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incubator-nuttx/mm/shm/shmat.c

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Add README files and configuration support for the shared memory logic
2014-09-23 21:11:47 +08:00
/****************************************************************************
* mm/shm/shmat.c
*
Squashed commit of the following: This commit backs out most of commit b4747286b19d3b15193b2a5e8a0fe48fa0a8638c. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point. In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable. In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable. sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
2017-10-05 05:22:27 +08:00
* Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved.
Add README files and configuration support for the shared memory logic
2014-09-23 21:11:47 +08:00
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/shm.h>
#include <errno.h>
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
#include <nuttx/sched.h>
#include <nuttx/arch.h>
#include <nuttx/pgalloc.h>
#include "shm/shm.h"
Add README files and configuration support for the shared memory logic
2014-09-23 21:11:47 +08:00
#ifdef CONFIG_MM_SHM
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: shmat
*
* Description:
* The shmat() function attaches the shared memory segment associated with
* the shared memory identifier specified by shmid to the address space of
* the calling process. The segment is attached at the address specified
* by one of the following criteria:
*
* - If shmaddr is a null pointer, the segment is attached at the first
* available address as selected by the system.
* - If shmaddr is not a null pointer and (shmflg & SHM_RND) is non-
* zero, the segment is attached at the address given by
* (shmaddr - ((uintptr_t)shmaddr % SHMLBA)).
* - If shmaddr is not a null pointer and (shmflg & SHM_RND) is 0, the
* segment is attached at the address given by shmaddr.
* - The segment is attached for reading if (shmflg & SHM_RDONLY) is
* non-zero and the calling process has read permission; otherwise, if
* it is 0 and the calling process has read and write permission, the
* segment is attached for reading and writing.
*
* Input Parameters:
* shmid - Shared memory identifier
* smaddr - Determines mapping of the shared memory region
* shmflg - See SHM_* definitions in include/sys/shm.h. Only SHM_RDONLY
* and SHM_RND are supported.
*
* Returned Value:
* Upon successful completion, shmat() will increment the value of
* shm_nattch in the data structure associated with the shared memory ID
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
* of the attached shared memory segment and return the segment's start
* address.
Add README files and configuration support for the shared memory logic
2014-09-23 21:11:47 +08:00
*
* Otherwise, the shared memory segment will not be attached, shmat() will
* return -1, and errno will be set to indicate the error.
*
* - EACCES
* Operation permission is denied to the calling process
* - EINVAL
* The value of shmid is not a valid shared memory identifier, the
* shmaddr is not a null pointer, and the value of
* (shmaddr -((uintptr_t)shmaddr % SHMLBA)) is an illegal address for
* attaching shared memory; or the shmaddr is not a null pointer,
* (shmflg & SHM_RND) is 0, and the value of shmaddr is an illegal
* address for attaching shared memory.
* - EMFILE
* The number of shared memory segments attached to the calling
* process would exceed the system-imposed limit.
* - ENOMEM
* The available data space is not large enough to accommodate the
* shared memory segment.
*
****************************************************************************/
FAR void *shmat(int shmid, FAR const void *shmaddr, int shmflg)
{
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
FAR struct shm_region_s *region;
FAR struct task_group_s *group;
FAR struct tcb_s *tcb;
uintptr_t vaddr;
unsigned int npages;
int ret;
/* Get the region associated with the shmid */
DEBUGASSERT(shmid >= 0 && shmid < CONFIG_ARCH_SHM_MAXREGIONS);
region = &g_shminfo.si_region[shmid];
DEBUGASSERT((region->sr_flags & SRFLAG_INUSE) != 0);
/* Get the TCB and group containing our virtual memory allocator */
include/nuttx/sched.h: Make naming of all internal names consistent: 1. Add internal scheduler functions should begin with nxsched_, not sched_ 2. Follow the consistent naming patter of https://cwiki.apache.org/confluence/display/NUTTX/Naming+of+OS+Internal+Functions
2020-05-09 22:04:45 +08:00
tcb = nxsched_self();
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
DEBUGASSERT(tcb && tcb->group);
group = tcb->group;
DEBUGASSERT(group->tg_shm.gs_handle != NULL &&
group->tg_shm.gs_vaddr[shmid] == 0);
/* Get exclusive access to the region data structure */
Squashed commit of the following: This commit backs out most of commit b4747286b19d3b15193b2a5e8a0fe48fa0a8638c. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point. In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable. In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable. sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
