Hide internal of pthread_mutex_t.
Bug: 19249079
Change-Id: Iffb79c8d861b698d474f212dc80c638fc2cf1620
diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index 24066ae..d2ff1ae 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -31,6 +31,7 @@
#include <errno.h>
#include <limits.h>
#include <stdatomic.h>
+#include <string.h>
#include <sys/cdefs.h>
#include <sys/mman.h>
#include <unistd.h>
@@ -80,7 +81,7 @@
#define MUTEX_STATE_FROM_BITS(v) FIELD_FROM_BITS(v, MUTEX_STATE_SHIFT, MUTEX_STATE_LEN)
#define MUTEX_STATE_TO_BITS(v) FIELD_TO_BITS(v, MUTEX_STATE_SHIFT, MUTEX_STATE_LEN)
-#define MUTEX_STATE_UNLOCKED 0 /* must be 0 to match __PTHREAD_MUTEX_INIT_VALUE */
+#define MUTEX_STATE_UNLOCKED 0 /* must be 0 to match PTHREAD_MUTEX_INITIALIZER */
#define MUTEX_STATE_LOCKED_UNCONTENDED 1 /* must be 1 due to atomic dec in unlock operation */
#define MUTEX_STATE_LOCKED_CONTENDED 2 /* must be 1 + LOCKED_UNCONTENDED due to atomic dec */
@@ -122,30 +123,17 @@
#define MUTEX_SHARED_MASK FIELD_MASK(MUTEX_SHARED_SHIFT,1)
/* Mutex type:
- *
* We support normal, recursive and errorcheck mutexes.
- *
- * The constants defined here *cannot* be changed because they must match
- * the C library ABI which defines the following initialization values in
- * <pthread.h>:
- *
- * __PTHREAD_MUTEX_INIT_VALUE
- * __PTHREAD_RECURSIVE_MUTEX_VALUE
- * __PTHREAD_ERRORCHECK_MUTEX_INIT_VALUE
*/
#define MUTEX_TYPE_SHIFT 14
#define MUTEX_TYPE_LEN 2
#define MUTEX_TYPE_MASK FIELD_MASK(MUTEX_TYPE_SHIFT,MUTEX_TYPE_LEN)
-#define MUTEX_TYPE_NORMAL 0 /* Must be 0 to match __PTHREAD_MUTEX_INIT_VALUE */
-#define MUTEX_TYPE_RECURSIVE 1
-#define MUTEX_TYPE_ERRORCHECK 2
-
#define MUTEX_TYPE_TO_BITS(t) FIELD_TO_BITS(t, MUTEX_TYPE_SHIFT, MUTEX_TYPE_LEN)
-#define MUTEX_TYPE_BITS_NORMAL MUTEX_TYPE_TO_BITS(MUTEX_TYPE_NORMAL)
-#define MUTEX_TYPE_BITS_RECURSIVE MUTEX_TYPE_TO_BITS(MUTEX_TYPE_RECURSIVE)
-#define MUTEX_TYPE_BITS_ERRORCHECK MUTEX_TYPE_TO_BITS(MUTEX_TYPE_ERRORCHECK)
+#define MUTEX_TYPE_BITS_NORMAL MUTEX_TYPE_TO_BITS(PTHREAD_MUTEX_NORMAL)
+#define MUTEX_TYPE_BITS_RECURSIVE MUTEX_TYPE_TO_BITS(PTHREAD_MUTEX_RECURSIVE)
+#define MUTEX_TYPE_BITS_ERRORCHECK MUTEX_TYPE_TO_BITS(PTHREAD_MUTEX_ERRORCHECK)
/* Mutex owner field:
*
@@ -237,55 +225,66 @@
return 0;
}
-static inline atomic_int* get_mutex_value_pointer(pthread_mutex_t* mutex) {
- static_assert(sizeof(atomic_int) == sizeof(mutex->value),
- "mutex->value should actually be atomic_int in implementation.");
+struct pthread_mutex_internal_t {
+ atomic_int state;
+#if defined(__LP64__)
+ char __reserved[36];
+#endif
+};
- // We prefer casting to atomic_int instead of declaring mutex->value to be atomic_int directly.
