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src/libcfa/concurrency/preemption.c (modified) (10 diffs)
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src/libcfa/concurrency/preemption.c
rb227f68 rc5ac6d5 15 15 // 16 16 17 #include "libhdr.h"18 17 #include "preemption.h" 19 18 20 19 extern "C" { 21 #include <errno.h>22 #include <execinfo.h>23 #define __USE_GNU24 20 #include <signal.h> 25 #undef __USE_GNU26 #include <stdio.h>27 #include <string.h>28 #include <unistd.h>29 21 } 30 22 31 32 #ifdef __USE_STREAM__ 33 #include "fstream" 34 #endif 35 36 #define __CFA_DEFAULT_PREEMPTION__ 10000 23 #define __CFA_DEFAULT_PREEMPTION__ 10 37 24 38 25 __attribute__((weak)) unsigned int default_preemption() { … … 40 27 } 41 28 42 #define __CFA_SIGCXT__ ucontext_t *43 #define __CFA_SIGPARMS__ __attribute__((unused)) int sig, __attribute__((unused)) siginfo_t *sfp, __attribute__((unused)) __CFA_SIGCXT__ cxt44 45 29 static void preempt( processor * this ); 46 30 static void timeout( thread_desc * this ); 47 48 void sigHandler_ctxSwitch( __CFA_SIGPARMS__ );49 void sigHandler_alarm ( __CFA_SIGPARMS__ );50 void sigHandler_segv ( __CFA_SIGPARMS__ );51 void sigHandler_abort ( __CFA_SIGPARMS__ );52 53 static void __kernel_sigaction( int sig, void (*handler)(__CFA_SIGPARMS__), int flags );54 31 55 32 //============================================================================================= … … 58 35 59 36 void kernel_start_preemption() { 60 LIB_DEBUG_PRINT_SAFE("Kernel : Starting preemption\n"); 61 __kernel_sigaction( SIGUSR1, sigHandler_ctxSwitch, SA_SIGINFO ); 62 __kernel_sigaction( SIGALRM, sigHandler_alarm , SA_SIGINFO ); 63 __kernel_sigaction( SIGSEGV, sigHandler_segv , SA_SIGINFO ); 64 __kernel_sigaction( SIGBUS , sigHandler_segv , SA_SIGINFO ); 65 // __kernel_sigaction( SIGABRT, sigHandler_abort , SA_SIGINFO ); 37 66 38 } 67 39 68 void kernel_stop_preemption() {69 //Block all signals, we are no longer in a position to handle them70 sigset_t mask;71 sigfillset( &mask );72 sigprocmask( SIG_BLOCK, &mask, NULL );73 LIB_DEBUG_PRINT_SAFE("Kernel : Preemption stopped\n");74 75 // assert( !systemProcessor->alarms.head );76 // assert( systemProcessor->alarms.tail == &systemProcessor->alarms.head );77 }78 79 LIB_DEBUG_DO( bool validate( alarm_list_t * this ); )80 81 40 void tick_preemption() { 82 // LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Ticking preemption\n" );83 84 41 alarm_list_t * alarms = &systemProcessor->alarms; 85 42 __cfa_time_t currtime = __kernel_get_time(); 86 43 while( alarms->head && alarms->head->alarm < currtime ) { 87 44 alarm_node_t * node = pop(alarms); 88 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ticking %p\n", node );89 90 45 if( node->kernel_alarm ) { 91 46 preempt( node->proc ); … … 95 50 } 96 51 97 verify( validate( alarms ) );98 99 52 if( node->period > 0 ) { 100 node->alarm = currtime +node->period;53 node->alarm += node->period; 101 54 insert( alarms, node ); 102 55 } … … 109 62 __kernel_set_timer( alarms->head->alarm - currtime ); 110 63 } 111 112 verify( validate( alarms ) );113 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ticking preemption done\n" );114 64 } 115 65 116 66 void update_preemption( processor * this, __cfa_time_t duration ) { 117 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Processor : %p updating preemption to %lu\n", this, duration ); 118 67 // assert( THREAD_GETMEM( disableInt ) && THREAD_GETMEM( disableIntCnt ) == 1 ); 119 68 alarm_node_t * alarm = this->preemption_alarm; 120 duration *= 1000;121 69 122 70 // Alarms need to be enabled … … 149 97 150 98 void ^?