Import SequenceLock from SMO

We now have a static local var that informs libspinscale whether or
not to print the callable traces at runtime.

CMakeLists.txt

@@ -76,6 +76,8 @@ add_library(spinscale SHARED
 	src/componentThread.cpp
 	src/component.cpp
 	src/puppetApplication.cpp
+	src/runtime.cpp
+	src/callableTracer.cpp
 )
 
 # Conditionally add qutexAcquisitionHistoryTracker.cpp only when debug locks

include/spinscale/callableTracer.h

@@ -8,11 +8,6 @@
 #include <cstdint>
 #include <spinscale/componentThread.h>
 
-// Forward declaration - OptionParser is defined in smocore/include/opts.h
-// If you need tracing, include opts.h before including this header
-// The code will check for OPTS_H define to see if opts.h has been included
-class OptionParser;
-
 namespace sscl {
 
 /**
@@ -50,11 +45,8 @@ public:
 
 	void operator()()
 	{
-		// OptionParser::getOptions() requires opts.h to be included
-		// Only check traceCallables if opts.h has been included (OPTS_H is defined)
 #ifdef CONFIG_DEBUG_TRACE_CALLABLES
-		#ifdef OPTS_H
+		if (optTraceCallables)
-		if (OptionParser::getOptions().traceCallables)
 		{
 			std::cout << "" << __func__ << ": On thread "
 				<< (ComponentThread::tlsInitialized()
@@ -66,11 +58,13 @@ public:
 				<< std::endl;
 		}
 #endif
-		#endif
 		callable();
 	}
 
 public:
+	/// Set by application (e.g. from opts) to enable per-callable trace output
+	static bool optTraceCallables;
+
 	/// Name of the function that created this callable
 	std::string callerFuncName;
 	/// Line number where this callable was created
@@ -115,7 +109,7 @@ private:
 		// e.g., "void smo::SomeClass::method(int, int)"
 		// __builtin_return_address(0) = direct caller
 		// __builtin_return_address(1) = caller before that
-		#define STC(arg) smo::CallableTracer( \
+		#define STC(arg) sscl::CallableTracer( \
 			__PRETTY_FUNCTION__, \
 			__LINE__, \
 			__builtin_return_address(0), \
@@ -126,7 +120,7 @@ private:
 		// e.g., "void __cdecl smo::SomeClass::method(int, int)"
 		// _ReturnAddress() = direct caller (only one level available)
 		#include <intrin.h>
-		#define STC(arg) smo::CallableTracer( \
+		#define STC(arg) sscl::CallableTracer( \
 			__FUNCSIG__, \
 			__LINE__, \
 			_ReturnAddress(), \
@@ -135,7 +129,7 @@ private:
 	#else
 		// Fallback to standard __func__ (unqualified name only)
 		// No return address support
-		#define STC(arg) smo::CallableTracer( \
+		#define STC(arg) sscl::CallableTracer( \
 			__func__, \
 			__LINE__, \
 			nullptr, \

include/spinscale/marionette.h

@@ -53,6 +53,8 @@ struct CrtCommandLineArgs
 	static void set(int argc, char *argv[], char *envp[]);
 };
 
+extern CrtCommandLineArgs crtCommandLineArgs;
+
 } // namespace sscl
 
 #endif // _MARIONETTE_H

include/spinscale/sequenceLock.h

@@ -0,0 +1,76 @@
+#ifndef SPINSCALE_SEQUENCE_LOCK_H
+#define SPINSCALE_SEQUENCE_LOCK_H
+
+#include <atomic>
+#include <optional>
+
+namespace sscl {
+
+/**
+ * @brief Sequence lock synchronization primitive
+ *
+ * A reader-writer synchronization primitive where writers increment the
+ * sequence number (odd = writing in progress, even = stable) and readers
+ * check the sequence number to detect concurrent modifications.
+ */
+class SequenceLock
+{
+public:
+	SequenceLock()
+	: sequenceNo(0)
+	{}
+
+	~SequenceLock() = default;
+
+	// Non-copyable, non-movable (std::atomic is neither copyable nor movable)
+	SequenceLock(const SequenceLock&) = delete;
+	SequenceLock& operator=(const SequenceLock&) = delete;
+	SequenceLock(SequenceLock&&) = delete;
+	SequenceLock& operator=(SequenceLock&&) = delete;
+
+	/* Atomically increments sequenceNo and issues a release barrier.
+	 * Makes the sequence number odd, indicating a write is in progress.
+	 */
+	void writeAcquire()
+		{ sequenceNo.fetch_add(1, std::memory_order_release); }
+
+	/* Atomically increments sequenceNo and issues a release barrier.
+	 * Makes the sequence number even again, indicating write is complete.
+	 */
+	void writeRelease()
+		{ sequenceNo.fetch_add(1, std::memory_order_release); }
+
+	/* Issues an acquire barrier and checks if the sequence number is even
+	 * (stable state). If odd (writer active), returns nullopt. Otherwise
+	 * returns the sequence number.
+	 *
+	 * @return std::nullopt if writer is active, otherwise the sequence number
+	 */
+	std::optional<size_t> readAcquire()
+	{
+		size_t seq = sequenceNo.load(std::memory_order_acquire);
+		if (seq & 1) {
+			return std::nullopt;
+		}
+		return seq;
+	}
+
+	/* Issues an acquire barrier and checks if the sequence number matches
+	 * the original value from readAcquire(). If equal, the read was consistent.
+	 *
+	 * @param originalSequenceNo The sequence number obtained from readAcquire()
+	 * @return true if read was consistent, false if writer modified during read
+	 */
+	bool readRelease(size_t originalSequenceNo)
+	{
+		size_t seq = sequenceNo.load(std::memory_order_acquire);
+		return seq == originalSequenceNo;
+	}
+
+private:
+	std::atomic<size_t> sequenceNo;
+};
+
+} // namespace sscl
+
+#endif // SPINSCALE_SEQUENCE_LOCK_H

src/callableTracer.cpp

@@ -0,0 +1,7 @@
+#include <spinscale/callableTracer.h>
+
+namespace sscl {
+
+bool CallableTracer::optTraceCallables = false;
+
+} // namespace sscl

src/runtime.cpp

@@ -0,0 +1,12 @@
+#include <spinscale/marionette.h>
+
+namespace sscl {
+
+CrtCommandLineArgs crtCommandLineArgs(0, nullptr, nullptr);
+
+void CrtCommandLineArgs::set(int argc, char *argv[], char *envp[])
+{
+	crtCommandLineArgs = CrtCommandLineArgs(argc, argv, envp);
+}
+
+} // namespace sscl