2017-10-05 05:22:27 +08:00
ret = nxsem_wait(&region->sr_sem);
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
if (ret < 0)
{
Squashed commit of the following: This commit backs out most of commit b4747286b19d3b15193b2a5e8a0fe48fa0a8638c. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point. In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable. In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable. sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
2017-10-05 05:22:27 +08:00
shmerr("ERROR: nxsem_wait failed: %d\n", ret);
goto errout_with_ret;
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
}
/* Set aside a virtual address space to span this physical region */
vaddr = (uintptr_t)gran_alloc(group->tg_shm.gs_handle,
region->sr_ds.shm_segsz);
if (vaddr == 0)
{
audio/, crypto/, libnx/, and mm/: Change some err() ERRORS to warn() WARNINGS or info()
2016-06-12 23:46:23 +08:00
shmerr("ERROR: gran_alloc() failed\n");
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
ret = -ENOMEM;
goto errout_with_semaphore;
}
/* Convert the region size to pages */
mm/shm: Convert bytes to pages by MM_NPAGES instead of MM_PGALIGNUP
2019-01-27 00:11:06 +08:00
npages = MM_NPAGES(region->sr_ds.shm_segsz);
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
/* Attach, i.e, map, on shared memory region to the user virtual address. */
ret = up_shmat(region->sr_pages, npages, vaddr);
if (ret < 0)
{
audio/, crypto/, libnx/, and mm/: Change some err() ERRORS to warn() WARNINGS or info()
2016-06-12 23:46:23 +08:00
shmerr("ERROR: up_shmat() failed\n");
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
goto errout_with_vaddr;
}
/* Save the virtual address of the region. We will need that in shmat()
* to do the reverse lookup: Give the virtual address of the region to
* detach, we need to get the region table index.
*/
group->tg_shm.gs_vaddr[shmid] = vaddr;
/* Increment the count of processes attached to this region */
region->sr_ds.shm_nattch++;
Fix lots of occurrences of 'the the', 'the there', 'the these', 'the then', 'the they.
2017-05-12 03:35:56 +08:00
/* Save the process ID of the last operation */
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
region->sr_ds.shm_lpid = tcb->pid;
/* Save the time of the last shmat() */
region->sr_ds.shm_atime = time(NULL);
/* Release our lock on the entry */
Squashed commit of the following: sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post(). sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy(). libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
2017-10-04 05:35:24 +08:00
nxsem_post(&region->sr_sem);
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
return (FAR void *)vaddr;
errout_with_vaddr:
gran_free(group->tg_shm.gs_handle, (FAR void *)vaddr,
region->sr_ds.shm_segsz);
Squashed commit of the following: This commit backs out most of commit b4747286b19d3b15193b2a5e8a0fe48fa0a8638c. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point. In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable. In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable. sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
2017-10-05 05:22:27 +08:00
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
errout_with_semaphore:
Squashed commit of the following: sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post(). sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy(). libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
2017-10-04 05:35:24 +08:00
nxsem_post(&region->sr_sem);
Squashed commit of the following: This commit backs out most of commit b4747286b19d3b15193b2a5e8a0fe48fa0a8638c. That change was added because sem_wait() would sometimes cause cancellation points inappropriated. But with these recent changes, nxsem_wait() is used instead and it is not a cancellation point. In the OS, all calls to sem_wait() changed to nxsem_wait(). nxsem_wait() does not return errors via errno so each place where nxsem_wait() is now called must not examine the errno variable. In all OS functions (not libraries), change sem_wait() to nxsem_wait(). This will prevent the OS from creating bogus cancellation points and from modifying the per-task errno variable. sched/semaphore: Add the function nxsem_wait(). This is a new internal OS interface. It is functionally equivalent to sem_wait() except that (1) it is not a cancellation point, and (2) it does not set the per-thread errno value on return.
2017-10-05 05:22:27 +08:00
errout_with_ret:
Completes the implemenation of the core shared memory logic: shmget(), shmctl(), shmat(), and shmdt(). This is still some unfinish platform-specific code that needs to be done before we can begin testing.
2014-09-24 06:07:12 +08:00
set_errno(-ret);
Add README files and configuration support for the shared memory logic
2014-09-23 21:11:47 +08:00
return (FAR void *)ERROR;
}
#endif /* CONFIG_MM_SHM */