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/****************************************************************
* *
* Copyright (c) 2015-2023 Fidelity National Information *
* Services, Inc. and/or its subsidiaries. All rights reserved. *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#ifndef GTM_MULTI_THREAD_H
#define GTM_MULTI_THREAD_H
#include "gtm_pthread.h"
typedef void *(*gtm_pthread_fnptr_t)(void *parm);
int gtm_multi_thread(gtm_pthread_fnptr_t fnptr, int ntasks, int max_threads,
pthread_t *thr_array, void **ret_array, void *parmarray, int parmElemSize);
GBLREF boolean_t multi_thread_in_use; /* TRUE => threads are in use. FALSE => not in use */
GBLREF boolean_t thread_mutex_initialized; /* TRUE => "thread_mutex" variable is initialized */
GBLREF pthread_mutex_t thread_mutex; /* mutex structure used to ensure serialization amongst threads */
GBLREF pthread_t thread_mutex_holder; /* pid/tid of the thread that has "thread_mutex" currently locked */
GBLREF pthread_key_t thread_gtm_putmsg_rname_key; /* points to region name corresponding to each running thread */
GBLREF boolean_t thread_block_sigsent; /* TRUE => block external signals SIGINT/SIGQUIT/SIGTERM/SIGTSTP/SIGCONT */
GBLREF int gtm_mupjnl_parallel; /* Maximum # of concurrent threads or procs to use in "gtm_multi_thread" */
#ifdef DEBUG
GBLREF boolean_t in_nondeferrable_signal_handler;
# define IN_GENERIC_SIGNAL_HANDLER 1
# define IN_TIMER_HANDLER 2
#endif
GBLREF boolean_t forced_thread_exit;
error_def(ERR_SYSCALL);
/* Some pthread operations don't do well when interrupted by signals, so provide deferred interrupt wrappers for them. */
#define PTHREAD_COND_SIGNAL(COND, RVAL) \
MBSTART { \
intrpt_state_t prev_intrpt_state; \
\
DEFER_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
(RVAL) = pthread_cond_signal(COND); \
ENABLE_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
} MBEND
#define PTHREAD_COND_BROADCAST(COND, RVAL) \
MBSTART { \
intrpt_state_t prev_intrpt_state; \
\
DEFER_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
(RVAL) = pthread_cond_broadcast(COND); \
ENABLE_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
} MBEND
#define PTHREAD_COND_WAIT(COND, MUTEX, RVAL) \
MBSTART { \
GBLREF VSIG_ATOMIC_T forced_exit; \
intrpt_state_t prev_intrpt_state; \
\
DEFER_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
(RVAL) = pthread_cond_wait(COND, MUTEX); \
if (forced_exit) \
pthread_mutex_unlock(MUTEX); \
ENABLE_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
assert(!forced_exit); \
} MBEND
#define PTHREAD_COND_TIMEDWAIT(COND, MUTEX, TIMEOUT, RVAL) \
MBSTART { \
GBLREF VSIG_ATOMIC_T forced_exit; \
intrpt_state_t prev_intrpt_state; \
\
DEFER_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
(RVAL) = pthread_cond_timedwait(COND, MUTEX, TIMEOUT); \
if (forced_exit) \
pthread_mutex_unlock(MUTEX); \
ENABLE_INTERRUPTS(INTRPT_IN_PTHREAD_NB, prev_intrpt_state); \
assert(!forced_exit); \
} MBEND
#ifdef GTM_PTHREAD
/* For use with gtm_multi_thread() */
typedef struct {
int ntasks;
gtm_pthread_fnptr_t fnptr;
void **ret_array;
void *parm_array;
int parmElemSize;
} thread_parm_t;
int gtm_multi_thread_helper(thread_parm_t *tparm);
#define IS_LIBPTHREAD_MUTEX_LOCK_HOLDER (pthread_self() == thread_mutex_holder)
#define PTHREAD_MUTEX_LOCK_IF_NEEDED(WAS_HOLDER) \
{ \
int rc; \
\
if (multi_thread_in_use) \
{ /* gtm_malloc/gtm_free is not thread safe. So use locks to serialize */ \
assert(thread_mutex_initialized); \
/* We should never use pthread_* calls inside a signal/timer handler. Assert that */ \
assert(!in_nondeferrable_signal_handler); \
/* Allow for self to already own the lock (due to nested codepaths that need the lock. */ \
if (!IS_LIBPTHREAD_MUTEX_LOCK_HOLDER) \
{ \
rc = pthread_mutex_lock(&thread_mutex); \
if (rc) \
rts_error_csa(CSA_ARG(NULL) VARLSTCNT(8) ERR_SYSCALL, 5, \
RTS_ERROR_LITERAL("pthread_mutex_lock()"), CALLFROM, rc); \
thread_mutex_holder = pthread_self(); \
WAS_HOLDER = FALSE; \
} else \
WAS_HOLDER = TRUE; \
} else \
{ \
assert(!thread_mutex_holder); \
WAS_HOLDER = FALSE; \
} \
}
#define PTHREAD_MUTEX_UNLOCK_IF_NEEDED(WAS_HOLDER) \
{ \
int rc; \
\
if (multi_thread_in_use) \
{ \
assert(thread_mutex_initialized); \
/* We should never use pthread_* calls inside a signal/timer handler. Assert that */ \
assert(!in_nondeferrable_signal_handler); \
/* assert self does own the lock */ \
assert(pthread_self() == thread_mutex_holder); \
if (!WAS_HOLDER) \
{ \
thread_mutex_holder = 0; \
rc = pthread_mutex_unlock(&thread_mutex); \
if (rc) \
rts_error_csa(CSA_ARG(NULL) VARLSTCNT(8) ERR_SYSCALL, 5, \
RTS_ERROR_LITERAL("pthread_mutex_unlock()"), CALLFROM, rc); \
} \
} else \
assert(!thread_mutex_holder); \
}
/* Below macro identifies if the caller is inside threaded code. A quick check of this is using the global
* "multi_thread_in_use". If that is FALSE, we are guaranteed not to be in threaded code. If it is TRUE though, it is
* still possible the caller is the master process (that spawned off the threads) and not the threads themselves.
