On systems that support either POSIX threads or WIN32 threads, IMSL C Stat Library can be safely called from a multithreaded application. When IMSL C Stat Library is used in a multithreaded application, the calling program must adhere to a few important guidelines. In particular, IMSL C Stat Library's implementation of signal handling, error handling, and I/O must be understood.
When calling C Stat Library from a multithreaded
application it is necessary to turn
C Stat Library 's signal-handling
capability off. This is accomplished by making a single call to imsls_error_options
before any calls are made to C Stat Library. For an example of
turning off C Stat Library's internal-signal handling , see Chapter 15,
“Utilities”, Example 3 of imsls_error_options.
C Stat Library 's error handling in a multithreaded application behaves similarly to how it behaves in a single-threaded application. The major difference is that an error stack exists for each thread calling C Stat Library functions. The result of separate error stacks for each thread is greater control of the error handler options for each thread. Each thread can set its own options for the C Stat Library error handler using imsls_error_options. For an example of setting error handler options for separate threads, see Chapter 15, “Utilities”, Example 3 of imsls_error_options.
A number of routines in C Stat Library can be used to produce output. The function imsls_output_file can be used to control which file the output is directed. In an application with a single thread of execution, a single call to imsls_output_file can be used to set the file to which the output will be directed. In a multithreaded application each thread must call imsls_output_file to change the default setting of where output will be directed. See Chapter 15, “Utilities”, Example 2 of imsls_output_ file for more details.
In a multithreaded application attention must be given to the data sent to C Stat Library. Some arguments that may appear to be input-only are temporarily modified during the call and restored before returning to the caller. Care must be used to avoid usage of the same data space in separate threads calling functions in C Stat Library.
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