On May 30, 10:33am, charles.cui1...@gmail.com (Charles Cui) wrote:
-- Subject: Re: pthread library related
Inline comments.
christos
diff --git a/lib/libpthread/pthread.h b/lib/libpthread/pthread.h
index 5970378..ed16d7c 100644
--- a/lib/libpthread/pthread.h
+++ b/lib/libpthread/pthread.h
@@ -94,6 +94,9 @@ int pthread_mutex_destroy(pthread_mutex_t *);
int pthread_mutex_lock(pthread_mutex_t *);
int pthread_mutex_trylock(pthread_mutex_t *);
int pthread_mutex_unlock(pthread_mutex_t *);
+int pthread_mutex_timedlock(pthread_mutex_t *, const struct
timespec*__restrict);
+int pthread_mutex_getprioceiling(const pthread_mutex_t *__restrict,
int*__restrict);
+int pthread_mutex_setprioceiling(pthread_mutex_t* __restrict, int,
int*__restrict);
Wrap lines, whitespace "const struct timespec *__restrict" etc. (space after
the type name)
+int pthread_mutexattr_getprotocol(const pthread_mutexattr_t * __restrict,
int*__restrict);
+int pthread_mutexattr_setprotocol(pthread_mutexattr_t* , int);
+int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t
*__restrict,int*__restrict);
+int pthread_mutexattr_setprioceiling(pthread_mutexattr_t*, int);
Again
int pthread_cond_init(pthread_cond_t * __restrict,
const pthread_condattr_t * __restrict);
int pthread_cond_destroy(pthread_cond_t *);
@@ -116,7 +122,7 @@ int pthread_cond_broadcast(pthread_cond_t *);
int pthread_condattr_init(pthread_condattr_t *);
#if defined(_NETBSD_SOURCE)
int pthread_condattr_setclock(pthread_condattr_t *, clockid_t);
-int pthread_condattr_getclock(pthread_condattr_t *);
+int pthread_condattr_getclock(const pthread_condattr_t *__restrict attr,
clockid_t *__restrict clock_id);
Again (wrap)
int
-pthread_condattr_getclock(pthread_condattr_t *attr)
+pthread_condattr_getclock(const pthread_condattr_t *__restrict attr, clockid_t
*__restrict clock_id)
Wrap
{
if (attr == NULL || attr->ptca_private == NULL)
return EINVAL;
- return *(int *)attr->ptca_private;
+ *clock_id = *(clockid_t*)attr->ptca_private;
Whitespace before *
+ return 0;
}
int
diff --git a/lib/libpthread/pthread_mutex.c b/lib/libpthread/pthread_mutex.c
index e755ade..ec46070 100644
--- a/lib/libpthread/pthread_mutex.c
+++ b/lib/libpthread/pthread_mutex.c
@@ -51,6 +51,7 @@ __RCSID("$NetBSD: pthread_mutex.c,v 1.59 2014/02/03 15:51:01
rmind Exp $");
#include <sys/types.h>
#include <sys/lwpctl.h>
+#include <sys/sched.h>
#include <sys/lock.h>
#include <errno.h>
@@ -67,10 +68,12 @@ __RCSID("$NetBSD: pthread_mutex.c,v 1.59 2014/02/03
15:51:01 rmind Exp $");
#define MUTEX_WAITERS_BIT ((uintptr_t)0x01)
#define MUTEX_RECURSIVE_BIT ((uintptr_t)0x02)
#define MUTEX_DEFERRED_BIT ((uintptr_t)0x04)
+#define MUTEX_PROTECT_BIT ((uintptr_t)0x08)
#define MUTEX_THREAD ((uintptr_t)-16L)
#define MUTEX_HAS_WAITERS(x) ((uintptr_t)(x) &