{}( preemption_scope * this ) { 151 disable_interrupts();152 153 99 update_preemption( this->proc, 0 ); 154 100 } … … 158 104 //============================================================================================= 159 105 160 LIB_DEBUG_DO( static thread_local void * last_interrupt = 0; )161 162 extern "C" {163 void disable_interrupts() {164 __attribute__((unused)) unsigned short new_val = __atomic_add_fetch_2( &disable_preempt_count, 1, __ATOMIC_SEQ_CST );165 verify( new_val < (unsigned short)65_000 );166 verify( new_val != (unsigned short) 0 );167 }168 169 void enable_interrupts_noRF() {170 __attribute__((unused)) unsigned short prev = __atomic_fetch_add_2( &disable_preempt_count, -1, __ATOMIC_SEQ_CST );171 verify( prev != (unsigned short) 0 );172 }173 174 void enable_interrupts( DEBUG_CTX_PARAM ) {175 processor * proc = this_processor;176 thread_desc * thrd = this_thread;177 unsigned short prev = __atomic_fetch_add_2( &disable_preempt_count, -1, __ATOMIC_SEQ_CST );178 verify( prev != (unsigned short) 0 );179 if( prev == 1 && proc->pending_preemption ) {180 proc->pending_preemption = false;181 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Executing deferred CtxSwitch on %p\n", this_processor );182 BlockInternal( thrd );183 LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Executing deferred back\n" );184 }185 186 LIB_DEBUG_DO( proc->last_enable = caller; )187 }188 }189 190 static inline void signal_unblock( int sig ) {191 // LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Processor : %p unblocking sig %i\n", this_processor, sig );192 193 // LIB_DEBUG_DO(194 // sigset_t waiting;195 // sigemptyset(&waiting);196 // sigpending(&waiting);197 // verify( !sigismember(&waiting, sig) );198 // )199 200 sigset_t mask;201 sigemptyset( &mask );202 sigaddset( &mask, sig );203 204 if ( sigprocmask( SIG_UNBLOCK, &mask, NULL ) == -1 ) {205 abortf( "internal error, sigprocmask" );206 } // if207 }208 209 106 static inline bool preemption_ready() { 210 return disable_preempt_count == 0;107 return this_processor->disable_preempt_count == 0; 211 108 } 212 109 … … 219 116 } 220 117 221 extern "C" { 222 __attribute__((noinline)) void __debug_break() { 223 pthread_kill( pthread_self(), SIGTRAP ); 118 void sigHandler_ctxSwitch( __attribute__((unused)) int sig ) { 119 if( preemption_ready() ) { 120 ScheduleInternal( this_processor->current_thread ); 121 } 122 else { 123 defer_ctxSwitch(); 224 124 } 225 125 } 226 126 227 void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ) { 228 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "CtxSw IRH %10p running %10p @ %10p\n", this_processor, this_thread, (void *)(cxt->uc_mcontext.gregs[REG_RIP]) ); 229 LIB_DEBUG_DO( last_interrupt = (void *)(cxt->uc_mcontext.gregs[REG_RIP]); ) 230 231 if( preemption_ready() ) { 232 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ctx Switch IRH : Blocking thread %p on %p\n", this_thread, this_processor ); 233 signal_unblock( SIGUSR1 ); 234 BlockInternal( (thread_desc*)this_thread ); 235 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ctx Switch IRH : Back\n\n"); 236 } 237 else { 238 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ctx Switch IRH : Defering\n" ); 239 defer_ctxSwitch(); 240 signal_unblock( SIGUSR1 ); 241 } 242 } 243 244 void sigHandler_alarm( __CFA_SIGPARMS__ ) { 245 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "\nAlarm IRH %10p running %10p @ %10p\n", this_processor, this_thread, (void *)(cxt->uc_mcontext.gregs[REG_RIP]) ); 246 LIB_DEBUG_DO( last_interrupt = (void *)(cxt->uc_mcontext.gregs[REG_RIP]); ) 247 248 if( try_lock( &systemProcessor->alarm_lock DEBUG_CTX2 ) ) { 127 void sigHandler_alarm( __attribute__((unused)) int sig ) { 128 if( try_lock( &systemProcessor->alarm_lock ) ) { 249 129 tick_preemption(); 250 130 unlock( &systemProcessor->alarm_lock ); … … 253 133 defer_alarm(); 254 134 } 255 256 signal_unblock( SIGALRM );257 258 if( preemption_ready() && this_processor->pending_preemption ) {259 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Alarm IRH : Blocking thread %p on %p\n", this_thread, this_processor );260 this_processor->pending_preemption = false;261 BlockInternal( (thread_desc*)this_thread );262 // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Alarm Switch IRH : Back\n\n");263 }264 135 } 265 136 266 137 static void preempt( processor * this ) { 267 // LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Processor : signalling %p\n", this ); 268 269 if( this != systemProcessor ) { 270 pthread_kill( this->kernel_thread, SIGUSR1 ); 271 } 272 else { 273 defer_ctxSwitch(); 274 } 138 pthread_kill( this->kernel_thread, SIGUSR1 ); 275 139 } 276 140 … … 278 142 //TODO : implement waking threads 279 143 } 280 281 static void __kernel_sigaction( int sig, void (*handler)(__CFA_SIGPARMS__), int flags ) {282 struct sigaction act;283 284 act.