diff options
Diffstat (limited to 'lib/qpthreads.c')
| -rw-r--r-- | lib/qpthreads.c | 212 |
1 files changed, 138 insertions, 74 deletions
diff --git a/lib/qpthreads.c b/lib/qpthreads.c index baa34d52..8909f64b 100644 --- a/lib/qpthreads.c +++ b/lib/qpthreads.c @@ -18,10 +18,7 @@ * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ - -/* This MUST come first... otherwise we don't get __USE_UNIX98, which is */ -/* essential if glibc is to allow pthread_mutexattr_settype() to be used. */ -#include "config.h" +#include "misc.h" #include <signal.h> #include <string.h> @@ -29,11 +26,6 @@ #include "qpthreads.h" #include "memory.h" -/* If this is not set, will get errors later. */ -//#ifndef __USE_UNIX98 -//#error "_USE_UNIX98 not defined" -//#endif - /*============================================================================== * Quagga Pthread Interface -- qpt_xxxx * @@ -251,49 +243,56 @@ enum qpthreads_enabled_state qpt_state_set_disabled = 2, qpt_state_set_enabled = 3, } ; +typedef enum qpthreads_enabled_state qpthreads_enabled_state_t ; -static enum qpthreads_enabled_state qpthreads_enabled_state = qpt_state_unset ; +static qpthreads_enabled_state_t qpthreads_enabled_state = qpt_state_unset ; -uint8_t qpthreads_enabled_flag = 0 ; -uint8_t qpthreads_thread_created_flag = 0 ; +bool qpthreads_enabled_flag = false ; +bool qpthreads_thread_created_flag = false ; -/* Function to set qpthreads_enabled, one way or the other. +/*------------------------------------------------------------------------------ + * Function to set qpthreads_enabled, one way or the other. * * Returns: true <=> successful set the required state. * false <=> it is too late to enable qpthreads :-( * * NB: can repeatedly set to the same state, but not change state once set. */ -extern int -qpt_set_qpthreads_enabled(int how) +extern bool +qpt_set_qpthreads_enabled(bool want_enabled) { switch (qpthreads_enabled_state) - { - case qpt_state_unset: - break ; - case qpt_state_set_frozen: - if (how != 0) - return 0 ; - break ; - case qpt_state_set_disabled: - if (how != 0) - zabort("qpthreads_enabled is already set: cannot set enabled") ; - break ; - case qpt_state_set_enabled: - if (how == 0) - zabort("qpthreads_enabled is already set: cannot set disabled") ; - break ; - default: - break ; - } - - qpthreads_enabled_flag = (how != 0) ; - qpthreads_enabled_state = (how != 0) ? qpt_state_set_enabled - : qpt_state_set_disabled ; - return 1 ; + { + case qpt_state_unset: + break ; + + case qpt_state_set_frozen: + if (want_enabled) + return false ; /* too late to set the state */ + break ; + + case qpt_state_set_disabled: + if (want_enabled) + zabort("qpthreads_enabled is already set: cannot set enabled") ; + break ; + + case qpt_state_set_enabled: + if (!want_enabled) + zabort("qpthreads_enabled is already set: cannot set disabled") ; + break ; + + default: + break ; + } ; + + qpthreads_enabled_flag = want_enabled ; + qpthreads_enabled_state = want_enabled ? qpt_state_set_enabled + : qpt_state_set_disabled ; + return true ; } ; -/* Get state of qpthreads_enabled, and freeze if not yet explictly set. +/*------------------------------------------------------------------------------ + * Get state of qpthreads_enabled, and freeze if not yet explictly set. * * Where some initialisation depends on the state of qpthreads_enabled(), this * returns the state and freezes it if it is implicitly not enabled. @@ -320,7 +319,8 @@ qpt_freeze_qpthreads_enabled(void) * are NULL, then the system defaults are used. */ -/* Initialise a set of attributes -- setting the scheduling options. +/*------------------------------------------------------------------------------ + * Initialise a set of attributes -- setting the scheduling options. * * Options: * @@ -351,7 +351,7 @@ qpt_freeze_qpthreads_enabled(void) * * Returns the address of the qpt_thread_attr_t structure. */ -qpt_thread_attr_t* +extern qpt_thread_attr_t* qpt_thread_attr_init(qpt_thread_attr_t* attr, enum qpt_attr_options opts, int scope, int policy, int priority) { @@ -420,7 +420,8 @@ qpt_thread_attr_init(qpt_thread_attr_t* attr, enum qpt_attr_options