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author | Ulrich Drepper <drepper@redhat.com> | 2002-11-26 22:50:54 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2002-11-26 22:50:54 +0000 |
commit | 76a50749f7af5935ba3739e815aa6a16ae4440d1 (patch) | |
tree | c16eac47f220f03fea74d80ef0a4e774809e94b7 /nptl/sem_open.c | |
parent | 6938e63f714b15c377d8cbf8e97b6f15b0e1b692 (diff) | |
download | glibc-76a50749f7af5935ba3739e815aa6a16ae4440d1.tar.gz glibc-76a50749f7af5935ba3739e815aa6a16ae4440d1.tar.xz glibc-76a50749f7af5935ba3739e815aa6a16ae4440d1.zip |
Initial revision cvs/initial
2002-11-26 Ulrich Drepper <drepper@redhat.com> * allocatestack.c (queue_stack): Don't remove stack from list here. Do it in the caller. Correct condition to prematurely terminate loop to free stacks. (__deallocate_stack): Remove stack from list here. 2002-11-26 Ulrich Drepper <drepper@redhat.com> * Makefile (tests): Add tst-stack1. * tst-stack1.c: New file. * allocatestack.c (allocate_stack): Initialize the TCB on a user provided stack. * pthread_attr_getstack.c: Return bottom of the thread area. 2002-11-25 Ulrich Drepper <drepper@redhat.com> * Makefile (libpthread-routines): Add pt-allocrtsig and pthread_kill_other_threads. * pt-allocrtsig.c: New file. * pthread_kill_other_threads.c: New file. * sysdeps/unix/sysv/linux/allocrtsig.c: Add additional aliases for all three functions. * sysdeps/unix/sysv/linux/Makefile (sysdep_routines): Remove allocrtsig. * sysdeps/unix/sysv/linux/Versions (libc:GLIBC_PRIVATE): Export __libc_current_sigrtmin_private, __libc_current_sigrtmax_private, and __libc_allocate_rtsig_private. * Versions (libpthread): Export pthread_kill_other_threads_np, __libc_current_sigrtmin, and __libc_current_sigrtmax. 2002-11-24 Ulrich Drepper <drepper@redhat.com> * allocatestack.c (allocate_stack): stackaddr in attribute points to the end of the stack. Adjust computations. When mprotect call fails dequeue stack and free it. * pthread_attr_setstack.c: Store top of the stack in stackaddr attribute. * pthread_getattr_np.c: Likewise. * descr.h (IS_DETACHED): Add some more parenthesis to prevent surprises. 2002-11-23 Ulrich Drepper <drepper@redhat.com> * sysdeps/pthread/pthread.h (pthread_self): __THROW must come before attribute definitions. Patch by Luca Barbieri <ldb@ldb.ods.org>. 2002-11-22 Ulrich Drepper <drepper@redhat.com> * pthread_getspecific.c: Optimize access to first 2nd-level array. * pthread_setspecific.c: Likewise. 2002-11-21 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/i386/createthread.c: Remove CLONE_ flags definitions. Get them from the official place. * sysdeps/unix/sysv/linux/i386/fork.c: Likewise. * sysdeps/unix/sysv/linux/i386/createthread.c: Update CLONE_* flags. Use new CLONE_ flags in clone() calls. * sysdeps/unix/sysv/linux/fork.c: Use ARCH_FORK to actually fork. * sysdeps/unix/sysv/linux/i386/fork.c: New file. * Versions: Add pthread_* functions for libc. * forward.c: New file. * sysdeps/pthread/Makefile (libpthread-sysdeps_routines): Add errno-loc. * herrno.c: New file. * res.c: New file. * Makefile (libpthread-routines): Remove sem_post, sem_wait, sem_trywait, and sem_timedwait. Add herrno and res. * sem_init.c: Don't initialize lock and waiters members. * sem_open.c: Likewise. * sem_post.c: Removed. * sem_wait.c: Removed. * sem_trywait.c: Removed. * sem_timedwait.c: Removed. * sysdeps/unix/sysv/linux/i386/i486/lowlevelsem.S: Complete rewrite. Includes full implementations of sem_post, sem_wait, sem_trywait, and sem_timedwait. * sysdeps/unix/sysv/linux/i386/lowlevelsem.h (lll_sem_post): Adjust for new implementation. * sysdeps/unix/sysv/linux/internaltypes.h (struct sem): Remove lock and waiters fields. * tst-sem3.c: Improve error message. * tst-signal3.c: Likewise. * init.c (__pthread_initialize_minimal): Use set_tid_address syscall to tell the kernel about the termination futex and to initialize tid member. Don't initialize main_thread. * descr.h (struct pthread): Remove main_thread member. * cancelllation.c (__do_cancel): Remove code handling main thread. The main thread is not special anymore. * allocatestack.c (__reclaim_stacks): Mark stacks as unused. Add size of the stacks to stack_cache_actsize. * pt-readv.c: Add missing "defined". * pt-sigwait.c: Likewise. * pt-writev.c: Likewise. 