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;285 act.sa_flags = flags;286 287 // disabled during signal handler288 sigemptyset( &act.sa_mask );289 sigaddset( &act.sa_mask, sig );290 291 if ( sigaction( sig, &act, NULL ) == -1 ) {292 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO,293 " __kernel_sigaction( sig:%d, handler:%p, flags:%d ), problem installing signal handler, error(%d) %s.\n",294 sig, handler, flags, errno, strerror( errno )295 );296 _exit( EXIT_FAILURE );297 }298 }299 300 typedef void (*sa_handler_t)(int);301 302 static void __kernel_sigdefault( int sig ) {303 struct sigaction act;304 305 // act.sa_handler = SIG_DFL;306 act.sa_flags = 0;307 sigemptyset( &act.sa_mask );308 309 if ( sigaction( sig, &act, NULL ) == -1 ) {310 LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO,311 " __kernel_sigdefault( sig:%d ), problem reseting signal handler, error(%d) %s.\n",312 sig, errno, strerror( errno )313 );314 _exit( EXIT_FAILURE );315 }316 }317 318 //=============================================================================================319 // Terminating Signals logic320 //=============================================================================================321 322 LIB_DEBUG_DO(323 static void __kernel_backtrace( int start ) {324 // skip first N stack frames325 326 enum { Frames = 50 };327 void * array[Frames];328 int size = backtrace( array, Frames );329 char ** messages = backtrace_symbols( array, size );330 331 // find executable name332 *index( messages[0], '(' ) = '\0';333 #ifdef __USE_STREAM__334 serr | "Stack back trace for:" | messages[0] | endl;335 #else336 fprintf( stderr, "Stack back trace for: %s\n", messages[0]);337 #endif338 339 // skip last 2 stack frames after main340 for ( int i = start; i < size && messages != NULL; i += 1 ) {341 char * name = NULL;342 char * offset_begin = NULL;343 char * offset_end = NULL;344 345 for ( char *p = messages[i]; *p; ++p ) {346 // find parantheses and +offset347 if ( *p == '(' ) {348 name = p;349 }350 else if ( *p == '+' ) {351 offset_begin = p;352 }353 else if ( *p == ')' ) {354 offset_end = p;355 break;356 }357 }358 359 // if line contains symbol print it360 int frameNo = i - start;361 if ( name && offset_begin && offset_end && name < offset_begin ) {362 // delimit strings363 *name++ = '\0';364 *offset_begin++ = '\0';365 *offset_end++ = '\0';366 367 #ifdef __USE_STREAM__368 serr | "(" | frameNo | ")" | messages[i] | ":"369 | name | "+" | offset_begin | offset_end | endl;370 #else371 fprintf( stderr, "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end);372 #endif373 }374 // otherwise, print the whole line375 else {376 #ifdef __USE_STREAM__377 serr | "(" | frameNo | ")" | messages[i] | endl;378 #else379 fprintf( stderr, "(%i) %s\n", frameNo, messages[i] );380 #endif381 }382 }383 384 free( messages );385 }386 )387 388 void sigHandler_segv( __CFA_SIGPARMS__ ) {389 LIB_DEBUG_DO(390 #ifdef __USE_STREAM__391 serr | "*CFA runtime error* program cfa-cpp terminated with"392 | (sig == SIGSEGV ? "segment fault." : "bus error.")393 | endl;394 #else395 fprintf( stderr, "*CFA runtime error* program cfa-cpp terminated with %s\n", sig == SIGSEGV ? "segment fault." : "bus error." );396 #endif397 398 // skip first 2 stack frames399 __kernel_backtrace( 1 );400 )401 exit( EXIT_FAILURE );402 }403 404 // void sigHandler_abort( __CFA_SIGPARMS__ ) {405 // // skip first 6 stack frames406 // LIB_DEBUG_DO( __kernel_backtrace( 6 ); )407 408 // // reset default signal handler409 // __kernel_sigdefault( SIGABRT );410 411 // raise( SIGABRT );412 // }
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