reorganize pthread data structures and move the definitions to alltypes.h

this allows sys/types.h to provide the pthread types, as required by
POSIX. this design also facilitates forcing ABI-compatible sizes in
the arch-specific alltypes.h, while eliminating the need for
developers changing the internals of the pthread types to poke around
with arch-specific headers they may not be able to test.
This commit is contained in:
Rich Felker
2011-02-17 17:16:20 -05:00
parent 4fd159568a
commit e882756311
28 changed files with 158 additions and 128 deletions

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@ -78,7 +78,22 @@ TYPEDEF int id_t;
TYPEDEF int uid_t; TYPEDEF int uid_t;
TYPEDEF int gid_t; TYPEDEF int gid_t;
TYPEDEF int key_t; TYPEDEF int key_t;
TYPEDEF struct __pthread * pthread_t; TYPEDEF struct __pthread * pthread_t;
TYPEDEF int pthread_once_t;
TYPEDEF int pthread_key_t;
TYPEDEF int pthread_spinlock_t;
TYPEDEF struct { union { int __i[9]; size_t __s[2]; } __u; } pthread_attr_t;
TYPEDEF unsigned pthread_mutexattr_t;
TYPEDEF unsigned pthread_condattr_t;
TYPEDEF unsigned pthread_barrierattr_t;
TYPEDEF struct { unsigned __attr[2]; } pthread_rwlockattr_t;
TYPEDEF struct { union { int __i[6]; void *__p[1]; } __u; } pthread_mutex_t;
TYPEDEF struct { union { int __i[12]; void *__p[1]; } __u; } pthread_cond_t;
TYPEDEF struct { union { int __i[8]; void *__p[1]; } __u; } pthread_rwlock_t;
TYPEDEF struct { union { int __i[5]; void *__p[1]; } __u; } pthread_barrier_t;
TYPEDEF long long off_t; TYPEDEF long long off_t;

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@ -78,7 +78,22 @@ TYPEDEF int id_t;
TYPEDEF unsigned int uid_t; TYPEDEF unsigned int uid_t;
TYPEDEF unsigned int gid_t; TYPEDEF unsigned int gid_t;
TYPEDEF int key_t; TYPEDEF int key_t;
TYPEDEF struct __pthread * pthread_t; TYPEDEF struct __pthread * pthread_t;
TYPEDEF int pthread_once_t;
TYPEDEF int pthread_key_t;
TYPEDEF int pthread_spinlock_t;
TYPEDEF struct { union { int __i[14]; size_t __s[2]; } __u; } pthread_attr_t;
TYPEDEF unsigned pthread_mutexattr_t;
TYPEDEF unsigned pthread_condattr_t;
TYPEDEF unsigned pthread_barrierattr_t;
TYPEDEF struct { unsigned __attr[2]; } pthread_rwlockattr_t;
TYPEDEF struct { union { int __i[10]; void *__p[1]; } __u; } pthread_mutex_t;
TYPEDEF struct { union { int __i[12]; void *__p[1]; } __u; } pthread_cond_t;
TYPEDEF struct { union { int __i[14]; void *__p[1]; } __u; } pthread_rwlock_t;
TYPEDEF struct { union { int __i[8]; void *__p[1]; } __u; } pthread_barrier_t;
TYPEDEF long off_t; TYPEDEF long off_t;

