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OpenSolaris 2009.06 - man page for td_sync_setstate (opensolaris section 3cdb)

td_sync_get_info(3C_DB) 				Threads Debugging Library Functions				   td_sync_get_info(3C_DB)

td_sync_get_info, td_ta_sync_tracking_enable, td_sync_get_stats, td_sync_setstate, td_sync_waiters - operations on a synchronization object in libc_db
cc [ flag... ] file... -lc_db [ library... ] #include <proc_service.h> #include <thread_db.h> td_err_e td_sync_get_info(const td_synchandle_t *sh_p, td_syncinfo_t *si_p); td_err_e td_ta_sync_tracking_enable(const td_thragent_t *ta_p, int on_off); td_err_e td_sync_get_stats(const td_synchandle_t *sh_p, td_syncstats_t *ss_p); td_err_e td_sync_setstate(const td_synchandle_t *sh_p); typedef int td_thr_iter_f(const td_thrhandle_t *th_p, void *cb_data_p); td_err_e td_sync_waiters(const td_synchandle_t *sh_p, td_thr_iter_f *cb, void *cb_data_p);
Synchronization objects include mutexes, condition variables, semaphores, and reader-writer locks. In the same way that thread operations use a thread handle of type td_thrhandle_t, operations on synchronization objects use a synchronization object handle of type td_synchan- dle_t. The controlling process obtains synchronization object handles either by calling the function td_ta_sync_iter() to obtain handles for all synchronization objects of the target process that are known to the libc_db library of interfaces, or by mapping the address of a synchro- nization object in the address space of the target process to a handle by calling td_ta_map_addr2sync(3C_DB). Not all synchronization objects that a process uses can be known to the libc_db library and returned by td_ta_sync_iter(3C_DB). A synchro- nization object is known to libc_db only if it has been the target of a synchronization primitive in the process (such as mutex_lock(), described on the mutex_init(3C) manual page) after td_ta_new(3C_DB) has been called to attach to the process and td_ta_sync_track- ing_enable() has been called to enable synchronization object tracking. The td_ta_sync_tracking_enable() function turns synchronization object tracking on or off for the process identified by ta_p, depending on whether on_off is 0 (off) or non-zero (on). The td_sync_get_info() function fills in the td_syncinfo_t structure *si_p with values for the synchronization object identified by sh_p. The td_syncinfo_t structure contains the following fields: td_thragent_t *si_ta_p The internal process handle identifying the target process through which this synchronization object handle was obtained. Synchronization objects may be process-private or process-shared. In the latter case, the same synchronization object may have multiple handles, one for each target process's "view" of the synchronization object. psaddr_t si_sv_addr The address of the synchronization object in this target process's address space. td_sync_type_e si_type The type of the synchronization variable: mutex, condition variable, semaphore, or readers-writer lock. int si_shared_type If si_shared_type is non-zero, this synchronization object is process-shared, otherwise it is process-private. td_sync_flags_t si_flags Flags dependent on the type of the synchronization object. int si_state.sema_count Semaphores only. The current value of the semaphore int si_state.nreaders Readers-writer locks only. The number of readers currently holding the lock, or -1, if a writer is currently holding the lock. int si_state.mutex_locked For mutexes only. Non-zero if and only if the mutex is currently locked. int si_size The size of the synchronization object. uint8_t si_has_waiters Non-zero if and only if at least one thread is blocked on this synchronization object. uint8_t si_is_wlocked For reader-writer locks only. The value is non-zero if and only if this lock is held by a writer. uint8_t si_rcount PTHREAD_MUTEX_RECURSIVE mutexes only. If the mutex is held, the recursion count. uint8_t si_prioceiling PTHREAD_PRIO_PROTECT protocol mutexes only. The priority ceiling. td_thrhandle_t si_owner Mutexes and readers-writer locks only. This is the thread holding the mutex, or the write lock, if this is a reader-writer lock. The value is NULL if no one holds the mutex or write-lock. pid_t si_ownerpid Mutexes only. For a locked process-shared mutex, this is the process-ID of the process containing the owning thread. The td_sync_get_stats() function fills in the td_syncstats_t structure *ss_p with values for the synchronization object identified by sh_p. The td_syncstats_t structure contains an embedded td_syncinfo_t structure that is filled in as described above for td_sync_get_info(). In addition, usage statistics gathered since td_ta_sync_tracking_enable() was called to enable synchronization object tracking are returned in the ss_un.mutex, ss_un.cond, ss_un.rwlock, or ss_un.sema members of the td_syncstats_t structure, depending on the type of the synchroniza- tion object. The td_sync_setstate function modifies the state of synchronization object si_p, depending on the synchronization object type. For mutexes, td_sync_setstate is unlocked if the value is 0. Otherwise it is locked. For semaphores, the semaphore's count is set to the value. For reader-writer locks, the reader count set to the value if value is >0. The count is set to write-locked if value is -1. It is set to unlocked if the value is 0. Setting the state of a synchronization object from a libc_db interface may cause the synchronization object's semantics to be violated from the point of view of the threads in the target process. For example, if a thread holds a mutex, and td_sync_setstate is used to set the mutex to unlocked, then a different thread will also be able to subsequently acquire the same mutex. The td_sync_waiters function iterates over the set of thread handles of threads blocked on sh_p. The callback function cb is called once for each such thread handle, and is passed the thread handle and cb_data_p. If the callback function returns a non-zero value, iteration is terminated early. See td_ta_thr_iter(3C_DB).
TD_OK The call returned successfully. TD_BADTH An invalid thread handle was passed in. TD_DBERR A call to one of the imported interface routines failed. TD_ERR A libc_db-internal error occurred.
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |Safe | +-----------------------------+-----------------------------+
libc_db(3LIB), mutex_init(3C), td_ta_map_addr2sync(3C_DB), td_ta_sync_iter(3C_DB), td_ta_thr_iter(3C_DB), attributes(5) SunOS 5.11 5 Jun 2007 td_sync_get_info(3C_DB)