1threads(5) Standards, Environments, and Macros threads(5)
2
6 threads, pthreads - POSIX pthreads and Solaris threads concepts
7
9 POSIX
10 cc -mt [ flag... ] file... [ -lrt library... ]
11 #include <pthread.h>
14 Solaris
17 cc -mt [ flag... ] file... [ library... ]
18 #include <sched.h>
21 #include <thread.h>
24
27 POSIX and Solaris threads each have their own implementation within
28 libc(3LIB). Both implementations are interoperable, their functionality
29 similar, and can be used within the same application. Only POSIX
30 threads are guaranteed to be fully portable to other POSIX-compliant
31 environments. POSIX and Solaris threads require different source,
32 include files and linking libraries. See SYNOPSIS.
33 Similarities
35 Most of the POSIX and Solaris threading functions have counterparts
36 with each other. POSIX function names, with the exception of the sema‐
37 phore names, have a "pthread" prefix. Function names for similar POSIX
38 and Solaris functions have similar endings. Typically, similar POSIX
39 and Solaris functions have the same number and use of arguments.
40 Differences
42 POSIX pthreads and Solaris threads differ in the following ways:
43 o POSIX threads are more portable.
45 o POSIX threads establish characteristics for each thread
47 according to configurable attribute objects.
48 o POSIX pthreads implement thread cancellation.
50 o POSIX pthreads enforce scheduling algorithms.
52 o POSIX pthreads allow for clean-up handlers for fork(2)
54 calls.
55 o Solaris threads can be suspended and continued.
57 o Solaris threads implement daemon threads, for whose demise
59 the process does not wait.
60
62 The following table compares the POSIX pthreads and Solaris threads
63 functions. When a comparable interface is not available either in POSIX
64 pthreads or Solaris threads, a hyphen (-) appears in the column.
65 Functions Related to Creation
67 POSIX Solaris
68 pthread_create() thr_create()
70 pthread_attr_init() -
71 pthread_attr_setdetachstate() -
72 pthread_attr_getdetachstate() -
73 pthread_attr_setinheritsched() -
74 pthread_attr_getinheritsched() -
75 pthread_attr_setschedparam() -
76 pthread_attr_getschedparam() -
77 pthread_attr_setschedpolicy() -
78 pthread_attr_getschedpolicy() -
79 pthread_attr_setscope() -
80 pthread_attr_getscope() -
81 pthread_attr_setstackaddr() -
82 pthread_attr_getstackaddr() -
83 pthread_attr_setstacksize() -
84 pthread_attr_getstacksize() -
85 pthread_attr_getguardsize() -
86 pthread_attr_setguardsize() -
87 pthread_attr_destroy() -
88 - thr_min_stack()
89 Functions Related to Exit
92 POSIX Solaris
93 pthread_exit() thr_exit()
94 pthread_join() thr_join()
95 pthread_detach() -
96 Functions Related to Thread Specific Data
99 POSIX Solaris
100 pthread_key_create() thr_keycreate()
101 pthread_setspecific() thr_setspecific()
102 pthread_getspecific() thr_getspecific()
103 pthread_key_delete() -
104 Functions Related to Signals
107 POSIX Solaris
108 pthread_sigmask() thr_sigsetmask()
109 pthread_kill() thr_kill()
110 Functions Related to IDs
113 POSIX Solaris
114 pthread_self() thr_self()
115 pthread_equal() -
116 - thr_main()
117 Functions Related to Scheduling
120 POSIX Solaris
121 - thr_yield()
122 - thr_suspend()
123 - thr_continue()
124 pthread_setconcurrency() thr_setconcurrency()
125 pthread_getconcurrency() thr_getconcurrency()
126 pthread_setschedparam() thr_setprio()
127 pthread_setschedprio() thr_setprio()
128 pthread_getschedparam() thr_getprio()
129 Functions Related to Cancellation
132 POSIX Solaris
133 pthread_cancel() -
134 pthread_setcancelstate() -
135 pthread_setcanceltype() -
136 pthread_testcancel() -
138 pthread_cleanup_pop() -
139 pthread_cleanup_push() -
140 Functions Related to Mutexes
143 POSIX Solaris
144 pthread_mutex_init() mutex_init()
145 pthread_mutexattr_init() -
146 pthread_mutexattr_setpshared() -
147 pthread_mutexattr_getpshared() -
148 pthread_mutexattr_setprotocol() -
149 pthread_mutexattr_getprotocol() -
150 pthread_mutexattr_setprioceiling() -
151 pthread_mutexattr_getprioceiling() -
152 pthread_mutexattr_settype() -
153 pthread_mutexattr_gettype() -
154 pthread_mutexattr_setrobust() -
155 pthread_mutexattr_getrobust() -
156 pthread_mutexattr_destroy() -
157 pthread_mutex_setprioceiling() -
158 pthread_mutex_getprioceiling() -
159 pthread_mutex_lock() mutex_lock()
160 pthread_mutex_trylock() mutex_trylock()
161 pthread_mutex_unlock() mutex_unlock()
162 pthread_mutex_destroy() mutex_destroy()
163 Functions Related to Condition Variables
166 POSIX Solaris
167 pthread_cond_init() cond_init()
168 pthread_condattr_init() -
169 pthread_condattr_setpshared() -
170 pthread_condattr_getpshared() -
171 pthread_condattr_destroy() -