2002-11-09 Ulrich Drepper <drepper@redhat.com> * Versions: Export __connect from libpthread. Patch by Luca Barbieri <ldb@ldb.ods.org>. * Makefile (libpthread-routines): Add pt-raise. * sysdeps/unix/sysv/linux/raise.c: New file. * sysdeps/unix/sysv/linux/pt-raise.c: New file. * sysdeps/generic/pt-raise.c: New file. * pthread_cond_init.c: Initialize all data elements of the condvar structure. Patch by Luca Barbieri <ldb@ldb.ods.org>. * pthread_attr_init.c: Actually implement 2.0 compatibility version. * pthread_create.c: Likewise. * Makefile (tests): Add tst-key1, tst-key2, tst-key3. * tst-key1.c: New file. * tst-key2.c: New file. * tst-key3.c: New file. * Versions: Export pthread_detach for version GLIBC_2.0. Reported by Saurabh Desai <sdesai@austin.ibm.com>. 2002-11-08 Ulrich Drepper <drepper@redhat.com> * pthread_key_create.c: Terminate search after an unused key was found. Patch by Luca Barbieri <ldb@ldb.ods.org>. * sysdeps/unix/sysv/linux/i386/pthread_once.S: Return zero. Patch by Luca Barbieri <ldb@ldb.ods.org>. 2002-10-10 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/i386/i486/lowlevelsem.S: Use slow generic dynamic lookup for errno in PIC. * allocatestack.c (get_cached_stack): Rearrange code slightly to release the stack lock as soon as possible. Call _dl_allocate_tls_init for TCB from the cache to re-initialize the static TLS block. (allocate_stack): Call _dl_allocate_tls_init for user-provided stack. * cancellation.c: Renamed from cancelation.c. * Makefile: Adjust accordingly. * pthreadP.h (CANCELLATION_P): Renamed from CANCELATION_P. * cleanup_defer.c: Use CANCELLATION_P. * pthread_testcancel.c: Likewise. * descr.h: Fix spelling in comments. * init.c: Likewise. * pthread_getattr_np.c: Likewise. * pthread_getschedparam.c: Likewise. * pthread_setschedparam.c: Likewise. * Versions: Likewise. * pt-pselect.c: New file. * Makefile (libpthread-routines): Add pt-pselect. * Versions: Add pselect. * tst-cancel4.c: New file. * Makefile (tests): Add tst-cancel4. 2002-10-09 Ulrich Drepper <drepper@redhat.com> * pthread_mutex_lock.c: Always record lock ownership. * pthread_mutex_timedlock.c: Likewise. * pthread_mutex_trylock.c: Likewise. * pt-readv.c: New file. * pt-writev.c: New file. * pt-creat.c: New file. * pt-msgrcv.c: New file. * pt-msgsnd.c: New file. * pt-poll.c: New file. * pt-select.c: New file. * pt-sigpause.c: New file. * pt-sigsuspend.c: New file. * pt-sigwait.c: New file. * pt-sigwaitinfo.c: New file. * pt-waitid.c: New file. * Makefile (libpthread-routines): Add pt-readv, pt-writev, pt-creat, pt-msgrcv, pt-msgsnd, pt-poll, pt-select, pt-sigpause, pt-sigsuspend, pt-sigwait, pt-sigwaitinfo, and pt-waitid. * Versions: Add all the new functions. * tst-exit1.c: New file. * Makefile (tests): Add tst-exit1. * sem_timedwait.c: Minor optimization for more optimal fastpath. 