pthread.h

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/*
 * Copyright (c) 2017 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef ZEPHYR_INCLUDE_POSIX_PTHREAD_H_
#define ZEPHYR_INCLUDE_POSIX_PTHREAD_H_
 
#include <kernel.h>
#include <wait_q.h>
#include <posix/time.h>
#include <posix/unistd.h>
#include "posix_types.h"
#include "posix_sched.h"
#include <posix/pthread_key.h>
#include <stdlib.h>
#include <string.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
enum pthread_state {
        /* The thread structure is unallocated and available for reuse. */
        PTHREAD_TERMINATED = 0,
        /* The thread is running and joinable. */
        PTHREAD_JOINABLE,
        /* The thread is running and detached. */
        PTHREAD_DETACHED,
        /* A joinable thread exited and its return code is available. */
        PTHREAD_EXITED
};
 
struct posix_thread {
        struct k_thread thread;
 
        /* List of keys that thread has called pthread_setspecific() on */
        sys_slist_t key_list;
 
        /* Exit status */
        void *retval;
 
        /* Pthread cancellation */
        int cancel_state;
        int cancel_pending;
        pthread_mutex_t cancel_lock;
 
        /* Pthread State */
        enum pthread_state state;
        pthread_mutex_t state_lock;
        pthread_cond_t state_cond;
};
 
/* Pthread detach/joinable */
#define PTHREAD_CREATE_JOINABLE     PTHREAD_JOINABLE
#define PTHREAD_CREATE_DETACHED     PTHREAD_DETACHED
 
/* Pthread cancellation */
#define _PTHREAD_CANCEL_POS     0
#define PTHREAD_CANCEL_ENABLE   (0U << _PTHREAD_CANCEL_POS)
#define PTHREAD_CANCEL_DISABLE  BIT(_PTHREAD_CANCEL_POS)
 
/* Passed to pthread_once */
#define PTHREAD_ONCE_INIT 1
 
#define PTHREAD_COND_DEFINE(name)                                       \
        struct pthread_cond name = {                                    \
                .wait_q = Z_WAIT_Q_INIT(&name.wait_q),                  \
        }
 
static inline int pthread_cond_init(pthread_cond_t *cv,
                                    const pthread_condattr_t *att)
{
        ARG_UNUSED(att);
        z_waitq_init(&cv->wait_q);
        return 0;
}
 
static inline int pthread_cond_destroy(pthread_cond_t *cv)
{
        return 0;
}
 
int pthread_cond_signal(pthread_cond_t *cv);
 
int pthread_cond_broadcast(pthread_cond_t *cv);
 
int pthread_cond_wait(pthread_cond_t *cv, pthread_mutex_t *mut);
 
int pthread_cond_timedwait(pthread_cond_t *cv, pthread_mutex_t *mut,
                           const struct timespec *abstime);
 
static inline int pthread_condattr_init(pthread_condattr_t *att)
{
        return 0;
}
 
static inline int pthread_condattr_destroy(pthread_condattr_t *att)
{
        return 0;
}
 
#define PTHREAD_MUTEX_DEFINE(name) \
        struct pthread_mutex name = \
        { \
                .lock_count = 0, \
                .wait_q = Z_WAIT_Q_INIT(&name.wait_q),  \
                .owner = NULL, \
        }
 
/*
 *  Mutex attributes - type
 *
 *  PTHREAD_MUTEX_NORMAL: Owner of mutex cannot relock it. Attempting
 *      to relock will cause deadlock.
 *  PTHREAD_MUTEX_RECURSIVE: Owner can relock the mutex.
 *  PTHREAD_MUTEX_ERRORCHECK: If owner attempts to relock the mutex, an
 *      error is returned.
 *
 */
#define PTHREAD_MUTEX_NORMAL        0
#define PTHREAD_MUTEX_RECURSIVE     1
#define PTHREAD_MUTEX_ERRORCHECK    2
#define PTHREAD_MUTEX_DEFAULT       PTHREAD_MUTEX_NORMAL
 
/*
 *  Mutex attributes - protocol
 *
 *  PTHREAD_PRIO_NONE: Ownership of mutex does not affect priority.
 *  PTHREAD_PRIO_INHERIT: Owner's priority is boosted to the priority of
 *      highest priority thread blocked on the mutex.
 *  PTHREAD_PRIO_PROTECT:  Mutex has a priority ceiling.  The owner's
 *      priority is boosted to the highest priority ceiling of all mutexes
 *      owned (regardless of whether or not other threads are blocked on
 *      any of these mutexes).
 *  FIXME: Only PRIO_NONE is supported. Implement other protocols.
 */
#define PTHREAD_PRIO_NONE           0
 
int pthread_mutex_destroy(pthread_mutex_t *m);
 
int pthread_mutex_lock(pthread_mutex_t *m);
 
int pthread_mutex_unlock(pthread_mutex_t *m);
 
int pthread_mutex_timedlock(pthread_mutex_t *m,
                            const struct timespec *abstime);
 
int pthread_mutex_trylock(pthread_mutex_t *m);
 
int pthread_mutex_init(pthread_mutex_t *m,
                                     const pthread_mutexattr_t *att);
 
int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol);
 
int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
 
int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr,
                                  int *protocol);
 
int pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *type);
 
static inline int pthread_mutexattr_init(pthread_mutexattr_t *m)
{
        ARG_UNUSED(m);
 
        return 0;
}
 
static inline int pthread_mutexattr_destroy(pthread_mutexattr_t *m)
{
        ARG_UNUSED(m);
 
        return 0;
}
 
/* FIXME: these are going to be tricky to implement.  Zephyr has (for
 * good reason) deprecated its own "initializer" macros in favor of a
 * static "declaration" macros instead.  Using such a macro inside a
 * gcc compound expression to declare and object then reference it
 * would work, but gcc limits such expressions to function context
 * (because they may need to generate code that runs at assignment
 * time) and much real-world use of these initializers is for static
 * variables.  The best trick I can think of would be to declare it in
 * a special section and then initialize that section at runtime
 * startup, which sort of defeats the purpose of having these be
 * static...
 *
 * Instead, see the nonstandard PTHREAD_*_DEFINE macros instead, which
 * work similarly but conform to Zephyr's paradigms.
 */
/* #define PTHREAD_MUTEX_INITIALIZER */
/* #define PTHREAD_COND_INITIALIZER */
 