opts, return attr ; } ; -/* Create Thread with given attributes (if any). +/*------------------------------------------------------------------------------ + * Create Thread with given attributes (if any). * * If no attributes are given (attr == NULL) the thread is created with system * default attributes -- *except* that it is created joinable. @@ -429,7 +430,7 @@ qpt_thread_attr_init(qpt_thread_attr_t* attr, enum qpt_attr_options opts, * * Returns the qpt_thread_t "thread id". */ -qpt_thread_t +extern qpt_thread_t qpt_thread_create(void* (*start)(void*), void* arg, qpt_thread_attr_t* attr) { qpt_thread_attr_t thread_attr ; @@ -438,7 +439,7 @@ qpt_thread_create(void* (*start)(void*), void* arg, qpt_thread_attr_t* attr) int err ; passert(qpthreads_enabled) ; - qpthreads_thread_created_flag = 1 ; /* and at least one thread created */ + qpthreads_thread_created_flag = true ; /* at least one thread created */ default_attr = (attr == NULL) ; if (default_attr) @@ -458,7 +459,8 @@ qpt_thread_create(void* (*start)(void*), void* arg, qpt_thread_attr_t* attr) return thread_id ; } ; -/* Join given thread -- do nothing if !qpthreads_enabled +/*------------------------------------------------------------------------------ + * Join given thread -- do nothing if !qpthreads_enabled * * Tolerates ESRCH (no thread known by given id). * @@ -490,7 +492,8 @@ qpt_thread_join(qpt_thread_t thread_id) * Mutex initialise and destroy. */ -/* Initialise Mutex (allocating if required) +/*------------------------------------------------------------------------------ + * Initialise Mutex (allocating if required) * * Does nothing if !qpthreads_enabled -- but freezes the state (attempting to * later enable qpthreads will be a FATAL error). @@ -508,7 +511,7 @@ qpt_thread_join(qpt_thread_t thread_id) * * Returns the mutex -- or original mx if !qpthreads_enabled. */ -qpt_mutex +extern qpt_mutex qpt_mutex_init_new(qpt_mutex mx, enum qpt_mutex_options opts) { pthread_mutexattr_t mutex_attr ; @@ -569,7 +572,8 @@ qpt_mutex_init_new(qpt_mutex mx, enum qpt_mutex_options opts) return mx ; } ; -/* Destroy given mutex, and (if required) free it. +/*------------------------------------------------------------------------------ + * Destroy given mutex, and (if required) free it. * -- or do nothing if !qpthreads_enabled. * * Returns NULL if freed the mutex, otherwise the address of same. @@ -578,7 +582,7 @@ qpt_mutex_init_new(qpt_mutex mx, enum qpt_mutex_options opts) * anything, so there can be nothing to release -- so does nothing, but * returns the original mutex address (if any). */ -qpt_mutex +extern qpt_mutex qpt_mutex_destroy(qpt_mutex mx, int free_mutex) { int err ; @@ -600,7 +604,8 @@ qpt_mutex_destroy(qpt_mutex mx, int free_mutex) * Condition Variable initialise and destroy. */ -/* Initialise Condition Variable (allocating if required). +/*------------------------------------------------------------------------------ + * Initialise Condition Variable (allocating if required). * * Does nothing if !qpthreads_enabled -- but freezes the state (attempting to * later enable qpthreads will be a FATAL error). @@ -615,7 +620,7 @@ qpt_mutex_destroy(qpt_mutex mx, int free_mutex) * * Returns the condition variable -- or original cv id !qpthreads_enabled. */ -qpt_cond +extern qpt_cond qpt_cond_init_new(qpt_cond cv, enum qpt_cond_options opts) { pthread_condattr_t cond_attr ; @@ -662,7 +667,8 @@ qpt_cond_init_new(qpt_cond cv, enum qpt_cond_options opts) return cv ; } ; -/* Destroy given condition variable, and (if required) free it +/*------------------------------------------------------------------------------ + * Destroy given condition variable, and (if required) free it * -- or do nothing if !qpthreads_enabled. * * NB: if !qpthreads_enabled qpt_cond_init_new() will not have allocated @@ -671,7 +677,7 @@ qpt_cond_init_new(qpt_cond cv, enum qpt_cond_options opts) * * Returns NULL if freed the condition variable, otherwise the address of same. */ -qpt_cond +extern qpt_cond qpt_cond_destroy(qpt_cond cv, int free_cond) { int err ; @@ -689,7 +695,8 @@ qpt_cond_destroy(qpt_cond cv, int