[go-nuts] Unique GO language features
I really like the 'defer' statement and think it would be a useful addition to other programming languages. The feature where GO performs escape analysis and promotes stack variables to the heap: Did that originate with GO or was it first implemented elsewhere? Thanks, Joe -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/aa60d506-7b98-49fd-8017-9601c18ff09dn%40googlegroups.com.
[go-nuts] Thread safe tree library?
Is there a simple tree library that is thread safe? If I have to write one for myself, do I have to set locks on nodes as I walk the tree to prevent another thread from changing nodes that are 'above' me? -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/6597198c-c439-4a1e-bff2-a2176204b272n%40googlegroups.com.
Re: [go-nuts] Thread safe tree library?
Well, I think I only need to lock on writes, and it'll be easier if I just lock the entire tree on writes. Reads will be the majority of the operations by far. This is for a bit of caching before we go to a K/V database like REDIS, etc. On Tuesday, January 5, 2021 at 5:16:36 PM UTC-8 k.alex...@gmail.com wrote: > On Tue, Jan 5, 2021, 6:59 PM Nathan Fisher wrote: > >> Does write only locking provide read correctness? I would’ve thought >> based on the memory model it could cause issues? >> >> https://golang.org/ref/mem#tmp_2 >> > > It depends on your notion of "read correctness", specifically when you > consider each read to have occurred with respect to its concurrent writes. > Linearizability may be a weaker guarantee than you want, and that's okay. > > Linearizability requires that, for each operation, you can pick some point > between the start and end of an operation when it can be said to have > "occurred". When you consider all the operations in that order, the results > you see must be the same as a sequential execution. > > In the case I have described, we can pick a linearization point for reads > just before the last write which they passed on their way down the tree. > The reads should then see all the writes which happened prior to this point. > > This isn't the order the operations enter the root, but linearizability > doesn't care. It doesn't have an opinion on when overlapping operations > "occur" with respect to one another. > > I don't think using a happens-before relation for the program order seen > by each goroutine is going to cause a problem with respect to choosing > these linearization points, but maybe I'm missing something. > > Maybe also there is a standardized notion of read correctness that you're > referring to which I am not aware of. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/8d97ad06-f7e6-4fdd-8ec4-0803e0ad3dd1n%40googlegroups.com.
Re: [go-nuts] Thread safe tree library?
Thanks! You all have given me much to look at. -joe On Friday, January 8, 2021 at 2:56:46 PM UTC-8 k.alex...@gmail.com wrote: > I was thinking of potential issues if you rebalance the tree as an example. >> >> I’m not certain what issues could arise as I’ve never considered a >> concurrent data structure that lacks some kind of synchronisation for both >> read and writes unless it’s immutable copy-on-write or similar. >> >> Do you happen to have references available for further research? >> >> You do have to be careful when rebalancing. The goal is to make the > rebalancing appear atomic to other reads as they go down the tree. IIRC a > technique to do this involves recreating the nodes involved in the > rebalance and completing the rebalance by updating a single edge at once. > That sounds a lot to me like copy-on-write but IIRC it doesn't require > copying the entire subtree. > > You might also be interested in some of the below references, although > they're all on lock-free and wait-free options. Disclaimer: They're all > from my Ph.D advisor. I was working in his lab when most of this work was > being done. Most of what I've posted here is based on my memory of their > approach. > > https://dl.acm.org/doi/10.1145/3391438 > https://dl.acm.org/doi/10.1145/3016078.2851173 > https://dl.acm.org/doi/10.1145/2688500.2688551 > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/59c67911-1769-4f8b-8c95-1c6a70978dc6n%40googlegroups.com.
[go-nuts] $GOPATH/go.mod exists but should not
I found (what I think is) a simple GO project to play with as a learning exercise: https://intersog.com/blog/how-to-write-a-custom-url-shortener-using-golang-and-redis/ The second step fails immediately. with the aforementioned error message. I'm using GO version 1.15.6 $GOPATH is undefined. Here's the content of ~/go Joes-iMac:go joe$ pwd /Users/joe/go Joes-iMac:go joe$ ls bin go.mod pkg src Joes-iMac:go joe$ more go.mod module urlShorter go 1.15 [eof] So, I googled for the error message. I find lots of hits, but no clear explanation of why the error message, but most importantly, no clear explanation of how to fix... Help please! Thanks, Joe -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/33438df6-65d0-4c6d-b905-b77a5d49c9e1n%40googlegroups.com.
