diff options
Diffstat (limited to 'winsup/cygwin/posix_ipc.cc')
| -rw-r--r-- | winsup/cygwin/posix_ipc.cc | 1112 |
1 files changed, 0 insertions, 1112 deletions
diff --git a/winsup/cygwin/posix_ipc.cc b/winsup/cygwin/posix_ipc.cc deleted file mode 100644 index 53caed031..000000000 --- a/winsup/cygwin/posix_ipc.cc +++ /dev/null @@ -1,1112 +0,0 @@ -/* posix_ipc.cc: POSIX IPC API for Cygwin. - - Copyright 2007, 2008, 2009, 2010 Red Hat, Inc. - -This file is part of Cygwin. - -This software is a copyrighted work licensed under the terms of the -Cygwin license. Please consult the file "CYGWIN_LICENSE" for -details. */ - -#include "winsup.h" -#include "shared_info.h" -#include "thread.h" -#include "path.h" -#include "cygtls.h" -#include "fhandler.h" -#include "dtable.h" -#include "cygheap.h" -#include "sigproc.h" -#include "ntdll.h" -#include <sys/mman.h> -#include <sys/param.h> -#include <stdlib.h> -#include <unistd.h> -#include <mqueue.h> -#include <semaphore.h> - -/* The prefix_len is the length of the path prefix ncluding trailing "/" - (or "/sem." for semaphores) as well as the trailing NUL. */ -static struct -{ - const char *prefix; - const size_t prefix_len; - const char *description; -} ipc_names[] = { - { "/dev/shm", 10, "POSIX shared memory object" }, - { "/dev/mqueue", 13, "POSIX message queue" }, - { "/dev/shm", 14, "POSIX semaphore" } -}; - -enum ipc_type_t -{ - shmem, - mqueue, - semaphore -}; - -static bool -check_path (char *res_name, ipc_type_t type, const char *name, size_t len) -{ - /* Note that we require the existance of the appropriate /dev subdirectories - for POSIX IPC object support, similar to Linux (which supports the - directories, but doesn't require to mount them). We don't create - these directory here, that's the task of the installer. But we check - for existance and give ample warning. */ - path_conv path (ipc_names[type].prefix, PC_SYM_NOFOLLOW); - if (path.error || !path.exists () || !path.isdir ()) - { - small_printf ( - "Warning: '%s' does not exists or is not a directory.\n\n" - "%ss require the existance of this directory.\n" - "Create the directory '%s' and set the permissions to 01777.\n" - "For instance on the command line: mkdir -m 01777 %s\n", - ipc_names[type].prefix, ipc_names[type].description, - ipc_names[type].prefix, ipc_names[type].prefix); - set_errno (EINVAL); - return false; - } - /* Name must not be empty, or just be a single slash, or start with more - than one slash. Same for backslash. - Apart from handling backslash like slash, the naming rules are identical - to Linux, including the names and requirements for subdirectories, if - the name contains further slashes. */ - if (!name || (strchr ("/\\", name[0]) - && (!name[1] || strchr ("/\\", name[1])))) - { - debug_printf ("Invalid %s name '%s'", ipc_names[type].description, name); - set_errno (EINVAL); - return false; - } - /* Skip leading (back-)slash. */ - if (strchr ("/\\", name[0])) - ++name; - if (len > PATH_MAX - ipc_names[type].prefix_len) - { - debug_printf ("%s name '%s' too long", ipc_names[type].description, name); - set_errno (ENAMETOOLONG); - return false; - } - __small_sprintf (res_name, "%s/%s%s", ipc_names[type].prefix, - type == semaphore ? "sem." : "", - name); - return true; -} - -static int -ipc_mutex_init (HANDLE *pmtx, const char *name) -{ - WCHAR