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pthread_create(3T) pthread_create(3T) NAME
pthread_create() - create a new thread of execution. SYNOPSIS
PARAMETERS
thread Pointer to the location where the created thread's ID is to be returned. attr Pointer to the thread attributes object describing the characteristics of the created thread. If the value is NULL, default attributes will be used. start_routine Function to be executed by the newly created thread. arg Parameter to be passed to the created thread's start_routine. DESCRIPTION
The function is used to create a new independent thread within the calling process. The thread will be created according to the attributes specified by attr. If attr is NULL, the default attributes will be used. The values of the attributes in attr describe the characteris- tics of the to-be-created thread in detail. Refer to the function for a list of the default attribute values. A single attributes object can be used in multiple calls to the function When a thread is created with an attributes object, the attributes are, in effect, copied into the created thread. Consequently, any change to the attributes object will not affect any previously created threads. Once all threads needing a specific attributes object have been created, the attributes object is no longer needed and may be destroyed. When the new thread is created, it will execute which has only one parameter, arg. If returns, an implicit call to is made. The return value of is used as the thread's exit status. The created thread's scheduling policy and priority, contention scope, detach state, stack size, and stack address are initialized accord- ing to their respective attributes in attr. The thread's signal mask is inherited from the creating thread. The thread's set of pending signals is cleared. Refer to pthread_exit(3T), pthread_detach(3T), and pthread_join(3T) for more information on thread termination and synchronizing with ter- minated threads. On success, the ID of the created thread is returned in thread. If fails, a thread is not created and the contents of thread are unde- fined. Thread IDs are guaranteed to be unique only within a process. NOTE: If the main thread returns from an implicit call to is made. The return value of is used as the process' exit status. The main thread can terminate without causing the process to terminate by calling Notes It is unspecified whether joinable threads that have exited but haven't been joined count against the limit. RETURN VALUE
Upon successful completion, returns zero. Otherwise, an error number is returned to indicate the error (the variable is not set). ERRORS
If any of the following occur, the function returns the corresponding error number: attr in an invalid thread attributes object. The value specified by thread is invalid. The necessary resources to create another thread are not available, or the number of threads in the calling process already equals The scheduling policy or scheduling attributes specified in attr are invalid. The caller does not have the appropriate privileges to create a thread with the scheduling policy and parameters specified in attr. AUTHOR
was derived from the IEEE POSIX P1003.1c standard. SEE ALSO
pthread_exit(3T), pthread_join(3T), fork(2). STANDARDS CONFORMANCE
Pthread Library pthread_create(3T)