Add a surrogate for thread priorities using PID niceness for systems with

Add a surrogate for thread priorities using PID niceness for systems with

2000-11-21  Sebastian Wilhelmi  <wilhelmi@ira.uka.de>

	* configure.in: Add a surrogate for thread priorities using PID
	niceness for systems with no thread priorities and different PIDs
	for threads of the same process (most notably: Linux). Define
	G_THREAD_USE_PID_SURROGATE in that case, as used by
	gthread-posix.c. Also make the system thread bigger by
	sizeof (long) to contain the thread's PID.

	* gfileutils.c: Include stdlib.h for mkstemp prototype.

	* gthread.c: Add priority range checks to the affected functions.

	* gthreadpool.c: Remove unused variable.

	* gthread-impl.c, gthread-posix.c, gthread-solaris.c: Removed
	g_thread_map_priority function in favour of the
	g_thread_priority_map array.  Initialize the array with
	PRIORITY_{...}_VALUE, if available and interpolate beetween the
	bounds if .._NORMAL_.. and .._HIGH_.. are not available.

	* gthread-posix.c: If we should use the PID niceness as a
	surrogate for thread priorities (G_THREAD_USE_PID_SURROGATE is
	defined), then disable normal priority handling and use PIDs and
	setpriority() instead. Depends on the thread to write its PID into
	the place after the thread id right after thread creation.