1, sizeof(int) * (pool->num_ids-1));
+	}
+	pool->num_ids -= 1;
+	pool->pipe_busy = 1;
+	return 0;
+}
+
+int pthreadpool_add_job(struct pthreadpool *pool, int job_id,
+			void (*fn)(void *private_data), void *private_data)
+{
+	int *tmp;
+
+	if (pool->sig_pipe[1] == -1) {
+		return EIO;
+	}
+
+	fn(private_data);
+
+	tmp = realloc(pool->ids, sizeof(int) * (pool->num_ids+1));
+	if (tmp == NULL) {
+		return ENOMEM;
+	}
+	pool->ids = tmp;
+	pool->ids[pool->num_ids] = job_id;
+	pool->num_ids += 1;
+
+	return pthreadpool_write_to_pipe(pool);
+
+}
+
+int pthreadpool_finished_job(struct pthreadpool *pool, int *jobid)
+{
+	int ret_jobid;
+	ssize_t nread;
+
+	nread = -1;
+	errno = EINTR;
+
+	while ((nread == -1) && (errno == EINTR)) {
+		nread = read(pool->sig_pipe[0], &ret_jobid, sizeof(int));
+	}
+	if (nread == -1) {
+		return errno;
+	}
+	if (nread != sizeof(int)) {
+		return EINVAL;
+	}
+	*jobid = ret_jobid;
+
+	pool->pipe_busy = 0;
+	return pthreadpool_write_to_pipe(pool);
+}
+
+int pthreadpool_destroy(struct pthreadpool *pool)
+{
+	if (pool->sig_pipe[0] != -1) {
+		close(pool->sig_pipe[0]);
+		pool->sig_pipe[0] = -1;
+	}
+
+	if (pool->sig_pipe[1] != -1) {
+		close(pool->sig_pipe[1]);
+		pool->sig_pipe[1] = -1;
+	}
+	free(pool->ids);
+	free(pool);
+	return 0;
+}