2002-10-08 Ulrich Drepper <drepper@redhat.com> * pt-fcntl.c: Only enable asynchronous cancellation for F_SETLKW. * pthread_join.c: Enable asynchronous cancellation around lll_wait_tid call. pthread_join is an official cancellation point. * pthread_timedjoin.c: Likewise. * pthread_cond_wait.c: Revert order in which internal lock are dropped and the condvar's mutex are retrieved. * pthread_cond_timedwait.c: Likewise. Reported by dice@saros.East.Sun.COM. 2002-10-07 Ulrich Drepper <drepper@redhat.com> * pthreadP.h: Cut out all type definitions and move them... * sysdeps/unix/sysv/linux/internaltypes.h: ...here. New file. * pthreadP.h: Include <internaltypes.h>. * sysdeps/unix/sysv/linux/i386/lowlevelsem.h (lll_sem_post): Little performance tweaks. * sem_trywait.c: Shuffle #includes around to get right order. * sem_timedwait.c: Likewise. * sem_post.c: Likewise. * sem_wait.c: Likewise. * nptl 0.3 released. * Makefile (tests): Add tst-signal3. * tst-signal3.c: New file. 2002-10-05 Ulrich Drepper <drepper@redhat.com> * sysdeps/unix/sysv/linux/i386/lowlevelsem.h: Tell the compiler that the asms modify the sem object. (__lll_sem_timedwait): Now takes struct sem* as first parameter. * sysdeps/unix/sysv/linux/i386/bits/semaphore.h (sem_t): Don't expose the actual members. * pthreadP.h (struct sem): New type. Actual semaphore type. * semaphoreP.h: Include pthreadP.h. * sem_getvalue.c: Adjust to sem_t change. * sem_init.c: Likewise. * sem_open.c: Likewise. * sem_post.c: Likewise. * sem_timedwait.c: Likewise. * sem_trywait.c: Likewise. * sem_wait.c: Likewise. 2002-10-04 Ulrich Drepper <drepper@redhat.com> * Makefile (tests): Add tst-basic2, tst-exec1, tst-exec3, tst-exec3. * tst-basic2.c: New file. * tst-exec1.c: New file. * tst-exec2.c: New file. * tst-exec3.c: New file. * tst-fork1.c: Remove extra */. * nptl 0.2 released. The API for IA-32 is complete.
Diffstat (limited to 'nptl/sem_open.c')
-rw-r--r-- | nptl/sem_open.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/nptl/sem_open.c b/nptl/sem_open.c new file mode 100644 index 0000000000..6fc72f7dc6 --- /dev/null +++ b/nptl/sem_open.c @@ -0,0 +1,258 @@ +/* Copyright (C) 2002 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <errno.h> +#include <fcntl.h> +#include <mntent.h> +#include <paths.h> +#include <pthread.h> +#include <semaphore.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/statfs.h> +#include <linux_fsinfo.h> +#include "semaphoreP.h" + + + +/* Information about the mount point. */ +struct mountpoint_info mountpoint attribute_hidden; + +/* This is the default mount point. */ +static const char defaultmount[] = "/dev/shm"; +/* This is the default directory. */ +static const char defaultdir[] = "/dev/shm/sem."; + +/* Protect the `mountpoint' variable above. */ +pthread_once_t __namedsem_once attribute_hidden = PTHREAD_ONCE_INIT; + + +/* Determine where the shmfs is mounted (if at all). */ +void +attribute_hidden +__where_is_shmfs (void) +{ + char buf[512]; + struct statfs f; + struct mntent resmem; + struct mntent *mp; + FILE *fp; + + /* The canonical place is /dev/shm. This is at least what the + documentation tells everybody to do. */ + if (__statfs (defaultmount, &f) == 0 && f.f_type == SHMFS_SUPER_MAGIC) + { + /* It is in the normal place. */ + mountpoint.dir = (char *) defaultdir; + mountpoint.dirlen = sizeof (defaultdir) - 1; + + return; + } + + /* OK, do it the hard way. Look through the /proc/mounts file and if + this does not exist through /etc/fstab to find the mount point. */ + fp = __setmntent ("/proc/mounts", "r"); + if (__builtin_expect (fp == NULL, 0)) + { + fp = __setmntent (_PATH_MNTTAB, "r"); + if (__builtin_expect (fp == NULL, 0)) + /* There is nothing we can do. Blind guesses are not helpful. */ + return; + } + + /* Now read the entries. */ + while ((mp = __getmntent_r (fp, &resmem, buf, sizeof buf)) != NULL) + /* The original name is "shm" but this got changed in early Linux + 2.4.x to "tmpfs". */ + if (strcmp (mp->mnt_type, "tmpfs") == 0 + || strcmp (mp->mnt_type, "shm") == 0) + { + /* Found it. There might be more than one place where the + filesystem is mounted but one is enough for us. */ + size_t namelen; + + /* First make sure this really is the correct entry. At least + some versions of the