- // Because using the second method pollutes pthread.h, and causes an error when compiling libcxx.
- return reinterpret_cast<atomic_int*>(&mutex->value);
+static_assert(sizeof(pthread_mutex_t) == sizeof(pthread_mutex_internal_t),
+ "pthread_mutex_t should actually be pthread_mutex_internal_t in implementation.");
+
+// For binary compatibility with old version of pthread_mutex_t, we can't use more strict alignment
+// than 4-byte alignment.
+static_assert(alignof(pthread_mutex_t) == 4,
+ "pthread_mutex_t should fulfill the alignment of pthread_mutex_internal_t.");
+
+static inline pthread_mutex_internal_t* __get_internal_mutex(pthread_mutex_t* mutex_interface) {
+ return reinterpret_cast<pthread_mutex_internal_t*>(mutex_interface);
}
-int pthread_mutex_init(pthread_mutex_t* mutex, const pthread_mutexattr_t* attr) {
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
+int pthread_mutex_init(pthread_mutex_t* mutex_interface, const pthread_mutexattr_t* attr) {
+ pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
+
+ memset(mutex, 0, sizeof(pthread_mutex_internal_t));
if (__predict_true(attr == NULL)) {
- atomic_init(mutex_value_ptr, MUTEX_TYPE_BITS_NORMAL);
+ atomic_init(&mutex->state, MUTEX_TYPE_BITS_NORMAL);
return 0;
}
- int value = 0;
+ int state = 0;
if ((*attr & MUTEXATTR_SHARED_MASK) != 0) {
- value |= MUTEX_SHARED_MASK;
+ state |= MUTEX_SHARED_MASK;
}
switch (*attr & MUTEXATTR_TYPE_MASK) {
case PTHREAD_MUTEX_NORMAL:
- value |= MUTEX_TYPE_BITS_NORMAL;
+ state |= MUTEX_TYPE_BITS_NORMAL;
break;
case PTHREAD_MUTEX_RECURSIVE:
- value |= MUTEX_TYPE_BITS_RECURSIVE;
+ state |= MUTEX_TYPE_BITS_RECURSIVE;
break;
case PTHREAD_MUTEX_ERRORCHECK:
- value |= MUTEX_TYPE_BITS_ERRORCHECK;
+ state |= MUTEX_TYPE_BITS_ERRORCHECK;
break;
default:
return EINVAL;
}
- atomic_init(mutex_value_ptr, value);
+ atomic_init(&mutex->state, state);
return 0;
}
-static inline int __pthread_normal_mutex_trylock(atomic_int* mutex_value_ptr, int shared) {
+static inline __always_inline int __pthread_normal_mutex_trylock(pthread_mutex_internal_t* mutex,
+ int shared) {
const int unlocked = shared | MUTEX_STATE_BITS_UNLOCKED;
const int locked_uncontended = shared | MUTEX_STATE_BITS_LOCKED_UNCONTENDED;
- int mvalue = unlocked;
- if (__predict_true(atomic_compare_exchange_strong_explicit(mutex_value_ptr, &mvalue,
- locked_uncontended,
- memory_order_acquire,
- memory_order_relaxed))) {
+ int old_state = unlocked;
+ if (__predict_true(atomic_compare_exchange_strong_explicit(&mutex->state, &old_state,
+ locked_uncontended, memory_order_acquire, memory_order_relaxed))) {
return 0;
}
return EBUSY;
@@ -303,9 +302,11 @@
* "type" value is zero, so the only bits that will be set are the ones in
* the lock state field.
*/
-static inline int __pthread_normal_mutex_lock(atomic_int* mutex_value_ptr, int shared,
- const timespec* abs_timeout_or_null, clockid_t clock) {
- if (__predict_true(__pthread_normal_mutex_trylock(mutex_value_ptr, shared) == 0)) {
+static inline __always_inline int __pthread_normal_mutex_lock(pthread_mutex_internal_t* mutex,
+ int shared,
+ const timespec* abs_timeout_or_null,
+ clockid_t clock) {
+ if (__predict_true(__pthread_normal_mutex_trylock(mutex, shared) == 0)) {
return 0;
}
@@ -316,13 +317,13 @@
// We want to go to sleep until the mutex is available, which requires
// promoting it to locked_contended. We need to swap in the new state
- // value and then wait until somebody wakes us up.
