Unix Advanced Environment programming-Chapter 11 Thread Learning
Piecemeal knowledge.
1. The type of thread id--- process id is pid_t, and the type of thread id is pthread_t
Compare two thread id:
# include
Int pthread_equal (pthread_t tid1, pthread_t tid2)
Get your own thread id:
Pthread_t pthread_self (void)
two。 Thread creation
Int pthread_create (pthread_t * restrict tidp, const pthread_attr_t * restrict attr
Void * (* start_rtn) (void *), void * restrict arg)
Here is an example of the print thread id:
# include
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# include
Pthread_t ntid
Void printids (const char * s) {
Pid_t pid
Pthread_t tid
Pid = getpid ()
Tid = pthread_self ()
Printf ("% s pid% u tid% u (0x%x)\ n", s, (unsigned int) pid
(unsigned int) tid, (unsigned int) tid)
}
Void * thr_fn (void * arg) {
Printids ("new thread:")
Return ((void*) 0)
}
Int main () {
Int err = 0
Err = pthread_create (& ntid, NULL, thr_fn, NULL)
/ / err = pthread_create (& ntid, NULL, thr_fn, NULL)
If (erratically ordered 0) {
Printf ("% s\ n", strerror (err))
}
Printids ("main thread:")
Sleep (1)
Exit (0)
}
Compiled with ubuntu,eclipse, prompts that pthread_create. The header file is defined, but there is no connection thread library. Eclipse needs to be set up. Select Project-Properties-c, c++build--settings---gcc c linker---libraries, and add the library pthread. Compile and run again. Ok .
Main thread: pid 2164 tid 3079145152 (0xb78806c0)
New thread: pid 2164 tid 3079142256 (0xb787fb70)
3. Thread termination
Void * thr_fn1 (void * arg) {
Printf ("thread 1 returning\ n")
Return ((void*) 1)
}
Void * thr_fn2 (void * arg) {
Printf ("thread 2 exiting\ n")
Pthread_exit ((void *) 1)
}
Int main () {
Int err
Pthread_t tid1, tid2
Void * tret
Err = pthread_create (& tid1, NULL, thr_fn1, NULL)
If (err! = 0) {
Printf ("can't create thread 1 err% s\ n", strerror (err))
}
Err = pthread_create (& tid2, NULL, thr_fn2, NULL)
If (erratically ordered 0) {
Printf ("can't create thread 2VR% s\ n", strerror (err))
}
Err = pthread_join (tid1, & tret)
If (erratically ordered 0) {
Printf ("can't join with thread 1 err% s\ n", strerror (err))
}
Printf ("thread 1 exit code% d\ n", (int) tret)
Err = pthread_join (tid2, & tret)
If (erratically ordered 0) {
Printf ("can't join eith thread 2VR% s\ n", strerror (err))
}
Printf ("thread 2 exit code% d\ n", (int) tret)
Exit (0)
}
