Changeset 21184e3 for libcfa

Timestamp:

Nov 18, 2019, 11:11:24 AM (5 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

57c764c, 7768b8d

Parents:

6559a9d

Message:

Added Thread-Local random number generator to kernel which will be needed for the ready-queue

Location:

libcfa/src

Files:

• bits/defs.hfa (modified) (1 diff)
• concurrency/invoke.h (modified) (2 diffs)
• concurrency/kernel.cfa (modified) (2 diffs)
• concurrency/kernel_private.hfa (modified) (1 diff)

libcfa/src/bits/defs.hfa

@@ -47 +47 @@
 #define OPTIONAL_THREAD __attribute__((weak))
 #endif
+
+static inline long long rdtscl(void) {
+    unsigned int lo, hi;
+    __asm__ __volatile__ ("rdtsc" : "=a"(lo), "=d"(hi));
+    return ( (unsigned long long)lo)|( ((unsigned long long)hi)<<32 );
+}

libcfa/src/concurrency/invoke.h

@@ -46 +46 @@
         #ifdef __cforall
         extern "Cforall" {
-                extern thread_local struct KernelThreadData {
+                extern __attribute__((aligned(128))) thread_local struct KernelThreadData {
                         struct thread_desc    * volatile this_thread;
                         struct processor      * volatile this_processor;
@@ -55 +55 @@
                                 volatile bool in_progress;
                         } preemption_state;
+
+                        uint32_t rand_seed;
                 } kernelTLS __attribute__ ((tls_model ( "initial-exec" )));
         }

libcfa/src/concurrency/kernel.cfa

@@ -133 +133 @@
         NULL,
         NULL,
-        { 1, false, false }
+        { 1, false, false },
+        6u //this should be seeded better but due to a bug calling rdtsc doesn't work
 };
 
@@ -260 +261 @@
 //Main of the processor contexts
 void main(processorCtx_t & runner) {
+        // Because of a bug, we couldn't initialized the seed on construction
+        // Do it here
+        kernelTLS.rand_seed ^= rdtsc();
+
         processor * this = runner.proc;
         verify(this);

libcfa/src/concurrency/kernel_private.hfa

@@ -101 +101 @@
 #define KERNEL_STORAGE(T,X) static char storage_##X[sizeof(T)]
 
+static inline uint32_t tls_rand() {
+        kernelTLS.rand_seed ^= kernelTLS.rand_seed << 6;
+        kernelTLS.rand_seed ^= kernelTLS.rand_seed >> 21;
+        kernelTLS.rand_seed ^= kernelTLS.rand_seed << 7;
+        return kernelTLS.rand_seed;
+}
+
 
 void doregister( struct cluster & cltr );