MUTEX_WAITERS_BIT)
#define MUTEX_RECURSIVE(x) ((uintptr_t)(x) &
MUTEX_RECURSIVE_BIT)
+#define MUTEX_PROTECT(x) ((uintptr_t)(x) &
MUTEX_PROTECT_BIT)
#define MUTEX_OWNER(x) ((uintptr_t)(x) & MUTEX_THREAD)
#if __GNUC_PREREQ__(3, 0)
@@ -80,7 +83,7 @@ __RCSID("$NetBSD: pthread_mutex.c,v 1.59 2014/02/03 15:51:01
rmind Exp $");
#endif
static void pthread__mutex_wakeup(pthread_t, pthread_mutex_t *);
-static int pthread__mutex_lock_slow(pthread_mutex_t *);
+static int pthread__mutex_lock_slow(pthread_mutex_t *, const struct
timespec*);
wrap and space
static int pthread__mutex_unlock_slow(pthread_mutex_t *);
static void pthread__mutex_pause(void);
@@ -103,16 +106,21 @@
__strong_alias(__libc_mutexattr_settype,pthread_mutexattr_settype)
int
pthread_mutex_init(pthread_mutex_t *ptm, const pthread_mutexattr_t *attr)
{
- intptr_t type;
+ uintptr_t type, proto, val, ceil;
if (__predict_false(__uselibcstub))
return __libc_mutex_init_stub(ptm, attr);
- if (attr == NULL)
+ if (attr == NULL) {
type = PTHREAD_MUTEX_NORMAL;
- else
- type = (intptr_t)attr->ptma_private;
-
+ proto = PTHREAD_PRIO_NONE;
+ ceil = 0;
+ } else {
+ val = (uintptr_t)attr->ptma_private;
+ type = val & 0xff;
+ proto = (val & 0xff00) >> 8;
+ ceil = (val & 0xff0000) >> 16;
+ }
switch (type) {
case PTHREAD_MUTEX_ERRORCHECK:
__cpu_simple_lock_set(&ptm->ptm_errorcheck);
@@ -127,10 +135,17 @@ pthread_mutex_init(pthread_mutex_t *ptm, const
pthread_mutexattr_t *attr)
ptm->ptm_owner = NULL;
break;
}
-
+ switch (proto) {
+ case PTHREAD_PRIO_PROTECT:
+ val = (uintptr_t)ptm->ptm_owner;
+ val |= MUTEX_PROTECT_BIT;
+ ptm->ptm_owner = (void*)val;
space
+ break;
+ }
ptm->ptm_magic = _PT_MUTEX_MAGIC;
ptm->ptm_waiters = NULL;
ptm->ptm_recursed = 0;
+ ptm->ptm_ceiling = (unsigned char)ceil;
return 0;
}
@@ -168,7 +183,24 @@ pthread_mutex_lock(pthread_mutex_t *ptm)
#endif
return 0;
}
- return pthread__mutex_lock_slow(ptm);
+ return pthread__mutex_lock_slow(ptm, NULL);
+}
+
+int
+pthread_mutex_timedlock(pthread_mutex_t* ptm, const struct timespec *ts)
+{
+ pthread_t self;
+ void *val;
+
+ self = pthread__self();
+ val = atomic_cas_ptr(&ptm->ptm_owner, NULL, self);
+ if (__predict_true(val == NULL)) {
+#ifndef PTHREAD__ATOMIC_IS_MEMBAR
+ membar_enter();
+#endif
+ return 0;
+ }
+ return pthread__mutex_lock_slow(ptm, ts);
}
/* We want function call overhead. */
@@ -258,11 +290,12 @@ again:
}
NOINLINE static int
-pthread__mutex_lock_slow(pthread_mutex_t *ptm)
+pthread__mutex_lock_slow(pthread_mutex_t *ptm, const struct timespec *ts)
{
void *waiters, *new, *owner, *next;
pthread_t self;
int serrno;
+ int error;
pthread__error(EINVAL, "Invalid mutex",
ptm->ptm_magic == _PT_MUTEX_MAGIC);
@@ -282,6 +315,10 @@ pthread__mutex_lock_slow(pthread_mutex_t *ptm)
return EDEADLK;
}