+ // and then wait until somebody wakes us up.
// An atomic_exchange is used to compete with other threads for the lock.
// If it returns unlocked, we have acquired the lock, otherwise another
// thread still holds the lock and we should wait again.
// If lock is acquired, an acquire fence is needed to make all memory accesses
// made by other threads visible to the current CPU.
- while (atomic_exchange_explicit(mutex_value_ptr, locked_contended,
+ while (atomic_exchange_explicit(&mutex->state, locked_contended,
memory_order_acquire) != unlocked) {
timespec ts;
timespec* rel_timeout = NULL;
@@ -332,7 +333,7 @@
return ETIMEDOUT;
}
}
- if (__futex_wait_ex(mutex_value_ptr, shared, locked_contended, rel_timeout) == -ETIMEDOUT) {
+ if (__futex_wait_ex(&mutex->state, shared, locked_contended, rel_timeout) == -ETIMEDOUT) {
return ETIMEDOUT;
}
}
@@ -343,7 +344,8 @@
* Release a mutex of type NORMAL. The caller is responsible for determining
* that we are in fact the owner of this lock.
*/
-static inline void __pthread_normal_mutex_unlock(atomic_int* mutex_value_ptr, int shared) {
+static inline __always_inline void __pthread_normal_mutex_unlock(pthread_mutex_internal_t* mutex,
+ int shared) {
const int unlocked = shared | MUTEX_STATE_BITS_UNLOCKED;
const int locked_contended = shared | MUTEX_STATE_BITS_LOCKED_CONTENDED;
@@ -352,7 +354,7 @@
// one of them.
// A release fence is required to make previous stores visible to next
// lock owner threads.
- if (atomic_exchange_explicit(mutex_value_ptr, unlocked,
+ if (atomic_exchange_explicit(&mutex->state, unlocked,
memory_order_release) == locked_contended) {
// Wake up one waiting thread. We don't know which thread will be
// woken or when it'll start executing -- futexes make no guarantees
@@ -372,7 +374,7 @@
// we call wake, the thread we eventually wake will find an unlocked mutex
// and will execute. Either way we have correct behavior and nobody is
// orphaned on the wait queue.
- __futex_wake_ex(mutex_value_ptr, shared, 1);
+ __futex_wake_ex(&mutex->state, shared, 1);
}
}
@@ -382,11 +384,12 @@
* Otherwise, it atomically increments the counter and returns 0.
*
*/
-static inline int __recursive_increment(atomic_int* mutex_value_ptr, int mvalue) {
+static inline __always_inline int __recursive_increment(pthread_mutex_internal_t* mutex,
+ int old_state) {
// Detect recursive lock overflow and return EAGAIN.
// This is safe because only the owner thread can modify the
// counter bits in the mutex value.
- if (MUTEX_COUNTER_BITS_WILL_OVERFLOW(mvalue)) {
+ if (MUTEX_COUNTER_BITS_WILL_OVERFLOW(old_state)) {
return EAGAIN;
}
@@ -395,32 +398,30 @@
// loop to update the counter. The counter will not overflow in the loop,
// as only the owner thread can change it.
// The mutex is still locked, so we don't need a release fence.
- atomic_fetch_add_explicit(mutex_value_ptr, MUTEX_COUNTER_BITS_ONE, memory_order_relaxed);
+ atomic_fetch_add_explicit(&mutex->state, MUTEX_COUNTER_BITS_ONE, memory_order_relaxed);
return 0;
}
-static int __pthread_mutex_lock_with_timeout(pthread_mutex_t* mutex,
+static int __pthread_mutex_lock_with_timeout(pthread_mutex_internal_t* mutex,
const timespec* abs_timeout_or_null, clockid_t clock) {
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
+ int old_state, mtype, tid, shared;
- int mvalue, mtype, tid, shared;
-
- mvalue = atomic_load_explicit(mutex_value_ptr, memory_order_relaxed);
- mtype = (mvalue & MUTEX_TYPE_MASK);
- shared = (mvalue & MUTEX_SHARED_MASK);
+ old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
+ mtype = (old_state & MUTEX_TYPE_MASK);
+ shared = (old_state & MUTEX_SHARED_MASK);
// Handle common case first.
