MFp4:

- Add flags CVWAIT_ABSTIME and CVWAIT_CLOCKID for umtx kernel based
  condition variable, this should eliminate an extra system call to get
  current time.

- Add sub-function UMTX_OP_NWAKE_PRIVATE to wake up N channels in single
  system call. Create userland sleep queue for condition variable, in most
  cases, thread will wait in the queue, the pthread_cond_signal will defer
  thread wakeup until the mutex is unlocked, it tries to avoid an extra
  system call and a extra context switch in time window of pthread_cond_signal
  and pthread_mutex_unlock.

The changes are part of process-shared mutex project.

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/libthr/thread/thr_umtx.h b/lib/libthr/thread/thr_umtx.h
index 3f53faf..0a8034b 100644
--- a/lib/libthr/thread/thr_umtx.h
+++ b/lib/libthr/thread/thr_umtx.h
@@ -36,6 +36,7 @@
 #define DEFAULT_URWLOCK {0,0,0,0,{0,0,0,0}}
 
 int __thr_umutex_lock(struct umutex *mtx, uint32_t id) __hidden;
+int __thr_umutex_lock_spin(struct umutex *mtx, uint32_t id) __hidden;
 int __thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
 	const struct timespec *timeout) __hidden;
 int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) __hidden;
@@ -50,6 +51,8 @@ int _thr_umtx_wait(volatile long *mtx, long exp,
 	const struct timespec *timeout) __hidden;
 int _thr_umtx_wait_uint(volatile u_int *mtx, u_int exp,
 	const struct timespec *timeout, int shared) __hidden;
+int _thr_umtx_timedwait_uint(volatile u_int *mtx, u_int exp, int clockid,
+	const struct timespec *timeout, int shared) __hidden;
 int _thr_umtx_wake(volatile void *mtx, int count, int shared) __hidden;
 int _thr_ucond_wait(struct ucond *cv, struct umutex *m,
         const struct timespec *timeout, int check_unpaking) __hidden;
@@ -97,6 +100,14 @@ _thr_umutex_lock(struct umutex *mtx, uint32_t id)
 }
 
 static inline int
+_thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
+{
+    if (_thr_umutex_trylock2(mtx, id) == 0)
+	return (0);
+    return (__thr_umutex_lock_spin(mtx, id));
+}
+
+static inline int
 _thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
 	const struct timespec *timeout)
 {