Brad King wrote:
> Markus Duft wrote:
>> Brad King wrote:
>>> Can you print out the state of signal masks?
>> how can i do that? i'm not really into that topic that much :) but i'll
>> read some man pages to figure it out.
>
> Look at "sigprocmask" docs.
ok - this was a dead end - not a single signal is blocked. it would have
surprised me if one was, actually. but better check, right? :)
>
>> it seems that i'm not hit by the select problem, as there is already a
>> "select has lied" path somewhere in that code path that catches exactly
>> my select() problem.
>
> Actually, if the select() path works other than the signal pipe
> you can probably get away with a minimal hack for this platform.
> Set a SIGALRM handler that wakes up every few milliseconds and
> writes to the signal pipes just like the SIGCHLD handler does.
> This code can be kept separate from the main select loop and
> activated only for this platform.
i implemented this, by effectively doing the same as already done for
SIGCHLD (i'm also using the same signal handler function, is this a
problem?). i'm setting the alarm right after i setup the signal handler,
and unsetting it right before removing the handler again.
i set the alarm to three seconds, which i guess is a little too long,
because the process hangs quite often sitting there for two seconds -
i'll reduce that to 1 second (is this too much overhead?). however this
seems to fix the problem
so thanks for the great idea :)
so now i have two patches to make it work - which one should i prefer?
(i guess the alarm one?). i attached both FYI.
thanks for the help.
Cheers, Markus
>
> -Brad
reported upstream:
http://www.cmake.org/pipermail/cmake/2010-February/035186.html
diff -ru cmake-2.6.4.orig/Source/kwsys/ProcessUNIX.c
cmake-2.6.4/Source/kwsys/ProcessUNIX.c
--- cmake-2.6.4.orig/Source/kwsys/ProcessUNIX.c 2010-02-17 14:39:20 +0100
+++ cmake-2.6.4/Source/kwsys/ProcessUNIX.c 2010-02-17 15:52:30 +0100
@@ -1018,6 +1018,9 @@
int numReady = 0;
int max = -1;
kwsysProcessTimeNative* timeout = 0;
+#ifdef __INTERIX
+ int is_sig_only = 0;
+#endif
/* Check for any open pipes with data reported ready by the last
call to select. According to "man select_tut" we must deal
@@ -1125,9 +1128,65 @@
/* Run select to block until data are available. Repeat call
until it is not interrupted. */
+#ifdef __INTERIX
+ /* hack around broken sh** ... */
+ is_sig_only = 1;
+ for(i=0; i < KWSYSPE_PIPE_COUNT; ++i) {
+ if(cp->PipeReadEnds[i] >= 0) {
+ if(i != KWSYSPE_PIPE_SIGNAL)
+ is_sig_only = 0;
+ } else {
+ if(i == KWSYSPE_PIPE_SIGNAL)
+ is_sig_only = 0;
+ }
+ }
+
+ if(is_sig_only && !timeout) {
+ static kwsysProcessTimeNative _tmp = { 1,0 };
+ timeout = &_tmp;
+ }
+
+ while(1) {
+#endif
+
while(((numReady = select(max+1, &cp->PipeSet, 0, 0, timeout)) < 0) &&
(errno == EINTR));
+#ifdef __INTERIX
+ if(!is_sig_only)
+ break;
+
+ if(numReady != 0)
+ break;
+
+ /* only signal pipe left over, and nothing waiting ...
+ * we'll just wait() for the process to see whether it still exists.
+ * if it does, we continue to select, otherwise we return 0. no need
+ * to modify the PipeSet as the pipe will be set in there anyway then.
*/
+ for(i=0; i < cp->NumberOfCommands; ++i)
+ {
+ if(cp->ForkPIDs[i])
+ {
+ int result;
+ while(((result = waitpid(cp->ForkPIDs[i],
+ &cp->CommandExitCodes[i], WNOHANG)) < 0) &&
+ (errno == EINTR));
+ if(result == cp->ForkPIDs[i])
+ {
+ /* uh ... process terminated, SIGCHLD got lost?
+ * what should i DO here? */
+
+ /* Set the pipe in a signalled state. */
+ kwsysProcessCleanupDescriptor(&cp->SignalPipe);
+ return 1;
+ }
+ }
+ }
+ /* no process terminated, nothing select()ed. */
+ continue;
+ }
+#endif
+
/* Check result of select. */
if(numReady == 0)
{
@@ -1215,12 +1274,16 @@
return 1;
}
+/* errr.... this looks wrong, and is not done for the select() part above.
+ * (the kwsysProcessGetTimeoutLeft part from above is in both code paths). */
+#if 0
if((timeoutLength.tv_sec == 0) && (timeoutLength.tv_usec == 0))
{
/* Timeout has already expired. */
wd->Expired = 1;
return 1;
}
+#endif
/* Sleep a little, try again. */
{
diff -ru cmake-2.6.4.orig/Source/kwsys/ProcessUNIX.c
cmake-2.6.4/Source/kwsys/ProcessUNIX.c
--- cmake-2.6.4.orig/Source/kwsys/ProcessUNIX.c 2010-02-18 08:47:44 +0100
+++ cmake-2.6.4/Source/kwsys/ProcessUNIX.c 2010-02-18 09:19:25 +0100
@@ -2444,6 +2444,9 @@
/* The old SIGCHLD handler. */
static struct sigaction kwsysProcessesOldSigChldAction;
+#ifdef __INTERIX
+static struct sigaction kwsysProcessesOldSigAlrmAction;
+#endif
/*--------------------------------------------------------------------------*/
static void kwsysProcessesUpdate(kwsysProcessInstances* newProcesses)
@@ -2561,6 +2564,14 @@
while((sigaction(SIGCHLD, &newSigChldAction,
&kwsysProcessesOldSigChldAction) < 0) &&
(errno == EINTR));
+
+#ifdef __INTERIX
+ while((sigaction(SIGALRM, &newSigChldAction,
+ &kwsysProcessesOldSigAlrmAction) < 0)
&&
+ (errno == EINTR));
+
+ alarm(1);
+#endif
}
}
@@ -2599,6 +2610,13 @@
while((sigaction(SIGCHLD, &kwsysProcessesOldSigChldAction, 0) < 0) &&
(errno == EINTR));
+#ifdef __INTERIX
+ alarm(0);
+
+ while((sigaction(SIGALRM, &kwsysProcessesOldSigAlrmAction, 0) < 0) &&
+ (errno == EINTR));
+#endif
+
/* Free the table of process pointers since it is now empty.
This is safe because the signal handler has been removed. */
newProcesses.Size = 0;
@@ -2653,6 +2671,11 @@
while((sigaction(SIGCHLD, &newSigChldAction,
&kwsysProcessesOldSigChldAction) < 0) &&
(errno == EINTR));
+#ifdef __INTERIX
+ while((sigaction(SIGALRM, &newSigChldAction,
+ &kwsysProcessesOldSigAlrmAction) < 0) &&
+ (errno == EINTR));
+#endif
}
#endif
}
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