if ( __predict_true(mtype == MUTEX_TYPE_BITS_NORMAL) ) {
- return __pthread_normal_mutex_lock(mutex_value_ptr, shared, abs_timeout_or_null, clock);
+ return __pthread_normal_mutex_lock(mutex, shared, abs_timeout_or_null, clock);
}
// Do we already own this recursive or error-check mutex?
tid = __get_thread()->tid;
- if (tid == MUTEX_OWNER_FROM_BITS(mvalue)) {
+ if (tid == MUTEX_OWNER_FROM_BITS(old_state)) {
if (mtype == MUTEX_TYPE_BITS_ERRORCHECK) {
return EDEADLK;
}
- return __recursive_increment(mutex_value_ptr, mvalue);
+ return __recursive_increment(mutex, old_state);
}
const int unlocked = mtype | shared | MUTEX_STATE_BITS_UNLOCKED;
@@ -429,12 +430,12 @@
// First, if the mutex is unlocked, try to quickly acquire it.
// In the optimistic case where this works, set the state to locked_uncontended.
- if (mvalue == unlocked) {
- int newval = MUTEX_OWNER_TO_BITS(tid) | locked_uncontended;
+ if (old_state == unlocked) {
+ int new_state = MUTEX_OWNER_TO_BITS(tid) | locked_uncontended;
// If exchanged successfully, an acquire fence is required to make
// all memory accesses made by other threads visible to the current CPU.
- if (__predict_true(atomic_compare_exchange_strong_explicit(mutex_value_ptr, &mvalue,
- newval, memory_order_acquire, memory_order_relaxed))) {
+ if (__predict_true(atomic_compare_exchange_strong_explicit(&mutex->state, &old_state,
+ new_state, memory_order_acquire, memory_order_relaxed))) {
return 0;
}
}
@@ -442,33 +443,33 @@
ScopedTrace trace("Contending for pthread mutex");
while (true) {
- if (mvalue == unlocked) {
+ if (old_state == unlocked) {
// NOTE: We put the state to locked_contended since we _know_ there
// is contention when we are in this loop. This ensures all waiters
// will be unlocked.
- int newval = MUTEX_OWNER_TO_BITS(tid) | locked_contended;
+ int new_state = MUTEX_OWNER_TO_BITS(tid) | locked_contended;
// If exchanged successfully, an acquire fence is required to make
// all memory accesses made by other threads visible to the current CPU.
- if (__predict_true(atomic_compare_exchange_weak_explicit(mutex_value_ptr,
- &mvalue, newval,
+ if (__predict_true(atomic_compare_exchange_weak_explicit(&mutex->state,
+ &old_state, new_state,
memory_order_acquire,
memory_order_relaxed))) {
return 0;
}
continue;
- } else if (MUTEX_STATE_BITS_IS_LOCKED_UNCONTENDED(mvalue)) {
+ } else if (MUTEX_STATE_BITS_IS_LOCKED_UNCONTENDED(old_state)) {
// We should set it to locked_contended beforing going to sleep. This can make
// sure waiters will be woken up eventually.
- int newval = MUTEX_STATE_BITS_FLIP_CONTENTION(mvalue);
- if (__predict_false(!atomic_compare_exchange_weak_explicit(mutex_value_ptr,
- &mvalue, newval,
+ int new_state = MUTEX_STATE_BITS_FLIP_CONTENTION(old_state);
+ if (__predict_false(!atomic_compare_exchange_weak_explicit(&mutex->state,
+ &old_state, new_state,
memory_order_relaxed,
memory_order_relaxed))) {
continue;
}
- mvalue = newval;
+ old_state = new_state;
}
// We are in locked_contended state, sleep until someone wakes us up.
