xref: /petsc/src/sys/objects/device/impls/impldevicebase.hpp (revision d18748622689843e8c5ce717aabfcc708e80ab43)
1 #ifndef IMPLDEVICEBASE_HPP
2 #define IMPLDEVICEBASE_HPP
3 
4 #if defined(__cplusplus)
5 #include <petsc/private/deviceimpl.h>
6 #include <petsc/private/viewerimpl.h>
7 
8 #include <petsc/private/cpp/crtp.hpp>
9 #include <petsc/private/cpp/type_traits.hpp>
10 #include <petsc/private/cpp/utility.hpp>
11 #include <petsc/private/cpp/array.hpp>
12 
13 #include <cstring> // for std::strlen
14 
15 namespace Petsc {
16 
17 namespace device {
18 
19 namespace impl {
20 
21 template <typename Derived> // CRTP
22 class DeviceBase : public util::crtp<Derived, DeviceBase> {
23 public:
24   using derived_type            = Derived;
25   using createContextFunction_t = PetscErrorCode (*)(PetscDeviceContext);
26 
27   // default constructor
28   constexpr DeviceBase(createContextFunction_t f) noexcept : create_(f) { }
29 
30   template <typename T = derived_type>
31   PETSC_NODISCARD static constexpr PetscDeviceType PETSC_DEVICE_IMPL() noexcept {
32     return T::PETSC_DEVICE_IMPL_();
33   }
34 
35   PETSC_NODISCARD PetscErrorCode        getDevice(PetscDevice, PetscInt) noexcept;
36   PETSC_NODISCARD static PetscErrorCode configureDevice(PetscDevice) noexcept;
37   PETSC_NODISCARD static PetscErrorCode viewDevice(PetscDevice, PetscViewer) noexcept;
38   PETSC_NODISCARD static PetscErrorCode getAttribute(PetscDevice, PetscDeviceAttribute, void *) noexcept;
39 
40 protected:
41   // function to create a PetscDeviceContext (the (*create) function pointer usually set
42   // via XXXSetType() for other PETSc objects)
43   const createContextFunction_t create_;
44 
45   // if you want the base class to handle the entire options query, has the same arguments as
46   // PetscOptionDeviceBasic
47   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceAll(MPI_Comm, std::pair<PetscDeviceInitType, PetscBool> &, std::pair<PetscInt, PetscBool> &, std::pair<PetscBool, PetscBool> &) noexcept;
48 
49   // if you want to start and end the options query yourself, but still want all the default
50   // options
51   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceBasic(PetscOptionItems *, std::pair<PetscDeviceInitType, PetscBool> &, std::pair<PetscInt, PetscBool> &, std::pair<PetscBool, PetscBool> &) noexcept;
52 
53   // option templates to follow, each one has two forms:
54   // - A simple form returning only the value and flag. This gives no control over the message,
55   //   arguments to the options query or otherwise
56   // - A complex form, which allows you to pass most of the options query arguments *EXCEPT*
57   //   - The options query function called
58   //   - The option string
59 
60   // option template for initializing the device
61   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceInitialize(PetscOptionItems *, PetscDeviceInitType *, PetscBool *) noexcept;
62   template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int> = 0>
63   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceInitialize(PetscOptionItems *, T &&...) noexcept;
64   // option template for selecting the default device
65   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceSelect(PetscOptionItems *, PetscInt *, PetscBool *) noexcept;
66   template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int> = 0>
67   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceSelect(PetscOptionItems *, T &&...) noexcept;
68   // option templates for viewing a device
69   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceView(PetscOptionItems *, PetscBool *, PetscBool *) noexcept;
70   template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int> = 0>
71   PETSC_NODISCARD static PetscErrorCode PetscOptionDeviceView(PetscOptionItems *, T &&...) noexcept;
72 
73 private:
74   // base function for all options templates above, they basically just reformat the arguments,
75   // create the option string and pass it off to this function
76   template <typename... T, typename F = PetscErrorCode (*)(PetscOptionItems *, const char *, T &&...)>
77   PETSC_NODISCARD static PetscErrorCode PetscOptionDevice(F &&, PetscOptionItems *, const char[], T &&...) noexcept;
78 