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@ -8,6 +8,18 @@ extern "C" {
#define __NEED_struct_timespec #define __NEED_struct_timespec
#define __NEED_sigset_t #define __NEED_sigset_t
#define __NEED_pthread_t #define __NEED_pthread_t
#define __NEED_pthread_attr_t
#define __NEED_pthread_mutexattr_t
#define __NEED_pthread_condattr_t
#define __NEED_pthread_rwlockattr_t
#define __NEED_pthread_barrierattr_t
#define __NEED_pthread_mutex_t
#define __NEED_pthread_cond_t
#define __NEED_pthread_rwlock_t
#define __NEED_pthread_barrier_t
#define __NEED_pthread_spinlock_t
#define __NEED_pthread_key_t
#define __NEED_pthread_once_t
#define __NEED_size_t #define __NEED_size_t
#include <bits/alltypes.h> #include <bits/alltypes.h>
@ -15,51 +27,6 @@ extern "C" {
#include <sched.h> #include <sched.h>
#include <time.h> #include <time.h>
typedef int pthread_once_t, pthread_key_t, pthread_spinlock_t;
typedef int pthread_mutexattr_t, pthread_condattr_t, pthread_barrierattr_t;
typedef struct {
size_t __guardsize;
size_t __stacksize;
unsigned __detach : 1;
unsigned __pad : 31;
int __attr[6];
} pthread_attr_t;
typedef struct {
int __attr[2];
} pthread_rwlockattr_t;
typedef struct {
int __type;
int __lock;
pthread_t __owner;
int __pad2;
int __waiters;
int __pad;
} pthread_mutex_t;
typedef struct {
int __block;
int __pad[11];
} pthread_cond_t;
typedef struct {
int __wrlock;
int __readers;
int __waiters;
int __owner;
int __pad[4];
} pthread_rwlock_t;
typedef struct {
int __count;
int __limit;
int __left;
int __waiters;
int __barrier[1];
} pthread_barrier_t;
#define PTHREAD_CREATE_JOINABLE 0 #define PTHREAD_CREATE_JOINABLE 0
#define PTHREAD_CREATE_DETACHED 1 #define PTHREAD_CREATE_DETACHED 1

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@ -42,6 +42,20 @@ extern "C" {
#define __NEED_suseconds_t #define __NEED_suseconds_t
#define __NEED_blksize_t #define __NEED_blksize_t
#define __NEED_pthread_t
#define __NEED_pthread_attr_t
#define __NEED_pthread_mutexattr_t
#define __NEED_pthread_condattr_t
#define __NEED_pthread_rwlockattr_t
#define __NEED_pthread_barrierattr_t
#define __NEED_pthread_mutex_t
#define __NEED_pthread_cond_t
#define __NEED_pthread_rwlock_t
#define __NEED_pthread_barrier_t
#define __NEED_pthread_spinlock_t
#define __NEED_pthread_key_t
#define __NEED_pthread_once_t
#include <bits/alltypes.h> #include <bits/alltypes.h>
#ifdef _GNU_SOURCE #ifdef _GNU_SOURCE

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@ -38,6 +38,25 @@ struct pthread {
pthread_attr_t attr; pthread_attr_t attr;
}; };
#define __SU (sizeof(size_t)/sizeof(int))
#define _a_stacksize __u.__s[0]
#define _a_guardsize __u.__s[1]
#define _a_detach __u.__i[2*__SU+0]
#define _m_type __u.__i[0]
#define _m_lock __u.__i[1]
#define _m_waiters __u.__i[2]
#define _m_owner __u.__i[3]
#define _c_block __u.__i[0]
#define _rw_wrlock __u.__i[0]
#define _rw_readers __u.__i[1]
#define _rw_waiters __u.__i[2]
#define _rw_owner __u.__i[3]
#define _b_count __u.__i[0]
#define _b_limit __u.__i[1]
#define _b_left __u.__i[2]
#define _b_waiters __u.__i[3]
#include "pthread_arch.h" #include "pthread_arch.h"
#define SIGCANCEL 32 #define SIGCANCEL 32

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@ -2,6 +2,6 @@
int pthread_attr_getdetachstate(pthread_attr_t *a, int *state) int pthread_attr_getdetachstate(pthread_attr_t *a, int *state)
{ {
*state = a->__detach; *state = a->_a_detach;
return 0; return 0;
} }

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@ -2,6 +2,6 @@
int pthread_attr_getguardsize(pthread_attr_t *a, size_t *size) int pthread_attr_getguardsize(pthread_attr_t *a, size_t *size)
{ {
*size = a->__guardsize + DEFAULT_GUARD_SIZE; *size = a->_a_guardsize + DEFAULT_GUARD_SIZE;
return 0; return 0;
} }

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@ -2,6 +2,6 @@
int pthread_attr_getstacksize(pthread_attr_t *a, size_t *size) int pthread_attr_getstacksize(pthread_attr_t *a, size_t *size)
{ {
*size = a->__stacksize + DEFAULT_STACK_SIZE; *size = a->_a_stacksize + DEFAULT_STACK_SIZE;
return 0; return 0;
} }