@@ -480,54 +481,54 @@
return ETIMEDOUT;
}
}
- if (__futex_wait_ex(mutex_value_ptr, shared, mvalue, rel_timeout) == -ETIMEDOUT) {
+ if (__futex_wait_ex(&mutex->state, shared, old_state, rel_timeout) == -ETIMEDOUT) {
return ETIMEDOUT;
}
- mvalue = atomic_load_explicit(mutex_value_ptr, memory_order_relaxed);
+ old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
}
}
-int pthread_mutex_lock(pthread_mutex_t* mutex) {
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
+int pthread_mutex_lock(pthread_mutex_t* mutex_interface) {
+ pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
- int mvalue = atomic_load_explicit(mutex_value_ptr, memory_order_relaxed);
- int mtype = (mvalue & MUTEX_TYPE_MASK);
- int shared = (mvalue & MUTEX_SHARED_MASK);
+ int old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
+ int mtype = (old_state & MUTEX_TYPE_MASK);
+ int shared = (old_state & MUTEX_SHARED_MASK);
// Avoid slowing down fast path of normal mutex lock operation.
if (__predict_true(mtype == MUTEX_TYPE_BITS_NORMAL)) {
- if (__predict_true(__pthread_normal_mutex_trylock(mutex_value_ptr, shared) == 0)) {
+ if (__predict_true(__pthread_normal_mutex_trylock(mutex, shared) == 0)) {
return 0;
}
}
return __pthread_mutex_lock_with_timeout(mutex, NULL, 0);
}
-int pthread_mutex_unlock(pthread_mutex_t* mutex) {
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
+int pthread_mutex_unlock(pthread_mutex_t* mutex_interface) {
+ pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
- int mvalue, mtype, tid, shared;
+ int old_state, mtype, tid, shared;
- mvalue = atomic_load_explicit(mutex_value_ptr, memory_order_relaxed);
- mtype = (mvalue & MUTEX_TYPE_MASK);
- shared = (mvalue & MUTEX_SHARED_MASK);
+ old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
+ mtype = (old_state & MUTEX_TYPE_MASK);
+ shared = (old_state & MUTEX_SHARED_MASK);
// Handle common case first.
if (__predict_true(mtype == MUTEX_TYPE_BITS_NORMAL)) {
- __pthread_normal_mutex_unlock(mutex_value_ptr, shared);
+ __pthread_normal_mutex_unlock(mutex, shared);
return 0;
}
// Do we already own this recursive or error-check mutex?
tid = __get_thread()->tid;
- if ( tid != MUTEX_OWNER_FROM_BITS(mvalue) )
+ if ( tid != MUTEX_OWNER_FROM_BITS(old_state) )
return EPERM;
// If the counter is > 0, we can simply decrement it atomically.
// Since other threads can mutate the lower state bits (and only the
// lower state bits), use a compare_exchange loop to do it.
- if (!MUTEX_COUNTER_BITS_IS_ZERO(mvalue)) {
+ if (!MUTEX_COUNTER_BITS_IS_ZERO(old_state)) {
// We still own the mutex, so a release fence is not needed.
- atomic_fetch_sub_explicit(mutex_value_ptr, MUTEX_COUNTER_BITS_ONE, memory_order_relaxed);
+ atomic_fetch_sub_explicit(&mutex->state, MUTEX_COUNTER_BITS_ONE, memory_order_relaxed);
return 0;
}
@@ -538,36 +539,36 @@
// A release fence is required to make previous stores visible to next
// lock owner threads.
const int unlocked = mtype | shared | MUTEX_STATE_BITS_UNLOCKED;
- mvalue = atomic_exchange_explicit(mutex_value_ptr, unlocked, memory_order_release);
- if (MUTEX_STATE_BITS_IS_LOCKED_CONTENDED(mvalue)) {
- __futex_wake_ex(mutex_value_ptr, shared, 1);
+ old_state = atomic_exchange_explicit(&mutex->state, unlocked, memory_order_release);
+ if (MUTEX_STATE_BITS_IS_LOCKED_CONTENDED(old_state)) {
+ __futex_wake_ex(&mutex->state, shared, 1);
}
return 0;
}
-int pthread_mutex_trylock(pthread_mutex_t* mutex) {
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
+int pthread_mutex_trylock(pthread_mutex_t* mutex_interface) {
+ pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
- int mvalue = atomic_load_explicit(mutex_value_ptr, memory_order_relaxed);
- int mtype = (mvalue & MUTEX_TYPE_MASK);
- int shared = (mvalue & MUTEX_SHARED_MASK);
+ int old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
+ int mtype = (old_state & MUTEX_TYPE_MASK);
+ int shared = (old_state & MUTEX_SHARED_MASK);
const int unlocked = mtype | shared | MUTEX_STATE_BITS_UNLOCKED;
const int locked_uncontended = mtype | shared | MUTEX_STATE_BITS_LOCKED_UNCONTENDED;
// Handle common case first.
