src/common/Thread.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2020 Christian Schoenebeck                       *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_THREAD_H__
#define __LS_THREAD_H__

//FIXME: this is a temorary solution because of problems with condition variables we use a polling lock in SignalStartThread()
#if defined(WIN32)
#define WIN32_SIGNALSTARTTHREAD_WORKAROUND 1
#endif

#include <iostream>
#include <stdio.h>
#include <stdlib.h>

#if defined(WIN32)
#include <windows.h>
#else
#include <sched.h>
#include <sys/mman.h>
#include <memory.h>
#include <pthread.h>
#endif
#include <errno.h>

#include "Condition.h"

namespace LinuxSampler {

/**
 * Abstract base class for classes that need to run in an own thread. The
 * deriving class needs to implement the abstract method Main() for the actual
 * task of the thread to be implemented.
 *
 * @b IMPORTANT: You @b MUST call StopThread() before destructing a running
 * Thread object! Destructing the Thread object without stopping it first can
 * lead to undefined behavior! The destructor will detect if the thread is still
 * running and will stop it automatically in this case, however once the
 * destructor is entered, this Thread object's vpointer is already been
 * modified, so if the thread is still running at this point this would cause a
 * data race condition since the active thread is calling virtual methods and
 * thus this can lead to undefined behavior.
 */
class Thread {
    public:
        Thread(bool LockMemory, bool RealTime, int PriorityMax, int PriorityDelta);
        virtual ~Thread();
        virtual int  StartThread();
        virtual int  StopThread();
        virtual int  SignalStopThread();
        virtual bool IsRunning();

        /**
         * Allocates an aligned block of memory. Allocated memory blocks
         * need to be freed using freeAlignedMem().
         *
         * @param boundary - the alignement boundary, usually a power of 2
         *                   e.g. 4 but it can be an arbitrary number
         *                   between 1 and 128
         * @param size     - size in bytes to be allocated
         * @returns  pointer to the allocated memory block
         */
        static void* allocAlignedMem(size_t boundary, size_t size) {
            unsigned char *ptr = (unsigned char *)malloc(size+boundary);
            size_t offset = boundary - ((size_t)ptr % boundary);
            ptr[offset-1] = (unsigned char)offset;
            return (ptr + offset);
        }

        /**
         * Frees an aligned block of memory allocated with allocAlignedMem()
         *
         * @param ptr - pointer to the memory block
         */
        static void freeAlignedMem(void *ptr) {
            unsigned char *p = (unsigned char *)ptr;
            p -= p[-1];
            free(p);
        }

        /**
         * Locks a region of memory in physical RAM.
         *
         * @param addr - address of the memory block
         * @param size - size of the memory block
         * @return true if the locking succeded, otherwise false
         */
        static bool lockMemory(void *addr, size_t size) {
            #if defined(WIN32)
            return VirtualLock(addr, size);
            #else
            return !mlock(addr, size);
            #endif
        }

        /**
         * Unlocks a region of memory in physical RAM.
         *
         * @param addr - address of the memory block
         * @param size - size of the memory block
         * @return true if the unlocking succeded, otherwise false
         */
        static bool unlockMemory(void *addr, size_t size) {
            #if defined(WIN32)
            return VirtualUnlock(addr, size);
            #else
            return !munlock(addr, size);
            #endif
        }

        static void pushCancelable(bool cancel);
        static void popCancelable();

        std::string name();
        static std::string nameOfCaller();
        static void setNameOfCaller(std::string name);

    protected:
        /**
         * This method needs to be implemented by the descending class and is
         * the entry point for the new thread.
         *
         * @b NOTE: If your thread runs for a longer time, i.e. if it is running
         * a loop, then you should explicitly call TestCancel() once in a while
         * in your Main() implementation, especially if your implementation does
         * not use any system calls.
         */
        virtual int Main() = 0;

