Event-based synchronization

A system comprising:

• a Unix operating system;
• a plurality of execution entities, the plurality of execution entities including a first execution entity;
• an event control module adapted to create event objects representing respective events each having a state, the first execution entity to wait on plural events;
• a data structure associated with the first execution entity, the data structure containing information of the plural events that the first execution entity is waiting on, the data structure further containing an indicator settable to one of plural values to specify respective plural logical relationships between the plural events;
• and
• a controller adapted to awaken the first execution entity by signaling the first execution entity in response to one or more event state changes of the states of the plural events according to the logical relationship specified by the indicator,
• wherein each event object contains an indication of the state of the event, wherein the indication has a first state to indicate that the corresponding event has been signaled and a second state to indicate that the corresponding event has not been signaled,
• wherein each event object has a type indication to indicate whether the event object state indication is to be automatically reset to the second state from the first state once the event has been signaled or to be manually reset to the second state from the first state by an explicit action,
• wherein if a particular one of the event objects is to be automatically reset, then only one of plural execution entities waiting on the particular event object will be awakened in response to the corresponding event being signaled, and
• wherein if the particular event object is to be manually reset, then all execution entities waiting on the particular event object will be awakened in response to the corresponding event being signaled.