kernel give wrong information because + of the implicit mount of the shmfs for SysV IPC. */ + if (__statfs (mp->mnt_dir, &f) != 0 || f.f_type != SHMFS_SUPER_MAGIC) + continue; + + namelen = strlen (mp->mnt_dir); + + if (namelen == 0) + /* Hum, maybe some crippled entry. Keep on searching. */ + continue; + + mountpoint.dir = (char *) malloc (namelen + 4 + 2); + if (mountpoint.dir != NULL) + { + char *cp = __mempcpy (mountpoint.dir, mp->mnt_dir, namelen); + if (cp[-1] != '/') + *cp++ = '/'; + cp = stpcpy (cp, "sem."); + mountpoint.dirlen = cp - mountpoint.dir; + } + + break; + } + + /* Close the stream. */ + __endmntent (fp); +} + + +sem_t * +sem_open (const char *name, int oflag, ...) +{ + char *finalname; + size_t namelen; + sem_t *result; + int fd; + + /* Determine where the shmfs is mounted. */ + pthread_once (&__namedsem_once, __where_is_shmfs); + + /* If we don't know the mount points there is nothing we can do. Ever. */ + if (mountpoint.dir == NULL) + { + __set_errno (ENOSYS); + return SEM_FAILED; + } + + /* Construct the filename. */ + while (name[0] == '/') + ++name; + + if (name[0] == '\0') + { + /* The name "/" is not supported. */ + __set_errno (EINVAL); + return SEM_FAILED; + } + namelen = strlen (name); + + /* Create the name of the final file. */ + finalname = (char *) alloca (mountpoint.dirlen + namelen + 1); + __mempcpy (__mempcpy (finalname, mountpoint.dir, mountpoint.dirlen), + name, namelen + 1); + + /* If the semaphore object has to exist simply open it. */ + if ((oflag & O_CREAT) == 0) + { + fd = open (finalname, oflag | O_NOFOLLOW); + + if (fd == -1) + /* Return. errno is already set. */ + return SEM_FAILED; + + /* Map the sem_t structure from the file. */ + result = (sem_t *) mmap (NULL, sizeof (sem_t), PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + } + else + { + /* We have to open a temporary file first since it must have the + correct form before we can start using it. */ + char *tmpfname; + mode_t mode; + unsigned int value; + va_list ap; + + va_start (ap, oflag); + + mode = va_arg (ap, mode_t); + value = va_arg (ap, unsigned int); + + va_end (ap); + + if (value > SEM_VALUE_MAX) + { + __set_errno (EINVAL); + return SEM_FAILED; + } + + tmpfname = (char *) alloca (mountpoint.dirlen + 6 + 1); + strcpy (__mempcpy (tmpfname, mountpoint.dir, mountpoint.dirlen), + "XXXXXX"); + + fd = mkstemp (tmpfname); + if (fd == -1) + return SEM_FAILED; + + /* Create the initial file content. */ + sem_t initsem; + + struct sem *iinitsem = (struct sem *) &initsem; + iinitsem->count = value; + + /* Initialize the remaining bytes as well. */ + memset ((char *) &initsem + sizeof (struct sem), '\0', + sizeof (sem_t) - sizeof (struct sem)); + + if (TEMP_FAILURE_RETRY (write (fd, &initsem, sizeof (sem_t))) + != sizeof (sem_t) + /* Adjust the permission. */ + || fchmod (fd, mode) != 0) + { + unlink_return: + unlink (tmpfname); + return SEM_FAILED; + } + + /* Map the sem_t structure from the file. */ + result = (sem_t *) mmap (NULL, sizeof (sem_t), PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (result == MAP_FAILED) + goto unlink_return; + + /* Create or overwrite the file. Depending on what is wanted we + use rename or link. */ + if ((oflag & O_EXCL) == 0) + { + /* An existing file gets overwritten. */ + if (rename (tmpfname, finalname) != 0) + { + unmap_unlink_return: + munmap (result, sizeof (sem_t)); + goto unlink_return; + } + } + else + { + /* Don't overwrite an existing file. */ + if (link (tmpfname, finalname) != 0) + goto unmap_unlink_return; + + /* This went well. Now remove the temporary name. This + should never fail. If it fails we leak a file name. + Better fix the kernel. */ + (void) unlink (tmpfname); + } + } + + /* We don't need the file descriptor anymore. */ + close (fd); + + return result; +} |