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mpctl(2) -- multiprocessor control
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mpctl provides a means of determining how many processors and locality domains are available in the system, and assigning processes or lightweight processes to execute on specific processors or within a specific locality domain. A locality domain consists of a related collection of processors, memory, and peripheral resources that comprise a fundamental building block of the system. All processors... |
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mprotect(2) -- set or check protection of memory mapping
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The mprotect() function changes the access protections on the mappings specified by the range [addr, addr+len], rounding len up to the next multiple of the page size as returned by sysconf(), to be that specified by prot. Legitimate values for prot are the same as those permitted for mmap() and are defined in : PROT_READ Page can be read. PROT_WRITE Page can be written. PROT_EXEC Page ... |
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mq_close(2) -- close a message queue descriptor
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The mq_close() system call removes the association between the message queue descriptor, mqdes, and a message queue. Use of this message queue descriptor by the process, after a successful return from this mq_close(), and until this descriptor is returned by a subsequent mq_open(), will result in the failure of message queue system calls, with errno set to [EBADF]. If the process has a registered ... |
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mq_getattr(2) -- get status information and attributes associated with a message queue
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The mq_getattr() system call collects status information and attributes associated with the message queue specified by mqdes which is copied into the mq_attr structure referenced by mqstat. Upon a successful return, the mq_msgsize and mq_maxmsg fields within the mq_attr structure contain the maximum size of a message for this queue and the maximum number of messages that can be queued at any time.... |
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mq_notify(2) -- register/cancel a notification request with a message queue
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If the argument notification is not NULL, the mq_notify() system call registers the calling process to be notified of message arrival at an empty message queue associated with the message queue descriptor mqdes. The notification specified by the notification argument will be sent to the process when the message queue transitions from the empty state to the non-empty state. At any time, only one pr... |
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mq_open(2) -- create/open a message queue
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The mq_open() system call establishes a connection between a process and a message queue. It returns a new message queue descriptor which is used by other message queue system calls to refer to that queue. The name argument points to the message queue name, and must conform to the rules listed in Message Queue Naming Convention. The oflag argument is the bitwise inclusive OR of the flags listed in... |
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mq_receive(2) -- receive a message from a message queue
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The mq_receive() system call receives the oldest of the highest priority message from the message queue specified by mqdes. The selected message is removed from the queue and copied to the buffer pointed to by the msg_ptr argument. The argument, msg_len, specifies the size of the buffer in bytes. The value of msg_len should be greater than or equal to the mq_msgsize attribute of the message queue,... |
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mq_send(2) -- send a message to a message queue
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The mq_send() system call adds a message pointed to by the argument msg_ptr to the message queue specified by mqdes. The msg_len argument specifies the length of the message in bytes. The value of msg_len should be less than or equal to the mq_msgsize attribute of the message queue, or mq_send() will fail. If the specified message queue is not full, mq_send() will insert the message into the queue... |
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mq_setattr(2) -- set the blocking status of a message queue associated with a descriptor
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The mq_setattr() system call changes the blocking status of a message queue associated with the descriptor, mqdes. The blocking status that is modified is per message queue descriptor and another open descriptor for the same message queue can have a different blocking status. The argument mqstat, points to an mq_attr structure that specifies the blocking status desired. More specifically, if the O... |
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mq_unlink(2) -- unlink a message queue
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The mq_unlink() system call disassociates the queue name, from a message queue specified by the argument, name. After a successful call to mq_unlink(), attempts to open a message queue with the same name will fail, if the flag O_CREAT is not set in oflags. If there are no processes with existing open descriptors for the message queue, the queue is destroyed. If one or more processes have the messa... |
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msem_init(2) -- initialize a semaphore in a mapped file or anonymous memory region
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msem_init() allocates a new binary semaphore and initializes the state of the new semaphore. sem points to an msemaphore structure in which the state of the semaphore is to be stored. If initial_value is MSEM_LOCKED, the new semaphore is initialized in the locked state. If initial_value is MSEM_UNLOCKED, the new semaphore is initialized in the unlocked state. The msemaphore structure must be locat... |
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msem_lock(2) -- lock a semaphore
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msem_lock() attempts to lock a binary semaphore. sem points to an msemaphore structure which specifies the semaphore to be locked. If the semaphore is not currently locked, it becomes locked and the function returns successfully. If the semaphore is currently locked, and condition is MSEM_IF_NOWAIT, then the function returns with an error. If the semaphore is currently locked and condition is zero... |
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msem_remove(2) -- remove a semaphore in mapped file or anonymous region
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msem_remove() removes a binary semaphore. sem points to an msemaphore structure that specifies the semaphore to be removed. Any subsequent use of the msemaphore structure before it is again initialized by calling msem_init() produces undefined results. msem_remove() also causes any process waiting in the msem_lock() function on the removed semaphore to return with an error. If the msemaphore struc... |
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msem_unlock(2) -- unlock a semaphore
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msem_unlock() unlocks a binary semaphore. sem points to an msemaphore structure that specifies the semaphore to be unlocked. If the condition argument is zero, the semaphore will be unlocked, whether or not any other processes are currently attempting to lock it. If the condition argument is MSEM_IF_WAITERS, and some other process is waiting to lock the semaphore or the implementation cannot relia... |
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msgctl(2) -- message control operations
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msgctl() provides a variety of message control operations as specified by cmd. The following cmds are available: IPC_STAT Place the current value of each member of the data structure associated with msqid into the structure pointed to by buf. The contents of this structure are defined in glossary(9). IPC_SET Set the value of the following members of the data structure associated with msqid to the ... |