* The only way to distinguish between the master and the threads is to get the rname_key. It is NULL for the
* master and non-NULL for the threads.
* Note: In the future, if more threads are implemented with no region context, we might be better off checking
* "gtm_main_thread_id" against "pthread_self()". Right now, the former is not maintained in all cases and is
* hence not used.
*/
#define INSIDE_THREADED_CODE(rname) (multi_thread_in_use && (NULL != (rname = pthread_getspecific(thread_gtm_putmsg_rname_key))))
#else
#define IS_LIBPTHREAD_MUTEX_LOCK_HOLDER FALSE
#define ASSERT_NO_THREAD_USAGE assert(!multi_thread_in_use && !thread_mutex_holder)
#define PTHREAD_MUTEX_LOCK_IF_NEEDED(WAS_HOLDER) ASSERT_NO_THREAD_USAGE
#define PTHREAD_MUTEX_UNLOCK_IF_NEEDED(WAS_HOLDER) ASSERT_NO_THREAD_USAGE
#define INSIDE_THREADED_CODE(rname) FALSE
#endif
/* Returns FALSE if threads are in use and we dont own the libpthread mutex lock. Returns TRUE otherwise */
#define IS_PTHREAD_LOCKED_AND_HOLDER (!multi_thread_in_use || IS_LIBPTHREAD_MUTEX_LOCK_HOLDER)
/* Below macro is invoked just before we read or write global variables that are also updated inside threaded code.
* Global variables currently in this list (of those that are updated inside threaded code) are
* TREF(util_outbuff_ptr)
* TREF(util_outptr)
* Any time any variable in the above list is read or written, the below macro needs to be added before the reference.
*/
#define ASSERT_SAFE_TO_UPDATE_THREAD_GBLS assert(IS_PTHREAD_LOCKED_AND_HOLDER)
/* Note: Below macro can be safely used even in threaded code since this variable only transitions from 0 to 1 inside threaded code.
* Also, it is okay for other threads to read a stale value of this since they keep checking this at logical points in their
* execution (using the PTHREAD_EXIT_IF_FORCED_EXIT macro). Reading a stale value will only delay thread exit a little.
* The 1 to 0 transition happens only in non-threaded code. Assert accordingly.
*/
#define SET_FORCED_THREAD_EXIT forced_thread_exit = 1
#define RESET_FORCED_THREAD_EXIT \
{ \
char *rname; \
\
assert(!INSIDE_THREADED_CODE(rname)); \
forced_thread_exit = 0; \
}
/* If a process with multiple threads receives a signal (e.g. SIGTERM) asking it to terminate,
* the master process sets forced_exit to a non-zero value. But does not initiate exit handling
* right then. Instead it goes back to what it was doing (most likely "pthread_join" inside
* "gtm_multi_thread") and continues waiting for the threads to die. The threads are supposed to
* check for "forced_exit" periodically (when they reach a logical stage in their processing) and
* exit as soon as possible thereby letting the master process initiate exit handling processing.
* The below macro helps with that.
*/
#define PTHREAD_EXIT_IF_FORCED_EXIT \
{ \
char *rname; \
\
GTM_PTHREAD_ONLY(assert(INSIDE_THREADED_CODE(rname))); \
NON_GTM_PTHREAD_ONLY(assert(FALSE)); \
if (forced_thread_exit) \
GTM_PTHREAD_EXIT(PTHREAD_CANCELED); \
}
/* Exit the thread with status "STATUS". But before that release any mutex locks you hold (possible for example
* if the exiting thread had done a "rts_error" call which would have grabbed the pthread_mutex_t lock but not
* released it anywhere until thread exit time (which is here). The release is needed to prevent other threads
* from deadlocking.
*/
#define GTM_PTHREAD_EXIT(STATUS) \
{ \
char *rname; \
\
GTM_PTHREAD_ONLY(assert(INSIDE_THREADED_CODE(rname));) \
NON_GTM_PTHREAD_ONLY(assert(FALSE)); \
/* If thread is exiting with abnormal status, signal other threads to stop execution \
* at a logical point since the parent is anyways going to return with a non-zero exit status. \
* This is necessary so only ONE thread modifies the condition-handler stack and other global variables \
* as part of error-handling. If multiple threads encounter errors, the first thread will go \
* through the condition handler scheme, the second thread onwards will exit in DRIVECH without \
* going through any condition handler invocations. \
*/ \
if (0 != STATUS) \
SET_FORCED_THREAD_EXIT; \
if (IS_LIBPTHREAD_MUTEX_LOCK_HOLDER) \
PTHREAD_MUTEX_UNLOCK_IF_NEEDED(FALSE); \
pthread_exit((void *)(INTPTR_T)STATUS); \
}
#endif
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