172 pthread_cond_wait() cond_wait()
173 pthread_cond_timedwait() cond_timedwait()
174 pthread_cond_signal() cond_signal()
175 pthread_cond_broadcast() cond_broadcast()
176 pthread_cond_destroy() cond_destroy()
177 Functions Related to Reader/Writer Locking
180 POSIX Solaris
181 pthread_rwlock_init() rwlock_init()
182 pthread_rwlock_rdlock() rw_rdlock()
183 pthread_rwlock_tryrdlock() rw_tryrdlock()
184 pthread_rwlock_wrlock() rw_wrlock()
185 pthread_rwlock_trywrlock() rw_trywrlock()
186 pthread_rwlock_unlock() rw_unlock()
187 pthread_rwlock_destroy() rwlock_destroy()
188 pthread_rwlockattr_init() -
189 pthread_rwlockattr_destroy() -
190 pthread_rwlockattr_getpshared() -
191 pthread_rwlockattr_setpshared() -
192 Functions Related to Semaphores
195 POSIX Solaris
196 sem_init() sema_init()
197 sem_open() -
198 sem_close() -
199 sem_wait() sema_wait()
200 sem_trywait() sema_trywait()
201 sem_post() sema_post()
202 sem_getvalue() -
203 sem_unlink() -
204 sem_destroy() sema_destroy()
206 Functions Related to fork() Clean Up
209 POSIX Solaris
210 pthread_atfork() -
211 Functions Related to Limits
214 POSIX Solaris
215 pthread_once() -
216 Functions Related to Debugging
219 POSIX Solaris
220 - thr_stksegment()
221
224 Synchronization
225 Multithreaded behavior is asynchronous, and therefore, optimized for
226 concurrent and parallel processing. As threads, always from within the
227 same process and sometimes from multiple processes, share global data
228 with each other, they are not guaranteed exclusive access to the shared
229 data at any point in time. Securing mutually exclusive access to shared
230 data requires synchronization among the threads. Both POSIX and
231 Solaris implement four synchronization mechanisms: mutexes, condition
232 variables, reader/writer locking (optimized frequent-read occasional-
233 write mutex), and semaphores.
234 Synchronizing multiple threads diminishes their concurrency. The
237 coarser the grain of synchronization, that is, the larger the block of
238 code that is locked, the lesser the concurrency.
239 MT fork()
241 If a threads program calls fork(2), it implicitly calls fork1(2), which
242 replicates only the calling thread. Should there be any outstanding
243 mutexes throughout the process, the application should call
244 pthread_atfork(3C) to wait for and acquire those mutexes prior to call‐
245 ing fork().
246
248 POSIX Threads
249 Solaris supports the following three POSIX scheduling policies:
250 SCHED_OTHER Traditional Timesharing scheduling policy. It is based
252 on the timesharing (TS) scheduling class.
253 SCHED_FIFO First-In-First-Out scheduling policy. Threads scheduled
256 to this policy, if not preempted by a higher priority,
257 will proceed until completion. Such threads are in real-
258 time (RT) scheduling class. The calling process must
259 have a effective user ID of 0.
260 SCHED_RR Round-Robin scheduling policy. Threads scheduled to this
263 policy, if not preempted by a higher priority, will exe‐
264 cute for a time period determined by the system. Such
265 threads are in real-time (RT) scheduling class and the
266 calling process must have a effective user ID of 0.
267 In addition to the POSIX-specified scheduling policies above, Solaris
271 also supports these scheduling policies:
272 SCHED_IA Threads are scheduled according to the Inter-Active Class
274 (IA) policy as described in priocntl(2).
275 SCHED_FSS Threads are scheduled according to the Fair-Share Class
278 (FSS) policy as described in priocntl(2).
279 SCHED_FX Threads are scheduled according to the Fixed-Priority
282 Class (FX) policy as described in priocntl(2).
283 Solaris Threads
286 Only scheduling policy supported is SCHED_OTHER, which is timesharing,
287 based on the TS scheduling class.
288
290 In a multithreaded application, EINTR can be returned from blocking
291 system calls when another thread calls forkall(2).
292
294 -mt compiler option
295 The -mt compiler option compiles and links for multithreaded code. It
296 compiles source files with −D_REENTRANT and augments the set of support
297 libraries properly.
298
300 See attributes(5) for descriptions of the following attributes:
301 ┌─────────────────────────────┬─────────────────────────────┐
306 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
307 ├─────────────────────────────┼─────────────────────────────┤
308 │MT-Level │MT-Safe, Fork 1-Safe │
309 └─────────────────────────────┴─────────────────────────────┘
310
312 crle(1), fork(2), priocntl(2), libpthread(3LIB), librt(3LIB),
313 libthread(3LIB), pthread_atfork(3C), pthread_create(3C), attributes(5),
314 standards(5)
315 Linker and Libraries Guide
318SunOS 5.11 11 Nov 2008 threads(5)