if (__predict_true(mtype == MUTEX_TYPE_BITS_NORMAL)) {
- return __pthread_normal_mutex_trylock(mutex_value_ptr, shared);
+ return __pthread_normal_mutex_trylock(mutex, shared);
}
// Do we already own this recursive or error-check mutex?
pid_t tid = __get_thread()->tid;
- if (tid == MUTEX_OWNER_FROM_BITS(mvalue)) {
+ if (tid == MUTEX_OWNER_FROM_BITS(old_state)) {
if (mtype == MUTEX_TYPE_BITS_ERRORCHECK) {
return EBUSY;
}
- return __recursive_increment(mutex_value_ptr, mvalue);
+ return __recursive_increment(mutex, old_state);
}
// Same as pthread_mutex_lock, except that we don't want to wait, and
@@ -575,9 +576,9 @@
// lock if it is released / not owned by anyone. No need for a complex loop.
// If exchanged successfully, an acquire fence is required to make
// all memory accesses made by other threads visible to the current CPU.
- mvalue = unlocked;
- int newval = MUTEX_OWNER_TO_BITS(tid) | locked_uncontended;
- if (__predict_true(atomic_compare_exchange_strong_explicit(mutex_value_ptr, &mvalue, newval,
+ old_state = unlocked;
+ int new_state = MUTEX_OWNER_TO_BITS(tid) | locked_uncontended;
+ if (__predict_true(atomic_compare_exchange_strong_explicit(&mutex->state, &old_state, new_state,
memory_order_acquire,
memory_order_relaxed))) {
return 0;
@@ -586,7 +587,7 @@
}
#if !defined(__LP64__)
-extern "C" int pthread_mutex_lock_timeout_np(pthread_mutex_t* mutex, unsigned ms) {
+extern "C" int pthread_mutex_lock_timeout_np(pthread_mutex_t* mutex_interface, unsigned ms) {
timespec abs_timeout;
clock_gettime(CLOCK_MONOTONIC, &abs_timeout);
abs_timeout.tv_sec += ms / 1000;
@@ -596,7 +597,8 @@
abs_timeout.tv_nsec -= NS_PER_S;
}
- int error = __pthread_mutex_lock_with_timeout(mutex, &abs_timeout, CLOCK_MONOTONIC);
+ int error = __pthread_mutex_lock_with_timeout(__get_internal_mutex(mutex_interface),
+ &abs_timeout, CLOCK_MONOTONIC);
if (error == ETIMEDOUT) {
error = EBUSY;
}
@@ -604,18 +606,19 @@
}
#endif
-int pthread_mutex_timedlock(pthread_mutex_t* mutex, const timespec* abs_timeout) {
- return __pthread_mutex_lock_with_timeout(mutex, abs_timeout, CLOCK_REALTIME);
+int pthread_mutex_timedlock(pthread_mutex_t* mutex_interface, const timespec* abs_timeout) {
+ return __pthread_mutex_lock_with_timeout(__get_internal_mutex(mutex_interface),
+ abs_timeout, CLOCK_REALTIME);
}
-int pthread_mutex_destroy(pthread_mutex_t* mutex) {
+int pthread_mutex_destroy(pthread_mutex_t* mutex_interface) {
// Use trylock to ensure that the mutex is valid and not already locked.
