WebSVN – HelenOS-historic – Diff – /uspace/trunk/libc/generic/as.c


/*
 * Copyright (C) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 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 AUTHOR 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.
 */
 
#include <libc.h>
#include <unistd.h>
 
/** Create address space area.
 *
 * @param address Virtual address where to place new address space area.
 * @param size Size of the area.
 * @param flags Flags describing type of the area.
 *
 * @return address on success, (void *) -1 otherwise.
 */
void *as_area_create(void *address, size_t size, int flags)
{
    return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
 
/** Resize address space area.
 *
 * @param address Virtual address pointing into already existing address space area.
 * @param size New requested size of the area.
 * @param flags Currently unused.
 *
 * @return address on success, (void *) -1 otherwise.
 */
void *as_area_resize(void *address, size_t size, int flags)
{
    return (void *) __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
 
static size_t heapsize = 0;
/* Start of heap linker symbol */
extern char _heap;
 
/** Sbrk emulation
 *
 * @param size New area that should be allocated or negative,
               if it should be shrinked
 * @return Pointer to newly allocated area
 */
void *sbrk(ssize_t incr)
{
    void *res;
    /* Check for invalid values */
    if (incr < 0 && -incr > heapsize)
        return NULL;
    /* Check for too large value */
    if (incr > 0 && incr+heapsize < heapsize)
        return NULL;
    /* Check for too small values */
    if (incr < 0 && incr+heapsize > heapsize)
        return NULL;
 
    res = as_area_resize(&_heap, heapsize + incr,0);
    if (!res)
        return NULL;
   
    /* Compute start of new area */
    res = (void *)&_heap + heapsize;
 
    heapsize += incr;
 
    return res;
}
 

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/libc/generic/as.c @ 1237 – Rev 1033 → 1228

Rev 1033		Rev 1228
1	/*	1	/*
2	* Copyright (C) 2006 Jakub Jermar	2	* Copyright (C) 2006 Jakub Jermar
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	#include <libc.h>	29	#include <libc.h>
30	#include <unistd.h>	30	#include <unistd.h>
31		31
32	/** mmap syscall	32	/** Create address space area.
33	*	33	*
34	* @param address Virtual address where to place new address space area.	34	* @param address Virtual address where to place new address space area.
35	* @param size Size of the area.	35	* @param size Size of the area.
36	* @param flags Flags describing type of the area.	36	* @param flags Flags describing type of the area.
37	*	37	*
38	* @return address on success, (void *) -1 otherwise.	38	* @return address on success, (void *) -1 otherwise.
39	*/	39	*/
40	void mmap(void address, size_t size, int flags)	40	void as_area_create(void address, size_t size, int flags)
41	{	41	{
42	return (void *) __SYSCALL3(SYS_MMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);	42	return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
43	}	43	}
44		44
45	/** mremap syscall	45	/** Resize address space area.
46	*	46	*
47	* @param address Virtual address pointing into already existing address space area.	47	* @param address Virtual address pointing into already existing address space area.
48	* @param size New requested size of the area.	48	* @param size New requested size of the area.
49	* @param flags Currently unused.	49	* @param flags Currently unused.
50	*	50	*
51	* @return address on success, (void *) -1 otherwise.	51	* @return address on success, (void *) -1 otherwise.
52	*/	52	*/
53	void mremap(void address, size_t size, int flags)	53	void as_area_resize(void address, size_t size, int flags)
54	{	54	{
55	return (void *) __SYSCALL3(SYS_MREMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);	55	return (void *) __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
56	}	56	}
57		57
58	static size_t heapsize = 0;	58	static size_t heapsize = 0;
59	/* Start of heap linker symbol */	59	/* Start of heap linker symbol */
60	extern char _heap;	60	extern char _heap;
61		61
62	/** Sbrk emulation	62	/** Sbrk emulation
63	*	63	*
64	* @param size New area that should be allocated or negative,	64	* @param size New area that should be allocated or negative,
65	if it should be shrinked	65	if it should be shrinked
66	* @return Pointer to newly allocated area	66	* @return Pointer to newly allocated area
67	*/	67	*/
68	void *sbrk(ssize_t incr)	68	void *sbrk(ssize_t incr)
69	{	69	{
70	void *res;	70	void *res;
71	/* Check for invalid values */	71	/* Check for invalid values */
72	if (incr < 0 && -incr > heapsize)	72	if (incr < 0 && -incr > heapsize)
73	return NULL;	73	return NULL;
74	/* Check for too large value */	74	/* Check for too large value */
75	if (incr > 0 && incr+heapsize < heapsize)	75	if (incr > 0 && incr+heapsize < heapsize)
76	return NULL;	76	return NULL;
77	/* Check for too small values */	77	/* Check for too small values */
78	if (incr < 0 && incr+heapsize > heapsize)	78	if (incr < 0 && incr+heapsize > heapsize)
79	return NULL;	79	return NULL;
80		80
81	res = mremap(&_heap, heapsize + incr,0);	81	res = as_area_resize(&_heap, heapsize + incr,0);
82	if (!res)	82	if (!res)
83	return NULL;	83	return NULL;
84		84
85	/* Compute start of new area */	85	/* Compute start of new area */
86	res = (void *)&_heap + heapsize;	86	res = (void *)&_heap + heapsize;
87		87
88	heapsize += incr;	88	heapsize += incr;
89		89
90	return res;	90	return res;
91	}	91	}
92		92