+ /*priority protect*/
+ if (MUTEX_PROTECT(owner) && _sched_protect(ptm->ptm_ceiling) == -1) {
+ return errno;
+ }
serrno = errno;
for (;; owner = ptm->ptm_owner) {
/* Spin while the owner is running. */
@@ -339,12 +376,23 @@ pthread__mutex_lock_slow(pthread_mutex_t *ptm)
*/
while (self->pt_mutexwait) {
self->pt_blocking++;
- (void)_lwp_park(CLOCK_REALTIME, TIMER_ABSTIME, NULL,
+ error = _lwp_park(CLOCK_REALTIME, TIMER_ABSTIME, ts,
self->pt_unpark, __UNVOLATILE(&ptm->ptm_waiters),
__UNVOLATILE(&ptm->ptm_waiters));
self->pt_unpark = 0;
self->pt_blocking--;
membar_sync();
+ if (__predict_true(error != -1)) {
+ continue;
+ }
+ if (errno == ETIMEDOUT && self->pt_mutexwait) {
+ /*Remove self from waiters list*/
+ pthread__mutex_wakeup(self, ptm);
+ /*priority protect*/
+ if (MUTEX_PROTECT(owner))
+ (void)_sched_protect(-1);
+ return ETIMEDOUT;
+ }
}
}
}
@@ -460,6 +508,10 @@ pthread__mutex_unlock_slow(pthread_mutex_t *ptm)
*/
if (new != owner) {
owner = atomic_swap_ptr(&ptm->ptm_owner, new);
+ if (__predict_false(MUTEX_PROTECT(owner))) {
+ /*restore elevated priority*/
+ (void)_sched_protect(-1);
+ }
if (MUTEX_HAS_WAITERS(owner) != 0) {
pthread__mutex_wakeup(self, ptm);
return 0;
@@ -591,16 +643,21 @@ pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
int
pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *typep)
{
+ uintptr_t val;
+
pthread__error(EINVAL, "Invalid mutex attribute",
attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
- *typep = (int)(intptr_t)attr->ptma_private;
+ val = (uintptr_t)attr->ptma_private & ~0x00ffL;
+ *typep = (int)val;
I'd use a constant for 0x00ff, instead of repeating it everywhere.
In fact I'd define and use accessor macros for fields setting and getting
return 0;
}
int
pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
{
+ uintptr_t val;
+
if (__predict_false(__uselibcstub))
return __libc_mutexattr_settype_stub(attr, type);
@@ -611,7 +668,8 @@ pthread_mutexattr_settype(pthread_mutexattr_t *attr, int
type)
case PTHREAD_MUTEX_NORMAL:
case PTHREAD_MUTEX_ERRORCHECK:
case PTHREAD_MUTEX_RECURSIVE:
- attr->ptma_private = (void *)(intptr_t)type;
+ val = (uintptr_t)attr->ptma_private & ~0x00ffL;
+ attr->ptma_private = (void*)(val | type);
return 0;
default:
return EINVAL;
@@ -619,6 +677,67 @@ pthread_mutexattr_settype(pthread_mutexattr_t *attr, int
type)
}
int
+pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr, int*proto)
+{
+ uintptr_t val;
+
+ pthread__error(EINVAL, "Invalid mutex attribute",
+ attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
+
+ val = (uintptr_t)attr->ptma_private & ~0xff00L;
+ *proto = (int)(val >> 8);
+ return 0;
+}
+
+int
+pthread_mutexattr_setprotocol(pthread_mutexattr_t* attr, int proto)
+{
+ uintptr_t val;
+
