Changes in src/libcfa/concurrency/preemption.c [d6ff3ff:c5ac6d5]

File:

• src/libcfa/concurrency/preemption.c (modified) (8 diffs)

src/libcfa/concurrency/preemption.c

@@ -15 +15 @@
 //
 
-#include "libhdr.h"
 #include "preemption.h"
 
 extern "C" {
-#include <errno.h>
-#include <execinfo.h>
-#define __USE_GNU
 #include <signal.h>
-#undef __USE_GNU
-#include <stdio.h>
-#include <string.h>
-#include <unistd.h>
 }
 
-
-#ifdef __USE_STREAM__
-#include "fstream"
-#endif
-
-#define __CFA_DEFAULT_PREEMPTION__ 10000
+#define __CFA_DEFAULT_PREEMPTION__ 10
 
 __attribute__((weak)) unsigned int default_preemption() {
@@ -40 +27 @@
 }
 
-#define __CFA_SIGCXT__ ucontext_t *
-#define __CFA_SIGPARMS__ __attribute__((unused)) int sig, __attribute__((unused)) siginfo_t *sfp, __attribute__((unused)) __CFA_SIGCXT__ cxt
-
 static void preempt( processor   * this );
 static void timeout( thread_desc * this );
-
-void sigHandler_ctxSwitch( __CFA_SIGPARMS__ );
-void sigHandler_alarm    ( __CFA_SIGPARMS__ );
-void sigHandler_segv     ( __CFA_SIGPARMS__ );
-void sigHandler_abort    ( __CFA_SIGPARMS__ );
-
-static void __kernel_sigaction( int sig, void (*handler)(__CFA_SIGPARMS__), int flags );
-LIB_DEBUG_DO( bool validate( alarm_list_t * this ); )
-
-#ifdef __x86_64__
-#define CFA_REG_IP REG_RIP
-#else
-#define CFA_REG_IP REG_EIP
-#endif
-
 
 //=============================================================================================
@@ -65 +34 @@
 //=============================================================================================
 
+void kernel_start_preemption() {
+
+}
+
 void tick_preemption() {
-        // LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Ticking preemption\n" );
-
         alarm_list_t * alarms = &systemProcessor->alarms;
         __cfa_time_t currtime = __kernel_get_time();
         while( alarms->head && alarms->head->alarm < currtime ) {
                 alarm_node_t * node = pop(alarms);
-                // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ticking %p\n", node );
-
                 if( node->kernel_alarm ) {
                         preempt( node->proc );
@@ -81 +50 @@
                 }
 
-                verify( validate( alarms ) );
-
                 if( node->period > 0 ) {
-                        node->alarm = currtime + node->period;
+                        node->alarm += node->period;
                         insert( alarms, node );
                 }
@@ -95 +62 @@
                 __kernel_set_timer( alarms->head->alarm - currtime );
         }
-
-        verify( validate( alarms ) );
-        // LIB_DEBUG_PRINT_BUFFER_LOCAL( STDERR_FILENO, "Ticking preemption done\n" );
 }
 
 void update_preemption( processor * this, __cfa_time_t duration ) {
-        LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO, "Processor : %p updating preemption to %lu\n", this, duration );
-
+        //     assert( THREAD_GETMEM( disableInt ) && THREAD_GETMEM( disableIntCnt ) == 1 );
         alarm_node_t * alarm = this->preemption_alarm;
-        duration *= 1000;
 
         // Alarms need to be enabled
@@ -127 +89 @@
 }
 
+void ?{}( preemption_scope * this, processor * proc ) {
+        (&this->alarm){ proc };
+        this->proc = proc;
+        this->proc->preemption_alarm = &this->alarm;
+        update_preemption( this->proc, this->proc->preemption );
+}
+
+void ^?{}( preemption_scope * this ) {
+        update_preemption( this->proc, 0 );
+}
+
 //=============================================================================================
-// Kernel Signal Tools
+// Kernel Signal logic
 //=============================================================================================
 
-LIB_DEBUG_DO( static thread_local void * last_interrupt = 0; )
-
-extern "C" {
-        void disable_interrupts() {
-                __attribute__((unused)) unsigned short new_val = __atomic_add_fetch_2( &disable_preempt_count, 1, __ATOMIC_SEQ_CST );
-                verify( new_val < (unsigned short)65_000 );
-                verify( new_val != (unsigned short) 0 );
-        }
-
-        void enable_interrupts_noRF() {
-                __attribute__((unused)) unsigned short prev = __atomic_fetch_add_2( &disable_preempt_count, -1, __ATOMIC_SEQ_CST );
-                verify( prev != (unsigned short) 0 );
-        }
-
-        void enable_interrupts( DEBUG_CTX_PARAM ) {
-                processor * proc   = this_processor;
-                thread_desc * thrd = this_thread;
-                unsigned short prev = __atomic_fetch_add_2( &disable_preempt_count, -1, __ATOMIC_SEQ_CST );
-                verify( prev != (unsigned short) 0 );
-                if( prev == 1 && proc->pending_preemption ) {
-                        proc->pending_preemption = false;
-                        BlockInternal( thrd );
-                }
-
-                LIB_DEBUG_DO( proc->last_enable = caller; )
-        }
-}
-
-static inline void signal_unblock( int sig ) {
-        sigset_t mask;
-        sigemptyset( &mask );
-        sigaddset( &mask, sig );
-
-        if ( pthread_sigmask( SIG_UNBLOCK, &mask, NULL ) == -1 ) {
-            abortf( "internal error, pthread_sigmask" );
-        }
-}
-
-static inline void signal_block( int sig ) {
-        sigset_t mask;
-        sigemptyset( &mask );
-        sigaddset( &mask, sig );
-
-        if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) {
-            abortf( "internal error, pthread_sigmask" );
-        }
-}
-
 static inline bool preemption_ready() {
-        return disable_preempt_count == 0 && !preemption_in_progress;
+        return this_processor->disable_preempt_count == 0;
 }
 
