Changes in src/libcfa/concurrency/preemption.c [381fdee:4dad189]

File:

• src/libcfa/concurrency/preemption.c (modified) (6 diffs)

src/libcfa/concurrency/preemption.c

@@ -10 +10 @@
 // Created On       : Mon Jun 5 14:20:42 2017
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Feb  9 14:42:34 2018
-// Update Count     : 25
+// Last Modified On : Tue Feb  6 15:00:36 2018
+// Update Count     : 10
 //
 
 #include "preemption.h"
 
+#define ftype `ftype`
 extern "C" {
 #include <errno.h>
@@ -22 +23 @@
 #include <unistd.h>
 }
+#undef ftype
 
 #include "bits/signal.h"
@@ -48 +50 @@
 
 // Machine specific register name
-#if   defined( __i386 )
+#if   defined(__x86_64__)
+#define CFA_REG_IP gregs[REG_RIP]
+#elif defined(__i386__)
 #define CFA_REG_IP gregs[REG_EIP]
-#elif defined( __x86_64 )
-#define CFA_REG_IP gregs[REG_RIP]
-#elif defined( __ARM_ARCH )
+#elif defined(__ARM_ARCH__)
 #define CFA_REG_IP arm_pc
-#else
-#error unknown hardware architecture
 #endif
 
@@ -66 +66 @@
         lock{};
 }
+
+enum {
+        PREEMPT_NORMAL    = 0,
+        PREEMPT_TERMINATE = 1,
+};
 
 //=============================================================================================
@@ -209 +214 @@
 // kill wrapper : signal a processor
 static void preempt( processor * this ) {
-        pthread_kill( this->kernel_thread, SIGUSR1 );
+        sigval_t value = { PREEMPT_NORMAL };
+        pthread_sigqueue( this->kernel_thread, SIGUSR1, value );
+}
+
+// kill wrapper : signal a processor
+void terminate(processor * this) {
+        this->do_terminate = true;
+        sigval_t value = { PREEMPT_TERMINATE };
+        pthread_sigqueue( this->kernel_thread, SIGUSR1, value );
 }
 
@@ -298 +311 @@
 void sigHandler_ctxSwitch( __CFA_SIGPARMS__ ) {
         __cfaabi_dbg_debug_do( last_interrupt = (void *)(cxt->uc_mcontext.CFA_REG_IP); )
+
+        // SKULLDUGGERY: if a thread creates a processor and the immediately deletes it,
+        // the interrupt that is supposed to force the kernel thread to preempt might arrive
+        // before the kernel thread has even started running. When that happens an iterrupt
+        // we a null 'this_processor' will be caught, just ignore it.
+        if(!this_processor) return;
+
+        choose(sfp->si_value.sival_int) {
+                case PREEMPT_NORMAL   : ;// Normal case, nothing to do here
+                case PREEMPT_TERMINATE: verify(this_processor->do_terminate);
+                default:
+                        abortf( "internal error, signal value is %d", sfp->si_value.sival_int );
+        }
 
         // Check if it is safe to preempt here