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authorVolker Lendecke <vl@samba.org>2009-04-25 20:02:24 +0200
committerVolker Lendecke <vl@samba.org>2009-05-01 12:30:59 +0200
commit8cf75770cf2b3905ca98c84b21fadca8e05f08b7 (patch)
treeafff0cbfb9967fed96ded881754adacf0d54363c /source3/lib
parentdb2cc8c9f2ec6f98884b1eb7738148cecdf6fd45 (diff)
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Add fncall_send/recv
Diffstat (limited to 'source3/lib')
-rw-r--r--source3/lib/fncall.c365
1 files changed, 365 insertions, 0 deletions
diff --git a/source3/lib/fncall.c b/source3/lib/fncall.c
new file mode 100644
index 0000000000..e810b6814e
--- /dev/null
+++ b/source3/lib/fncall.c
@@ -0,0 +1,365 @@
+/*
+ * Unix SMB/CIFS implementation.
+ * Async fn calls
+ * 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 "includes.h"
+
+#if WITH_PTHREADPOOL
+
+#include "pthreadpool.h"
+
+struct fncall_state {
+ struct fncall_context *ctx;
+ int job_id;
+ bool done;
+
+ void *private_parent;
+ void *job_private;
+};
+
+struct fncall_context {
+ struct pthreadpool *pool;
+ int next_job_id;
+ int sig_fd;
+ struct tevent_req **pending;
+
+ struct fncall_state **orphaned;
+ int num_orphaned;
+
+ struct fd_event *fde;
+};
+
+static void fncall_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, void *private_data);
+
+static int fncall_context_destructor(struct fncall_context *ctx)
+{
+ while (talloc_array_length(ctx->pending) != 0) {
+ /* No TALLOC_FREE here */
+ talloc_free(ctx->pending[0]);
+ }
+
+ while (ctx->num_orphaned != 0) {
+ /*
+ * We've got jobs in the queue for which the tevent_req has
+ * been finished already. Wait for all of them to finish.
+ */
+ fncall_handler(NULL, NULL, TEVENT_FD_READ, ctx);
+ }
+
+ pthreadpool_destroy(ctx->pool);
+ ctx->pool = NULL;
+
+ return 0;
+}
+
+struct fncall_context *fncall_context_init(TALLOC_CTX *mem_ctx,
+ int max_threads)
+{
+ struct fncall_context *ctx;
+ int ret;
+
+ ctx = talloc_zero(mem_ctx, struct fncall_context);
+ if (ctx == NULL) {
+ return NULL;
+ }
+
+ ret = pthreadpool_init(max_threads, &ctx->pool);
+ if (ret != 0) {
+ TALLOC_FREE(ctx);
+ return NULL;
+ }
+ talloc_set_destructor(ctx, fncall_context_destructor);
+
+ ctx->sig_fd = pthreadpool_sig_fd(ctx->pool);
+ if (ctx->sig_fd == -1) {
+ TALLOC_FREE(ctx);
+ return NULL;
+ }
+
+ return ctx;
+}
+
+static int fncall_next_job_id(struct fncall_context *ctx)
+{
+ int num_pending = talloc_array_length(ctx->pending);
+ int result;
+
+ while (true) {
+ int i;
+
+ result = ctx->next_job_id++;
+ if (result == 0) {
+ continue;
+ }
+
+ for (i=0; i<num_pending; i++) {
+ struct fncall_state *state = tevent_req_data(
+ ctx->pending[i], struct fncall_state);
+
+ if (result == state->job_id) {
+ break;
+ }
+ }
+ if (i == num_pending) {
+ return result;
+ }
+ }
+}
+
+static void fncall_unset_pending(struct tevent_req *req);
+static int fncall_destructor(struct tevent_req *req);
+
+static bool fncall_set_pending(struct tevent_req *req,
+ struct fncall_context *ctx,
+ struct tevent_context *ev)
+{
+ struct tevent_req **pending;
+ int num_pending, orphaned_array_length;
+
+ num_pending = talloc_array_length(ctx->pending);
+
+ pending = talloc_realloc(ctx, ctx->pending, struct tevent_req *,
+ num_pending+1);
+ if (pending == NULL) {
+ return false;
+ }
+ pending[num_pending] = req;
+ num_pending += 1;
+ ctx->pending = pending;
+ talloc_set_destructor(req, fncall_destructor);
+
+ /*
+ * Make sure that the orphaned array of fncall_state structs has
+ * enough space. A job can change from pending to orphaned in
+ * fncall_destructor, and to fail in a talloc destructor should be
+ * avoided if possible.