free_cond) return cv ; } ; -/* Wait for given condition variable or time-out +/*------------------------------------------------------------------------------ + * Wait for given condition variable or time-out * -- or return immediate success if !qpthreads_enabled. * * Returns: wait succeeded (1 => success, 0 => timed-out). @@ -698,8 +705,7 @@ qpt_cond_destroy(qpt_cond cv, int free_cond) * * Has to check the return value, so zabort_errno if not EBUSY. */ - -int +extern int qpt_cond_timedwait(qpt_cond cv, qpt_mutex mx, qtime_mono_t timeout_time) { struct timespec ts ; @@ -729,40 +735,43 @@ qpt_cond_timedwait(qpt_cond cv, qpt_mutex mx, qtime_mono_t timeout_time) * Signal Handling. */ -/* Set thread signal mask -- requires qpthreads_enabled. - * - * Thin wrapper around pthread_sigmask. +/*------------------------------------------------------------------------------ + * Set thread signal mask. * - * zaborts if gets any error. + * If !qpthreads_enabled will use sigprocmask(), otherwise pthread_sigmask(). * - * NB: it is a FATAL error to do this if !qpthreads_enabled. + * In fact pthread_sigmask() works for single-threaded processes, but we avoid + * depending on pthread library if it's not essential. * - * This is mostly because wish to avoid all pthreads_xxx calls when not - * using pthreads. There is no reason not to use this in a single threaded - * program. + * zaborts if gets any error. */ -void +extern void qpt_thread_sigmask(int how, const sigset_t* set, sigset_t* oset) { - int err ; - - passert(qpthreads_enabled) ; - if (oset != NULL) sigemptyset(oset) ; /* to make absolutely sure */ - err = pthread_sigmask(how, set, oset) ; - if (err != 0) - zabort_err("pthread_sigmask failed", err) ; + if (qpthreads_enabled) + { + int err = pthread_sigmask(how, set, oset) ; + if (err != 0) + zabort_err("pthread_sigmask failed", err) ; + } + else + { + if (sigprocmask(how, set, oset) != 0) + zabort_errno("sigprocmask failed") ; + } ; } ; -/* Send given thread the given signal -- requires qpthreads_enabled (!) +/*------------------------------------------------------------------------------ + * Send given thread the given signal -- requires qpthreads_enabled (!) * * Thin wrapper around pthread_kill. * * zaborts if gets any error. */ -void +extern void qpt_thread_signal(qpt_thread_t thread, int signum) { int err ; @@ -773,3 +782,58 @@ qpt_thread_signal(qpt_thread_t thread, int signum) if (err != 0) zabort_err("pthread_kill failed", err) ; } ; + +/*============================================================================== + * Thread Specific Data Handling. + * + * When creating a key for a piece of thread specific data one could: + * + * a. arrange for all keys to be created before any threads are + * created -- or at least before any have a need for the key. + * + * b. use pthread_once() to protect the creation of the key. + * + * Note that there does not appear to be a way of distinguishing a key + * that has been created from one that has not. + * + * For !qpthreads_enabled systems, the "thread specific" data is embedded in + * the qpt_data object. + */ + +/*------------------------------------------------------------------------------ + * Create the given thread specific data. + * + * NB: if no value is ever set, then qpt_data_get_value() will return NULL + * (whether qpthreads_enabled, or not). + */ +extern void +qpt_data_create(qpt_data data) +{ + memset(data, 0, sizeof(union qpt_data)) ; + + if (qpthreads_enabled_freeze) + { + int err = pthread_key_create(&data->key, NULL) ; + if (err != 0) + zabort_err("pthread_key_create failed", err) ; + } ; +} ; + +/*------------------------------------------------------------------------------ + * Delete the given thread specific data. + * + * NB: it is the caller's responsibility to release any memory the value of + * the thread specific data may refer to. + */ +extern void +qpt_data_delete(qpt_data data) +{ + if (qpthreads_enabled) + { + int err = pthread_key_delete(data->key) ; + if (err != 0) + zabort_err("pthread_key_delete failed", err) ; + } ; + + memset(data, 0, sizeof(union qpt_data)) ; +} ; |