Pike-devel November 2017

pike-devel@lists.lysator.liu.se

7 participants
43 discussions

"old" mails on the list
by Peter Bortas 22 Nov '17

22 Nov '17

Hello list subscribers, I finally took over responsibility for the LysKOM exporter, and ran it through the backlog. Which means you just got a bunch of new mails that have a send date of today but might have been written months and months ago in LysKOM. From now on the exporter will export new texts every few minutes. Regards, -- Peter Bortas, NSC

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image loading
by Lance Dillon 22 Nov '17

22 Nov '17

So I'm working on a program to decode .pic files from old grasp .gl files. I have code to extract the parts of the .gl file into individual files. There is a script file, plus a bunch of images, either in .pic or .clp format. I'm only working on decoding the .pic files. It supports multiple bit depths, but I'm only doing the vga format, 1 plane with a 768 byte palette (256 each for b, g, r). I have the code to decode into bgri from the rle encoded file. I still have to work on converting it either to rgb or rgba, which might just be a simple map. Anyway, how would I convert this raw pixel data (8 bits for each color) into, say, an Image.Image so I can write as png? I'm looking at the reference documentation and I don't really see anything for importing raw pixel data. I might be able to do it using the gtk2 pixmap functions, but I was wondering if it can be done with the pike functions. Thanks

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Irregularities in HMAC implementation of Pike 8.0 or 8.1?
by Stephen R. van den Berg 22 Nov '17

22 Nov '17

Pike v8.0 release 509 running Hilfe v3.5 (Incremental Pike Frontend) > Crypto.SHA256.HMAC("a")("b"); (1) Result: "\b\336""2\231""1\342\225h7v\252\232CR\233\320\262u(m\363\26\3\0\304\233\244\350A\203""0\23" > Crypto.SHA256.HMAC("a",32)("b"); (2) Result: "\av\242\236\370\215K@N\230/h\351\236\236\254v\320\370\270""2\17\231[\202xb+i\222\3 " Pike v8.1 release 11 running Hilfe v3.5 (Incremental Pike Frontend) > Crypto.SHA256.HMAC("a")("b"); (1) Result: "\b\336""2\231""1\342\225h7v\252\232CR\233\320\262u(m\363\26\3\0\304\233\244\350A\203""0\23" > Crypto.SHA256.HMAC("a",32)("b"); (2) Result: "\b\336""2\231""1\342\225h7v\252\232CR\233\320\262u(m\363\26\3\0\304\233\244\350A\203""0\23" They can't both be right. Any ideas? I tried to debug it, but got lost in the multitude of Nettle inheritance-spaghetti levels. -- Stephen.

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Thread.ResourceCount
by Stephen R. van den Berg 22 Nov '17

22 Nov '17

A proposed new class, currently in 8.1. It allows for resource counting where the decrement is implicit by tieing it to the destruction of a key object that you got when incrementing. The implementation has already been battle-tested in pgsql in 8.1. Any suggestions related to functionality, interface and/or naming? As far as I could determine, there does not seem to be any established name for this kind of object. It's related to a semaphore, but it does things markedly different. Because it allows me to get rid of some convoluted code in pgsql, and because it automatically solves (if any) remaining races related to asynchronous destruction of objects; I'd like to use this class in 8.0 as well (in order to keep the pgsql driver in sync between 8.0 and 8.1). Any objections if I add this to 8.0? -- Stephen.

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Crypto.hmac_abc
by Martin Nilsson (Coppermist) ＠ Pike (-) developers forum 22 Nov '17

22 Nov '17

Is there a point to the latest additions to the Crypto module besides putting hex-string output directly into crypto functions? So instead of previously writing String.hex2string(Crypto.MD5.HMAC(a)(b)); you can now do Crypto.hash_hmac(Crypto.MD5, 1)(a)(b);

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Proposed improvements to Hilfe
by Chris Angelico 22 Nov '17

22 Nov '17

Branch: rosuav/hilfe-improvements Two smallish improvements to Hilfe. One is suppressing "quit" and "exit", per the TODO at the top; fairly simple but I'd like someone else's eyeballing to make sure it's going about things the right way. The other is the addition of a new help() built-in function, which gives human-readable information about whatever object it's given. Currently it shows a little information about functions and programs, and not much else; the intent is that it can be expanded at will, since it's purely human-readable. There is no backwards-compatibility guarantee about its specific output format. There's nothing particularly invasive about either of these changes, but I'd appreciate someone else's view on the code before it gets merged. Thanks! ChrisA

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signals and fork does not mix well
by ceder (-) Per Cederqvist ＠ Pike (-) developers forum 22 Nov '17

