............................Contents


1. Covering Multithreading Basics	1
..Defining Multithreading Terms	2
....Defining Concurrency and Parallelism	2
..Benefiting From Multithreading	3
....Improve Application Responsiveness	3
....Use Multiprocessors Efficiently	3
....Improve Program Structure	3
....Use Fewer System Resources	3
....Combine Threads and RPC	4
....Improve Performance	4
..Looking At Multithreading Structure	5
....User-level Threads	6
....Lightweight Processes	8
....Unbound Threads	9
....Bound Threads	9


..Meeting Multithreading Standards	10
2. Programming With Threads	11
..The Threads Library	11
....Create a Thread--the Basics	12
....Get the Thread Identifier	14
....Yield Thread Execution	14
....Suspend or Continue Thread Execution	15
....Send a Signal to a Thread	16
....Access the Signal Mask of the Calling Thread	16
....Terminate a Thread	17
....Wait for Thread Termination	19
....A Simple Threads Example	21
....Maintain Thread-Specific Data	22
....Create a Thread--Advanced Features	27
....Get the Minimal Stack Size	32
....Get and Set Thread Concurrency Level	33
....Get and Set Thread Priority	34
....Scheduling and the Threads Library	35
3. Programming With Synchronization Objects	37
..Mutual Exclusion Locks	38
....Initialize a Mutual Exclusion Lock	39
....Lock a Mutex	40
....Lock With a Nonblocking Mutex	40
....Unlock a Mutex	41


....Destroy Mutex State	42
....Mutex Lock Code Example	43
....Nested Locking With a Singly Linked List	46
....Nested Locking With a Circular Linked List	47
..Condition Variables	48
....Initialize a Condition Variable	49
....Block on a Condition Variable	50
....Unblock a Specific Thread	51
....Block Until a Specified Event	52
....Unblock All Threads	54
....Destroy Condition Variable State	55
....The Lost Wake-Up Problem	56
....The Producer/Consumer Problem	56
..Multiple-Readers, Single-Writer Locks	60
....Initialize a Readers/Writer Lock	61
....Acquire a Read Lock	62
....Try to Acquire a Read Lock	62
....Acquire a Write Lock	63
....Try to Acquire a Write Lock	64
....Unlock a Readers/Writer Lock	64
....Destroy Readers/Writer Lock State	65
.. Semaphores	66
....Counting Semaphores	68
....Initialize a Semaphore	69


....Increment a Semaphore	70
....Block on a Semaphore Count	70
....Decrement a Semaphore Count	71
....Destroy the Semaphore State	72
....The Producer/Consumer Problem, Using Semaphores	73
..Synchronization Across Process Boundaries	75
..Comparing Primitives	77
4. Programming With the Operating System	79
..Processes--Changes for Multithreading	79
....Duplicating Parent Threads	79
....Executing Files and Terminating Processes	81
..Alarms, Interval Timers, and Profiling	81
..Nonlocal Goto`--setjmp`(3C) and `longjmp`(3C)	82
..Resource Limits	82
..LWPs and Scheduling Classes	82
....Timeshare Scheduling	83
....Realtime Scheduling	84
....LWP Scheduling and Thread Binding	84
....SIGWAITING--Creating LWPs for Waiting Threads	85
....Aging LWPs	85
..Extending Traditional Signals	86
....Synchronous Signals	87
....Asynchronous Signals	87
....Continuation Semantics	88


....New Operations on Signals	89
....Thread-Directed Signals	90
....Completion Semantics	92
....Signal Handlers and Async Safety	93
....Interrupted Waits on Condition Variables	94
..I/O Issues	96
....I/O as a Remote Procedure Call	96
....Tamed Asynchrony	96
....Asynchronous I/O	97
....Shared I/O and New I/O System Calls	98
....Alternatives to `getc`(3S) and `putc`(3S)	99
5. Safe and Unsafe Interfaces	101
..Thread Safety	101
..MT Interface Safety Levels	103
....Reentrant Functions for Unsafe Interfaces	104
..Async-Safe Functions	105
..MT Safety Levels for Libraries	105
....Unsafe Libraries	106
6. Compiling And Debugging	107
..Compiling a Multithreaded Application	107
....Using The C Compiler	107
....Compiling With the `_REENTRANT` Flag	108
....Using `libthread`	108
....Using Non-C Compilers	109


..Debugging Multithreaded Programs	109
.....Common Oversights	109
.....Using `adb`	110
.....Using `dbx`	111
7. Programming Guidelines	113
..Rethinking Global Variables	114
..Providing For Static Local Variables	115
..Synchronizing Threads	115
.....Single-Threaded Strategy	116
.....Reentrance	116
..Avoiding Deadlock	119
.....Scheduling Deadlocks	120
.....Locking Guidelines	120
..Following Some Basic Guidelines	121
.....Creating Threads	122
..Working With Multiprocessors	124
.....The Underlying Architecture	124
.....Summary	130
A. Sample Application Code	131
..File Copy	131
..Matrix Multiplication	133
..RPC Program	135
..Window System Server	141
B. MT Safety Levels: Library Interfaces	145


Index	163