tailscale

Commit Graph

Author	SHA1	Message	Date
Joe Tsai	d209b032ab	syncs: add Map.WithLock to allow mutations to the underlying map (#8101 ) Some operations cannot be implemented with the prior API: * Iterating over the map and deleting keys * Iterating over the map and replacing items * Calling APIs that expect a native Go map Add a Map.WithLock method that acquires a write-lock on the map and then calls a user-provided closure with the underlying Go map. This allows users to interact with the Map as a regular Go map, but with the gaurantees that it is concurrent safe. Updates tailscale/corp#9115 Signed-off-by: Joe Tsai <joetsai@digital-static.net>	4 months ago
Joe Tsai	5db80cf2d8	syncs: fix AtomicValue for interface kinds (#11943 ) If AtomicValue[T] is used with a T that is an interface kind, then Store may panic if different concret types are ever stored. Fix this by always wrapping in a concrete type. Technically, this is only needed if T is an interface kind, but there is no harm in doing it also for non-interface kinds. Updates #cleanup Signed-off-by: Joe Tsai <joetsai@digital-static.net>	6 months ago
Andrew Dunham	e382e4cee6	syncs: add Swap method To mimic sync.Map.Swap, sync/atomic.Value.Swap, etc. Updates tailscale/corp#1297 Signed-off-by: Andrew Dunham <andrew@du.nham.ca> Change-Id: If7627da1bce8b552873b21d7e5ebb98904e9a650	8 months ago
Joe Tsai	674beabc73	syncs: add Map.LoadFunc (#9869 ) The LoadFunc loads a value and calls a user-provided function. The utility of this method is to ensure that the map lock is held while executing user-provided logic. This allows us to solve TOCTOU bugs that would be nearly imposible to the solve without this API. Updates tailscale/corp#14772 Signed-off-by: Joe Tsai <joetsai@digital-static.net>	1 year ago
James Tucker	498f7ec663	syncs: add Map.LoadOrInit for lazily initialized values I was reviewing some code that was performing this by hand, and wanted to suggest using syncs.Map, however as the code in question was allocating a non-trivial structure this would be necessary to meet the target. Updates #cleanup Signed-off-by: James Tucker <james@tailscale.com>	1 year ago
Brad Fitzpatrick	e8551d6b40	all: use Go 1.21 slices, maps instead of x/exp/{slices,maps} Updates #8419 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	1 year ago
Denton Gentry	7e15c78a5a	syncs: add map.Clear() method Updates https://github.com/tailscale/corp/issues/13979 Signed-off-by: Denton Gentry <dgentry@tailscale.com>	1 year ago
James Tucker	b3c3a9f174	syncs: add Map.Len to get the length of the Map I need this for a corp change where I have a set as a queue, and make a different decisison if the set is empty. Updates tailscale/corp#10344 Signed-off-by: James Tucker <james@tailscale.com>	2 years ago
James Tucker	d35ce1add9	syncs: add documentation to Map.Range Updates #cleanup Signed-off-by: James Tucker <james@tailscale.com>	2 years ago
Joe Tsai	dad78f31f3	syncs: add WaitGroup wrapper (#7481 ) The addition of WaitGroup.Go in the standard library has been repeatedly proposed and rejected. See golang/go#18022, golang/go#23538, and golang/go#39863 In summary, the argument for WaitGroup.Go is that it avoids bugs like: go func() { wg.Add(1) defer wg.Done() ... }() where the increment happens after execution (not before) and also (to a lesser degree) because: wg.Go(func() { ... }) is shorter and more readble. The argument against WaitGroup.Go is that the provided function takes no arguments and so inputs and outputs must closed over by the provided function. The most common race bug for goroutines is that the caller forgot to capture the loop iteration variable, so this pattern may make it easier to be accidentally racy. However, that is changing with golang/go#57969. In my experience the probability of race bugs due to the former still outwighs the latter, but I have no concrete evidence to prove it. The existence of errgroup.Group.Go and frequent utility of the method at least proves that this is a workable pattern and the possibility of accidental races do not appear to manifest as frequently as feared. A reason not to use errgroup.Group everywhere is that there are many situations where it doesn't make sense for the goroutine to return an error since the error is handled in a different mechanism (e.g., logged and ignored, formatted and printed to the frontend, etc.). While you can use errgroup.Group by always returning nil, the fact that you can return nil makes it easy to accidentally return an error when nothing is checking the return of group.Wait. This is not a hypothetical problem, but something that has bitten us in usages that was only using errgroup.Group without intending to use the error reporting part of it. Thus, add a (yet another) variant of WaitGroup here that is identical to sync.WaitGroup, but with an extra method. Signed-off-by: Joe Tsai <joetsai@digital-static.net>	2 years ago
Will Norris	71029cea2d	all: update copyright and license headers This updates all source files to use a new standard header for copyright and license declaration. Notably, copyright no longer includes a date, and we now use the standard SPDX-License-Identifier header. This commit was done almost entirely mechanically with perl, and then some minimal manual fixes. Updates #6865 Signed-off-by: Will Norris <will@tailscale.com>	2 years ago
Joe Tsai	9a05cdd2b5	syncs: add Map (#6260 ) Map is a concurrent safe map that is a trivial wrapper over a Go map and a sync.RWMutex. It is optimized for use-cases where the entries change often, which is the opposite use-case of what sync.Map is optimized for. The API is patterned off of sync.Map, but made generic. Signed-off-by: Joe Tsai <joetsai@digital-static.net>	2 years ago
Maisem Ali	b75f81ec00	syncs: add generic AtomicValue Signed-off-by: Maisem Ali <maisem@tailscale.com>	2 years ago
Brad Fitzpatrick	4950fe60bd	syncs, all: move to using Go's new atomic types instead of ours Fixes #5185 Change-Id: I850dd532559af78c3895e2924f8237ccc328449d Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	2 years ago
Brad Fitzpatrick	e4fecfe31d	wgengine/{monitor,router}: restore Linux ip rules when systemd deletes them Thanks. Fixes #1591 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	3 years ago
David Crawshaw	676e32ad72	syncs: add AtomicUint32 Signed-off-by: David Crawshaw <crawshaw@tailscale.com>	3 years ago
Brad Fitzpatrick	77ec80538a	syncs: add Semaphore Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>	4 years ago
Dmytro Tananayskiy	c431382720	Fix receiver in order to be consistent: syncs.WaitGroupChan Signed-off-by: Dmytro Tananayskiy <dmitriyminer@gmail.com>	4 years ago
Josh Bleecher Snyder	bf24d54143	syncs: add AssertLocked This allows us to check lock invariants. It was proposed upstream and rejected in: https://github.com/golang/go/issues/1366 Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>	4 years ago
Brad Fitzpatrick	d3134ad0c8	syncs: add AtomicBool	4 years ago
Brad Fitzpatrick	b4d02a251a	syncs: add new package for extra sync types	5 years ago

21 Commits (59cbfb186e38ac5aa32984e93ecc9d0206945707)