        /**
         * Synchronization point for potentially terminating the thread. Like
         * already described in Main() you should call TestCancel() in your
         * Main() implementation once in a while to provide the system a chance
         * to perform a clean termination of your thread. Depending on the
         * underlying OS, and also depending on whether your are using any
         * system call in your Main() implementation, it might otherwise be
         * possible that the thread cannot be terminated at all! And even if the
         * underlying OS supports terminating busy threads which do not call
         * TestCancel(), this might still cause undefined behavior on such OSes!
         */
        void TestCancel();

        virtual int  SignalStartThread();
        virtual int  SetSchedulingPriority();
        virtual int  LockMemory();
        virtual void EnableDestructor();
        virtual int  onThreadEnd();

    private:
        enum state_t {
            NOT_RUNNING,
            RUNNING,
            PENDING_JOIN,
            DETACHED
        };

    #if defined(WIN32)
        HANDLE hThread;
        DWORD lpThreadId;
        #if defined(WIN32_SIGNALSTARTTHREAD_WORKAROUND)
        bool win32isRunning;
        #endif
    #else
        pthread_attr_t  __thread_attr;
        pthread_t       __thread_id;
        pthread_key_t   __thread_destructor_key;
    #endif
        Condition       RunningCondition;
        int             PriorityMax;
        int             PriorityDelta;
        bool            isRealTime;
        bool            bLockedMemory;
        state_t         state;

    #if defined(WIN32)
        static DWORD WINAPI win32threadLauncher(LPVOID lpParameter);
    #else
        static void* pthreadLauncher(void* thread);
        static void  pthreadDestructor(void* thread);
    #endif
};

