Use the stack bottom value from the old threadData, if available

On linux, fetching the stack bottom involves huge amounts of user
and kernel CPU time. Assuming the stack bottom does not change over
time, copy it from the old threadData structure.

Belonging to [master]:
  - #2884

Author: atrosinenko

SimulationRuntime/c/meta/meta_modelica_data.h

@@ -248,11 +248,11 @@ void mmc_catch_dummy_fn();
 #define MMC_THROW() {longjmp(*((threadData_t*)pthread_getspecific(mmc_thread_data_key))->mmc_jumper,1);}
 #define MMC_ELSE() } else { threadData->mmc_jumper = old_jumper;
 
-#define MMC_TRY_TOP() { threadData_t threadDataOnStack = {0}, *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key),*threadData = &threadDataOnStack; pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow(threadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper; /* Let the default stack overflow handler be the top-level handler */
+#define MMC_TRY_TOP() { threadData_t threadDataOnStack = {0}, *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key),*threadData = &threadDataOnStack; pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow_fast(threadData, oldThreadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper; /* Let the default stack overflow handler be the top-level handler */
 
-#define MMC_TRY_TOP_SET(X) { threadData_t threadDataOnStack = *((threadData_t*)X), *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key),*threadData = &threadDataOnStack; pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow(threadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper; /* Let the default stack overflow handler be the top-level handler */
+#define MMC_TRY_TOP_SET(X) { threadData_t threadDataOnStack = *((threadData_t*)X), *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key),*threadData = &threadDataOnStack; pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow_fast(threadData, oldThreadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper; /* Let the default stack overflow handler be the top-level handler */
 
-#define MMC_TRY_TOP_INTERNAL() { threadData_t *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key); pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow(threadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper;
+#define MMC_TRY_TOP_INTERNAL() { threadData_t *oldThreadData = (threadData_t*)pthread_getspecific(mmc_thread_data_key); pthread_setspecific(mmc_thread_data_key,threadData); pthread_mutex_init(&threadData->parentMutex,NULL); mmc_init_stackoverflow_fast(threadData, oldThreadData); MMC_TRY_INTERNAL(mmc_jumper) threadData->mmc_stack_overflow_jumper = threadData->mmc_jumper;
 #define MMC_CATCH_TOP(X) pthread_setspecific(mmc_thread_data_key,oldThreadData); } else {pthread_setspecific(mmc_thread_data_key,oldThreadData);X;}}}
 
 /* use this to allocate and initialize threadData */

SimulationRuntime/c/meta/meta_modelica_segv.h

@@ -57,6 +57,21 @@ static inline void mmc_init_stackoverflow(threadData_t *threadData)
 void mmc_init_stackoverflow(threadData_t *threadData);
 #endif
 
+#if defined(linux)
+static inline void mmc_init_stackoverflow_fast(threadData_t *threadData, threadData_t *oldThreadData)
+{
+  if (oldThreadData)
+    threadData->stackBottom = oldThreadData->stackBottom;
+  else
+    mmc_init_stackoverflow(threadData);
+}
+#else
+static inline void mmc_init_stackoverflow_fast(threadData_t *threadData, threadData_t *oldThreadData)
+{
+  mmc_init_stackoverflow(threadData);
+}
+#endif
+
 #ifndef __has_builtin
   #define __has_builtin(x) 0  /* Compatibility with non-clang compilers */
 #endif