buf[MAX_PATH]; - UNICODE_STRING uname; - OBJECT_ATTRIBUTES attr; - NTSTATUS status; - - __small_swprintf (buf, L"mqueue/mtx_%s", name); - RtlInitUnicodeString (&uname, buf); - InitializeObjectAttributes (&attr, &uname, - OBJ_INHERIT | OBJ_OPENIF | OBJ_CASE_INSENSITIVE, - get_shared_parent_dir (), - everyone_sd (CYG_MUTANT_ACCESS)); - status = NtCreateMutant (pmtx, CYG_MUTANT_ACCESS, &attr, FALSE); - if (!NT_SUCCESS (status)) - { - debug_printf ("NtCreateMutant: %p", status); - return geterrno_from_win_error (RtlNtStatusToDosError (status)); - } - return 0; -} - -static int -ipc_mutex_lock (HANDLE mtx) -{ - HANDLE h[2] = { mtx, signal_arrived }; - - switch (WaitForMultipleObjects (2, h, FALSE, INFINITE)) - { - case WAIT_OBJECT_0: - case WAIT_ABANDONED_0: - return 0; - case WAIT_OBJECT_0 + 1: - set_errno (EINTR); - return 1; - default: - break; - } - return geterrno_from_win_error (); -} - -static inline int -ipc_mutex_unlock (HANDLE mtx) -{ - return ReleaseMutex (mtx) ? 0 : geterrno_from_win_error (); -} - -static inline int -ipc_mutex_close (HANDLE mtx) -{ - return CloseHandle (mtx) ? 0 : geterrno_from_win_error (); -} - -static int -ipc_cond_init (HANDLE *pevt, const char *name, char sr) -{ - WCHAR buf[MAX_PATH]; - UNICODE_STRING uname; - OBJECT_ATTRIBUTES attr; - NTSTATUS status; - - __small_swprintf (buf, L"mqueue/evt_%s%c", name, sr); - RtlInitUnicodeString (&uname, buf); - InitializeObjectAttributes (&attr, &uname, - OBJ_INHERIT | OBJ_OPENIF | OBJ_CASE_INSENSITIVE, - get_shared_parent_dir (), - everyone_sd (CYG_EVENT_ACCESS)); - status = NtCreateEvent (pevt, CYG_EVENT_ACCESS, &attr, - NotificationEvent, FALSE); - if (!NT_SUCCESS (status)) - { - debug_printf ("NtCreateEvent: %p", status); - return geterrno_from_win_error (RtlNtStatusToDosError (status)); - } - return 0; -} - -static int -ipc_cond_timedwait (HANDLE evt, HANDLE mtx, const struct timespec *abstime) -{ - struct timeval tv; - DWORD timeout; - HANDLE h[2] = { mtx, evt }; - - if (!abstime) - timeout = INFINITE; - else if (abstime->tv_sec < 0 - || abstime->tv_nsec < 0 - || abstime->tv_nsec > 999999999) - return EINVAL; - else - { - gettimeofday (&tv, NULL); - /* Check for immediate timeout. */ - if (tv.tv_sec > abstime->tv_sec - || (tv.tv_sec == abstime->tv_sec - && tv.tv_usec > abstime->tv_nsec / 1000)) - return ETIMEDOUT; - timeout = (abstime->tv_sec - tv.tv_sec) * 1000; - timeout += (abstime->tv_nsec / 1000 - tv.tv_usec) / 1000; - } - ResetEvent (evt); - if (ipc_mutex_unlock (mtx)) - return -1; - switch (WaitForMultipleObjects (2, h, TRUE, timeout)) - { - case WAIT_OBJECT_0: - case WAIT_ABANDONED_0: - return 0; - case WAIT_TIMEOUT: - ipc_mutex_lock (mtx); - return ETIMEDOUT; - default: - break; - } - return geterrno_from_win_error (); -} - -static inline int -ipc_cond_signal (HANDLE evt) -{ - return SetEvent (evt) ? 0 : geterrno_from_win_error (); -} - -static inline int -ipc_cond_close (HANDLE evt) -{ - return CloseHandle (evt) ? 