22 Nov '17

This test program should print and endless row of "/" and "\" characters, but instead it often crashes like this: > \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\//\\//\/\/\/\\/\//\\//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\\/Parent got SIGQUIT! > /home/cederp/pike-fun/forked-signals.pike:10: /main()->handler_quit() > /home/cederp/pike-fun/forked-signals.pike:33: /main()->arm_hup() > -:1: Pike.Backend(0)->`()(3600.0) > Child got SIGHUP! > /home/cederp/pike-fun/forked-signals.pike:26: /main()->handler_hup() > /home/cederp/pike-fun/forked-signals.pike:17: /main()->arm_quit() > -:1: Pike.Backend(0)->`()(3600.0) The cause: when Pike is compiled with NEED_SIGNAL_SAFE_FIFO the signal handler writes the signal number as a single byte to the write end of a pipe(2) set up by INIT_FIFO (in src/signal_handler.c). This pipe is set to close on exec -- but it doesn't close when the process forks. So, if a Pike program uses fork, and one of the processes receives a signal, it is undefined if it is handled by the parent or the child process. Both processes will read from the same pipe. I think this patch fixes the issue (comments welcome): --- cut here --- Invoke signal handlers in the correct process after fork When using fork() from Pike, the child needs to have its own pipe to send pending signals over. If it is shared with the parent, either the child or the parent may receive the signal. Close the pipe and create a new one in the child after a fork. Do the same for the process wait info. diff --git a/src/signal_handler.c b/src/signal_handler.c index dca9fe3..55b8a13 100644 --- a/src/signal_handler.c +++ b/src/signal_handler.c @@ -317,6 +317,7 @@ #define QUICK_CHECK_FIFO(pre,TYPE) ( PIKE_CONCAT(pre,_first) != PIKE_CONCAT(pre,_last) ) #define INIT_FIFO(pre,TYPE) +#define REINIT_FIFO(pre,TYPE) #else /* NEED_SIGNAL_SAFE_FIFO */ @@ -361,6 +362,12 @@ set_close_on_exec(PIKE_CONCAT(pre,_fd)[1], 1); \ }while(0) +#define REINIT_FIFO(pre,TYPE) do { \ + close(PIKE_CONCAT(pre,_fd)[0]); \ + close(PIKE_CONCAT(pre,_fd)[1]); \ + INIT_FIFO(pre,TYPE); \ +} while(0) + #endif /* else NEED_SIGNAL_SAFE_FIFO */ #ifndef SAFE_FIFO_DEBUG_END @@ -4373,6 +4380,10 @@ void Pike_f_fork(INT32 args) /* forked copy. there is now only one thread running, this one. */ num_threads=1; #endif + + REINIT_FIFO(sig, unsigned char); + REINIT_FIFO(wait,wait_data); + /* FIXME: Ought to clear pid_mapping here. */ call_callback(&fork_child_callback, 0); push_int(0); --- cut here --- Perhaps REINIT_FIFO should reset the counters when !NEED_SIGNAL_SAFE_FIFO? The test program: --- cut here --- #!/usr/bin/env pike int is_child = 0; // This code runs in the child and repeatedly sends SIGQUIT to itself. void handler_quit() { if (!is_child) error("Parent got SIGQUIT!\n"); werror("\\"); call_out(arm_quit, 0.1); } void arm_quit() { if (!kill(getpid(), signum("SIGQUIT"))) error("Failed to send QUIT: %s\n", strerror(errno())); } // This code runs in the parent and repeatedly sends SIGHUP to itself. void handler_hup() { if (is_child) error("Child got SIGHUP!\n"); werror("/"); call_out(arm_hup, 0.1); } void arm_hup() { if (!kill(getpid(), signum("SIGHUP"))) error("Failed to send HUP: %s\n", strerror(errno())); } // Setup code. int main() { // Set up the same signal handlers in both the parent and the child. signal(signum("SIGHUP"), handler_hup); signal(signum("SIGQUIT"), handler_quit); if (fork()) { // Start the parent. is_child = 0; call_out(arm_hup, 0.1); } else { // Start the child. is_child = 1; call_out(arm_quit, 0.1); } // Both the parent and the child runs in the pike backend. return -1; }

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Re: Conditional inclusion of inotify_config.h?
by Chris Angelico 22 Nov '17

22 Nov '17

On Thu, Nov 23, 2017 at 7:58 AM, Martin Nilsson (Coppermist) @ Pike (-) developers forum <10353(a)lyskom.lysator.liu.se> wrote: > The change look good. I've no idea when you posted this, but I only just saw it. So I've merged that branch in now. The lyskom => mailing list gateway must have been down again. ChrisA

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Abbreviated function definitions
by Marcus Comstedt (ACROSS) (Hail Ilpalazzo!) ＠ Pike (-) developers forum 22 Nov '17

22 Nov '17

The "return void values from functions" issue reminded me of an idea I had several years ago for shorter "functional programming" style function definitions. The idea is that a function that just returns an expression can be written without the block and return statement: int add(int a, int b) = a + b; string `id() = "foo"; void delay(int ms) = sleep(ms*0.001); (The last example is where the "returning void" thing becomes relevant. :) It turns out that this can be implemented by adding a single line to language.yacc, so I pushed an implementation to the branch marcus/short_func. Opinions on adding this to 8.1?

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Returning void from void functions
by Martin Nilsson (Coppermist) ＠ Pike (-) developers forum 22 Nov '17

22 Nov '17

Could we make this work without errors and warnings? Pike v8.1 release 9 running Hilfe v3.5 (Incremental Pike Frontend) > void foo() { } > void bar() { return foo(); } Compiler Warning: 1: Returning a void expression. Converted to zero. Compiler Error: 1: Wrong return type. Compiler Error: 1: Expected: void. Compiler Error: 1: Got : zero.

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Pike-devel November 2017