--- /dev/null
+
+/* ====================================================================
+ * Copyright (c) 1995 The Apache Group. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ * software must display the following acknowledgment:
+ * "This product includes software developed by the Apache Group
+ * for use in the Apache HTTP server project (http://www.apache.org/)."
+ *
+ * 4. The names "Apache Server" and "Apache Group" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission.
+ *
+ * 5. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the Apache Group
+ * for use in the Apache HTTP server project (http://www.apache.org/)."
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE APACHE GROUP OR
+ * IT'S CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Group and was originally based
+ * on public domain software written at the National Center for
+ * Supercomputing Applications, University of Illinois, Urbana-Champaign.
+ * For more information on the Apache Group and the Apache HTTP server
+ * project, please see <http://www.apache.org/>.
+ *
+ */
+
+
+/*
+ * Resource allocation routines...
+ *
+ * designed so that we don't have to keep track of EVERYTHING so that
+ * it can be explicitly freed later (a fundamentally unsound strategy ---
+ * particularly in the presence of die()).
+ *
+ * Instead, we maintain pools, and allocate items (both memory and I/O
+ * handlers) from the pools --- currently there are two, one for per
+ * transaction info, and one for config info. When a transaction is over,
+ * we can delete everything in the per-transaction pool without fear, and
+ * without thinking too hard about it either.
+ *
+ * rst
+ */
+
+/* Arenas for configuration info and transaction info
+ * --- actual layout of the pool structure is private to
+ * alloc.c.
+ */
+
+typedef struct pool pool;
+
+extern pool *permanent_pool;
+void init_alloc(); /* Set up everything */
+pool *make_sub_pool (pool *); /* All pools are subpools of permanent_pool */
+void destroy_pool (pool *);
+
+/* Clearing out EVERYTHING in an pool... destroys any sub-pools */
+
+void clear_pool (struct pool *);
+
+/* Preparing for exec() --- close files, etc., but *don't* flush I/O
+ * buffers, *don't* wait for subprocesses, and *don't* free any memory.
+ */
+
+void cleanup_for_exec ();
+
+/* routines to allocate memory from an pool... */
+
+void *palloc(struct pool *, int nbytes);
+void *pcalloc(struct pool *, int nbytes);
+char *pstrdup(struct pool *, char *s);
+char *pstrcat(struct pool *, ...); /* all '...' must be char* */
+
+/* array and alist management... keeping lists of things.
+ * Common enough to want common support code ...
+ */
+
+typedef struct {
+ pool *pool;
+ int elt_size;
+ int nelts;
+ int nalloc;
+ char *elts;
+} array_header;
+
+array_header *make_array (pool *p, int nelts, int elt_size);
+void *push_array (array_header *);
+void array_cat (array_header *dst, array_header *src);
+array_header *append_arrays (pool *, array_header *, array_header *);
+
+/* copy_array copies the *entire* array. copy_array_hdr just copies
+ * the header, and arranges for the elements to be copied if (and only
+ * if) the code subsequently does a push or arraycat.
+ */
+
+array_header *copy_array (pool *p, array_header *src);
+array_header *copy_array_hdr (pool *p, array_header *src);
+
+
+/* Tables. Implemented alist style, for now, though we try to keep
+ * it so that imposing a hash table structure on top in the future
+ * wouldn't be *too* hard...
+ *
+ * Note that key comparisons for these are case-insensitive, largely
+ * because that's what's appropriate and convenient everywhere they're
+ * currently being used...
+ */
+
+typedef array_header table;
+
+typedef struct {
+ char *key; /* maybe NULL in future;
+ * check when iterating thru table_elts
+ */
+ char *val;
+} table_entry;
+
+table *make_table (pool *p, int nelts);
+table *copy_table (pool *p, table *);
+char *table_get (table *, char *);
+void table_set (table *, char *name, char *val);
+void table_merge (table *, char *name, char *more_val);
+
+table *overlay_tables (pool *p, table *overlay, table *base);
+
+array_header *table_elts (table *);
+
+/* routines to remember allocation of other sorts of things...
+ * generic interface first. Note that we want to have two separate
+ * cleanup functions in the general case, one for exec() preparation,
+ * to keep CGI scripts and the like from inheriting access to things
+ * they shouldn't be able to touch, and one for actually cleaning up,
+ * when the actual server process wants to get rid of the thing,
+ * whatever it is.
+ *
+ * kill_cleanup disarms a cleanup, presumably because the resource in
+ * question has been closed, freed, or whatever, and it's scarce
+ * enough to want to reclaim (e.g., descriptors). It arranges for the
+ * resource not to be cleaned up a second time (it might have been
+ * reallocated). run_cleanup does the same, but runs it first.
+ *
+ * Cleanups are identified for purposes of finding & running them off by the
+ * plain_cleanup and data, which should presumably be unique.
+ *
+ * NB any code which invokes register_cleanup or kill_cleanup directly
+ * is a critical section which should be guarded by block_alarms() and
+ * unblock_alarms() below...
+ */
+
+void register_cleanup (pool *p, void *data,
+ void (*plain_cleanup)(void *),
+ void (*child_cleanup)(void *));
+
+void kill_cleanup (pool *p, void *data, void (*plain_cleanup)(void *));
+
+/* The time between when a resource is actually allocated, and when it
+ * its cleanup is registered is a critical section, during which the
+ * resource could leak if we got interrupted or timed out. So, anything
+ * which registers cleanups should bracket resource allocation and the
+ * cleanup registry with these. (This is done internally by run_cleanup).
+ *
+ * NB they are actually implemented in http_main.c, since they are bound
+ * up with timeout handling in general...
+ */
+
+extern void block_alarms();
+extern void unblock_alarms();
+
+/* Common cases which want utility support..
+ * the note_cleanups_for_foo routines are for
+ */
+
+FILE *pfopen(struct pool *, char *name, char *fmode);
+FILE *pfdopen(struct pool *, int fd, char *fmode);
+int popenf(struct pool *, char *name, int flg, int mode);
+
+void note_cleanups_for_file (pool *, FILE *);
+void note_cleanups_for_fd (pool *, int);
+
+/* routines to note closes... file descriptors are constrained enough
+ * on some systems that we want to support this.
+ */
+
+int pfclose(struct pool *, FILE *);
+int pclosef(struct pool *, int fd);
+
+/* ... even child processes (which we may want to wait for,
+ * or to kill outright, on unexpected termination).
+ *
+ * spawn_child is a utility routine which handles an awful lot of
+ * the rigamarole associated with spawning a child --- it arranges
+ * for pipes to the child's stdin and stdout, if desired (if not,
+ * set the associated args to NULL). It takes as args a function
+ * to call in the child, and an argument to be passed to the function.
+ */
+
+enum kill_conditions { kill_never, kill_always, kill_after_timeout, just_wait};
+
+int spawn_child (pool *, void (*)(void *), void *,
+ enum kill_conditions, FILE **pipe_in, FILE **pipe_out);
+
+/* magic numbers --- only one so far, min free bytes in a new pool block */
+
+#define BLOCK_MINFREE 8192
+
+/* Finally, some accounting */
+
+long bytes_in_pool(pool *p);
+long bytes_in_free_blocks();
projects / thirdparty / apache / httpd.git / commitdiff
