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-rw-r--r--base/random.cc27
-rw-r--r--base/random.hh26
-rw-r--r--dev/etherlink.cc20
-rw-r--r--dev/etherlink.hh5
4 files changed, 65 insertions, 13 deletions
diff --git a/base/random.cc b/base/random.cc
index a6d9da6c1..babe93db5 100644
--- a/base/random.cc
+++ b/base/random.cc
@@ -31,6 +31,7 @@
#include "sim/param.hh"
#include "base/random.hh"
+#include "base/trace.hh"
using namespace std;
@@ -52,15 +53,33 @@ seed(&paramContext, "seed", "seed to random number generator", 1);
void
RandomContext::checkParams()
{
- ::srandom(seed);
+ ::srand48(seed);
}
long
getLong()
{
- return random();
+ return mrand48();
}
+int64_t
+getUniform(int64_t maxmin)
+{
+ double r;
+ r = (drand48() - 0.500) * 2 * maxmin;
+ DPRINTFN("getUniform %f\n", r);
+ return (int64_t)round(r);
+}
+
+uint64_t
+getUniformPos(uint64_t max)
+{
+ double r;
+ r = drand48() * 2 * max;
+ return (uint64_t)round(r);
+}
+
+
// idea for generating a double from erand48
double
getDouble()
@@ -70,8 +89,8 @@ getDouble()
uint16_t _short[4];
};
- _long[0] = random();
- _long[1] = random();
+ _long[0] = mrand48();
+ _long[1] = mrand48();
return ldexp((double) _short[0], -48) +
ldexp((double) _short[1], -32) +
diff --git a/base/random.hh b/base/random.hh
index b4d20a274..eac91a53c 100644
--- a/base/random.hh
+++ b/base/random.hh
@@ -33,6 +33,8 @@
long getLong();
double getDouble();
+uint64_t getUniformPos(uint64_t max);
+int64_t getUniform(int64_t max);
template <typename T>
struct Random;
@@ -41,48 +43,72 @@ template<> struct Random<int8_t>
{
static int8_t get()
{ return getLong() & (int8_t)-1; }
+
+ static int8_t uniform(int8_t maxmin)
+ { return getUniform(maxmin); }
};
template<> struct Random<uint8_t>
{
static uint8_t get()
{ return getLong() & (uint8_t)-1; }
+
+ static uint8_t uniform(uint8_t max)
+ { return getUniformPos(max); }
};
template<> struct Random<int16_t>
{
static int16_t get()
{ return getLong() & (int16_t)-1; }
+
+ static int16_t uniform(int16_t maxmin)
+ { return getUniform(maxmin); }
};
template<> struct Random<uint16_t>
{
static uint16_t get()
{ return getLong() & (uint16_t)-1; }
+
+ static uint16_t uniform(uint16_t max)
+ { return getUniformPos(max); }
};
template<> struct Random<int32_t>
{
static int32_t get()
{ return (int32_t)getLong(); }
+
+ static int32_t uniform(int32_t maxmin)
+ { return getUniform(maxmin); }
};
template<> struct Random<uint32_t>
{
static uint32_t get()
{ return (uint32_t)getLong(); }
+
+ static uint32_t uniform(uint32_t max)
+ { return getUniformPos(max); }
};
template<> struct Random<int64_t>
{
static int64_t get()
{ return (int64_t)getLong() << 32 || (uint64_t)getLong(); }
+
+ static int64_t uniform(int64_t maxmin)
+ { return getUniform(maxmin); }
};
template<> struct Random<uint64_t>
{
static uint64_t get()
{ return (uint64_t)getLong() << 32 || (uint64_t)getLong(); }
+
+ static uint64_t uniform(uint64_t max)
+ { return getUniformPos(max); }
};
template<> struct Random<float>
diff --git a/dev/etherlink.cc b/dev/etherlink.cc
index 75360f368..f5c47bd22 100644
--- a/dev/etherlink.cc
+++ b/dev/etherlink.cc
@@ -35,6 +35,7 @@
#include <string>
#include <vector>
+#include "base/random.hh"
#include "base/trace.hh"
#include "dev/etherdump.hh"
#include "dev/etherint.hh"
@@ -48,11 +49,11 @@
using namespace std;
