SE_ptable_set_concurrency

Establishes point table concurrency control for threaded client applications

Usage syntax

LONG SE_ptable_set_concurrency (SE_PTABLE ptable, LONG policy);

Parameters

Description

SE_ptable_set_concurrency sets the concurrency policy for a particular point table. The concurrency policy affects how calls to the API for this point table behave in a multithreaded environment.

The policies for concurrency are:

• SE_UNPROTECTED_POLICY—ArcSDE provides no protection. Calls by multiple threads to the same handle could cause problems, but there is no overhead.
• SE_ONE_THREAD_POLICY—The handle is owned by the calling thread, and a call by another thread immediately returns with an error code of SE_CONNECTION_LOCKED. The owning thread must yield ownership by calling this function with an argument other than SE_ONE_THREAD_POLICY before another thread can use this handle. If the owning thread terminates, then it automatically releases its ownership.
• SE_TRYLOCK_POLICY—Whenever an ArcSDE function with a connection or stream argument is entered, the entering thread tries to lock. If it succeeds, it proceeds; if it fails, it immediately returns with an error code of SE_CONNECTION_IN_USE.
• SE_LOCK_POLICY—Similar to SE_TRYLOCK_POLICY, but instead of failing if the connection is currently in use, the call hangs until the thread that has the connection currently locked returns from its ArcSDE function call. If multiple threads are waiting on the connection, it is impossible to determine which thread will get the lock next.

The environment set by SE_ptable_set_concurrency applies to subsequent calls to SE_ptable_set_concurrency. For safety in a multithreaded environment, call SE_ptable_set_concurrency on the point table before passing it to any other thread than the one that created the point table.

Returns

SE_SUCCESS
SE_FAILURE
SE_INVALID_PARAM_VALUE
SE_INVALID_POINTER
SE_OUT_OF_MUTEXES