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Code Issues

More fixes for bug CORE-2444 : make remapping of shared memory work correctly

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This commit is contained in:
hvlad 2009-05-28 20:38:07 +00:00
parent 0321fe6674
commit 5fc195efa8
2 changed files with 35 additions and 119 deletions
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149
src/jrd/event.cpp
View File

@ -122,7 +122,6 @@ static SH_MEM_T EVENT_data;
static MTX_T event_mutex[1];
#endif
void EVENT_cancel(SLONG request_id)
{
/**************************************
@ -527,34 +526,16 @@ static EVH acquire(void)
if (EVENT_header->evh_length > EVENT_data.sh_mem_length_mapped) {
const SLONG length = EVENT_header->evh_length;
#ifdef WIN_NT
/* Before remapping the memory, wakeup the watcher thread.
* Then remap the shared memory and allow the watcher thread
* to remap.
*/
/* Need to make the following code generic to all SUPERSERVER
* platforms. Postponed for now. B.Sriram, 10-Jul-1997
*/
EVH header = NULL;
#if (defined HAVE_MMAP || defined WIN_NT)
PRB process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
process->prb_flags |= PRB_remap;
event_t* event = process->prb_event;
post_process(process);
while (true) {
release();
Sleep(3);
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
if (!(process->prb_flags & PRB_remap))
break;
if (process->prb_flags & PRB_dont_remap)
{
ISC_event_post(process->prb_event);
while (process->prb_flags & PRB_dont_remap)
THREAD_SLEEP(10);
}
#endif /* WIN_NT */
EVH header = NULL;
#if (!(defined SUPERSERVER) && (defined HAVE_MMAP))
ISC_STATUS_ARRAY status_vector;
header = (evh*) ISC_remap_file(status_vector, &EVENT_data, length, false);
#endif
@ -564,11 +545,6 @@ static EVH acquire(void)
exit(FINI_ERROR);
}
EVENT_header = header;
#ifdef WIN_NT
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
process->prb_flags &= ~PRB_remap_over;
#endif /* WIN_NT */
}
return EVENT_header;
@ -594,22 +570,6 @@ static FRB alloc_global(UCHAR type, ULONG length, bool recurse)
length = ROUNDUP(length, sizeof(IPTR));
SRQ_PTR* best = NULL;
#ifdef WIN_NT
// hvlad: wait for end of shared memory remapping if it is in progress
PRB process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
while (process->prb_flags & (PRB_remap | PRB_remap_over))
{
release();
THREAD_EXIT();
Sleep(3);
THREAD_ENTER();
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
}
#endif
for (ptr = &EVENT_header->evh_free; (free = (FRB) SRQ_ABS_PTR(*ptr)) && *ptr;
ptr = &free->frb_next)
{
@ -624,33 +584,16 @@ static FRB alloc_global(UCHAR type, ULONG length, bool recurse)
const SLONG old_length = EVENT_data.sh_mem_length_mapped;
const SLONG ev_length = old_length + EVENT_EXTEND_SIZE;
#ifdef WIN_NT
/* Before remapping the memory, wakeup the watcher thread.
* Then remap the shared memory and allow the watcher thread
* to remap.
*/
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
process->prb_flags |= PRB_remap;
event_t* event = process->prb_event;
post_process(process);
while (true) {
release();
THREAD_EXIT();
Sleep(3);
THREAD_ENTER();
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
if (!(process->prb_flags & PRB_remap))
break;
}
#endif /* WIN_NT */
EVH header = 0;
#if !((defined SUPERSERVER) && (defined HAVE_MMAP))
#if (defined HAVE_MMAP || defined WIN_NT)
PRB process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
if (process->prb_flags & PRB_dont_remap)
{
ISC_event_post(process->prb_event);
while (process->prb_flags & PRB_dont_remap)
THREAD_SLEEP(10);
}
ISC_STATUS_ARRAY status_vector;
header =
reinterpret_cast<EVH>
@ -671,11 +614,6 @@ static FRB alloc_global(UCHAR type, ULONG length, bool recurse)
free_global(free);
#ifdef WIN_NT
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
process->prb_flags &= ~PRB_remap_over;
#endif /* WIN_NT */
return alloc_global(type, length, true);
}
}
@ -798,37 +736,28 @@ static void delete_process(SLONG process_offset)
delete_session(SRQ_REL_PTR(session));
}
/* Untangle and release process block */
remove_que(&process->prb_processes);
free_global((FRB) process);
if (EVENT_process_offset == process_offset) {
#ifdef MULTI_THREAD
/* Terminate the event watcher thread */
/* When we come through the exit handler, the event semaphore might
have already been released by another exit handler. So we cannot
use that semaphore to post the event. Besides, the watcher thread
would be terminated anyway because the whole NLM is being unloaded. */
// CVC: NLM??? is this Novell Netware specific code???
process->prb_flags |= PRB_exiting;
BOOLEAN timeout = FALSE;
while (process->prb_flags & PRB_exiting && !timeout) {
while (process->prb_flags & PRB_exiting) {
ISC_event_post(process->prb_event);
SLONG value = ISC_event_clear(process->prb_event);
release();
#ifdef SOLARIS_MT
event_t* events = EVENT_process->prb_event;
#else
event_t* events = process->prb_event;
#endif
timeout = ISC_event_wait(1, &events, &value, 5 * 1000000, 0, 0);
THREAD_SLEEP(10);
acquire();
process = (PRB) SRQ_ABS_PTR(process_offset);
}
EVENT_process_offset = 0;
#endif
}
/* Untangle and release process block */
remove_que(&process->prb_processes);
free_global((FRB) process);
}
@ -1575,40 +1504,28 @@ static THREAD_ENTRY_DECLARE watcher_thread(THREAD_ENTRY_PARAM)
if (process->prb_flags & PRB_exiting) {
process->prb_flags &= ~PRB_exiting;
ISC_event_post(process->prb_event);
release();
break;
}
#ifdef WIN_NT
while (process->prb_flags & PRB_remap) {
process->prb_flags |= PRB_remap_over;
process->prb_flags &= ~PRB_remap;
release();
while (true) {
Sleep(3);
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
release();
if (!(process->prb_flags & PRB_remap_over))
break;
}
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
}
#endif
SLONG value = ISC_event_clear(process->prb_event);
release();
deliver(NULL);
acquire();
process = (PRB) SRQ_ABS_PTR(EVENT_process_offset);
release();
// we going to wait on event, allocated in shared memory
// forbid shared memory remapping until waiting
process->prb_flags |= PRB_dont_remap;
#ifdef SOLARIS_MT
event_t* events = EVENT_process->prb_event;
#else
event_t* events = process->prb_event;
#endif
release();
ISC_event_wait(1, &events, &value, 0, 0, 0);
process->prb_flags &= ~PRB_dont_remap;
}
return 0;
}

5
src/jrd/event.h
View File

@ -98,9 +98,8 @@ typedef prb *PRB;
const int PRB_wakeup = 1; /* Schedule a wakeup for process */
const int PRB_pending = 2; /* Wakeup has been requested, and is dangling */
const int PRB_remap = 4; /* need to remap shared memory */
const int PRB_remap_over= 8; /* remap is over */
const int PRB_exiting = 16; /* Process is exiting */
const int PRB_exiting = 4; /* Process is exiting */
const int PRB_dont_remap = 8; /* Don't remap shared memory until watcher thread waits */
/* Session block */