EtherLink::EtherLink(const string &name, EtherInt *peer0, EtherInt *peer1,
- double rate, Tick delay, EtherDump *dump)
+ double rate, Tick delay, Tick delayVar, EtherDump *dump)
: SimObject(name)
{
- link[0] = new Link(name + ".link0", this, 0, rate, delay, dump);
- link[1] = new Link(name + ".link1", this, 1, rate, delay, dump);
+ link[0] = new Link(name + ".link0", this, 0, rate, delay, delayVar, dump);
+ link[1] = new Link(name + ".link1", this, 1, rate, delay, delayVar, dump);
interface[0] = new Interface(name + ".int0", link[0], link[1]);
interface[1] = new Interface(name + ".int1", link[1], link[0]);
@@ -80,9 +81,9 @@ EtherLink::Interface::Interface(const string &name, Link *tx, Link *rx)
}
EtherLink::Link::Link(const string &name, EtherLink *p, int num,
- double rate, Tick delay, EtherDump *d)
+ double rate, Tick delay, Tick delay_var, EtherDump *d)
: objName(name), parent(p), number(num), txint(NULL), rxint(NULL),
- ticksPerByte(rate), linkDelay(delay), dump(d),
+ ticksPerByte(rate), linkDelay(delay), delayVar(delay_var), dump(d),
doneEvent(this)
{ }
@@ -158,7 +159,9 @@ EtherLink::Link::transmit(PacketPtr pkt)
DDUMP(EthernetData, pkt->data, pkt->length);
packet = pkt;
- Tick delay = (Tick)ceil(((double)pkt->length * ticksPerByte) + 1.0);
+ Random<Tick> var;
+ Tick delay = (Tick)ceil(((double)pkt->length * ticksPerByte) + 1.0 +
+ var.uniform(delayVar));
DPRINTF(Ethernet, "scheduling packet: delay=%d, (rate=%f)\n",
delay, ticksPerByte);
doneEvent.schedule(curTick + delay);
@@ -270,6 +273,7 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(EtherLink)
SimObjectParam<EtherInt *> int2;
Param<double> speed;
Param<Tick> delay;
+ Param<Tick> delay_var;
SimObjectParam<EtherDump *> dump;
END_DECLARE_SIM_OBJECT_PARAMS(EtherLink)
@@ -280,13 +284,15 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(EtherLink)
INIT_PARAM(int2, "interface 2"),
INIT_PARAM(speed, "link speed in bits per second"),
INIT_PARAM(delay, "transmit delay of packets in us"),
+ INIT_PARAM(delay_var, "Difference in amount of time to traverse wire"),
INIT_PARAM(dump, "object to dump network packets to")
END_INIT_SIM_OBJECT_PARAMS(EtherLink)
CREATE_SIM_OBJECT(EtherLink)
{
- return new EtherLink(getInstanceName(), int1, int2, speed, delay, dump);
+ return new EtherLink(getInstanceName(), int1, int2, speed, delay, delay_var,
+ dump);
}
REGISTER_SIM_OBJECT("EtherLink", EtherLink)
diff --git a/dev/etherlink.hh b/dev/etherlink.hh
index b9e6047fc..305007d9e 100644
--- a/dev/etherlink.hh
+++ b/dev/etherlink.hh
@@ -66,6 +66,7 @@ class EtherLink : public SimObject
double ticksPerByte;
Tick linkDelay;
+ Tick delayVar;
EtherDump *dump;
protected:
@@ -83,7 +84,7 @@ class EtherLink : public SimObject
public:
Link(const std::string &name, EtherLink *p, int num,
- double rate, Tick delay, EtherDump *dump);
+ double rate, Tick delay, Tick delay_var, EtherDump *dump);
~Link() {}
const std::string name() const { return objName; }
@@ -118,7 +119,7 @@ class EtherLink : public SimObject
public:
EtherLink(const std::string &name, EtherInt *peer0, EtherInt *peer1,
- double rate, Tick delay, EtherDump *dump);
+ double rate, Tick delay, Tick delayVar, EtherDump *dump);
virtual ~EtherLink();
virtual void serialize(std::ostream &os);
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-23 04:05:48 +0000