Only wait out already-started pauses, not pause reqests.
ltp_pause now says whether a pause is requested or has started.
This reduces the chance that slapd:send_ldap_ber() will start
a pause in the middle of an operation.
Fix rev 1.91 patch: Reset ltp_pending_count when flushing ltp_pending_list.
Remove flush_pending_list() again and the now-unnecessary 2nd call to it.
Help the compiler a little.
Move ltp_work_list in case it makes a difference for caching.
Move mutex unlock in pool_destroy() to make concurrency debuggers happier.
Replace ltp_state with ltp_finishing. Drop state
LDAP_INT_THREAD_POOL_STOPPING, flush pending list instead.
ltp_max_pending = default value instead of 0, and negative when finishing.
Add ldap_pvt_thread_pool_pausing(): pause check for slapd without locking.
Make counters int instead of long; INT_MAX pending tasks is enough.
Nitpick cleanup: goto failure instead of if() to not-failure in _submit().
Not needed after ldap_int_thread_userctx_t.ltu_id was added and
_pool_wrapper took care not to update thread_keys[] during pauses.
Fix bogus thread_keys[].ctx comment.
- Move problematic mutex_unlock()-mutex_lock() into the unused #ifdef
LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL and add a FIXME comment inside.
- Delay ltp_starting--; until pool_wrapper(). Nonzero value could otherwise
no longer be exposed when !defined LDAP_PVT_THREAD_POOL_SEM_LOAD_CONTROL.
(setkey/getkey expected that, but purgekey could set a NULL in the middle.)
Added some checks for input key!=NULL.
API changes, need review - I'm not sure what's indented here:
- setkey(data=NULL, kfree!=NULL) searched as if intended to reset
the key, but updated by setting the key. Now always updates.
- setkey(key=<not found>, data=NULL) could return either success or
failure. Now succeeds iff (data == NULL && kfree == NULL).
ldap_pvt_thread_pool_purgekey() which may only be called during pauses.
Thus, also wait for pauses to finish before accessing thread_keys in
ldap_int_thread_pool_wrapper(). This may prevent pending tasks from
being started when a pause had been requested, which seems to have been
possible. If that was a feature, we can split ltp_pause==1 in 2 states:
in pause (causes wait), and pause requested.
Also move 'thread_keys[].id = <thread id>' from pool_submit to
pool_wrapper. Until pool_wrapper set the ctx as well, thread context
lookup would just return NULL anyway.
so a pause will work during states FINISHING and STOPPING.
Add missing waits and signals, and move waits in pool_wrapper().
Replace if(test) with while(test) when waiting for the multi-purpose
condition variable ltp_cond.
In ldap_pvt_thread_pool_submit(), when backing out of thread creation:
ltp_pending_count '++' -> '--'. Signal if there are no more threads.
In ldap_int_thread_pool_wrapper():
if() -> assert() where false would result in eternal loop.
