#include <cdsannotate.h>
#include <specannotation.h>
#include <model_memory.h>
-#include "common.h"
/**
@Begin
struct mpmc_boundq_1_alt
{
private:
-
+
+ unsigned int MASK;
+
+ atomic<t_element*> arr;
+
// elements should generally be cache-line-size padded :
t_element m_array[t_size];
public:
- mpmc_boundq_1_alt()
+ mpmc_boundq_1_alt(int _MASK = 0xFFFF)
{
/**
@Begin
m_rdwr = 0;
m_read = 0;
m_written = 0;
+ // For this we want MASK = 1; MASK wrap around
+ MASK = _MASK; //0x11;
+ arr = m_array;
}
LANG = CPP;
CLASS = mpmc_boundq_1_alt;
@Global_define:
- @DeclareVar:
- id_tag_t *tag;
- @InitVar:
- tag = NULL;
- @Happens_before:
- Publish -> Fetch
+ @Happens_before:
+ Publish -> Fetch
+ Consume -> Prepare
+ @Commutativity: Prepare <-> Prepare: _Method1.__RET__ !=
+ _Method2.__RET__ || !_Method1.__RET__ || !_Method2.__RET__
+ @Commutativity: Prepare <-> Publish: _Method1.__RET__ != _Method2.bin ||
+ !_Method1.__RET__
+ @Commutativity: Prepare <-> Fetch: _Method1.__RET__ != _Method2.__RET__
+ || !_Method1.__RET__ || !_Method2.__RET__
+ @Commutativity: Prepare <-> Consume : _Method1.__RET__ != _Method2.bin || !_Method1.__RET__
+
+ @Commutativity: Publish <-> Publish: _Method1.bin != _Method2.bin
+ @Commutativity: Publish <-> Fetch: _Method1.bin != _Method2.__RET__ ||
+ !_Method2.__RET__
+ @Commutativity: Publish <-> Consume : _Method1.bin != _Method2.bin
+
+ @Commutativity: Fetch <-> Fetch: _Method1.__RET__ != _Method2.__RET__ ||
+ !_Method1.__RET__ || !_Method2.__RET__
+ @Commutativity: Fetch <-> Consume : _Method1.__RET__ != _Method2.bin || !_Method1.__RET__
+
+ @Commutativity: Consume <-> Consume : _Method1.bin != _Method2.bin
+
@End
*/
/**
@Begin
@Interface: Fetch
- @Commit_point_set: Fetch_Succ_Point
+ @Commit_point_set: FetchReadRW1 | FetchReadRW2 | FetchReadPointer
@ID: (call_id_t) __RET__
+ //@Action: model_print("Fetch: %d\n", __RET__);
@End
*/
t_element * read_fetch() {
+ // Since we have a lool to CAS the value of m_rdwr, this can be relaxed
unsigned int rdwr = m_rdwr.load(mo_acquire);
+ //unsigned int rdwr = m_rdwr.load(mo_relaxed);
/**
@Begin
- @Commit_point_define_check: (rdwr>>16) & 0xFFFF == rdwr & 0xFFFF
- @Label: Fetch_Succ_Point1
+ @Commit_point_define_check: true
+ @Label: FetchReadRW1
@End
*/
unsigned int rd,wr;
for(;;) {
- rd = (rdwr>>16) & 0xFFFF;
- wr = rdwr & 0xFFFF;
+ rd = (rdwr>>16) & MASK;
+ wr = rdwr & MASK;
if ( wr == rd ) { // empty
return false;
}
-
- bool succ = m_rdwr.compare_exchange_weak(rdwr,rdwr+(1<<16),mo_acq_rel);
-
- if (succ)
+ /**** Inadmissibility (testcase2.cc, MASK = 1, size = 1) ****/
+ bool succ =
+ m_rdwr.compare_exchange_weak(rdwr,rdwr+(1<<16),mo_acq_rel);
+ if (succ) {
break;
- else
+ } else {
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: FetchClear1
+ @End
+ */
+
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: FetchReadRW2
+ @End
+ */
thrd_yield();
+ }
}
// (*1)
rl::backoff bo;
- while ( true ) {
- unsigned int tmp = m_written.load(mo_acquire);
- /**
- @Begin
- @Commit_point_define_check: (tmp & 0xFFFF) == wr
- @Label: Fetch_Succ_Point2
- @End
- */
- if ((tmp & 0xFFFF) == wr)
+ while (true) {
+ /**** Inadmissibility (testcase2.c) ****/
+ int written = m_written.load(mo_acquire);
+ if ((written & MASK) != wr) {
+ thrd_yield();
+ } else {
+ printf("Fetch: m_written=%d\n", written);
break;
- thrd_yield();
+ }
}
-
t_element * p = & ( m_array[ rd % t_size ] );
+
+ // This is just a hack to tell the CDSChecker that we have a memory
+ // operation here
+ arr.load(memory_order_relaxed);
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: FetchClear2
