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#pragma once
#include "../goodies.h" // printStackTrace
namespace mongo {
/** some self-testing of synchronization and attempts to catch race conditions.
use something like:
CodeBlock myBlock;
void foo() {
CodeBlock::Within w(myBlock);
...
}
In _DEBUG builds, will (sometimes/maybe) fail if two threads are in the same code block at
the same time. Also detects and disallows recursion.
*/
#ifdef _WIN32
typedef unsigned threadId_t;
#else
typedef pthread_t threadId_t;
#endif
#if defined(_DEBUG)
namespace race {
class CodePoint {
public:
string lastName;
threadId_t lastTid;
string file;
CodePoint(string f) : lastTid(0), file(f) { }
};
class Check {
public:
Check(CodePoint& p) {
threadId_t t = GetCurrentThreadId();
if( p.lastTid == 0 ) {
p.lastTid = t;
p.lastName = getThreadName();
}
else if( t != p.lastTid ) {
log() << "\n\n\n\n\nRACE? error assert\n " << p.file << '\n'
<< " " << p.lastName
<< " " << getThreadName() << "\n\n" << endl;
mongoAbort("racecheck");
}
};
};
}
#define RACECHECK
// dm TODO - the right code for this file is in a different branch at the moment (merge)
//#define RACECHECK
//static race::CodePoint __cp(__FILE__);
//race::Check __ck(__cp);
class CodeBlock {
volatile int n;
threadId_t tid;
void fail() {
log() << "synchronization (race condition) failure" << endl;
printStackTrace();
::abort();
}
void enter() {
if( ++n != 1 ) fail();
#if defined(_WIN32)
tid = GetCurrentThreadId();
#endif
}
void leave() {
if( --n != 0 ) fail();
}
public:
CodeBlock() : n(0) { }
class Within {
CodeBlock& _s;
public:
Within(CodeBlock& s) : _s(s) { _s.enter(); }
~Within() { _s.leave(); }
};
void assertWithin() {
assert( n == 1 );
#if defined(_WIN32)
assert( GetCurrentThreadId() == tid );
#endif
}
};
#else
#define RACECHECK
class CodeBlock{
public:
class Within {
public:
Within(CodeBlock&) { }
};
void assertWithin() { }
};
#endif
} // namespace
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