| 1 | /*
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| 2 | Unix SMB/CIFS implementation.
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| 3 | Infrastructure for async requests
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| 4 | Copyright (C) Volker Lendecke 2008
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| 5 |
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| 6 | This program is free software; you can redistribute it and/or modify
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| 7 | it under the terms of the GNU General Public License as published by
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| 8 | the Free Software Foundation; either version 3 of the License, or
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| 9 | (at your option) any later version.
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| 10 |
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| 11 | This program is distributed in the hope that it will be useful,
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 14 | GNU General Public License for more details.
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| 15 |
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| 16 | You should have received a copy of the GNU General Public License
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| 17 | along with this program. If not, see <http://www.gnu.org/licenses/>.
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| 18 | */
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| 19 |
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| 20 | #ifndef __ASYNC_REQ_H__
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| 21 | #define __ASYNC_REQ_H__
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| 22 |
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| 23 | #include "includes.h"
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| 24 |
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| 25 | /*
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| 26 | * An async request moves between the following 4 states.
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| 27 | */
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| 28 | enum async_req_state {
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| 29 | ASYNC_REQ_INIT, /* we are creating the request */
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| 30 | ASYNC_REQ_IN_PROGRESS, /* we are waiting the request to complete */
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| 31 | ASYNC_REQ_DONE, /* the request is finished */
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| 32 | ASYNC_REQ_ERROR }; /* an error has occured */
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| 33 |
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| 34 | struct async_req {
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| 35 | /* the external state - will be queried by the caller */
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| 36 | enum async_req_state state;
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| 37 |
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| 38 | /* a private pointer for use by the async function implementation */
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| 39 | void *private_data;
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| 40 |
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| 41 | /* print yourself, for debugging purposes */
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| 42 | char *(*print)(TALLOC_CTX *mem_ctx, struct async_req *);
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| 43 |
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| 44 | /* status code when finished */
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| 45 | NTSTATUS status;
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| 46 |
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| 47 | /* the event context we are using */
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| 48 | struct event_context *event_ctx;
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| 49 |
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| 50 | /* information on what to do on completion */
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| 51 | struct {
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| 52 | void (*fn)(struct async_req *);
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| 53 | void *priv;
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| 54 | } async;
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| 55 | };
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| 56 |
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| 57 | /*
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| 58 | * Print an async_req structure for debugging purposes
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| 59 | */
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| 60 | char *async_req_print(TALLOC_CTX *mem_ctx, struct async_req *req);
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| 61 |
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| 62 | /*
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| 63 | * Create an async request
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| 64 | */
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| 65 | struct async_req *async_req_new(TALLOC_CTX *mem_ctx, struct event_context *ev);
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| 66 |
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| 67 | /*
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| 68 | * An async request has successfully finished, invoke the callback
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| 69 | */
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| 70 | void async_req_done(struct async_req *req);
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| 71 |
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| 72 | /*
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| 73 | * An async request has seen an error, invoke the callback
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| 74 | */
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| 75 | void async_req_error(struct async_req *req, NTSTATUS status);
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| 76 |
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| 77 | /*
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| 78 | * If a request is finished or ends in error even before it has the chance to
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| 79 | * trigger the event loop, post a status. This creates an immediate timed
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| 80 | * event to call the async function if there is any.
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| 81 | */
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| 82 | bool async_post_status(struct async_req *req, NTSTATUS status);
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| 83 |
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| 84 | /*
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| 85 | * Convenience helper to easily check alloc failure within a callback.
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| 86 | *
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| 87 | * Call pattern would be
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| 88 | * p = talloc(mem_ctx, bla);
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| 89 | * if (async_req_nomem(p, req)) {
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| 90 | * return;
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| 91 | * }
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| 92 | *
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| 93 | */
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| 94 | bool async_req_nomem(const void *p, struct async_req *req);
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| 95 |
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| 96 | #endif
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