Commit graph

5 commits

Author SHA1 Message Date
徐志强
43a5402ce7 semaphore: unblock waiters when the front waiter cancels
When `Release`, if the remaining tokens are not enough for the front waiter, no waiters will be notified.

So if the canceled waiter is the front one, it should try to notify following waiters if there are remaining tokens.

I found this bug when implementing a cancelable rwmutex based on semaphore:

https://github.com/zhiqiangxu/util/blob/master/mutex/crwmutex.go

This bug can be verified by this test:

https://github.com/zhiqiangxu/util/blob/master/mutex/crwmutex_test.go#L43

Change-Id: Id8564976bd375a82c4fbc6cb08b0bb83118a346c
GitHub-Last-Rev: 29b6ff26bf779d23239cfe64a395378a9e41d1fc
GitHub-Pull-Request: golang/sync#10
Reviewed-on: https://go-review.googlesource.com/c/sync/+/223418
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
2020-03-17 01:50:54 +00:00
Jean de Klerk
112230192c semaphore: better error message when releasing more than held
Change-Id: Ibe69007b2d7565a33d9e64ae51142478f495509a
Reviewed-on: https://go-review.googlesource.com/c/sync/+/173377
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-04-23 02:48:10 +00:00
Jean de Klerk
37e7f081c4 semaphore: add more Acquire documentation
Change-Id: Ie64db438145a307ec8aef8fd412d445a2fe74d40
Reviewed-on: https://go-review.googlesource.com/c/136995
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-21 19:32:16 +00:00
Jean de Klerk
42b317875d all: remove x/net/context in favour of context
Change-Id: Idbfe40e7cb9f99ca3dc7d4c214de6b9e028eefb7
Reviewed-on: https://go-review.googlesource.com/c/148277
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-11-08 01:04:31 +00:00
Jonathan Amsterdam
5a06fca2c3 semaphore: add a weighted semaphore implementation
This package provides a weighted semaphore that is context-aware.

The code is derived from a similar package inside Google.

Change-Id: Id1dad96d79e8ccfd289e4299e8265aa5bdad3a5b
Reviewed-on: https://go-review.googlesource.com/38298
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-17 23:16:01 +00:00