+ */
+
+ orphaned_array_length = talloc_array_length(ctx->orphaned);
+ if (num_pending > orphaned_array_length) {
+ struct fncall_state **orphaned;
+
+ orphaned = talloc_realloc(ctx, ctx->orphaned,
+ struct fncall_state *,
+ orphaned_array_length + 1);
+ if (orphaned == NULL) {
+ fncall_unset_pending(req);
+ return false;
+ }
+ ctx->orphaned = orphaned;
+ }
+
+ if (ctx->fde != NULL) {
+ return true;
+ }
+
+ ctx->fde = tevent_add_fd(ev, ctx->pending, ctx->sig_fd, TEVENT_FD_READ,
+ fncall_handler, ctx);
+ if (ctx->fde == NULL) {
+ fncall_unset_pending(req);
+ return false;
+ }
+ return true;
+}
+
+static void fncall_unset_pending(struct tevent_req *req)
+{
+ struct fncall_state *state = tevent_req_data(req, struct fncall_state);
+ struct fncall_context *ctx = state->ctx;
+ int num_pending = talloc_array_length(ctx->pending);
+ int i;
+
+ if (num_pending == 1) {
+ TALLOC_FREE(ctx->fde);
+ TALLOC_FREE(ctx->pending);
+ return;
+ }
+
+ for (i=0; i<num_pending; i++) {
+ if (req == ctx->pending[i]) {
+ break;
+ }
+ }
+ if (i == num_pending) {
+ return;
+ }
+ if (num_pending > 1) {
+ ctx->pending[i] = ctx->pending[num_pending-1];
+ }
+ ctx->pending = talloc_realloc(NULL, ctx->pending, struct tevent_req *,
+ num_pending - 1);
+}
+
+static int fncall_destructor(struct tevent_req *req)
+{
+ struct fncall_state *state = tevent_req_data(
+ req, struct fncall_state);
+ struct fncall_context *ctx = state->ctx;
+
+ fncall_unset_pending(req);
+
+ if (state->done) {
+ return 0;
+ }
+
+ /*
+ * Keep around the state of the deleted request until the request has
+ * finished in the helper thread. fncall_handler will destroy it.
+ */
+ ctx->orphaned[ctx->num_orphaned] = talloc_move(ctx->orphaned, &state);
+ ctx->num_orphaned += 1;
+
+ return 0;
+}
+
+struct tevent_req *fncall_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct fncall_context *ctx,
+ void (*fn)(void *private_data),
+ void *private_data)
+{
+ struct tevent_req *req;
+ struct fncall_state *state;
+ int ret;
+
+ req = tevent_req_create(mem_ctx, &state, struct fncall_state);
+ if (req == NULL) {
+ return NULL;
+ }
+ state->ctx = ctx;
+ state->job_id = fncall_next_job_id(state->ctx);
+ state->done = false;
+
+ /*
+ * We need to keep the private data we handed out to the thread around
+ * as long as the job is not finished. This is a bit of an abstraction
+ * violation, because the "req->state1->subreq->state2" (we're
+ * "subreq", "req" is the request our caller creates) is broken to
+ * "ctx->state2->state1", but we are right now in the destructor for
+ * "subreq2", so what can we do. We need to keep state1 around,
+ * otherwise the helper thread will have no place to put its results.
+ */
+
+ state->private_parent = talloc_parent(private_data);
+ state->job_private = talloc_move(state, &private_data);
+
+ ret = pthreadpool_add_job(state->ctx->pool, state->job_id, fn,
+ state->job_private);
+ if (ret == -1) {
+ tevent_req_error(req, errno);
+ return tevent_req_post(req, ev);
+ }
+ if (!fncall_set_pending(req, state->ctx, ev)) {
+ tevent_req_nomem(NULL, req);
+ return tevent_req_post(req, ev);
+ }
+ return req;
+}
+
+static void fncall_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct fncall_context *ctx = talloc_get_type_abort(
+ private_data, struct fncall_context);
+ int i, num_pending;
+ int job_id;
+
+ job_id = pthreadpool_finished_job(ctx->pool);
+ if (job_id <= 0) {
+ return;
+ }
+
+ num_pending = talloc_array_length(ctx->pending);
+
+ for (i=0; i<num_pending; i++) {
+ struct fncall_state *state = tevent_req_data(
+ ctx->pending[i], struct fncall_state);
+
+ if (job_id == state->job_id) {
+ state->done = true;
+ talloc_move(state->private_parent,
+ &state->job_private);
+ tevent_req_done(ctx->pending[i]);
+ return;
+ }
+ }
+
+ for (i=0; i<ctx->num_orphaned; i++) {
+ if (job_id == ctx->orphaned[i]->job_id) {
+ break;
+ }
+ }
+ if (i == ctx->num_orphaned) {
+ return;
+ }
+
+ TALLOC_FREE(ctx->orphaned[i]);
+
+ if (i < ctx->num_orphaned-1) {
+ ctx->orphaned[i] = ctx->orphaned[ctx->num_orphaned-1];
+ }
+ ctx->num_orphaned -= 1;
+}
+
+int fncall_recv(struct tevent_req *req, int *perr)
+{
+ if (tevent_req_is_unix_error(req, perr)) {
+ return -1;
+ }
+ return 0;
+}
+
+#else /* WITH_PTHREADPOOL */
+
+struct fncall_context {
+ uint8_t dummy;
+};
+
+struct fncall_context *fncall_context_init(TALLOC_CTX *mem_ctx,
+ int max_threads)
+{
+ return talloc(mem_ctx, struct fncall_context);
+}
+
+struct fncall_state {
+ uint8_t dummy;
+};
+
+struct tevent_req *fncall_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
+ struct fncall_context *ctx,
+ void (*fn)(void *private_data),
+ void *private_data)
+{
+ struct tevent_req *req;
+ struct fncall_state *state;
+
+ req = tevent_req_create(mem_ctx, &state, struct fncall_state);
+ if (req == NULL) {
+ return NULL;
+ }
+ fn(private_data);
+ tevent_req_post(req, ev);
+ return req;
+}
+
+int fncall_recv(struct tevent_req *req, int *perr)
+{
+ return 0;
+}
+
+#endif