Follow-up Comment #7, bug #59204 (project gnustep):
Actually the proposed fix creates (incidentally) a bug that causes NSOperation
threads never to exit!
-[NSOperationQueue _thread] (now) starts off like this (the
ENTER_POOL/LEAVE_POOL were recently added as part of the fix here):
for (;;)
{
/* We use a pool for each operation in case releasing the operation
* causes it to be deallocated, and the deallocation of the operation
* autoreleases something which needs to be cleaned up.
*/
ENTER_POOL
NSOperation *op;
NSDate *when;
BOOL found;
when = [[NSDate alloc] initWithTimeIntervalSinceNow: 5.0];
found = [internal->cond lockWhenCondition: 1 beforeDate: when];
RELEASE(when);
if (NO == found)
{
break; // Idle for 5 seconds ... exit thread.
}
ENTER_POOL is a macro that expands to:
#define ENTER_POOL @autoreleasepool{do{
This is *extremely dangerous!* The 'break' above in thread breaks from the do
loop started by ENTER_POOL, not from the for(;;) loop in _thread, which is
what was obviously intended, and what the code did before the ENTER_POOL was
added in commit 41badcb417.
I really don't understand why ENTER_POOl isn't defined as
#define ENTER_POOL @autoreleasepool{do{
and LEAVE_POOL as
#define LEAVE_POOL }
This is safer, does not hijack 'break' and 'continue' statements between them,
and everything compiles fine this way (except for Tools/AGSHtml.m, which is
clearly confused about its break statement at line 1087).
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