} // namespace LinuxSampler

#endif // __LS_THREAD_H__
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6	* Copyright (C) 2005 - 2020 Christian Schoenebeck *
7	* *
8	* This program is free software; you can redistribute it and/or modify *
9	* it under the terms of the GNU General Public License as published by *
10	* the Free Software Foundation; either version 2 of the License, or *
11	* (at your option) any later version. *
12	* *
13	* This program is distributed in the hope that it will be useful, *
14	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16	* GNU General Public License for more details. *
17	* *
18	* You should have received a copy of the GNU General Public License *
19	* along with this program; if not, write to the Free Software *
20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21	* MA 02111-1307 USA *
22	***************************************************************************/
23
24	#ifndef __LS_THREAD_H__
25	#define __LS_THREAD_H__
26
27	//FIXME: this is a temorary solution because of problems with condition variables we use a polling lock in SignalStartThread()
28	#if defined(WIN32)
29	#define WIN32_SIGNALSTARTTHREAD_WORKAROUND 1
30	#endif
31
32	#include <iostream>
33	#include <stdio.h>
34	#include <stdlib.h>
35
36	#if defined(WIN32)
37	#include <windows.h>
38	#else
39	#include <sched.h>
40	#include <sys/mman.h>
41	#include <memory.h>
42	#include <pthread.h>
43	#endif
44	#include <errno.h>
45
46	#include "Condition.h"
47
48	namespace LinuxSampler {
49
50	/**
51	* Abstract base class for classes that need to run in an own thread. The
52	* deriving class needs to implement the abstract method Main() for the actual
53	* task of the thread to be implemented.
54	*
55	* @b IMPORTANT: You @b MUST call StopThread() before destructing a running
56	* Thread object! Destructing the Thread object without stopping it first can
57	* lead to undefined behavior! The destructor will detect if the thread is still
58	* running and will stop it automatically in this case, however once the
59	* destructor is entered, this Thread object's vpointer is already been
60	* modified, so if the thread is still running at this point this would cause a
61	* data race condition since the active thread is calling virtual methods and
62	* thus this can lead to undefined behavior.
63	*/
64	class Thread {
65	public:
66	Thread(bool LockMemory, bool RealTime, int PriorityMax, int PriorityDelta);
67	virtual ~Thread();
68	virtual int StartThread();
69	virtual int StopThread();
70	virtual int SignalStopThread();
71	virtual bool IsRunning();
72
73	/**
74	* Allocates an aligned block of memory. Allocated memory blocks
75	* need to be freed using freeAlignedMem().
76	*
77	* @param boundary - the alignement boundary, usually a power of 2
78	* e.g. 4 but it can be an arbitrary number
79	* between 1 and 128
80	* @param size - size in bytes to be allocated
81	* @returns pointer to the allocated memory block
82	*/
83	static void* allocAlignedMem(size_t boundary, size_t size) {
84	unsigned char ptr = (unsigned char )malloc(size+boundary);
85	size_t offset = boundary - ((size_t)ptr % boundary);
86	ptr[offset-1] = (unsigned char)offset;
87	return (ptr + offset);
88	}
89
90	/**
91	* Frees an aligned block of memory allocated with allocAlignedMem()
92	*
93	* @param ptr - pointer to the memory block
94	*/
95	static void freeAlignedMem(void *ptr) {
96	unsigned char p = (unsigned char )ptr;
97	p -= p[-1];
98	free(p);
99	}
100
101	/**
102	* Locks a region of memory in physical RAM.
103	*
104	* @param addr - address of the memory block
105	* @param size - size of the memory block
106	* @return true if the locking succeded, otherwise false
107	*/
108	static bool lockMemory(void *addr, size_t size) {
109	#if defined(WIN32)
110	return VirtualLock(addr, size);
111	#else
112	return !mlock(addr, size);
113	#endif
114	}
115
116	/**
117	* Unlocks a region of memory in physical RAM.
118	*
119	* @param addr - address of the memory block
120	* @param size - size of the memory block
121	* @return true if the unlocking succeded, otherwise false
122	*/
123	static bool unlockMemory(void *addr, size_t size) {
124	#if defined(WIN32)
125	return VirtualUnlock(addr, size);
126	#else
127	return !munlock(addr, size);
128	#endif
129	}
130
131	static void pushCancelable(bool cancel);
132	static void popCancelable();
133
134	std::string name();
135	static std::string nameOfCaller();
136	static void setNameOfCaller(std::string name);
137
138	protected:
139	/**
140	* This method needs to be implemented by the descending class and is
141	* the entry point for the new thread.
142	*
143	* @b NOTE: If your thread runs for a longer time, i.e. if it is running
144	* a loop, then you should explicitly call TestCancel() once in a while
145	* in your Main() implementation, especially if your implementation does
146	* not use any system calls.
147	*/
148	virtual int Main() = 0;
149
150	/**
151	* Synchronization point for potentially terminating the thread. Like
152	* already described in Main() you should call TestCancel() in your
153	* Main() implementation once in a while to provide the system a chance
154	* to perform a clean termination of your thread. Depending on the
155	* underlying OS, and also depending on whether your are using any
156	* system call in your Main() implementation, it might otherwise be
157	* possible that the thread cannot be terminated at all! And even if the
158	* underlying OS supports terminating busy threads which do not call
159	* TestCancel(), this might still cause undefined behavior on such OSes!
160	*/
161	void TestCancel();
162
163	virtual int SignalStartThread();
164	virtual int SetSchedulingPriority();
165	virtual int LockMemory();
166	virtual void EnableDestructor();
167	virtual int onThreadEnd();
168
169	private:
170	enum state_t {
171	NOT_RUNNING,
172	RUNNING,
173	PENDING_JOIN,
174	DETACHED
175	};
176
177	#if defined(WIN32)
178	HANDLE hThread;
179	DWORD lpThreadId;
180	#if defined(WIN32_SIGNALSTARTTHREAD_WORKAROUND)
181	bool win32isRunning;
182	#endif
183	#else
184	pthread_attr_t __thread_attr;
185	pthread_t __thread_id;
186	pthread_key_t __thread_destructor_key;
187	#endif
188	Condition RunningCondition;
189	int PriorityMax;
190	int PriorityDelta;
191	bool isRealTime;
192	bool bLockedMemory;
193	state_t state;
194
195	#if defined(WIN32)
196	static DWORD WINAPI win32threadLauncher(LPVOID lpParameter);
197	#else
198	static void* pthreadLauncher(void* thread);
199	static void pthreadDestructor(void* thread);
200	#endif
201	};
202
203	} // namespace LinuxSampler
204
205	#endif // __LS_THREAD_H__