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@ -2,6 +2,6 @@
int pthread_attr_setdetachstate(pthread_attr_t *a, int state) int pthread_attr_setdetachstate(pthread_attr_t *a, int state)
{ {
a->__detach = state; a->_a_detach = state;
return 0; return 0;
} }

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@ -3,6 +3,6 @@
int pthread_attr_setguardsize(pthread_attr_t *a, size_t size) int pthread_attr_setguardsize(pthread_attr_t *a, size_t size)
{ {
if (size > SIZE_MAX/8) return EINVAL; if (size > SIZE_MAX/8) return EINVAL;
a->__guardsize = size - DEFAULT_GUARD_SIZE; a->_a_guardsize = size - DEFAULT_GUARD_SIZE;
return 0; return 0;
} }

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@ -3,6 +3,6 @@
int pthread_attr_setstacksize(pthread_attr_t *a, size_t size) int pthread_attr_setstacksize(pthread_attr_t *a, size_t size)
{ {
if (size-PAGE_SIZE > SIZE_MAX/4) return EINVAL; if (size-PAGE_SIZE > SIZE_MAX/4) return EINVAL;
a->__stacksize = size - DEFAULT_STACK_SIZE; a->_a_stacksize = size - DEFAULT_STACK_SIZE;
return 0; return 0;
} }

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@ -3,6 +3,6 @@
int pthread_barrier_init(pthread_barrier_t *b, const pthread_barrierattr_t *a, unsigned count) int pthread_barrier_init(pthread_barrier_t *b, const pthread_barrierattr_t *a, unsigned count)
{ {
if (!count) return EINVAL; if (!count) return EINVAL;
*b = (pthread_barrier_t){ .__limit = count-1 }; *b = (pthread_barrier_t){ ._b_limit = count-1 };
return 0; return 0;
} }

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@ -5,27 +5,27 @@ int pthread_barrier_wait(pthread_barrier_t *b)
int cur; int cur;
/* Trivial case: count was set at 1 */ /* Trivial case: count was set at 1 */
if (!b->__limit) return PTHREAD_BARRIER_SERIAL_THREAD; if (!b->_b_limit) return PTHREAD_BARRIER_SERIAL_THREAD;
/* Wait for anyone still suspended at previous use of barrier */ /* Wait for anyone still suspended at previous use of barrier */
while ((cur=b->__left)) while ((cur=b->_b_left))
__wait(&b->__left, &b->__waiters, cur, 0); __wait(&b->_b_left, &b->_b_waiters, cur, 0);
/* If we are the last to reach barrier, reset it and wake others */ /* If we are the last to reach barrier, reset it and wake others */
if (a_fetch_add(&b->__count, 1) == b->__limit) { if (a_fetch_add(&b->_b_count, 1) == b->_b_limit) {
b->__left = b->__limit; b->_b_left = b->_b_limit;
b->__count = 0; b->_b_count = 0;
__wake(&b->__count, -1, 0); __wake(&b->_b_count, -1, 0);
return PTHREAD_BARRIER_SERIAL_THREAD; return PTHREAD_BARRIER_SERIAL_THREAD;
} }
/* Wait for our peers to reach the barrier */ /* Wait for our peers to reach the barrier */
while ((cur=b->__count)) while ((cur=b->_b_count))
__wait(&b->__count, 0, cur, 0); __wait(&b->_b_count, 0, cur, 0);
/* If we're the last to wake up and barrier is awaiting reuse */ /* If we're the last to wake up and barrier is awaiting reuse */
if (a_fetch_add(&b->__left, -1) == 1 && b->__waiters) if (a_fetch_add(&b->_b_left, -1) == 1 && b->_b_waiters)
__wake(&b->__left, -1, 0); __wake(&b->_b_left, -1, 0);
return 0; return 0;
} }

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@ -2,7 +2,7 @@
int pthread_cond_broadcast(pthread_cond_t *c) int pthread_cond_broadcast(pthread_cond_t *c)
{ {
c->__block = 0; c->_c_block = 0;
__wake(&c->__block, -1, 0); __wake(&c->_c_block, -1, 0);
return 0; return 0;
} }