- int error = pthread_mutex_trylock(mutex);
+ int error = pthread_mutex_trylock(mutex_interface);
if (error != 0) {
return error;
}
- atomic_int* mutex_value_ptr = get_mutex_value_pointer(mutex);
- atomic_store_explicit(mutex_value_ptr, 0xdead10cc, memory_order_relaxed);
+ pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
+ atomic_store_explicit(&mutex->state, 0xdead10cc, memory_order_relaxed);
return 0;
}
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 234a43d..0ad14dd 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -36,30 +36,15 @@
#include <sys/types.h>
#include <time.h>
-#if defined(__LP64__)
- #define __RESERVED_INITIALIZER , {0}
-#else
- #define __RESERVED_INITIALIZER
-#endif
-
typedef struct {
- int value;
-#ifdef __LP64__
- char __reserved[36];
+#if defined(__LP64__)
+ int32_t __private[10];
+#else
+ int32_t __private[1];
#endif
} pthread_mutex_t;
-#define __PTHREAD_MUTEX_INIT_VALUE 0
-#define __PTHREAD_RECURSIVE_MUTEX_INIT_VALUE 0x4000
-#define __PTHREAD_ERRORCHECK_MUTEX_INIT_VALUE 0x8000
-
-#define PTHREAD_MUTEX_INITIALIZER {__PTHREAD_MUTEX_INIT_VALUE __RESERVED_INITIALIZER}
-#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP {__PTHREAD_ERRORCHECK_MUTEX_INIT_VALUE __RESERVED_INITIALIZER}
-#define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP {__PTHREAD_RECURSIVE_MUTEX_INIT_VALUE __RESERVED_INITIALIZER}
-
-/* TODO: remove this namespace pollution. */
-#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
-#define PTHREAD_RECURSIVE_MUTEX_INITIALIZER PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
+typedef long pthread_mutexattr_t;
enum {
PTHREAD_MUTEX_NORMAL = 0,
@@ -72,28 +57,35 @@
PTHREAD_MUTEX_DEFAULT = PTHREAD_MUTEX_NORMAL
};
+#define PTHREAD_MUTEX_INITIALIZER { { ((PTHREAD_MUTEX_NORMAL & 3) << 14) } }
+#define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP { { ((PTHREAD_MUTEX_RECURSIVE & 3) << 14) } }
+#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP { { ((PTHREAD_MUTEX_ERRORCHECK & 3) << 14) } }
+
+/* TODO: remove this namespace pollution. */
+#define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
+#define PTHREAD_RECURSIVE_MUTEX_INITIALIZER PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
+
typedef struct {
#if defined(__LP64__)
- char __private[48];
+ int32_t __private[12];
#else
- char __private[4];
+ int32_t __private[1];
#endif
-} pthread_cond_t __attribute__((aligned(4)));
+} pthread_cond_t;
+
+typedef long pthread_condattr_t;
#define PTHREAD_COND_INITIALIZER { { 0 } }
-typedef long pthread_mutexattr_t;
-typedef long pthread_condattr_t;
-
-typedef long pthread_rwlockattr_t;
-
typedef struct {
#if defined(__LP64__)
- char __private[56];
+ int32_t __private[14];
#else
- char __private[40];
+ int32_t __private[10];
#endif
-} pthread_rwlock_t __attribute__((aligned(4)));
+} pthread_rwlock_t;
+
+typedef long pthread_rwlockattr_t;
#define PTHREAD_RWLOCK_INITIALIZER { { 0 } }
diff --git a/libc/stdio/fileext.h b/libc/stdio/fileext.h
index 209815a..6cacc0f 100644
--- a/libc/stdio/fileext.h
+++ b/libc/stdio/fileext.h
@@ -61,7 +61,11 @@
_UB(fp)._base = NULL; \
_UB(fp)._size = 0; \
WCIO_INIT(fp); \
- _FLOCK(fp).value = __PTHREAD_RECURSIVE_MUTEX_INIT_VALUE; \
+ pthread_mutexattr_t attr; \
+ pthread_mutexattr_init(&attr); \
+ pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); \
+ pthread_mutex_init(&_FLOCK(fp), &attr); \
+ pthread_mutexattr_destroy(&attr); \
_EXT(fp)->_stdio_handles_locking = true; \
} while (0)