drivers/audio/iasiothiscallresolver.h

// ****************************************************************************
// File:                        IASIOThiscallResolver.h
// Description:     The IASIOThiscallResolver class implements the IASIO
//                                      interface and acts as a proxy to the real IASIO interface by
//                  calling through its vptr table using the thiscall calling
//                  convention. To put it another way, we interpose
//                  IASIOThiscallResolver between ASIO SDK code and the driver.
//                  This is necessary because most non-Microsoft compilers don't
//                  implement the thiscall calling convention used by IASIO.
//
//                                      iasiothiscallresolver.cpp contains the background of this
//                                      problem plus a technical description of the vptr
//                  manipulations.
//
//                                      In order to use this mechanism one simply has to add
//                                      iasiothiscallresolver.cpp to the list of files to compile
//                  and #include <iasiothiscallresolver.h>
//
//                                      Note that this #include must come after the other ASIO SDK
//                  #includes, for example:
//
//                                      #include <windows.h>
//                                      #include <asiosys.h>
//                                      #include <asio.h>
//                                      #include <asiodrivers.h>
//                                      #include <iasiothiscallresolver.h>
//
//                                      Actually the important thing is to #include
//                  <iasiothiscallresolver.h> after <asio.h>. We have
//                  incorporated a test to enforce this ordering.
//
//                                      The code transparently takes care of the interposition by
//                  using macro substitution to intercept calls to ASIOInit()
//                  and ASIOExit(). We save the original ASIO global
//                  "theAsioDriver" in our "that" variable, and then set
//                  "theAsioDriver" to equal our IASIOThiscallResolver instance.
//
//                                      Whilst this method of resolving the thiscall problem requires
//                                      the addition of #include <iasiothiscallresolver.h> to client
//                  code it has the advantage that it does not break the terms
//                  of the ASIO licence by publishing it. We are NOT modifying
//                  any Steinberg code here, we are merely implementing the IASIO
//                                      interface in the same way that we would need to do if we
//                                      wished to provide an open source ASIO driver.
//
//                                      For compilation with MinGW -lole32 needs to be added to the
//                  linker options. For BORLAND, linking with Import32.lib is
//                  sufficient.
//
//                                      The dependencies are with: CoInitialize, CoUninitialize,
//                                      CoCreateInstance, CLSIDFromString - used by asiolist.cpp
//                                      and are required on Windows whether ThiscallResolver is used
//                                      or not.
//
//                                      Searching for the above strings in the root library path
//                                      of your compiler should enable the correct libraries to be
//                                      identified if they aren't immediately obvious.
//
//                  Note that the current implementation of IASIOThiscallResolver
//                  is not COM compliant - it does not correctly implement the
//                  IUnknown interface. Implementing it is not necessary because
//                  it is not called by parts of the ASIO SDK which call through
//                  theAsioDriver ptr. The IUnknown methods are implemented as
//                  assert(false) to ensure that the code fails if they are
//                  ever called.
// Restrictions:        None. Public Domain & Open Source distribute freely
//                                      You may use IASIOThiscallResolver commercially as well as
//                  privately.
//                                      You the user assume the responsibility for the use of the
//                                      files, binary or text, and there is no guarantee or warranty,
//                                      expressed or implied, including but not limited to the
//                                      implied warranties of merchantability and fitness for a
//                                      particular purpose. You assume all responsibility and agree
//                                      to hold no entity, copyright holder or distributors liable
//                                      for any loss of data or inaccurate representations of data
//                                      as a result of using IASIOThiscallResolver.
// Version:         1.4 Added separate macro CALL_THISCALL_1_DOUBLE from
//                  Andrew Baldwin, and volatile for whole gcc asm blocks,
//                  both for compatibility with newer gcc versions. Cleaned up
//                  Borland asm to use one less register.
//                  1.3 Switched to including assert.h for better compatibility.
//                  Wrapped entire .h and .cpp contents with a check for
//                  _MSC_VER to provide better compatibility with MS compilers.
//                  Changed Singleton implementation to use static instance
//                  instead of freestore allocated instance. Removed ASIOExit
//                  macro as it is no longer needed.
//                  1.2 Removed semicolons from ASIOInit and ASIOExit macros to
//                  allow them to be embedded in expressions (if statements).
//                  Cleaned up some comments. Removed combase.c dependency (it
//                  doesn't compile with BCB anyway) by stubbing IUnknown.
//                  1.1 Incorporated comments from Ross Bencina including things
//                                      such as changing name from ThiscallResolver to
//                                      IASIOThiscallResolver, tidying up the constructor, fixing
//                                      a bug in IASIOThiscallResolver::ASIOExit() and improving
//                                      portability through the use of conditional compilation
//                                      1.0 Initial working version.
// Created:                     6/09/2003
// Authors:         Fraser Adams
//                  Ross Bencina
//                  Rene G. Ceballos
//                  Martin Fay
//                  Antti Silvast
//                  Andrew Baldwin
//
// ****************************************************************************