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@ -2,7 +2,7 @@
int pthread_cond_signal(pthread_cond_t *c) int pthread_cond_signal(pthread_cond_t *c)
{ {
c->__block = 0; c->_c_block = 0;
__wake(&c->__block, 1, 0); __wake(&c->_c_block, 1, 0);
return 0; return 0;
} }

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@ -11,11 +11,11 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
CANCELPT(0); CANCELPT(0);
pthread_cleanup_push(relock, m); pthread_cleanup_push(relock, m);
c->__block = 1; c->_c_block = 1;
if ((r=pthread_mutex_unlock(m))) return r; if ((r=pthread_mutex_unlock(m))) return r;
CANCELPT(1); CANCELPT(1);
e = __timedwait(&c->__block, 1, CLOCK_REALTIME, ts, 0); e = __timedwait(&c->_c_block, 1, CLOCK_REALTIME, ts, 0);
CANCELPT(0); CANCELPT(0);
pthread_cleanup_pop(0); pthread_cleanup_pop(0);

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@ -173,8 +173,8 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
if (!init && ++init) init_threads(); if (!init && ++init) init_threads();
if (!attr) attr = &default_attr; if (!attr) attr = &default_attr;
guard = ROUND(attr->__guardsize + DEFAULT_GUARD_SIZE); guard = ROUND(attr->_a_guardsize + DEFAULT_GUARD_SIZE);
size = guard + ROUND(attr->__stacksize + DEFAULT_STACK_SIZE); size = guard + ROUND(attr->_a_stacksize + DEFAULT_STACK_SIZE);
size += __pthread_tsd_size; size += __pthread_tsd_size;
map = mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON, -1, 0); map = mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON, -1, 0);
if (!map) return EAGAIN; if (!map) return EAGAIN;
@ -190,7 +190,7 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo
new->start_arg = arg; new->start_arg = arg;
new->self = new; new->self = new;
new->tsd = (void *)tsd; new->tsd = (void *)tsd;
new->detached = attr->__detach; new->detached = attr->_a_detach;
new->attr = *attr; new->attr = *attr;
memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc); memcpy(new->tlsdesc, self->tlsdesc, sizeof new->tlsdesc);
new->tlsdesc[1] = (uintptr_t)new; new->tlsdesc[1] = (uintptr_t)new;

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@ -4,6 +4,6 @@ int pthread_mutex_lock(pthread_mutex_t *m)
{ {
int r; int r;
while ((r=pthread_mutex_trylock(m)) == EBUSY) while ((r=pthread_mutex_trylock(m)) == EBUSY)
__wait(&m->__lock, &m->__waiters, 1, 0); __wait(&m->_m_lock, &m->_m_waiters, 1, 0);
return r; return r;
} }

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@ -4,12 +4,12 @@ int pthread_mutex_timedlock(pthread_mutex_t *m, const struct timespec *at)
{ {
int r, w=0; int r, w=0;
while ((r=pthread_mutex_trylock(m)) == EBUSY) { while ((r=pthread_mutex_trylock(m)) == EBUSY) {
if (!w) a_inc(&m->__waiters), w++; if (!w) a_inc(&m->_m_waiters), w++;
if (__timedwait(&m->__lock, 1, CLOCK_REALTIME, at, 0) == ETIMEDOUT) { if (__timedwait(&m->_m_lock, 1, CLOCK_REALTIME, at, 0) == ETIMEDOUT) {
if (w) a_dec(&m->__waiters); if (w) a_dec(&m->_m_waiters);
return ETIMEDOUT; return ETIMEDOUT;
} }
} }
if (w) a_dec(&m->__waiters); if (w) a_dec(&m->_m_waiters);
return r; return r;
} }