+ pthread__error(EINVAL, "Invalid mutex attribute",
+ attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
+
+ switch (proto) {
+ case PTHREAD_PRIO_NONE:
+ case PTHREAD_PRIO_PROTECT:
+ val = (uintptr_t)attr->ptma_private & ~0xff00L;
+ attr->ptma_private = (void *)(val | (proto << 8));
+ return 0;
+ case PTHREAD_PRIO_INHERIT:
+ return ENOTSUP;
+ default:
+ return EINVAL;
+ }
+}
+
+int
+pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *attr, int *ceil)
+{
+ uintptr_t val;
+
+ pthread__error(EINVAL, "Invalid mutex attribute",
+ attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
+
+ val = (uintptr_t)attr->ptma_private & ~0xff0000L;
+ *ceil = (int)(val >> 16);
+ return 0;
+}
+
+int
+pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int ceil)
+{
+ uintptr_t val;
+
+ pthread__error(EINVAL, "Invalid mutex attribute",
+ attr->ptma_magic == _PT_MUTEXATTR_MAGIC);
Indent, second level indent is 4 spaces
+
+ /*check range*/
+ val = (uintptr_t)attr->ptma_private & ~0xff0000L;
+ attr->ptma_private = (void*)(val | (ceil << 16));
+ return 0;
+}
+
+int
pthread_mutexattr_getpshared(const pthread_mutexattr_t *__restrict attr, int*
__restrict pshared) {
*pshared = PTHREAD_PROCESS_PRIVATE;
return 0;
@@ -662,6 +781,28 @@ pthread__mutex_deferwake(pthread_t self, pthread_mutex_t
*ptm)
}
int
+pthread_mutex_getprioceiling(const pthread_mutex_t *ptm, int*ceil)
+{
+ *ceil = (unsigned int)ptm->ptm_ceiling;
+ return 0;
+}
+
+int
+pthread_mutex_setprioceiling(pthread_mutex_t *ptm, int ceil, int *old_ceil)
+{
+ int error;
+
+ error = pthread_mutex_lock(ptm);
+ if (error == 0) {
+ *old_ceil = (unsigned int)ptm->ptm_ceiling;
+ /*check range*/
+ ptm->ptm_ceiling = (unsigned char)ceil;
+ pthread_mutex_unlock(ptm);
+ }
+ return error;
+}
+
+int
_pthread_mutex_held_np(pthread_mutex_t *ptm)
{
diff --git a/lib/libpthread/pthread_types.h b/lib/libpthread/pthread_types.h
index a25be8e..7981348 100644
--- a/lib/libpthread/pthread_types.h
+++ b/lib/libpthread/pthread_types.h
@@ -115,7 +115,7 @@ struct __pthread_mutex_st {
#ifdef __CPU_SIMPLE_LOCK_PAD
uint8_t ptm_pad1[3];
#endif
- __pthread_spin_t ptm_interlock; /* unused - backwards compat */
+ __pthread_spin_t ptm_ceiling;
#ifdef __CPU_SIMPLE_LOCK_PAD
uint8_t ptm_pad2[3];
#endif
@@ -130,14 +130,14 @@ struct __pthread_mutex_st {
#ifdef __CPU_SIMPLE_LOCK_PAD
#define _PTHREAD_MUTEX_INITIALIZER { _PT_MUTEX_MAGIC, \
- __SIMPLELOCK_UNLOCKED, { 0, 0, 0 }, \
+ __SIMPLELOCK_UNLOCKED, { 0, 0, 0 },
\
__SIMPLELOCK_UNLOCKED, { 0, 0, 0 }, \
NULL, NULL, 0, NULL \
}
#else
#define _PTHREAD_MUTEX_INITIALIZER { _PT_MUTEX_MAGIC, \
- __SIMPLELOCK_UNLOCKED, \
- __SIMPLELOCK_UNLOCKED, \
+ __SIMPLELOCK_UNLOCKED, \
+ __SIMPLELOCK_UNLOCKED, \
NULL, NULL, 0, NULL \
}
These were not changed, why are there whitespace diffs?
christos