#ifndef included_iasiothiscallresolver_h
#define included_iasiothiscallresolver_h

// We only need IASIOThiscallResolver at all if we are on Win32. For other
// platforms we simply bypass the IASIOThiscallResolver definition to allow us
// to be safely #include'd whatever the platform to keep client code portable
#if defined(WIN32) || defined(_WIN32) || defined(__WIN32__)

// If microsoft compiler we can call IASIO directly so IASIOThiscallResolver
// is not used.
#if !defined(_MSC_VER)

// The following is in order to ensure that this header is only included after
// the other ASIO headers (except for the case of iasiothiscallresolver.cpp).
// We need to do this because IASIOThiscallResolver works by eclipsing the
// original definition of ASIOInit() with a macro (see below).
#if !defined(iasiothiscallresolver_sourcefile)
        #if !defined(__ASIO_H)
        #error iasiothiscallresolver.h must be included AFTER asio.h
        #endif
#endif

#include <windows.h>
#include <asiodrvr.h> /* From ASIO SDK */

class IASIOThiscallResolver : public IASIO {
private:
        IASIO* that_; // Points to the real IASIO

        static IASIOThiscallResolver instance; // Singleton instance

        // Constructors - declared private so construction is limited to
    // our Singleton instance
    IASIOThiscallResolver();
        IASIOThiscallResolver(IASIO* that);

public:
    // Methods from the IUnknown interface. We don't fully implement IUnknown
    // because the ASIO SDK never calls these methods through theAsioDriver ptr.
    // These methods are implemented as assert(false).
    virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void **ppv);
    virtual ULONG STDMETHODCALLTYPE AddRef();
    virtual ULONG STDMETHODCALLTYPE Release();

    // Methods from the IASIO interface, implemented as forwarning calls to that.
        virtual ASIOBool init(void *sysHandle);
        virtual void getDriverName(char *name);
        virtual long getDriverVersion();
        virtual void getErrorMessage(char *string);
        virtual ASIOError start();
        virtual ASIOError stop();
        virtual ASIOError getChannels(long *numInputChannels, long *numOutputChannels);
        virtual ASIOError getLatencies(long *inputLatency, long *outputLatency);
        virtual ASIOError getBufferSize(long *minSize, long *maxSize, long *preferredSize, long *granularity);
        virtual ASIOError canSampleRate(ASIOSampleRate sampleRate);
        virtual ASIOError getSampleRate(ASIOSampleRate *sampleRate);
        virtual ASIOError setSampleRate(ASIOSampleRate sampleRate);
        virtual ASIOError getClockSources(ASIOClockSource *clocks, long *numSources);
        virtual ASIOError setClockSource(long reference);
        virtual ASIOError getSamplePosition(ASIOSamples *sPos, ASIOTimeStamp *tStamp);
        virtual ASIOError getChannelInfo(ASIOChannelInfo *info);
        virtual ASIOError createBuffers(ASIOBufferInfo *bufferInfos, long numChannels, long bufferSize, ASIOCallbacks *callbacks);
        virtual ASIOError disposeBuffers();
        virtual ASIOError controlPanel();
        virtual ASIOError future(long selector,void *opt);
        virtual ASIOError outputReady();

    // Class method, see ASIOInit() macro below.
    static ASIOError ASIOInit(ASIODriverInfo *info); // Delegates to ::ASIOInit
};

// Replace calls to ASIOInit with our interposing version.
// This macro enables us to perform thiscall resolution simply by #including
// <iasiothiscallresolver.h> after the asio #includes (this file _must_ be
// included _after_ the asio #includes)

#define ASIOInit(name) IASIOThiscallResolver::ASIOInit((name))