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@ -2,27 +2,27 @@
int pthread_mutex_trylock(pthread_mutex_t *m) int pthread_mutex_trylock(pthread_mutex_t *m)
{ {
if (m->__type == PTHREAD_MUTEX_RECURSIVE) { if (m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
pthread_t self = pthread_self(); pthread_t self = pthread_self();
if (m->__owner == self) { if (m->_m_owner == self->tid) {
if ((unsigned)m->__lock >= INT_MAX) return EAGAIN; if ((unsigned)m->_m_lock >= INT_MAX) return EAGAIN;
a_inc(&m->__lock); a_inc(&m->_m_lock);
return 0; return 0;
} }
if (a_fetch_add(&m->__lock, 1)) { if (a_fetch_add(&m->_m_lock, 1)) {
if (a_fetch_add(&m->__lock, -1)==1 && m->__waiters) if (a_fetch_add(&m->_m_lock, -1)==1 && m->_m_waiters)
__wake(&m->__lock, 1, 0); __wake(&m->_m_lock, 1, 0);
return EBUSY; return EBUSY;
} }
m->__owner = self; m->_m_owner = self->tid;
return 0; return 0;
} }
if (a_xchg(&m->__lock, 1)) if (a_xchg(&m->_m_lock, 1))
if (m->__type == PTHREAD_MUTEX_ERRORCHECK if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK
&& m->__owner == pthread_self()) return EDEADLK; && m->_m_owner == pthread_self()->tid) return EDEADLK;
else return EBUSY; else return EBUSY;
if (m->__type == PTHREAD_MUTEX_ERRORCHECK) if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK)
m->__owner = pthread_self(); m->_m_owner = pthread_self()->tid;
return 0; return 0;
} }

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@ -2,18 +2,18 @@
int pthread_mutex_unlock(pthread_mutex_t *m) int pthread_mutex_unlock(pthread_mutex_t *m)
{ {
if (m->__type == PTHREAD_MUTEX_RECURSIVE) { if (m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
if (a_fetch_add(&m->__lock, -1)==1 && m->__waiters) if (a_fetch_add(&m->_m_lock, -1)==1 && m->_m_waiters)
__wake(&m->__lock, 1, 0); __wake(&m->_m_lock, 1, 0);
return 0; return 0;
} }
if (m->__type == PTHREAD_MUTEX_ERRORCHECK if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK
&& m->__owner != pthread_self()) && m->_m_owner != pthread_self()->tid)
return EPERM; return EPERM;
m->__owner = 0; m->_m_owner = 0;
m->__lock = 0; m->_m_lock = 0;
if (m->__waiters) __wake(&m->__lock, 1, 0); if (m->_m_waiters) __wake(&m->_m_lock, 1, 0);
return 0; return 0;
} }

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@ -3,6 +3,6 @@
int pthread_rwlock_rdlock(pthread_rwlock_t *rw) int pthread_rwlock_rdlock(pthread_rwlock_t *rw)
{ {
while (pthread_rwlock_tryrdlock(rw)) while (pthread_rwlock_tryrdlock(rw))
__wait(&rw->__wrlock, &rw->__waiters, 1, 0); __wait(&rw->_rw_wrlock, &rw->_rw_waiters, 1, 0);
return 0; return 0;
} }

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@ -4,12 +4,12 @@ int pthread_rwlock_timedrdlock(pthread_rwlock_t *rw, const struct timespec *at)
{ {
int w=0; int w=0;
while (pthread_rwlock_tryrdlock(rw)) { while (pthread_rwlock_tryrdlock(rw)) {
if (!w) a_inc(&rw->__waiters), w++; if (!w) a_inc(&rw->_rw_waiters), w++;
if (__timedwait(&rw->__wrlock, 1, CLOCK_REALTIME, at, 0)==ETIMEDOUT) { if (__timedwait(&rw->_rw_wrlock, 1, CLOCK_REALTIME, at, 0)==ETIMEDOUT) {
if (w) a_dec(&rw->__waiters); if (w) a_dec(&rw->_rw_waiters);
return ETIMEDOUT; return ETIMEDOUT;
} }
} }
if (w) a_dec(&rw->__waiters); if (w) a_dec(&rw->_rw_waiters);
return 0; return 0;
} }

