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Perl Language Reference Manual
by Larry Wall and others
Paperback (6"x9"), 724 pages
ISBN 9781906966027
RRP £29.95 ($39.95)

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cond_broadcast() called on unlocked variable

(W threads) Within a thread-enabled program, you tried to call cond_broadcast() on a variable which wasn't locked. The cond_broadcast() function is used to wake up another thread that is waiting in a cond_wait(). To ensure that the signal isn't sent before the other thread has a chance to enter the wait, it is usual for the signaling thread to first wait for a lock on variable. This lock attempt will only succeed after the other thread has entered cond_wait() and thus relinquished the lock.

ISBN 9781906966027Perl Language Reference ManualSee the print edition