Add IpcNamedSignal.

Author: asfernandes

builds/win32/msvc15/common.vcxproj

@@ -199,6 +199,7 @@
     <ClInclude Include="..\..\..\src\common\IntlUtil.h" />
     <ClInclude Include="..\..\..\src\common\ipc\IpcChat.h" />
     <ClInclude Include="..\..\..\src\common\ipc\IpcMessage.h" />
+    <ClInclude Include="..\..\..\src\common\ipc\IpcNamedSignal.h" />
     <ClInclude Include="..\..\..\src\common\isc_f_proto.h" />
     <ClInclude Include="..\..\..\src\common\isc_proto.h" />
     <ClInclude Include="..\..\..\src\common\isc_s_proto.h" />

builds/win32/msvc15/common.vcxproj.filters

@@ -632,5 +632,8 @@
     <ClInclude Include="..\..\..\src\common\ipc\IpcMessage.h">
       <Filter>headers</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\..\src\common\ipc\IpcNamedSignal.h">
+      <Filter>headers</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

src/common/ipc/IpcNamedSignal.h

@@ -0,0 +1,220 @@
+/*
+ *  The contents of this file are subject to the Initial
+ *  Developer's Public License Version 1.0 (the "License");
+ *  you may not use this file except in compliance with the
+ *  License. You may obtain a copy of the License at
+ *  http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_idpl.
+ *
+ *  Software distributed under the License is distributed AS IS,
+ *  WITHOUT WARRANTY OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing rights
+ *  and limitations under the License.
+ *
+ *  The Original Code was created by Adriano dos Santos Fernandes
+ *  for the Firebird Open Source RDBMS project.
+ *
+ *  Copyright (c) 2025 Adriano dos Santos Fernandes <[email protected]>
+ *  and all contributors signed below.
+ *
+ *  All Rights Reserved.
+ *  Contributor(s): ______________________________________.
+ */
+
+#ifndef COMMON_IPC_NAMED_SIGNAL_H
+#define COMMON_IPC_NAMED_SIGNAL_H
+
+#include "firebird.h"
+#include "../classes/fb_string.h"
+#include "../StatusArg.h"
+#include "../utils_proto.h"
+#include <chrono>
+#ifdef WIN_NT
+#include <windows.h>
+#else
+#include "fb_pthread.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <semaphore.h>
+#endif
+
+#ifdef ANDROID
+#error This is not supported in Android.
+#endif
+
+namespace Firebird {
+
+
+// An event in Windows, a semaphore in POSIX.
+class IpcNamedSignal
+{
+public:
+	explicit IpcNamedSignal(const string& name);
+	~IpcNamedSignal();
+
+	IpcNamedSignal(const IpcNamedSignal&) = delete;
+	IpcNamedSignal& operator=(const IpcNamedSignal&) = delete;
+
+private:
+	static string fixName(const string& name);
+
+#ifndef WIN_NT
+public:
+	static void remove(const string& name)
+	{
+		if (sem_unlink(fixName(name).c_str()) != 0)
+			fb_assert(false);
+	}
+#endif
+
+public:
+	void reset();
+	void signal();
+	bool wait(std::chrono::microseconds timeout);
+
+private:
+#ifdef WIN_NT
+	HANDLE handle = INVALID_HANDLE_VALUE;
+#else
+	sem_t* handle = nullptr;
+#endif
+};
+
+
+#ifdef WIN_NT
+
+
+inline IpcNamedSignal::IpcNamedSignal(const string& name)
+{
+	TEXT objectName[BUFFER_TINY];
+	strncpy(objectName, name.c_str(), sizeof(objectName));
+
+	if (!fb_utils::private_kernel_object_name(objectName, sizeof(objectName)))
+		(Arg::Gds(isc_random) << "private_kernel_object_name failed").raise();
+
+	handle = CreateEvent(nullptr, TRUE, FALSE, objectName);
+
+	if (!handle)
+		system_error::raise("CreateEvent");
+
+	SetHandleInformation(handle, HANDLE_FLAG_INHERIT, 0);
+}
+
+inline IpcNamedSignal::~IpcNamedSignal()
+{
+	if (handle)
+		CloseHandle(handle);
+}
+
+inline string IpcNamedSignal::fixName(const string& name)
+{
+	return name;
+}
+
+inline void IpcNamedSignal::reset()
+{
+	ResetEvent(handle);
+}
+
+inline void IpcNamedSignal::signal()
+{
+	if (!SetEvent(handle))
+		system_error::raise("SetEvent");
+}
+
+inline bool IpcNamedSignal::wait(std::chrono::microseconds timeout)
+{
+	const auto wait = WaitForSingleObject(handle, timeout.count() / 1'000);
+
+	if (wait == WAIT_OBJECT_0)
+		return true;
+	else if (wait == WAIT_TIMEOUT)
+		return false;
+	else
+		system_error::raise("WaitForSingleObject");
+}
+
+
+#else
+
+
+inline IpcNamedSignal::IpcNamedSignal(const string& name)
+{
+	handle = sem_open(fixName(name).c_str(), O_CREAT, S_IRUSR | S_IWUSR, 0);
+
+	if (handle == SEM_FAILED)
+		system_error::raise("sem_open");
+}
+
+inline IpcNamedSignal::~IpcNamedSignal()
+{
+	if (handle)
+		sem_close(handle);
+}
+
+inline string IpcNamedSignal::fixName(const string& name)
+{
+	if (name[0] == '/')
+		return name;
+
+	return "/" + name;
+}
+
+inline void IpcNamedSignal::reset()
+{
+	int semVal;
+
+	while (sem_getvalue(handle, &semVal) == 0 && semVal > 0)
+		sem_trywait(handle);
+}
+
+inline void IpcNamedSignal::signal()
+{
+	if (sem_post(handle) != 0)
+		system_error::raise("sem_post");
+}
+
+inline bool IpcNamedSignal::wait(std::chrono::microseconds timeout)
+{
+	timespec timer;
+
+#if defined(HAVE_CLOCK_GETTIME)
+	clock_gettime(CLOCK_REALTIME, &timer);
+#elif defined(HAVE_GETTIMEOFDAY)
+	struct timeval tp;
+	GETTIMEOFDAY(&tp);
+	timer.tv_sec = tp.tv_sec;
+	timer.tv_nsec = tp.tv_usec * 1'000;
+#else
+	struct timeb time_buffer;
+	ftime(&time_buffer);
+	timer.tv_sec = time_buffer.time;
+	timer.tv_nsec = time_buffer.millitm * 1'000'000;
+#endif
+
+	constexpr SINT64 BILLION = 1'000'000'000;
+	const SINT64 nanos =
+		std::chrono::seconds(timer.tv_sec).count() + timer.tv_nsec + std::chrono::nanoseconds(timeout).count();
+	timer.tv_sec = nanos / BILLION;
+	timer.tv_nsec = nanos % BILLION;
+
+#ifdef HAVE_SEM_TIMEDWAIT
+	const auto wait = sem_timedwait(handle, &timer);
+#else
+	const auto wait = sem_timedwait_fallback(handle, &timer);
+#endif
+
+	if (wait == 0)
+		return true;
+	else if (errno == ETIMEDOUT)
+		return false;
+	else
+		system_error::raise("sem_timedwait");
+}
+
+
+#endif
+
+
+} // namespace Firebird
+
+#endif // COMMON_IPC_NAMED_SIGNAL_H