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@ -4,14 +4,14 @@ int pthread_rwlock_timedwrlock(pthread_rwlock_t *rw, const struct timespec *at)
{ {
int nr, *p, w=0; int nr, *p, w=0;
while (pthread_rwlock_trywrlock(rw)==EAGAIN) { while (pthread_rwlock_trywrlock(rw)==EAGAIN) {
if (!w) a_inc(&rw->__waiters), w++; if (!w) a_inc(&rw->_rw_waiters), w++;
if ((nr=rw->__readers)) p = &rw->__readers; if ((nr=rw->_rw_readers)) p = &rw->_rw_readers;
else nr=1, p = &rw->__wrlock; else nr=1, p = &rw->_rw_wrlock;
if (__timedwait(p, nr, CLOCK_REALTIME, at, 0)==ETIMEDOUT) { if (__timedwait(p, nr, CLOCK_REALTIME, at, 0)==ETIMEDOUT) {
if (w) a_dec(&rw->__waiters); if (w) a_dec(&rw->_rw_waiters);
return ETIMEDOUT; return ETIMEDOUT;
} }
} }
if (w) a_dec(&rw->__waiters); if (w) a_dec(&rw->_rw_waiters);
return 0; return 0;
} }

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@ -2,11 +2,11 @@
int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw) int pthread_rwlock_tryrdlock(pthread_rwlock_t *rw)
{ {
a_inc(&rw->__readers); a_inc(&rw->_rw_readers);
if (rw->__wrlock) { if (rw->_rw_wrlock) {
a_dec(&rw->__readers); a_dec(&rw->_rw_readers);
if (rw->__waiters && !rw->__readers) if (rw->_rw_waiters && !rw->_rw_readers)
__wake(&rw->__readers, 1, 0); __wake(&rw->_rw_readers, 1, 0);
return EAGAIN; return EAGAIN;
} }
return 0; return 0;

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@ -2,12 +2,12 @@
int pthread_rwlock_trywrlock(pthread_rwlock_t *rw) int pthread_rwlock_trywrlock(pthread_rwlock_t *rw)
{ {
if (a_xchg(&rw->__wrlock, 1)) if (a_xchg(&rw->_rw_wrlock, 1))
return EAGAIN; return EAGAIN;
if (rw->__readers) { if (rw->_rw_readers) {
a_store(&rw->__wrlock, 0); a_store(&rw->_rw_wrlock, 0);
return EAGAIN; return EAGAIN;
} }
rw->__owner = pthread_self()->tid; rw->_rw_owner = pthread_self()->tid;
return 0; return 0;
} }

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@ -3,15 +3,15 @@
int pthread_rwlock_unlock(pthread_rwlock_t *rw) int pthread_rwlock_unlock(pthread_rwlock_t *rw)
{ {
struct pthread *self = pthread_self(); struct pthread *self = pthread_self();
if (rw->__owner == self->tid) { if (rw->_rw_owner == self->tid) {
rw->__owner = 0; rw->_rw_owner = 0;
a_store(&rw->__wrlock, 0); a_store(&rw->_rw_wrlock, 0);
if (rw->__waiters) if (rw->_rw_waiters)
__wake(&rw->__wrlock, -1, 0); __wake(&rw->_rw_wrlock, -1, 0);
return 0; return 0;
} }
a_dec(&rw->__readers); a_dec(&rw->_rw_readers);
if (rw->__waiters && !rw->__readers) if (rw->_rw_waiters && !rw->_rw_readers)
__wake(&rw->__readers, 1, 0); __wake(&rw->_rw_readers, 1, 0);
return 0; return 0;
} }

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@ -4,10 +4,10 @@ int pthread_rwlock_wrlock(pthread_rwlock_t *rw)
{ {
int nr; int nr;
while (pthread_rwlock_trywrlock(rw)==EAGAIN) { while (pthread_rwlock_trywrlock(rw)==EAGAIN) {
if ((nr=rw->__readers)) if ((nr=rw->_rw_readers))
__wait(&rw->__readers, &rw->__waiters, nr, 0); __wait(&rw->_rw_readers, &rw->_rw_waiters, nr, 0);
else else
__wait(&rw->__wrlock, &rw->__waiters, 1, 0); __wait(&rw->_rw_wrlock, &rw->_rw_waiters, 1, 0);
} }
return 0; return 0;
} }