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{$ifdef fpc}
{$mode objfpc}
{$h+}
{$endif}
uses
{$ifdef unix}
cthreads,
{$endif}
SysUtils, Classes;
var
lock: TMultiReadExclusiveWriteSynchronizer;
gcount: longint;
waiting: boolean;
type
terrorcheck = class(tthread)
procedure execute; override;
end;
tcounter = class(tthread)
private
flock: TMultiReadExclusiveWriteSynchronizer;
flocalcount: longint;
public
constructor create;
property localcount: longint read flocalcount;
end;
treadcounter = class(tcounter)
procedure execute; override;
end;
twritecounter = class(tcounter)
procedure execute; override;
end;
constructor tcounter.create;
begin
{ create suspended }
inherited create(true);
freeonterminate:=false;
flock:=lock;
flocalcount:=0;
end;
procedure treadcounter.execute;
var
i: longint;
l: longint;
r: longint;
begin
for i:=1 to 100000 do
begin
lock.beginread;
inc(flocalcount);
l:=gcount;
{ guarantee at least one sleep }
if i=50000 then
sleep(20+random(30))
else if (random(10000)=0) then
sleep(20);
{ this must cause data races/loss at some point }
gcount:=l+1;
lock.endread;
r:=random(30000);
if (r=0) then
sleep(30);
end;
end;
procedure twritecounter.execute;
var
i: longint;
l: longint;
r: longint;
begin
for i:=1 to 500 do
begin
lock.beginwrite;
inc(flocalcount);
l:=gcount;
{ guarantee at least one sleep }
if i=250 then
sleep(20+random(30))
else if (random(100)=0) then
sleep(20);
{ we must be exclusive }
if gcount<>l then
begin
writeln('error 1');
halt(1);
end;
gcount:=l+1;
lock.endwrite;
r:=random(30);
if (r>28) then
sleep(r);
end;
end;
procedure terrorcheck.execute;
begin
{ make sure we don't exit before this thread has initialised, since }
{ it can allocate memory in its initialisation, which would cause }
{ problems for heaptrc as it goes over the memory map in its exit code }
waiting:=true;
{ avoid deadlocks/bugs from causing this test to never quit }
sleep(1000*15);
writeln('error 4');
halt(4);
end;
var
r1,r2,r3,r4,r5,r6: treadcounter;
w1,w2,w3,w4: twritecounter;
begin
waiting:=false;
terrorcheck.create(false);
randomize;
lock:=TMultiReadExclusiveWriteSynchronizer.create;
{ verify that the lock is recursive }
lock.beginwrite;
lock.beginwrite;
lock.endwrite;
lock.endwrite;
{ first try some writers }
w1:=twritecounter.create;
w2:=twritecounter.create;
w3:=twritecounter.create;
w4:=twritecounter.create;
w1.resume;
w2.resume;
w3.resume;
w4.resume;
w1.waitfor;
w2.waitfor;
w3.waitfor;
w4.waitfor;
{ must not have caused any data races }
if (gcount<>w1.localcount+w2.localcount+w3.localcount+w4.localcount) then
begin
writeln('error 2');
halt(2);
end;
w1.free;
w2.free;
w3.free;
w4.free;
{ now try some mixed readers/writers }
gcount:=0;
r1:=treadcounter.create;
r2:=treadcounter.create;
r3:=treadcounter.create;
r4:=treadcounter.create;
r5:=treadcounter.create;
r6:=treadcounter.create;
w1:=twritecounter.create;
w2:=twritecounter.create;
r1.resume;
r2.resume;
r3.resume;
r4.resume;
r5.resume;
r6.resume;
w1.resume;
w2.resume;
r1.waitfor;
r2.waitfor;
r3.waitfor;
r4.waitfor;
r5.waitfor;
r6.waitfor;
w1.waitfor;
w2.waitfor;
{ updating via the readcount must have caused data races }
if (gcount>=r1.localcount+r2.localcount+r3.localcount+r4.localcount+r5.localcount+r6.localcount+w1.localcount+w2.localcount) then
begin
writeln('error 3');
halt(3);
end;
r1.free;
r2.free;
r3.free;
r4.free;
r5.free;
r6.free;
w1.free;
w2.free;
lock.free;
while not waiting do
sleep(20);
end.
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