+ @End
+ */
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: FetchReadPointer
+ @End
+ */
return p;
}
- void read_consume() {
+ /**
+ @Begin
+ @Interface: Consume
+ @Commit_point_set: ConsumeFetchAdd
+ @ID: (call_id_t) bin
+ //@Action: model_print("Consume: %d\n", bin);
+ @End
+ */
+ void read_consume(t_element *bin) {
+ /**** Inadmissibility (testcase1.c) ****/
m_read.fetch_add(1,mo_release);
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: ConsumeFetchAdd
+ @End
+ */
}
//-----------------------------------------------------
+ /**
+ @Begin
+ @Interface: Prepare
+ @Commit_point_set: PrepareReadRW1 | PrepareReadRW2 | PrepareReadPointer
+ @ID: (call_id_t) __RET__
+ //@Action: model_print("Prepare: %d\n", __RET__);
+ @End
+ */
t_element * write_prepare() {
+ // Try weaker semantics
+ // Since we have a lool to CAS the value of m_rdwr, this can be relaxed
unsigned int rdwr = m_rdwr.load(mo_acquire);
+ //unsigned int rdwr = m_rdwr.load(mo_relaxed);
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: PrepareReadRW1
+ @End
+ */
unsigned int rd,wr;
for(;;) {
- rd = (rdwr>>16) & 0xFFFF;
- wr = rdwr & 0xFFFF;
+ rd = (rdwr>>16) & MASK;
+ wr = rdwr & MASK;
+ //printf("write_prepare: rd=%d, wr=%d\n", rd, wr);
- if ( wr == ((rd + t_size)&0xFFFF) ) { // full
+ if ( wr == ((rd + t_size)&MASK) ) { // full
return NULL;
}
+ // FIXME: Theoretically we have a bug here, it is not so likely to
+ // happen!!! The following acq_rel can not guarantee that the load
+ // acquire on m_read to read the most recent value. However, it can
+ // decrease the chance of the load acquire of m_read to read a too
+ // old value. Same as the case in read_fetch(). Maybe making things
+ // SC can fix it. We can run testcase3.c to expose this bug (set the
+ // array size = 1, the MASK = 1).
+
+ /**** Inadmissibility (testcase3.cc, MASK = 1, size = 1) ****/
bool succ = m_rdwr.compare_exchange_weak(rdwr,(rd<<16) |
- ((wr+1)&0xFFFF),mo_acq_rel);
- if (succ)
+ ((wr+1)&MASK),mo_acq_rel);
+ //printf("wr=%d\n", (wr+1)&MASK);
+ if (succ) {
break;
- else
+ } else {
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: PrepareClear1
+ @End
+ */
+
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: PrepareReadRW2
+ @End
+ */
thrd_yield();
+ }
}
// (*1)
rl::backoff bo;
- while ( (m_read.load(mo_acquire) & 0xFFFF) != rd ) {
- thrd_yield();
+ while (true) {
+ /**** Inadmissibility (testcase1.c) ****/
+ int read = m_read.load(mo_acquire);
+ if ((read & MASK) != rd)
+ thrd_yield();
+ else
+ break;
}
t_element * p = & ( m_array[ wr % t_size ] );
+ // This is also just a hack to tell the CDSChecker that we have a memory
+ // operation here
+ arr.load(memory_order_relaxed);
+ /**
+ @Begin
+ @Commit_point_clear: true
+ @Label: PrepareClear2
+ @End
+ */
+ /**
+ @Begin
+ @Commit_point_define_check: true
+ @Label: PrepareReadPointer
+ @End
+ */
+
return p;
}
/**
@Begin
@Interface: Publish
- @Commit_point_set: Publish_Point
- @ID: (uint64_t) elem
+ @Commit_point_set: PublishFetchAdd
+ @ID: (call_id_t) bin
+ //@Action: model_print("Publish: %d\n", bin);
@End
*/
- void write_publish(t_element *elem)
+ void write_publish(t_element *bin)
{
- m_written.fetch_add(1,mo_release);
+ /**** Inadmissibility (testcase2.c) ****/
+ int tmp = m_written.fetch_add(1,mo_release);
/**
@Begin
@Commit_point_define_check: true
- @Label: Publish_Point
+ @Label: PublishFetchAdd
@End
*/
+ printf("publish: m_written=%d\n", tmp + 1);
}
//-----------------------------------------------------
projects / cdsspec-compiler.git / blobdiff