#endif /* !defined(_MSC_VER) */

#endif /* Win32 */

#endif /* included_iasiothiscallresolver_h */
1	// ****************************************************************************
2	// File: IASIOThiscallResolver.h
3	// Description: The IASIOThiscallResolver class implements the IASIO
4	// interface and acts as a proxy to the real IASIO interface by
5	// calling through its vptr table using the thiscall calling
6	// convention. To put it another way, we interpose
7	// IASIOThiscallResolver between ASIO SDK code and the driver.
8	// This is necessary because most non-Microsoft compilers don't
9	// implement the thiscall calling convention used by IASIO.
10	//
11	// iasiothiscallresolver.cpp contains the background of this
12	// problem plus a technical description of the vptr
13	// manipulations.
14	//
15	// In order to use this mechanism one simply has to add
16	// iasiothiscallresolver.cpp to the list of files to compile
17	// and #include <iasiothiscallresolver.h>
18	//
19	// Note that this #include must come after the other ASIO SDK
20	// #includes, for example:
21	//
22	// #include <windows.h>
23	// #include <asiosys.h>
24	// #include <asio.h>
25	// #include <asiodrivers.h>
26	// #include <iasiothiscallresolver.h>
27	//
28	// Actually the important thing is to #include
29	// <iasiothiscallresolver.h> after <asio.h>. We have
30	// incorporated a test to enforce this ordering.
31	//
32	// The code transparently takes care of the interposition by
33	// using macro substitution to intercept calls to ASIOInit()
34	// and ASIOExit(). We save the original ASIO global
35	// "theAsioDriver" in our "that" variable, and then set
36	// "theAsioDriver" to equal our IASIOThiscallResolver instance.
37	//
38	// Whilst this method of resolving the thiscall problem requires
39	// the addition of #include <iasiothiscallresolver.h> to client
40	// code it has the advantage that it does not break the terms
41	// of the ASIO licence by publishing it. We are NOT modifying
42	// any Steinberg code here, we are merely implementing the IASIO
43	// interface in the same way that we would need to do if we
44	// wished to provide an open source ASIO driver.
45	//
46	// For compilation with MinGW -lole32 needs to be added to the
47	// linker options. For BORLAND, linking with Import32.lib is
48	// sufficient.
49	//
50	// The dependencies are with: CoInitialize, CoUninitialize,
51	// CoCreateInstance, CLSIDFromString - used by asiolist.cpp
52	// and are required on Windows whether ThiscallResolver is used
53	// or not.
54	//
55	// Searching for the above strings in the root library path
56	// of your compiler should enable the correct libraries to be
57	// identified if they aren't immediately obvious.
58	//
59	// Note that the current implementation of IASIOThiscallResolver
60	// is not COM compliant - it does not correctly implement the
61	// IUnknown interface. Implementing it is not necessary because
62	// it is not called by parts of the ASIO SDK which call through
63	// theAsioDriver ptr. The IUnknown methods are implemented as
64	// assert(false) to ensure that the code fails if they are
65	// ever called.
66	// Restrictions: None. Public Domain & Open Source distribute freely
67	// You may use IASIOThiscallResolver commercially as well as
68	// privately.
69	// You the user assume the responsibility for the use of the
70	// files, binary or text, and there is no guarantee or warranty,
71	// expressed or implied, including but not limited to the
72	// implied warranties of merchantability and fitness for a
73	// particular purpose. You assume all responsibility and agree
74	// to hold no entity, copyright holder or distributors liable
75	// for any loss of data or inaccurate representations of data
76	// as a result of using IASIOThiscallResolver.
77	// Version: 1.4 Added separate macro CALL_THISCALL_1_DOUBLE from
78	// Andrew Baldwin, and volatile for whole gcc asm blocks,
79	// both for compatibility with newer gcc versions. Cleaned up
80	// Borland asm to use one less register.
81	// 1.3 Switched to including assert.h for better compatibility.
82	// Wrapped entire .h and .cpp contents with a check for
83	// _MSC_VER to provide better compatibility with MS compilers.
84	// Changed Singleton implementation to use static instance
85	// instead of freestore allocated instance. Removed ASIOExit
86	// macro as it is no longer needed.
87	// 1.2 Removed semicolons from ASIOInit and ASIOExit macros to
88	// allow them to be embedded in expressions (if statements).
