"Fossies" - the Fresh Open Source Software Archive 
Member "pigz-2.8/yarn.h" (13 Apr 2020, 6848 Bytes) of package /linux/privat/pigz-2.8.tar.gz:
As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) C and C++ source code syntax highlighting (style:
standard) with prefixed line numbers and
code folding option.
Alternatively you can here
view or
download the uninterpreted source code file.
For more information about "yarn.h" see the
Fossies "Dox" file reference documentation and the last
Fossies "Diffs" side-by-side code changes report:
2.4_vs_2.5.
1 /* yarn.h -- generic interface for thread operations
2 * Copyright (C) 2008, 2011, 2012, 2015, 2018, 2019, 2020 Mark Adler
3 * Version 1.7 12 Apr 2020 Mark Adler
4 */
5
6 /*
7 This software is provided 'as-is', without any express or implied
8 warranty. In no event will the author be held liable for any damages
9 arising from the use of this software.
10
11 Permission is granted to anyone to use this software for any purpose,
12 including commercial applications, and to alter it and redistribute it
13 freely, subject to the following restrictions:
14
15 1. The origin of this software must not be misrepresented; you must not
16 claim that you wrote the original software. If you use this software
17 in a product, an acknowledgment in the product documentation would be
18 appreciated but is not required.
19 2. Altered source versions must be plainly marked as such, and must not be
20 misrepresented as being the original software.
21 3. This notice may not be removed or altered from any source distribution.
22
23 Mark Adler
24 madler@alumni.caltech.edu
25 */
26
27 /* Basic thread operations
28
29 This interface isolates the local operating system implementation of threads
30 from the application in order to facilitate platform independent use of
31 threads. All of the implementation details are deliberately hidden.
32
33 Assuming adequate system resources and proper use, none of these functions
34 can fail. As a result, any errors encountered will cause an exit() to be
35 executed, or the execution of your own optionally-provided abort function.
36
37 These functions allow the simple launching and joining of threads, and the
38 locking of objects and synchronization of changes of objects. The latter is
39 implemented with a single lock type that contains an integer value. The
40 value can be ignored for simple exclusive access to an object, or the value
41 can be used to signal and wait for changes to an object.
42
43 -- Arguments --
44
45 thread *thread; identifier for launched thread, used by join
46 void probe(void *); pointer to function "probe", run when thread starts
47 void *payload; single argument passed to the probe function
48 lock *lock; a lock with a value -- used for exclusive access to
49 an object and to synchronize threads waiting for
50 changes to an object
51 long val; value to set lock, increment lock, or wait for
52 int n; number of threads joined
53
54 -- Thread functions --
55
56 thread = launch(probe, payload) - launch a thread -- exit via probe() return
57 join(thread) - join a thread and by joining end it, waiting for the thread
58 to exit if it hasn't already -- will free the resources allocated by
59 launch() (don't try to join the same thread more than once)
60 n = join_all() - join all threads launched by launch() that are not joined
61 yet and free the resources allocated by the launches, usually to clean
62 up when the thread processing is done -- join_all() returns an int with
63 the count of the number of threads joined (join_all() should only be
64 called from the main thread, and should only be called after any calls
65 of join() have completed)
66
67 -- Lock functions --
68
69 lock = new_lock(val) - create a new lock with initial value val (lock is
70 created in the released state)
71 possess(lock) - acquire exclusive possession of a lock, waiting if necessary
72 twist(lock, [TO | BY], val) - set lock to or increment lock by val, signal
73 all threads waiting on this lock and then release the lock -- must
74 possess the lock before calling (twist releases, so don't do a
75 release() after a twist() on the same lock)
76 wait_for(lock, [TO_BE | NOT_TO_BE | TO_BE_MORE_THAN | TO_BE_LESS_THAN], val)
77 - wait on lock value to be, not to be, be greater than, or be less than
78 val -- must possess the lock before calling, will possess the lock on
79 return but the lock is released while waiting to permit other threads
80 to use twist() to change the value and signal the change (so make sure
81 that the object is in a usable state when waiting)
82 release(lock) - release a possessed lock (do not try to release a lock that
83 the current thread does not possess)
84 val = peek_lock(lock) - return the value of the lock (assumes that lock is
85 already possessed, no possess or release is done by peek_lock())
86 free_lock(lock) - free the resources allocated by new_lock() (application
87 must assure that the lock is released before calling free_lock())
88
89 -- Memory allocation ---
90
91 yarn_mem(better_malloc, better_free) - set the memory allocation and free
92 routines for use by the yarn routines where the supplied routines have
93 the same interface and operation as malloc() and free(), and may be
94 provided in order to supply thread-safe memory allocation routines or
95 for any other reason -- by default malloc() and free() will be used
96
97 -- Error control --
98
99 yarn_prefix - a char pointer to a string that will be the prefix for any
100 error messages that these routines generate before exiting -- if not
101 changed by the application, "yarn" will be used
102 yarn_abort - an external function that will be executed when there is an
103 internal yarn error, due to out of memory or misuse -- this function
104 may exit to abort the application, or if it returns, the yarn error
105 handler will exit (set to NULL by default for no action)
106 */
107
108 extern char *yarn_prefix;
109 extern void (*yarn_abort)(int);
110
111 void yarn_mem(void *(*)(size_t), void (*)(void *));
112
113 typedef struct thread_s thread;
114 thread *launch_(void (*)(void *), void *, char const *, long);
115 #define launch(a, b) launch_(a, b, __FILE__, __LINE__)
116 void join_(thread *, char const *, long);
117 #define join(a) join_(a, __FILE__, __LINE__)
118 int join_all_(char const *, long);
119 #define join_all() join_all_(__FILE__, __LINE__)
120
121 typedef struct lock_s lock;
122 lock *new_lock_(long, char const *, long);
123 #define new_lock(a) new_lock_(a, __FILE__, __LINE__)
124 void possess_(lock *, char const *, long);
125 #define possess(a) possess_(a, __FILE__, __LINE__)
126 void release_(lock *, char const *, long);
127 #define release(a) release_(a, __FILE__, __LINE__)
128 enum twist_op { TO, BY };
129 void twist_(lock *, enum twist_op, long, char const *, long);
130 #define twist(a, b, c) twist_(a, b, c, __FILE__, __LINE__)
131 enum wait_op {
132 TO_BE, /* or */ NOT_TO_BE, /* that is the question */
133 TO_BE_MORE_THAN, TO_BE_LESS_THAN };
134 void wait_for_(lock *, enum wait_op, long, char const *, long);
135 #define wait_for(a, b, c) wait_for_(a, b, c, __FILE__, __LINE__)
136 long peek_lock(lock *);
137 void free_lock_(lock *, char const *, long);
138 #define free_lock(a) free_lock_(a, __FILE__, __LINE__)