[go-nuts] Packages vs methods
When I’m reading go source and I see something like foo.bar(), my brain stutters for a second while I’m trying to determine if this is a reference to a package function or a receiver/method. Is there an easy way to make this determination? Thanks -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/e33c9734-4d83-4e21-9a95-b23be5e5a9bcn%40googlegroups.com.
[go-nuts] Home directory?
In the ‘Create a Go Module’ documentation, it keeps referencing ‘home directory’ and uses the unix command ‘cd’. Do they literally mean my unix home directory or do they mean my GOPATH directory? Have GOPATH and GOROOT been deprecated? Thanks, Hoe -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/adf24fcc-3530-4e7c-8e74-b48f3b54933cn%40googlegroups.com.
[go-nuts] Go modules question
I’m reading a GO book for beginners. They’re always naming their module in the form: github.com/username/program Is the ‘github.com’ portion of the module name mandatory? I really have no intention of saving my code to github. If i’m saving my code locally, can i use an arbitrary module name? Thanks -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/8055599f-949e-4eab-8ec2-116be3715099n%40googlegroups.com.
[go-nuts] templates not working for me
I'm goofing around with GIN and trying some examples. I can't get
templating to work for me.
File inclusion works, but variable substitution does not.
GOLANG version 1.20.12
package main
import "github.com/gin-gonic/gin"
import "net/http"
// import "gorm.io/driver/sqlite"
// import "gorm.io/gorm"
func main() {
server := gin.Default()
server.Static("/stylesheets", "./")
server.LoadHTMLGlob("templates/*.html")
server.GET("/test", func(ctx *gin.Context) {
ctx.JSON(200, gin.H{
"message": "OK!!",
})
})
server.GET("/temp", func(ctx *gin.Context) {
ctx.HTML(http.StatusOK, "index.html", gin.H{
"title": "Main website",
"foo": "bar",
})
})
server.GET("/index", func(ctx *gin.Context) {
ctx.JSON(200, gin.H{
"message": "OK!!",
})
})
server.Run(":8080")
}
Specifically, opening a browser and accessing the /temp endpoint doesn't
change the title or print the text of 'foo'
templates/header.html:
{{.title}}
https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css";
rel="stylesheet"
integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN"
crossorigin="anonymous">
What's going on here?
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[go-nuts] Re: templates not working for me
Ok,
Variable substitution doesn't seem to work in an included template file. Is
that a known limitation?
On Saturday, February 3, 2024 at 11:40:40 PM UTC-8 joseph.p...@gmail.com
wrote:
> I'm goofing around with GIN and trying some examples. I can't get
> templating to work for me.
>
> File inclusion works, but variable substitution does not.
>
> GOLANG version 1.20.12
>
> package main
>
>
> import "github.com/gin-gonic/gin"
>
> import "net/http"
>
> // import "gorm.io/driver/sqlite"
>
> // import "gorm.io/gorm"
>
>
> func main() {
>
>
> server := gin.Default()
>
>
> server.Static("/stylesheets", "./")
>
>
> server.LoadHTMLGlob("templates/*.html")
>
>
> server.GET("/test", func(ctx *gin.Context) {
>
> ctx.JSON(200, gin.H{
>
> "message": "OK!!",
>
> })
>
> })
>
> server.GET("/temp", func(ctx *gin.Context) {
>
> ctx.HTML(http.StatusOK, "index.html", gin.H{
>
> "title": "Main website",
>
> "foo": "bar",
>
> })
>
> })
>
> server.GET("/index", func(ctx *gin.Context) {
>
> ctx.JSON(200, gin.H{
>
> "message": "OK!!",
>
> })
>
> })
>
> server.Run(":8080")
>
> }
>
> Specifically, opening a browser and accessing the /temp endpoint doesn't
> change the title or print the text of 'foo'
>
> templates/header.html:
>
>
>
>{{.title}}
>
>
>
>https://cdn.jsdelivr.net/npm/boot...@5.3.2/dist/css/bootstrap.min.css
> <https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/css/bootstrap.min.css>"
> rel="stylesheet"
> integrity="sha384-T3c6CoIi6uLrA9TneNEoa7RxnatzjcDSCmG1MXxSR1GAsXEV/Dwwykc2MPK8M2HN"
>
> crossorigin="anonymous">
>
>
>
>
>
>
>
>
> What's going on here?
>
>
>
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