89	// Cleaned up some comments. Removed combase.c dependency (it
90	// doesn't compile with BCB anyway) by stubbing IUnknown.
91	// 1.1 Incorporated comments from Ross Bencina including things
92	// such as changing name from ThiscallResolver to
93	// IASIOThiscallResolver, tidying up the constructor, fixing
94	// a bug in IASIOThiscallResolver::ASIOExit() and improving
95	// portability through the use of conditional compilation
96	// 1.0 Initial working version.
97	// Created: 6/09/2003
98	// Authors: Fraser Adams
99	// Ross Bencina
100	// Rene G. Ceballos
101	// Martin Fay
102	// Antti Silvast
103	// Andrew Baldwin
104	//
105	// ****************************************************************************
106
107	#ifndef included_iasiothiscallresolver_h
108	#define included_iasiothiscallresolver_h
109
110	// We only need IASIOThiscallResolver at all if we are on Win32. For other
111	// platforms we simply bypass the IASIOThiscallResolver definition to allow us
112	// to be safely #include'd whatever the platform to keep client code portable
113	#if defined(WIN32) \|\| defined(_WIN32) \|\| defined(__WIN32__)
114
115	// If microsoft compiler we can call IASIO directly so IASIOThiscallResolver
116	// is not used.
117	#if !defined(_MSC_VER)
118
119	// The following is in order to ensure that this header is only included after
120	// the other ASIO headers (except for the case of iasiothiscallresolver.cpp).
121	// We need to do this because IASIOThiscallResolver works by eclipsing the
122	// original definition of ASIOInit() with a macro (see below).
123	#if !defined(iasiothiscallresolver_sourcefile)
124	#if !defined(__ASIO_H)
125	#error iasiothiscallresolver.h must be included AFTER asio.h
126	#endif
127	#endif
128
129	#include <windows.h>
130	#include <asiodrvr.h> /* From ASIO SDK */
131
132	class IASIOThiscallResolver : public IASIO {
133	private:
134	IASIO* that_; // Points to the real IASIO
135
136	static IASIOThiscallResolver instance; // Singleton instance
137
138	// Constructors - declared private so construction is limited to
139	// our Singleton instance
140	IASIOThiscallResolver();
141	IASIOThiscallResolver(IASIO* that);
142
143	public:
144	// Methods from the IUnknown interface. We don't fully implement IUnknown
145	// because the ASIO SDK never calls these methods through theAsioDriver ptr.
146	// These methods are implemented as assert(false).
147	virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void **ppv);
148	virtual ULONG STDMETHODCALLTYPE AddRef();
149	virtual ULONG STDMETHODCALLTYPE Release();
150
151	// Methods from the IASIO interface, implemented as forwarning calls to that.
152	virtual ASIOBool init(void *sysHandle);
153	virtual void getDriverName(char *name);
154	virtual long getDriverVersion();
155	virtual void getErrorMessage(char *string);
156	virtual ASIOError start();
157	virtual ASIOError stop();
158	virtual ASIOError getChannels(long numInputChannels, long numOutputChannels);
159	virtual ASIOError getLatencies(long inputLatency, long outputLatency);
160	virtual ASIOError getBufferSize(long minSize, long maxSize, long preferredSize, long granularity);
161	virtual ASIOError canSampleRate(ASIOSampleRate sampleRate);
162	virtual ASIOError getSampleRate(ASIOSampleRate *sampleRate);
163	virtual ASIOError setSampleRate(ASIOSampleRate sampleRate);
164	virtual ASIOError getClockSources(ASIOClockSource clocks, long numSources);
165	virtual ASIOError setClockSource(long reference);
166	virtual ASIOError getSamplePosition(ASIOSamples sPos, ASIOTimeStamp tStamp);
167	virtual ASIOError getChannelInfo(ASIOChannelInfo *info);
168	virtual ASIOError createBuffers(ASIOBufferInfo bufferInfos, long numChannels, long bufferSize, ASIOCallbacks callbacks);
169	virtual ASIOError disposeBuffers();
170	virtual ASIOError controlPanel();
171	virtual ASIOError future(long selector,void *opt);
172	virtual ASIOError outputReady();
173
174	// Class method, see ASIOInit() macro below.
175	static ASIOError ASIOInit(ASIODriverInfo *info); // Delegates to ::ASIOInit
176	};
177
178	// Replace calls to ASIOInit with our interposing version.
179	// This macro enables us to perform thiscall resolution simply by #including
180	// <iasiothiscallresolver.h> after the asio #includes (this file _must_ be
181	// included _after_ the asio #includes)
182
183	#define ASIOInit(name) IASIOThiscallResolver::ASIOInit((name))
184
185	#endif /* !defined(_MSC_VER) */
186
187	#endif /* Win32 */
188
189	#endif /* included_iasiothiscallresolver_h */