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Diffstat (limited to 'usr/src/man/man3c/cnd.3c')
| -rw-r--r-- | usr/src/man/man3c/cnd.3c | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/usr/src/man/man3c/cnd.3c b/usr/src/man/man3c/cnd.3c index 7e2ce29d66..e2bd8041cc 100644 --- a/usr/src/man/man3c/cnd.3c +++ b/usr/src/man/man3c/cnd.3c @@ -15,7 +15,7 @@ .Dt CND 3C .Os .Sh NAME -.Nm cnd +.Nm cnd , .Nm cnd_broadcast , .Nm cnd_destroy , .Nm cnd_init , @@ -57,9 +57,10 @@ The .Sy cnd family of functions implement condition variables which allow threads within a process to wait until a condition occurs and be signaled when -it does. These functions behave similar to both the POSIX threads and -illumos threads; however, they have slightly different call signatures -and return values. For more information, see +it does. +These functions behave similar to both the POSIX threads and illumos threads; +however, they have slightly different call signatures and return values. +For more information, see .Xr threads 5 . Importantly, they do not allow for inter-process synchronization. .Ss Creating and Destroy Condition Variables @@ -67,8 +68,9 @@ The function .Fn cnd_init initializes the condition variable referred to by .Fa cnd . -The condition variable is suitable for intra-process use. Initializing -an already initialized condition variable results in undefined behavior. +The condition variable is suitable for intra-process use. +Initializing an already initialized condition variable results in undefined +behavior. .Pp The function .Fn cnd_destroy @@ -77,9 +79,9 @@ to use it, though it may be initialized again. .Ss Condition Waiting The function .Fn cond_wait -can be used to wait on a condition variable. A thread that waits on a -condition variable blocks until another thread signals that the -condition has changed, generally after making the condition that was +can be used to wait on a condition variable. +A thread that waits on a condition variable blocks until another thread signals +that the condition has changed, generally after making the condition that was false, true. .Pp The function @@ -90,10 +92,11 @@ and blocks on the condition variable .Fa cond . When the thread returns, it will once again be holding .Fa mtx -and must check the current state of the condition. There is no -guarantee that another thread has not gotten in and changed the value -before being woken. In addition, a thread blocking on a condition -variable, may be woken spuriously, such as when a signal is received or +and must check the current state of the condition. +There is no guarantee that another thread has not gotten in and changed the +value before being woken. +In addition, a thread blocking on a condition variable, may be woken spuriously, +such as when a signal is received or .Fn fork is called . .Pp @@ -104,8 +107,8 @@ allows a thread to block in a similar fashion to except that when the absolute time specified in seconds since the epoch (based on .Sy CLOCK_REALTIME ) -in UTC, expires, then the thread will be woken up. The timeout is -specified in +in UTC, expires, then the thread will be woken up. +The timeout is specified in .Fa abstime . .Ss Conditional Signaling The @@ -114,7 +117,8 @@ and .Fn cnd_broadcast functions can be used to signal threads waiting on the condition variable .Fa cnd -that they should be woken up and check the variable again. The +that they should be woken up and check the variable again. +The .Fn cnd_signal function will only wake a single thread that is blocked on the condition variable |