#define PTHREAD_BARRIER_DEFINE(name, count)                     \
        struct pthread_barrier name = {                         \
                .wait_q = Z_WAIT_Q_INIT(&name.wait_q),          \
                .max = count,                                   \
        }
 
#define PTHREAD_BARRIER_SERIAL_THREAD 1
 
int pthread_barrier_wait(pthread_barrier_t *b);
 
static inline int pthread_barrier_init(pthread_barrier_t *b,
                                       const pthread_barrierattr_t *attr,
                                       unsigned int count)
{
        ARG_UNUSED(attr);
 
        b->max = count;
        b->count = 0;
        z_waitq_init(&b->wait_q);
 
        return 0;
}
 
static inline int pthread_barrier_destroy(pthread_barrier_t *b)
{
        ARG_UNUSED(b);
 
        return 0;
}
 
static inline int pthread_barrierattr_init(pthread_barrierattr_t *b)
{
        ARG_UNUSED(b);
 
        return 0;
}
 
static inline int pthread_barrierattr_destroy(pthread_barrierattr_t *b)
{
        ARG_UNUSED(b);
 
        return 0;
}
 
/* Predicates and setters for various pthread attribute values that we
 * don't support (or always support: the "process shared" attribute
 * can only be true given the way Zephyr implements these
 * objects). Leave these undefined for simplicity instead of defining
 * stubs to return an error that would have to be logged and
 * interpreted just to figure out that we didn't support it in the
 * first place. These APIs are very rarely used even in production
 * Unix code.  Leave the declarations here so they can be easily
 * uncommented and implemented as needed.
 
int pthread_condattr_getclock(const pthread_condattr_t * clockid_t *);
int pthread_condattr_getpshared(const pthread_condattr_t * int *);
int pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
int pthread_condattr_setpshared(pthread_condattr_t *, int);
int pthread_mutex_consistent(pthread_mutex_t *);
int pthread_mutex_getprioceiling(const pthread_mutex_t * int *);
int pthread_mutex_setprioceiling(pthread_mutex_t *, int int *);
int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *, int *);
int pthread_mutexattr_getpshared(const pthread_mutexattr_t * int *);
int pthread_mutexattr_getrobust(const pthread_mutexattr_t * int *);
int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *, int);
int pthread_mutexattr_setpshared(pthread_mutexattr_t *, int);
int pthread_mutexattr_setrobust(pthread_mutexattr_t *, int);
int pthread_barrierattr_getpshared(const pthread_barrierattr_t *, int *);
int pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);
*/
 
/* Base Pthread related APIs */
 
static inline pthread_t pthread_self(void)
{
        return (pthread_t)k_current_get();
}
 
 
static inline int pthread_equal(pthread_t pt1, pthread_t pt2)
{
        return (pt1 == pt2);
}
 
static inline int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr)
{
        return 0;
}
 
static inline int pthread_rwlockattr_init(pthread_rwlockattr_t *attr)
{
        return 0;
}
 
int pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize);
int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);
int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy);
int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);
int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate);
int pthread_attr_init(pthread_attr_t *attr);
int pthread_attr_destroy(pthread_attr_t *attr);
int pthread_attr_getschedparam(const pthread_attr_t *attr,
                               struct sched_param *schedparam);
int pthread_getschedparam(pthread_t pthread, int *policy,
                          struct sched_param *param);
int pthread_attr_getstack(const pthread_attr_t *attr,
                          void **stackaddr, size_t *stacksize);
int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr,
                          size_t stacksize);
int pthread_once(pthread_once_t *once, void (*initFunc)(void));
void pthread_exit(void *retval);
int pthread_join(pthread_t thread, void **status);
int pthread_cancel(pthread_t pthread);
int pthread_detach(pthread_t thread);
int pthread_create(pthread_t *newthread, const pthread_attr_t *attr,
                   void *(*threadroutine)(void *), void *arg);
int pthread_setcancelstate(int state, int *oldstate);
int pthread_attr_setschedparam(pthread_attr_t *attr,
                               const struct sched_param *schedparam);
int pthread_setschedparam(pthread_t pthread, int policy,
                          const struct sched_param *param);
int pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
int pthread_rwlock_init(pthread_rwlock_t *rwlock,
                        const pthread_rwlockattr_t *attr);
int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
int pthread_rwlock_timedrdlock(pthread_rwlock_t *rwlock,
                               const struct timespec *abstime);
int pthread_rwlock_timedwrlock(pthread_rwlock_t *rwlock,
                               const struct timespec *abstime);
int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock);
int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);
int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
int pthread_key_create(pthread_key_t *key,
                void (*destructor)(void *));
int pthread_key_delete(pthread_key_t key);
int pthread_setspecific(pthread_key_t key, const void *value);
void *pthread_getspecific(pthread_key_t key);
 
/* Glibc / Oracle Extension Functions */
 
int pthread_setname_np(pthread_t thread, const char *name);
 
int pthread_getname_np(pthread_t thread, char *name, size_t len);
 
#ifdef __cplusplus
}
#endif
 
#endif /* ZEPHYR_INCLUDE_POSIX_PTHREAD_H_ */