0 : geterrno_from_win_error (); -} - -class ipc_flock -{ - struct __flock64 fl; - -public: - ipc_flock () { memset (&fl, 0, sizeof fl); } - - int lock (int fd, size_t size) - { - fl.l_type = F_WRLCK; - fl.l_whence = SEEK_SET; - fl.l_start = 0; - fl.l_len = size; - return fcntl64 (fd, F_SETLKW, &fl); - } - int unlock (int fd) - { - if (!fl.l_len) - return 0; - fl.l_type = F_UNLCK; - return fcntl64 (fd, F_SETLKW, &fl); - } -}; - -/* POSIX shared memory object implementation. */ - -extern "C" int -shm_open (const char *name, int oflag, mode_t mode) -{ - size_t len = strlen (name); - char shmname[ipc_names[shmem].prefix_len + len]; - - if (!check_path (shmname, shmem, name, len)) - return -1; - - /* Check for valid flags. */ - if (((oflag & O_ACCMODE) != O_RDONLY && (oflag & O_ACCMODE) != O_RDWR) - || (oflag & ~(O_ACCMODE | O_CREAT | O_EXCL | O_TRUNC))) - { - debug_printf ("Invalid oflag 0%o", oflag); - set_errno (EINVAL); - return -1; - } - - return open (shmname, oflag | O_CLOEXEC, mode & 0777); -} - -extern "C" int -shm_unlink (const char *name) -{ - size_t len = strlen (name); - char shmname[ipc_names[shmem].prefix_len + len]; - - if (!check_path (shmname, shmem, name, len)) - return -1; - - return unlink (shmname); -} - -/* The POSIX message queue implementation is based on W. Richard STEVENS - implementation, just tweaked for Cygwin. The main change is - the usage of Windows mutexes and events instead of using the pthread - synchronization objects. The pathname is massaged so that the - files are created under /dev/mqueue. mq_timedsend and mq_timedreceive - are implemented additionally. */ - -struct mq_hdr -{ - struct mq_attr mqh_attr; /* the queue's attributes */ - long mqh_head; /* index of first message */ - long mqh_free; /* index of first free message */ - long mqh_nwait; /* #threads blocked in mq_receive() */ - pid_t mqh_pid; /* nonzero PID if mqh_event set */ - char mqh_uname[36]; /* unique name used to identify synchronization - objects connected to this queue */ - struct sigevent mqh_event; /* for mq_notify() */ -}; - -struct msg_hdr -{ - long msg_next; /* index of next on linked list */ - ssize_t msg_len; /* actual length */ - unsigned int msg_prio; /* priority */ -}; - -struct mq_info -{ - struct mq_hdr *mqi_hdr; /* start of mmap'ed region */ - unsigned long mqi_magic; /* magic number if open */ - int mqi_flags; /* flags for this process */ - HANDLE mqi_lock; /* mutex lock */ - HANDLE mqi_waitsend; /* and condition variable for full queue */ - HANDLE mqi_waitrecv; /* and condition variable for empty queue */ -}; - -#define MQI_MAGIC 0x98765432UL - -#define MSGSIZE(i) roundup((i), sizeof(long)) - -#define MAX_TRIES 10 /* for waiting for initialization */ - -struct mq_attr defattr = { 0, 10, 8192, 0 }; /* Linux defaults. */ - -extern "C" _off64_t lseek64 (int, _off64_t, int); -extern "C" void *mmap64 (void *, size_t, int, int, int, _off64_t); - -extern "C" mqd_t -mq_open (const char *name, int oflag, ...) -{ - int i, fd = -1, nonblock, created; - long msgsize, index; - _off64_t filesize = 0; - va_list ap; - mode_t mode; - int8_t *mptr; - struct __stat64 statbuff; - struct mq_hdr *mqhdr; - struct msg_hdr *msghdr; - struct mq_attr *attr; - struct mq_info *mqinfo; - LUID luid; - - size_t len = strlen (name); - char mqname[ipc_names[mqueue].prefix_len + len]; - - if (!check_path (mqname, mqueue, name, len)) - return (mqd_t) -1; - - myfault efault; - if (efault.faulted (EFAULT)) - return (mqd_t) -1; - - oflag &= (O_CREAT | O_EXCL | O_NONBLOCK); - created = 0; - nonblock = oflag & O_NONBLOCK; - oflag &= ~O_NONBLOCK; - mptr = (int8_t *) MAP_FAILED; - mqinfo = NULL; - -again: - if (oflag & O_CREAT) - { - va_start (ap, oflag); /* init