chickadee » thread-utils

thread-utils

Documentation

Some SRFI 18 related utility routines.

Rather Chicken centric.

Thread Reaper

Allows a thread to be joined to the primordial thread asynchronously.

Usage

(require-extension thread-reaper)

thread-reap!

(thread-reap! THREAD) procedure

Queues the supplied THREAD for reaping.

thread-reaper-stop!

(thread-reaper-stop!) procedure

Processes any threads queued for reaping and terminates the reaper.

thread-reaper-timeout

(thread-reaper-timeout) => (or #f number) procedure
(thread-reaper-timeout SECONDS) procedure

Gets and sets the number of seconds to wait for a thread to quit. The default is #f or wait till termination. Should threads submitted to the reaper be known to "run off with the cpu" then something other than wait forever is warranted.

thread-reaper-retries

(thread-reaper-retries) => fixnum procedure
(thread-reaper-retries SECONDS) procedure

Gets and sets the number of attempts to wait for a thread to quit.

Default is 1.

thread-reaper-greedy

(thread-reaper-greedy) => boolean procedure
(thread-reaper-greedy FLAG) procedure

Gets and sets the reaper greedy mode. When greedy the queue is exhausted whenever possible. Otherwise only one queue item is processed per time-slice.

Default is #f.

thread-reaper-wait-seconds

(thread-reaper-wait-seconds) => (or #f number) procedure
(thread-reaper-wait-seconds SECONDS) procedure

Gets and sets the number of seconds to wait before another attempt by the reaper. The default is 1.0.

thread-reaper-quantum

(thread-reaper-quantum) => number procedure
(thread-reaper-quantum MILLISECONDS) procedure

Gets and sets the time-slice for the reaper.

Default is 2500.

thread-reaper-shutdown?

(thread-reaper-shutdown?) => boolean procedure

Is the reaper shutting down?

Thread Utilities

Usage

(require-extension thread-utils)

print-exception-error

(print-exception-error EXN [THREAD [PORT]]) procedure

Prints the error EXN and the current call chain. The message header is supplied by thread-warning-message. This routine duplicates the uncaught exception in a thread handling behavior of Chicken. Useful for caught exceptions that cannot in fact be handled.

The EXN is a condition or any other object. The default for THREAD is the (current-thread). The default for PORT is the (current-error-port).

print-exception-warning

(print-exception-warning EXN [THREAD [PORT]]) procedure

Invokes print-exception-error when warnings are enabled.

The EXN is a condition or any other object. The default for THREAD is the (current-thread). The default for PORT is the (current-error-port).

thread-warning-message

(thread-warning-message THREAD) => string procedure

Returns the string "Warning (<THREAD>): ".

thread-timeout?

check-timeout

error-timeout

(thread-timeout? OBJECT) => boolean procedure
(check-timeout LOCATION OBJECT [ARGUMENT-NAME]) => (or #f time number) procedure
(error-timeout LOCATION OBJECT [ARGUMENT-NAME]) procedure

Is the OBJECT a thread-timeout object? A thread-timeout is #f, a number, or a SRFI 18 time object.

make-thread-timeout

(make-thread-timeout OFFSET [BASE]) => (or #f time) procedure

Returns the SRFI 18 time object representing the OFFSET + BASE. The BASE is a thread-timeout object with default (current-time).

Should OFFSET be #f or a time object the BASE is ignored and OFFSET is returned. Assumes an absolute OFFSET indicates a timeout already calculated.

check-thread

error-thread

(check-thread LOCATION OBJECT [ARGUMENT-NAME]) => thread procedure
(error-thread LOCATION OBJECT [ARGUMENT-NAME]) procedure

Type checking for thread.

thread-created?

thread-ready?

thread-running?

thread-blocked?

thread-suspended?

thread-sleeping?

thread-terminated?

thread-dead?

(thread-created? THREAD) => boolean procedure
(thread-ready? THREAD) => boolean procedure
(thread-running? THREAD) => boolean procedure
(thread-blocked? THREAD) => boolean procedure
(thread-suspended? THREAD) => boolean procedure
(thread-sleeping? THREAD) => boolean procedure
(thread-terminated? THREAD) => boolean procedure
(thread-dead? THREAD) => boolean procedure

Is the THREAD in the indicated state?

thread-obstructed?

(thread-obstructed? THREAD) => boolean procedure

Is the THREAD blocked or sleeping?

thread-state=?

(thread-state=? THREAD TOKEN) => boolean procedure

Does the state token of the THREAD equal the supplied TOKEN.

thread-blocked?/termination

thread-blocked?/io

thread-blocked?/timeout

(thread-blocked?/termination THREAD) => boolean procedure
(thread-blocked?/io THREAD) => boolean procedure
(thread-blocked?/timeout THREAD) => boolean procedure

Is the THREAD in the indicated blocking state?

thread-unblock!

(thread-unblock! THREAD) procedure

Attempts to cleanly unblock the THREAD.

Currently only threads blocked for timeout can be unblocked. Threads blocked for any other reason are ignored.

Bugs & Limitations

- thread-reaper-timeout & thread-reaper-retries are poorly named.

Notes

Requirements

miscmacros synch thread-utils record-variants check-errors

Author

Kon Lovett

Version history

1.0.2
"Fix" for ticket #981. Added thread-reaper-wait-seconds.
1.0.1
Use compiled setup-helper (& un-hide).
1.0.0
Moved from srfi-27 into own extension.

License

Copyright (C) 2010 Kon Lovett. All rights reserved.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the Software), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED ASIS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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