@@ -191 +116 @@
 }
 
+void sigHandler_ctxSwitch( __attribute__((unused)) int sig ) {
+        if( preemption_ready() ) {
+                ScheduleInternal( this_processor->current_thread );
+        }
+        else {
+                defer_ctxSwitch();
+        }
+}
+
+void sigHandler_alarm( __attribute__((unused)) int sig ) {
+        if( try_lock( &systemProcessor->alarm_lock ) ) {
+                tick_preemption();
+                unlock( &systemProcessor->alarm_lock );
+        }
+        else {
+                defer_alarm();
+        }
+}
+
 static void preempt( processor * this ) {
         pthread_kill( this->kernel_thread, SIGUSR1 );
@@ -198 +142 @@
         //TODO : implement waking threads
 }
-
-//=============================================================================================
-// Kernel Signal Startup/Shutdown logic
-//=============================================================================================
-
-static pthread_t alarm_thread;
-void * alarm_loop( __attribute__((unused)) void * args );
-
-void kernel_start_preemption() {
-        LIB_DEBUG_PRINT_SAFE("Kernel : Starting preemption\n");
-        __kernel_sigaction( SIGUSR1, sigHandler_ctxSwitch, SA_SIGINFO );
-        // __kernel_sigaction( SIGSEGV, sigHandler_segv     , SA_SIGINFO );
-        // __kernel_sigaction( SIGBUS , sigHandler_segv     , SA_SIGINFO );
-
-        signal_block( SIGALRM );
-
-        pthread_create( &alarm_thread, NULL, alarm_loop, NULL );
-}
-
-void kernel_stop_preemption() {
-        LIB_DEBUG_PRINT_SAFE("Kernel : Preemption stopping\n");
-
-        sigset_t mask;
-        sigfillset( &mask );
-        sigprocmask( SIG_BLOCK, &mask, NULL );
-
-        sigval val = { 1 };
-        pthread_sigqueue( alarm_thread, SIGALRM, val );
-        pthread_join( alarm_thread, NULL );
-        LIB_DEBUG_PRINT_SAFE("Kernel : Preemption stopped\n");
-}
-
-void ?{}( preemption_scope * this, processor * proc ) {
-        (&this->alarm){ proc };
-        this->proc = proc;
-        this->proc->preemption_alarm = &this->alarm;
-        update_preemption( this->proc, this->proc->preemption );
-}
-
-void ^?{}( preemption_scope * this ) {
-        disable_interrupts();
-
-        update_preemption( this->proc, 0 );
-}
-
-//=============================================================================================
-// Kernel Signal Handlers
-//=============================================================================================
-
-void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ) {
-        LIB_DEBUG_DO( last_interrupt = (void *)(cxt->uc_mcontext.gregs[CFA_REG_IP]); )
-        if( preemption_ready() ) {
-                preemption_in_progress = true;
-                signal_unblock( SIGUSR1 );
-                this_processor->pending_preemption = false;
-                preemption_in_progress = false;
-                BlockInternal( (thread_desc*)this_thread );
-        }
-        else {
-                defer_ctxSwitch();
-        }
-}
-
-void * alarm_loop( __attribute__((unused)) void * args ) {
-        sigset_t mask;
-        sigemptyset( &mask );
-        sigaddset( &mask, SIGALRM );
-
-        if ( pthread_sigmask( SIG_BLOCK, &mask, NULL ) == -1 ) {
-            abortf( "internal error, pthread_sigmask" );
-        }
-
-        while( true ) {
-                siginfo_t info;
-                int sig = sigwaitinfo( &mask, &info );
-                if( sig < 0 ) {
-                        abortf( "internal error, sigwait" );
-                }
-                else if( sig == SIGALRM )
-                {
-                        LIB_DEBUG_PRINT_SAFE("Kernel : Caught signal %d (%d)\n", sig, info.si_value.sival_int );
-                        if( info.si_value.sival_int == 0 )
-                        {
-                                LIB_DEBUG_PRINT_SAFE("Kernel : Preemption thread tick\n");
-                                lock( &systemProcessor->alarm_lock DEBUG_CTX2 );
-                                tick_preemption();
-                                unlock( &systemProcessor->alarm_lock );
-                        }
-                        else if( info.si_value.sival_int == 1 )
-                        {
-                                break;
-                        }
-                }
-                else
-                {
-                        LIB_DEBUG_PRINT_SAFE("Kernel : Unexpected signal %d (%d)\n", sig, info.si_value.sival_int);
-                }
-        }
-
-        LIB_DEBUG_PRINT_SAFE("Kernel : Preemption thread stopping\n");
-        return NULL;
-}
-
-static void __kernel_sigaction( int sig, void (*handler)(__CFA_SIGPARMS__), int flags ) {
-        struct sigaction act;
-
-        act.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;
-        act.sa_flags = flags;
-
-        if ( sigaction( sig, &act, NULL ) == -1 ) {
-                LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO,
