Abstract: In response to the detection of an external event by the first thread, the first thread sends a quiesce event to each additional thread of the application and suspends execution. The quiesce event may be either a suspension event requesting suspension of the additional threads or a termination event requesting termination of the additional threads. Each additional thread, upon receiving the quiesce event, checks its environment to determine whether it is holding any critical system resource. If the additional thread determines that is not holding any critical system resource and that it is therefore safe to quiesce, the additional thread quiesces. Before quiescing, the last additional thread to quiesce resumes the first thread, which is now free to perform critical operations without interference from the additional threads. If the quiesce type is suspension, the first thread resumes the additional threads upon completing its critical operations, whereupon the application resumes its normal operation.

Abstract: In a client/server system, a method and apparatus for handing requests for access to a host resource purportedly on behalf of a client from an untrusted application server that may be capable of operating as a “rogue” server. Upon receiving a service request from a client, an untrusted application server creates a new thread within its address space for the client and obtains from the security server a client security context, which is anchored to the task control block (TCB) for that thread. The client security context specifies the client and indicates whether the client is an authenticated client or an unauthenticated client. When the application server makes a request for access to a host resource purportedly on behalf of the client, the security server examines the security context created for the requesting thread.

Abstract: Segments of storage of a computer system are shared among any number of users at varying virtual addresses. The virtual addresses can be in the same address space or different address spaces. The sharing of a segment of storage is provided by storing the real address of a page table corresponding to the segment of storage to be shared at different virtual addresses. This allows users of the same or different address spaces to share the same segment of storage by referencing the same page table.

Abstract: A method and apparatus for enabling a listening daemon in a client/server system to execute a specified task on behalf of a user. Upon receiving a user request, the listening daemon sets an environment variable in accordance with the user identity specified in the request and issues a system call to the operating system kernel to spawn the user task specified in the request. In response to the system call, the operating system kernel creates a new address space for the specified user task and creates a security environment for the user task in accordance with the environment variable before starting the user task in the new address space.