diff options
Diffstat (limited to 'linuxthreads')
| -rw-r--r-- | linuxthreads/internals.h | 2 | ||||
| -rw-r--r-- | linuxthreads/manager.c | 33 | ||||
| -rw-r--r-- | linuxthreads/mutex.c | 91 | ||||
| -rw-r--r-- | linuxthreads/pthread.c | 29 |
4 files changed, 95 insertions, 60 deletions
diff --git a/linuxthreads/internals.h b/linuxthreads/internals.h index c56829684e..ab6b66a857 100644 --- a/linuxthreads/internals.h +++ b/linuxthreads/internals.h @@ -288,7 +288,7 @@ int __pthread_manager(void *reqfd); void __pthread_manager_sighandler(int sig); void __pthread_reset_main_thread(void); void __fresetlockfiles(void); - +void __pthread_manager_adjust_prio(int thread_prio); /* Prototypes for the function without cancelation support when the normal version has it. */ diff --git a/linuxthreads/manager.c b/linuxthreads/manager.c index e7de399cde..c9625327c1 100644 --- a/linuxthreads/manager.c +++ b/linuxthreads/manager.c @@ -93,6 +93,8 @@ int __pthread_manager(void *arg) sigfillset(&mask); sigdelset(&mask, PTHREAD_SIG_RESTART); sigprocmask(SIG_SETMASK, &mask, NULL); + /* Raise our priority to match that of main thread */ + __pthread_manager_adjust_prio(__pthread_main_thread->p_priority); /* Enter server loop */ while(1) { FD_ZERO(&readfds); @@ -276,6 +278,8 @@ static int pthread_handle_create(pthread_t *thread, const pthread_attr_t *attr, new_thread->p_start_args.start_routine = start_routine; new_thread->p_start_args.arg = arg; new_thread->p_start_args.mask = *mask; + /* Raise priority of thread manager if needed */ + __pthread_manager_adjust_prio(new_thread->p_priority); /* Do the cloning */ pid = __clone(pthread_start_thread, (void **) new_thread, CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND | @@ -390,10 +394,22 @@ static void pthread_reap_children(void) } } -/* Free the resources of a thread */ +/* Try to free the resources of a thread when requested by pthread_join + or pthread_detach on a terminated thread. */ static void pthread_handle_free(pthread_descr th) { + pthread_descr t; + + /* Check that the thread th is still there -- pthread_reap_children + might have deallocated it already */ + t = __pthread_main_thread; + do { + if (t == th) break; + t = t->p_nextlive; + } while (t != __pthread_main_thread); + if (t != th) return; + acquire(th->p_spinlock); if (th->p_exited) { release(th->p_spinlock); @@ -455,3 +471,18 @@ void __pthread_manager_sighandler(int sig) { terminated_children = 1; } + +/* Adjust priority of thread manager so that it always run at a priority + higher than all threads */ + +void __pthread_manager_adjust_prio(int thread_prio) +{ + struct sched_param param; + + if (thread_prio <= __pthread_manager_thread.p_priority) return; + param.sched_priority = + thread_prio < __sched_get_priority_max(SCHED_FIFO) + ? thread_prio + 1 : thread_prio; + __sched_setscheduler(__pthread_manager_thread.p_pid, SCHED_FIFO, ¶m); + __pthread_manager_thread.p_priority = thread_prio; +} diff --git a/linuxthreads/mutex.c b/linuxthreads/mutex.c index d4ebcb827a..3b40ac04c5 100644 --- a/linuxthreads/mutex.c +++ b/linuxthreads/mutex.c @@ -91,47 +91,49 @@ int __pthread_mutex_lock(pthread_mutex_t * mutex) { pthread_descr self; - while(1) { - acquire(&mutex->m_spinlock); - switch(mutex->m_kind) { - case PTHREAD_MUTEX_FAST_NP: - if (mutex->m_count == 0) { - mutex->m_count = 1; - release(&mutex->m_spinlock); - return 0; - } - self = thread_self(); - break; - case PTHREAD_MUTEX_RECURSIVE_NP: - self = thread_self(); - if (mutex->m_count == 0 || mutex->m_owner == self) { - mutex->m_count++; - mutex->m_owner = self; - release(&mutex->m_spinlock); - return 0; - } - break; - case PTHREAD_MUTEX_ERRORCHECK_NP: - self = thread_self(); - if (mutex->m_count == 0) { - mutex->m_count = 1; - mutex->m_owner = self; - release(&mutex->m_spinlock); - return 0; - } else if (mutex->m_owner == self) { - release(&mutex->m_spinlock); - return EDEADLK; - } - break; - default: + acquire(&mutex->m_spinlock); + switch(mutex->m_kind) { + case PTHREAD_MUTEX_FAST_NP: + if (mutex->m_count == 0) { + mutex->m_count = 1; + release(&mutex->m_spinlock); + return 0; + } + self = thread_self(); + break; + case PTHREAD_MUTEX_RECURSIVE_NP: + self = thread_self(); + if (mutex->m_count == 0 || mutex->m_owner == self) { + mutex->m_count++; + mutex->m_owner = self; + release(&mutex->m_spinlock); + return 0; + } + break; + case PTHREAD_MUTEX_ERRORCHECK_NP: + self = thread_self(); + if (mutex->m_count == 0) { + mutex->m_count = 1; + mutex->m_owner = self; release(&mutex->m_spinlock); - return EINVAL; + return 0; + } else if (mutex->m_owner == self) { + release(&mutex->m_spinlock); + return EDEADLK; } - /* Suspend ourselves, then try again */ - enqueue(&mutex->m_waiting, self); + break; + default: release(&mutex->m_spinlock); - suspend(self); /* This is not a cancellation point */ + return EINVAL; } + /* Suspend ourselves */ + enqueue(&mutex->m_waiting, self); + release(&mutex->m_spinlock); + suspend(self); /* This is not a cancellation point */ + /* Now we own the mutex */ + ASSERT(mutex->m_count == 1); + mutex->m_owner = self; /* for recursive and errorcheck mutexes */ + return 0; } weak_alias (__pthread_mutex_lock, pthread_mutex_lock) @@ -142,30 +144,33 @@ int __pthread_mutex_unlock(pthread_mutex_t * mutex) acquire(&mutex->m_spinlock); switch (mutex->m_kind) { case PTHREAD_MUTEX_FAST_NP: - mutex->m_count = 0; break; case PTHREAD_MUTEX_RECURSIVE_NP: - mutex->m_count--; - if (mutex->m_count > 0) { + if (mutex->m_count >= 2) { + mutex->m_count--; release(&mutex->m_spinlock); return 0; } - mutex->m_count = 0; /* so that excess unlocks do not break everything */ break; case PTHREAD_MUTEX_ERRORCHECK_NP: if (mutex->m_count == 0 || mutex->m_owner != thread_self()) { release(&mutex->m_spinlock); return EPERM; } - mutex->m_count = 0; break; default: release(&mutex->m_spinlock); return EINVAL; } th = dequeue(&mutex->m_waiting); + /* If no waiters, unlock the mutex */ + if (th == NULL) mutex->m_count = 0; release(&mutex->m_spinlock); - if (th != NULL) restart(th); + /* If there is a waiter, restart it with the mutex still locked */ + if (th != NULL) { + mutex->m_owner = NULL; /* we no longer own the mutex */ + restart(th); + } return 0; } weak_alias (__pthread_mutex_unlock, pthread_mutex_unlock) diff --git a/linuxthreads/pthread.c b/linuxthreads/pthread.c index 9699b4ddcc..83d160622d 100644 --- a/linuxthreads/pthread.c +++ b/linuxthreads/pthread.c @@ -58,7 +58,8 @@ struct _pthread_descr_struct __pthread_initial_thread = { }; /* Descriptor of the manager thread; none of this is used but the error - variables and the address for identification. */ + variables, the p_pid and p_priority fields, + and the address for identification. */ struct _pthread_descr_struct __pthread_manager_thread = { NULL, /* pthread_descr p_nextlive */ @@ -108,10 +109,6 @@ int __pthread_manager_request = -1; int __pthread_manager_reader; -/* PID of thread manager */ - -static int __pthread_manager_pid; - /* Limits of the thread manager stack */ char *__pthread_manager_thread_bos = NULL; @@ -203,6 +200,7 @@ static void pthread_initialize(void) static int pthread_initialize_manager(void) { int manager_pipe[2]; + int pid; /* If basic initialization not done yet (e.g. we're called from a constructor run before our constructor), do it now */ @@ -217,20 +215,19 @@ static int pthread_initialize_manager(void) free(__pthread_manager_thread_bos); return -1; } - __pthread_manager_request = manager_pipe[1]; /* writing end */ - __pthread_manager_reader = manager_pipe[0]; /* reading end */ /* Start the thread manager */ - __pthread_manager_pid = - __clone(__pthread_manager, (void **) __pthread_manager_thread_tos, - CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, - (void *)(long)manager_pipe[0]); - if (__pthread_manager_pid == -1) { + pid = __clone(__pthread_manager, (void **) __pthread_manager_thread_tos, + CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND, + (void *)(long)manager_pipe[0]); + if (pid == -1) { free(__pthread_manager_thread_bos); __libc_close(manager_pipe[0]); __libc_close(manager_pipe[1]); - __pthread_manager_request = -1; return -1; } + __pthread_manager_request = manager_pipe[1]; /* writing end */ + __pthread_manager_reader = manager_pipe[0]; /* reading end */ + __pthread_manager_thread.p_pid = pid; return 0; } @@ -319,6 +316,8 @@ int pthread_setschedparam(pthread_t thread, int policy, } th->p_priority = policy == SCHED_OTHER ? 0 : param->sched_priority; release(&handle->h_spinlock); + if (__pthread_manager_request >= 0) + __pthread_manager_adjust_prio(th->p_priority); return 0; } @@ -359,7 +358,7 @@ static void pthread_exit_process(int retcode, void *arg) /* Main thread should accumulate times for thread manager and its children, so that timings for main thread account for all threads. */ if (self == __pthread_main_thread) - waitpid(__pthread_manager_pid, NULL, __WCLONE); + waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); } } @@ -392,7 +391,7 @@ static void pthread_handle_sigcancel(int sig) /* Main thread should accumulate times for thread manager and its children, so that timings for main thread account for all threads. */ if (self == __pthread_main_thread) - waitpid(__pthread_manager_pid, NULL, __WCLONE); + waitpid(__pthread_manager_thread.p_pid, NULL, __WCLONE); _exit(__pthread_exit_code); } if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE) { |