-                        " __kernel_sigaction( sig:%d, handler:%p, flags:%d ), problem installing signal handler, error(%d) %s.\n",
-                        sig, handler, flags, errno, strerror( errno )
-                );
-                _exit( EXIT_FAILURE );
-        }
-}
-
-typedef void (*sa_handler_t)(int);
-
-static void __kernel_sigdefault( int sig ) {
-        struct sigaction act;
-
-        // act.sa_handler = SIG_DFL;
-        act.sa_flags = 0;
-        sigemptyset( &act.sa_mask );
-
-        if ( sigaction( sig, &act, NULL ) == -1 ) {
-                LIB_DEBUG_PRINT_BUFFER_DECL( STDERR_FILENO,
-                        " __kernel_sigdefault( sig:%d ), problem reseting signal handler, error(%d) %s.\n",
-                        sig, errno, strerror( errno )
-                );
-                _exit( EXIT_FAILURE );
-        }
-}
-
-//=============================================================================================
-// Terminating Signals logic
-//=============================================================================================
-
-LIB_DEBUG_DO(
-        static void __kernel_backtrace( int start ) {
-                // skip first N stack frames
-
-                enum { Frames = 50 };
-                void * array[Frames];
-                int size = backtrace( array, Frames );
-                char ** messages = backtrace_symbols( array, size );
-
-                // find executable name
-                *index( messages[0], '(' ) = '\0';
-                #ifdef __USE_STREAM__
-                serr | "Stack back trace for:" | messages[0] | endl;
-                #else
-                fprintf( stderr, "Stack back trace for: %s\n", messages[0]);
-                #endif
-
-                // skip last 2 stack frames after main
-                for ( int i = start; i < size && messages != NULL; i += 1 ) {
-                        char * name = NULL;
-                        char * offset_begin = NULL;
-                        char * offset_end = NULL;
-
-                        for ( char *p = messages[i]; *p; ++p ) {
-                                // find parantheses and +offset
-                                if ( *p == '(' ) {
-                                        name = p;
-                                }
-                                else if ( *p == '+' ) {
-                                        offset_begin = p;
-                                }
-                                else if ( *p == ')' ) {
-                                        offset_end = p;
-                                        break;
-                                }
-                        }
-
-                        // if line contains symbol print it
-                        int frameNo = i - start;
-                        if ( name && offset_begin && offset_end && name < offset_begin ) {
-                                // delimit strings
-                                *name++ = '\0';
-                                *offset_begin++ = '\0';
-                                *offset_end++ = '\0';
-
-                                #ifdef __USE_STREAM__
-                                serr    | "("  | frameNo | ")" | messages[i] | ":"
-                                        | name | "+" | offset_begin | offset_end | endl;
-                                #else
-                                fprintf( stderr, "(%i) %s : %s + %s %s\n", frameNo, messages[i], name, offset_begin, offset_end);
-                                #endif
-                        }
-                        // otherwise, print the whole line
-                        else {
-                                #ifdef __USE_STREAM__
-                                serr | "(" | frameNo | ")" | messages[i] | endl;
-                                #else
-                                fprintf( stderr, "(%i) %s\n", frameNo, messages[i] );
-                                #endif
-                        }
-                }
-
-                free( messages );
-        }
-)
-
-// void sigHandler_segv( __CFA_SIGPARMS__ ) {
-//      LIB_DEBUG_DO(
-//              #ifdef __USE_STREAM__
-//              serr    | "*CFA runtime error* program cfa-cpp terminated with"
-//                      | (sig == SIGSEGV ? "segment fault." : "bus error.")
-//                      | endl;
-//              #else
-//              fprintf( stderr, "*CFA runtime error* program cfa-cpp terminated with %s\n", sig == SIGSEGV ? "segment fault." : "bus error." );
-//              #endif
-
-//              // skip first 2 stack frames
-//              __kernel_backtrace( 1 );
-//      )
-//      exit( EXIT_FAILURE );
-// }
-
-// void sigHandler_abort( __CFA_SIGPARMS__ ) {
-//      // skip first 6 stack frames
-//      LIB_DEBUG_DO( __kernel_backtrace( 6 ); )
-
-//      // reset default signal handler
-//      __kernel_sigdefault( SIGABRT );
-
-//      raise( SIGABRT );
-// }