ap to final named argument */ - mode = va_arg (ap, mode_t) & ~S_IXUSR; - attr = va_arg (ap, struct mq_attr *); - va_end (ap); - - /* Open and specify O_EXCL and user-execute */ - fd = open (mqname, oflag | O_EXCL | O_RDWR | O_CLOEXEC, mode | S_IXUSR); - if (fd < 0) - { - if (errno == EEXIST && (oflag & O_EXCL) == 0) - goto exists; /* already exists, OK */ - return (mqd_t) -1; - } - created = 1; - /* First one to create the file initializes it */ - if (attr == NULL) - attr = &defattr; - else if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) - { - set_errno (EINVAL); - goto err; - } - /* Calculate and set the file size */ - msgsize = MSGSIZE (attr->mq_msgsize); - filesize = sizeof (struct mq_hdr) - + (attr->mq_maxmsg * (sizeof (struct msg_hdr) + msgsize)); - if (lseek64 (fd, filesize - 1, SEEK_SET) == -1) - goto err; - if (write (fd, "", 1) == -1) - goto err; - - /* Memory map the file */ - mptr = (int8_t *) mmap64 (NULL, (size_t) filesize, PROT_READ | PROT_WRITE, - MAP_SHARED, fd, 0); - if (mptr == (int8_t *) MAP_FAILED) - goto err; - - /* Allocate one mq_info{} for the queue */ - if (!(mqinfo = (struct mq_info *) calloc (1, sizeof (struct mq_info)))) - goto err; - mqinfo->mqi_hdr = mqhdr = (struct mq_hdr *) mptr; - mqinfo->mqi_magic = MQI_MAGIC; - mqinfo->mqi_flags = nonblock; - - /* Initialize header at beginning of file */ - /* Create free list with all messages on it */ - mqhdr->mqh_attr.mq_flags = 0; - mqhdr->mqh_attr.mq_maxmsg = attr->mq_maxmsg; - mqhdr->mqh_attr.mq_msgsize = attr->mq_msgsize; - mqhdr->mqh_attr.mq_curmsgs = 0; - mqhdr->mqh_nwait = 0; - mqhdr->mqh_pid = 0; - if (!AllocateLocallyUniqueId (&luid)) - { - __seterrno (); - goto err; - } - __small_sprintf (mqhdr->mqh_uname, "%016X%08x%08x", - hash_path_name (0,mqname), - luid.HighPart, luid.LowPart); - mqhdr->mqh_head = 0; - index = sizeof (struct mq_hdr); - mqhdr->mqh_free = index; - for (i = 0; i < attr->mq_maxmsg - 1; i++) - { - msghdr = (struct msg_hdr *) &mptr[index]; - index += sizeof (struct msg_hdr) + msgsize; - msghdr->msg_next = index; - } - msghdr = (struct msg_hdr *) &mptr[index]; - msghdr->msg_next = 0; /* end of free list */ - - /* Initialize mutex & condition variables */ - i = ipc_mutex_init (&mqinfo->mqi_lock, mqhdr->mqh_uname); - if (i != 0) - goto pthreaderr; - - i = ipc_cond_init (&mqinfo->mqi_waitsend, mqhdr->mqh_uname, 'S'); - if (i != 0) - goto pthreaderr; - - i = ipc_cond_init (&mqinfo->mqi_waitrecv, mqhdr->mqh_uname, 'R'); - if (i != 0) - goto pthreaderr; - - /* Initialization complete, turn off user-execute bit */ - if (fchmod (fd, mode) == -1) - goto err; - close (fd); - return ((mqd_t) mqinfo); - } - -exists: - /* Open the file then memory map */ - if ((fd = open (mqname, O_RDWR | O_CLOEXEC)) < 0) - { - if (errno == ENOENT && (oflag & O_CREAT)) - goto again; - goto err; - } - /* Make certain initialization is complete */ - for (i = 0; i < MAX_TRIES; i++) - { - if (stat64 (mqname, &statbuff) == -1) - { - if (errno == ENOENT && (oflag & O_CREAT)) - { - close (fd); - fd = -1; - goto again; - } - goto err; - } - if ((statbuff.st_mode & S_IXUSR) == 0) - break; - sleep (1); - } - if (i == MAX_TRIES) - { - set_errno (ETIMEDOUT); - goto err; - } - - filesize = statbuff.st_size; - mptr = (int8_t *) mmap64 (NULL, (size_t) filesize, PROT_READ | PROT_WRITE, - MAP_SHARED, fd, 0); - if (mptr == (int8_t *) MAP_FAILED) - goto err; - close (fd); - fd = -1; - - /* Allocate one mq_info{} for each open */ - if (!(mqinfo = (struct mq_info *) calloc (1, sizeof (struct mq_info)))) - goto err; - mqinfo->mqi_hdr = mqhdr = (struct mq_hdr *) mptr; - mqinfo->mqi_magic = MQI_MAGIC; - mqinfo->mqi_flags = nonblock; - - /* Initialize mutex & condition variable */ - i = ipc_mutex_init (&mqinfo->mqi_lock, mqhdr->mqh_uname); - if (i != 0) - goto pthreaderr; - - i = ipc_cond_init (&mqinfo->mqi_waitsend, mqhdr->mqh_uname, 'S'); - if (i != 0) - goto pthreaderr; - - i = ipc_cond_init (&mqinfo->mqi_waitrecv, mqhdr->mqh_uname, 'R'); - if (i != 0) - goto pthreaderr; - - return (mqd_t) mqinfo; - -pthreaderr: - errno = i; -err: - /* Don't let following function calls change errno */ - save_errno save; - - if (created) - unlink (mqname); - if (mptr != (int8_t *) MAP_FAILED) - munmap((void *) mptr, (size_t) filesize); - if (mqinfo) - { - if (mqinfo->mqi_lock) - ipc_mutex_close (mqinfo->mqi_lock); - if (mqinfo->mqi_waitsend) - ipc_cond_close (mqinfo->mqi_waitsend); - if (mqinfo->mqi_waitrecv) - ipc_cond_close (mqinfo->mqi_waitrecv); - free (mqinfo); - } - if (fd >= 0) - close (fd); - return (mqd_t) -1; -} - -extern "C" int -mq_getattr (mqd_t mqd, struct mq_attr *mqstat) -{ - int n; - struct mq_hdr *mqhdr; - struct mq_attr *attr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - mqhdr = mqinfo->mqi_hdr; - attr = &mqhdr->mqh_attr; - if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) - { - errno = n; - return -1; - } - mqstat->mq_flags = mqinfo->mqi_flags; /* per-open */ - mqstat->mq_maxmsg = attr->mq_maxmsg; /* remaining three per-queue */ - mqstat->mq_msgsize = attr->mq_msgsize; - mqstat->mq_curmsgs = attr->mq_curmsgs; - - ipc_mutex_unlock (mqinfo->mqi_lock); - return 0; -} - -extern "C" int -mq_setattr (mqd_t mqd, const struct mq_attr *mqstat, struct mq_attr *omqstat) -{ - int n; - struct mq_hdr *mqhdr; - struct mq_attr *attr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - mqhdr = mqinfo->mqi_hdr; - attr = &mqhdr->mqh_attr; - if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) - { - errno = n; - return -1; - } - - if (omqstat != NULL) - { - omqstat->mq_flags = mqinfo->mqi_flags; /* previous attributes */ - omqstat->mq_maxmsg = attr->mq_maxmsg; - omqstat->mq_msgsize = attr->mq_msgsize; - omqstat->mq_curmsgs = attr->mq_curmsgs; /* and current status */ - } - - if (mqstat->mq_flags & O_NONBLOCK) - mqinfo->mqi_flags |= O_NONBLOCK; - else - mqinfo->mqi_flags &= ~O_NONBLOCK; - - ipc_mutex_unlock (mqinfo->mqi_lock); - return 0; -} - -extern "C" int -mq_notify (mqd_t mqd, const struct sigevent *notification) -{ - int n; - pid_t pid; - struct mq_hdr *mqhdr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - mqhdr = mqinfo->mqi_hdr; - if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) - { - errno = n; - return -1; - } - - pid = getpid (); - if (!notification) - { - if (mqhdr->mqh_pid == pid) - mqhdr->mqh_pid = 0; /* unregister calling process */ - } - else - { - if (mqhdr->mqh_pid != 0) - { - if (kill (mqhdr->mqh_pid, 0) != -1 || errno != ESRCH) - { - set_errno (EBUSY); - ipc_mutex_unlock (mqinfo->mqi_lock); - return -1; - } - } - mqhdr->mqh_pid = pid; - mqhdr->mqh_event = *notification; - } - ipc_mutex_unlock (mqinfo->mqi_lock); - return 0; -} - -static int -_mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, - const struct timespec *abstime) -{ - int n; - long index, freeindex; - int8_t *mptr; - struct sigevent *sigev; - struct mq_hdr *mqhdr; - struct mq_attr *attr; - struct msg_hdr *msghdr, *nmsghdr, *pmsghdr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - if (prio > MQ_PRIO_MAX) - { - set_errno (EINVAL); - return -1; - } - - mqhdr = mqinfo->mqi_hdr; /* struct pointer */ - mptr = (int8_t *) mqhdr; /* byte pointer */ - attr = &mqhdr->mqh_attr; - if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) - { - errno = n; - return -1; - } - - if (len > (size_t) attr->mq_msgsize) - { - set_errno (EMSGSIZE); - goto err; - } - if (attr->mq_curmsgs == 0) - { - if (mqhdr->mqh_pid != 0 && mqhdr->mqh_nwait == 0) - { - sigev = &mqhdr->mqh_event; - if (sigev->sigev_notify == SIGEV_SIGNAL) - sigqueue (mqhdr->mqh_pid, sigev->sigev_signo, sigev->sigev_value); - mqhdr->mqh_pid = 0; /* unregister */ - } - } - else if (attr->mq_curmsgs >= attr->mq_maxmsg) - { - /* Queue is full */ - if (mqinfo->mqi_flags & O_NONBLOCK) - { - set_errno (EAGAIN); - goto err; - } - /* Wait for room for one message on the queue */ - while (attr->mq_curmsgs >= attr->mq_maxmsg) - ipc_cond_timedwait (mqinfo->mqi_waitsend, mqinfo->mqi_lock, abstime); - } - - /* nmsghdr will point to new message */ - if ((freeindex = mqhdr->mqh_free) == 0) - api_fatal ("mq_send: curmsgs = %ld; free = 0", attr->mq_curmsgs); - - nmsghdr = (struct msg_hdr *) &mptr[freeindex]; - nmsghdr->msg_prio = prio; - nmsghdr->msg_len = len; - memcpy (nmsghdr + 1, ptr, len); /* copy message from caller */ - mqhdr->mqh_free = nmsghdr->msg_next; /* new freelist head */ - - /* Find right place for message in linked list */ - index = mqhdr->mqh_head; - pmsghdr = (struct msg_hdr *) &(mqhdr->mqh_head); - while (index) - { - msghdr = (struct msg_hdr *) &mptr[index]; - if (prio > msghdr->msg_prio) - { - nmsghdr->msg_next = index; - pmsghdr->msg_next = freeindex; - break; - } - index = msghdr->msg_next; - pmsghdr = msghdr; - } - if (index == 0) - { - /* Queue was empty or new goes at end of list */ - pmsghdr->msg_next = freeindex; - nmsghdr->msg_next = 0; - } - /* Wake up anyone blocked in mq_receive waiting for a message */ - if (attr->mq_curmsgs == 0) - ipc_cond_signal (mqinfo->mqi_waitrecv); - attr->mq_curmsgs++; - - ipc_mutex_unlock (mqinfo->mqi_lock); - return 0; - -err: - ipc_mutex_unlock (mqinfo->mqi_lock); - return -1; -} - -extern "C" int -mq_send (mqd_t mqd, const char *ptr, size_t len, unsigned int prio) -{ - return _mq_send (mqd, ptr, len, prio, NULL); -} - -extern "C" int -mq_timedsend (mqd_t mqd, const char *ptr, size_t len, unsigned int prio, - const struct timespec *abstime) -{ - return _mq_send (mqd, ptr, len, prio, abstime); -} - -static ssize_t -_mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, - const struct timespec *abstime) -{ - int n; - long index; - int8_t *mptr; - ssize_t len; - struct mq_hdr *mqhdr; - struct mq_attr *attr; - struct msg_hdr *msghdr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - mqhdr = mqinfo->mqi_hdr; /* struct pointer */ - mptr = (int8_t *) mqhdr; /* byte pointer */ - attr = &mqhdr->mqh_attr; - if ((n = ipc_mutex_lock (mqinfo->mqi_lock)) != 0) - { - errno = n; - return -1; - } - - if (maxlen < (size_t) attr->mq_msgsize) - { - set_errno (EMSGSIZE); - goto err; - } - if (attr->mq_curmsgs == 0) /* queue is empty */ - { - if (mqinfo->mqi_flags & O_NONBLOCK) - { - set_errno (EAGAIN); - goto err; - } - /* Wait for a message to be placed onto queue */ - mqhdr->mqh_nwait++; - while (attr->mq_curmsgs == 0) - ipc_cond_timedwait (mqinfo->mqi_waitrecv, mqinfo->mqi_lock, abstime); - mqhdr->mqh_nwait--; - } - - if ((index = mqhdr->mqh_head) == 0) - api_fatal ("mq_receive: curmsgs = %ld; head = 0", attr->mq_curmsgs); - - msghdr = (struct msg_hdr *) &mptr[index]; - mqhdr->mqh_head = msghdr->msg_next; /* new head of list */ - len = msghdr->msg_len; - memcpy(ptr, msghdr + 1, len); /* copy the message itself */ - if (priop != NULL) - *priop = msghdr->msg_prio; - - /* Just-read message goes to front of free list */ - msghdr->msg_next = mqhdr->mqh_free; - mqhdr->mqh_free = index; - - /* Wake up anyone blocked in mq_send waiting for room */ - if (attr->mq_curmsgs == attr->mq_maxmsg) - ipc_cond_signal (mqinfo->mqi_waitsend); - attr->mq_curmsgs--; - - ipc_mutex_unlock (mqinfo->mqi_lock); - return len; - -err: - ipc_mutex_unlock (mqinfo->mqi_lock); - return -1; -} - -extern "C" ssize_t -mq_receive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop) -{ - return _mq_receive (mqd, ptr, maxlen, priop, NULL); -} - -extern "C" ssize_t -mq_timedreceive (mqd_t mqd, char *ptr, size_t maxlen, unsigned int *priop, - const struct timespec *abstime) -{ - return _mq_receive (mqd, ptr, maxlen, priop, abstime); -} - -extern "C" int -mq_close (mqd_t mqd) -{ - long msgsize, filesize; - struct mq_hdr *mqhdr; - struct mq_attr *attr; - struct mq_info *mqinfo; - - myfault efault; - if (efault.faulted (EBADF)) - return -1; - - mqinfo = (struct mq_info *) mqd; - if (mqinfo->mqi_magic != MQI_MAGIC) - { - set_errno (EBADF); - return -1; - } - mqhdr = mqinfo->mqi_hdr; - attr = &mqhdr->mqh_attr; - - if (mq_notify (mqd, NULL)) /* unregister calling process */ - return -1; - - msgsize = MSGSIZE (attr->mq_msgsize); - filesize = sizeof (struct mq_hdr) - + (attr->mq_maxmsg * (sizeof (struct msg_hdr) + msgsize)); - if (munmap (mqinfo->mqi_hdr, filesize) == -1) - return -1; - - mqinfo->mqi_magic = 0; /* just in case */ - ipc_cond_close (mqinfo->mqi_waitsend); - ipc_cond_close (mqinfo->mqi_waitrecv); - ipc_mutex_close (mqinfo->mqi_lock); - free (mqinfo); - return 0; -} - -extern "C" int -mq_unlink (const char *name) -{ - size_t len = strlen (name); - char mqname[ipc_names[mqueue].prefix_len + len]; - - if (!check_path (mqname, mqueue, name, len)) - return -1; - if (unlink (mqname) == -1) - return -1; - return 0; -} - -/* POSIX named semaphore implementation. Loosely based on Richard W. STEPHENS - implementation as far as sem_open is concerned, but under the hood using - the already existing semaphore class in thread.cc. Using a file backed - solution allows to implement kernel persistent named semaphores. */ - -struct sem_finfo -{ - unsigned int value; - unsigned long long hash; - LUID luid; -}; - -extern "C" sem_t * -sem_open (const char *name, int oflag, ...) -{ - int i, fd = -1, created; - va_list ap; - mode_t mode = 0; - unsigned int value = 0; - struct __stat64 statbuff; - sem_t *sem = SEM_FAILED; - sem_finfo sf; - bool wasopen = false; - ipc_flock file; - - size_t len = strlen (name); - char semname[ipc_names[semaphore].prefix_len + len]; - - if (!check_path (semname, semaphore, name, len)) - return SEM_FAILED; - - myfault efault; - if (efault.faulted (EFAULT)) - return SEM_FAILED; - - created = 0; - oflag &= (O_CREAT | O_EXCL); - -again: - if (oflag & O_CREAT) - { - va_start (ap, oflag); /* init ap to final named argument */ - mode = va_arg (ap, mode_t) & ~S_IXUSR; - value = va_arg (ap, unsigned int); - va_end (ap); - - /* Open and specify O_EXCL and user-execute */ - fd = open (semname, oflag | O_EXCL | O_RDWR | O_CLOEXEC, mode | S_IXUSR); - if (fd < 0) - { - if (errno == EEXIST && (oflag & O_EXCL) == 0) - goto exists; /* already exists, OK */ - return SEM_FAILED; - } - created = 1; - /* First one to create the file initializes it. */ - if (!AllocateLocallyUniqueId (&sf.luid)) - { - __seterrno (); - goto err; - } - sf.value = value; - sf.hash = hash_path_name (0, semname); - if (write (fd, &sf, sizeof sf) != sizeof sf) - goto err; - sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, value, wasopen); - if (sem == SEM_FAILED) - goto err; - /* Initialization complete, turn off user-execute bit */ - if (fchmod (fd, mode) == -1) - goto err; - /* Don't close (fd); */ - return sem; - } - -exists: - /* Open the file and fetch the semaphore name. */ - if ((fd = open (semname, O_RDWR | O_CLOEXEC)) < 0) - { - if (errno == ENOENT && (oflag & O_CREAT)) - goto again; - goto err; - } - /* Make certain initialization is complete */ - for (i = 0; i < MAX_TRIES; i++) - { - if (stat64 (semname, &statbuff) == -1) - { - if (errno == ENOENT && (oflag & O_CREAT)) - { - close (fd); - fd = -1; - goto again; - } - goto err; - } - if ((statbuff.st_mode & S_IXUSR) == 0) - break; - sleep (1); - } - if (i == MAX_TRIES) - { - set_errno (ETIMEDOUT); - goto err; - } - if (file.lock (fd, sizeof sf)) - goto err; - if (read (fd, &sf, sizeof sf) != sizeof sf) - goto err; - sem = semaphore::open (sf.hash, sf.luid, fd, oflag, mode, sf.value, wasopen); - file.unlock (fd); - if (sem == SEM_FAILED) - goto err; - /* If wasopen is set, the semaphore was already opened and we already have - an open file descriptor pointing to the file. This means, we have to - close the file descriptor created in this call. It won't be stored - anywhere anyway. */ - if (wasopen) - close (fd); - return sem; - -err: - /* Don't let following function calls change errno */ - save_errno save; - - file.unlock (fd); - if (created) - unlink (semname); - if (sem != SEM_FAILED) - semaphore::close (sem); - if (fd >= 0) - close (fd); - return SEM_FAILED; -} - -int -_sem_close (sem_t *sem, bool do_close) -{ - sem_finfo sf; - int fd, ret = -1; - ipc_flock file; - - if (semaphore::getinternal (sem, &fd, &sf.hash, &sf.luid, &sf.value) == -1) - return -1; - if (!file.lock (fd, sizeof sf) - && lseek64 (fd, 0LL, SEEK_SET) != (_off64_t) -1 - && write (fd, &sf, sizeof sf) == sizeof sf) - ret = do_close ? semaphore::close (sem) : 0; - - /* Don't let following function calls change errno */ - save_errno save; - file.unlock (fd); - close (fd); - - return ret; -} - -extern "C" int -sem_close (sem_t *sem) -{ - return _sem_close (sem, true); -} - -extern "C" int -sem_unlink (const char *name) -{ - size_t len = strlen (name); - char semname[ipc_names[semaphore].prefix_len + len]; - - if (!check_path (semname, semaphore, name, len)) - return -1; - if (unlink (semname) == -1) - return -1; - return 0; -} |