79   // default crtp implementations
80   PETSC_NODISCARD static PetscErrorCode init_device_id_(PetscInt *id) noexcept {
81     PetscFunctionBegin;
82     *id = 0;
83     PetscFunctionReturn(0);
84   }
85 
86   PETSC_NODISCARD static constexpr PetscErrorCode configure_device_(PetscDevice) noexcept { return 0; }
87   PETSC_NODISCARD static constexpr PetscErrorCode view_device_(PetscDevice, PetscViewer) noexcept { return 0; }
88 };
89 
90 template <typename D>
91 inline PetscErrorCode DeviceBase<D>::getDevice(PetscDevice device, PetscInt id) noexcept {
92   PetscFunctionBegin;
93   PetscCall(this->underlying().init_device_id_(&id));
94   device->deviceId           = id;
95   device->ops->createcontext = this->underlying().create_;
96   device->ops->configure     = this->underlying().configureDevice;
97   device->ops->view          = this->underlying().viewDevice;
98   device->ops->getattribute  = this->underlying().getAttribute;
99   PetscFunctionReturn(0);
100 }
101 
102 template <typename D>
103 inline PetscErrorCode DeviceBase<D>::configureDevice(PetscDevice device) noexcept {
104   PetscFunctionBegin;
105   PetscCall(derived_type::configure_device_(device));
106   PetscFunctionReturn(0);
107 }
108 
109 template <typename D>
110 inline PetscErrorCode DeviceBase<D>::viewDevice(PetscDevice device, PetscViewer viewer) noexcept {
111   PetscFunctionBegin;
112   PetscCall(derived_type::view_device_(device, viewer));
113   PetscFunctionReturn(0);
114 }
115 
116 template <typename D>
117 inline PetscErrorCode DeviceBase<D>::getAttribute(PetscDevice device, PetscDeviceAttribute attr, void *value) noexcept {
118   PetscFunctionBegin;
119   PetscCall(derived_type::get_attribute_(device->deviceId, attr, value));
120   PetscFunctionReturn(0);
121 }
122 
123 template <typename D>
124 template <typename... T, typename F>
125 inline PetscErrorCode DeviceBase<D>::PetscOptionDevice(F &&OptionsFunction, PetscOptionItems *PetscOptionsObject, const char optstub[], T &&...args) noexcept {
126   constexpr auto dtype    = PETSC_DEVICE_IMPL();
127   const auto     implname = PetscDeviceTypes[dtype];
128   auto           buf      = std::array<char, 128>{};
129   constexpr auto buflen   = buf.size() - 1;
130 
131   PetscFunctionBegin;
132   if (PetscDefined(USE_DEBUG)) {
133     const auto len = std::strlen(optstub) + std::strlen(implname);
134 
135     PetscCheck(len < buflen, PetscOptionsObject->comm, PETSC_ERR_PLIB, "char buffer is not large enough to hold '%s%s'; have %zu need %zu", optstub, implname, buflen, len);
136   }
137   PetscCall(PetscSNPrintf(buf.data(), buflen, "%s%s", optstub, implname));
138   PetscCall(OptionsFunction(PetscOptionsObject, buf.data(), std::forward<T>(args)...));
139   PetscFunctionReturn(0);
140 }
141 
142 template <typename D>
143 template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int>>
144 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceInitialize(PetscOptionItems *PetscOptionsObject, T &&...args) noexcept {
145   PetscFunctionBegin;
146   PetscCall(PetscOptionDevice(PetscOptionsEList_Private, PetscOptionsObject, "-device_enable_", std::forward<T>(args)...));
147   PetscFunctionReturn(0);
148 }
149 
150 template <typename D>
151 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceInitialize(PetscOptionItems *PetscOptionsObject, PetscDeviceInitType *inittype, PetscBool *flag) noexcept {
152   auto type = static_cast<PetscInt>(util::integral_value(*inittype));
153 
154   PetscFunctionBegin;
155   PetscCall(PetscOptionDeviceInitialize(PetscOptionsObject, "How (or whether) to initialize a device", "PetscDeviceInitialize()", PetscDeviceInitTypes, 3, PetscDeviceInitTypes[type], &type, flag));
156   *inittype = static_cast<PetscDeviceInitType>(type);
157   PetscFunctionReturn(0);
158 }
159 
160 template <typename D>
161 template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int>>
162 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceSelect(PetscOptionItems *PetscOptionsObject, T &&...args) noexcept {
163   PetscFunctionBegin;
164   PetscCall(PetscOptionDevice(PetscOptionsInt_Private, PetscOptionsObject, "-device_select_", std::forward<T>(args)...));
165   PetscFunctionReturn(0);
166 }
167 
168 template <typename D>
169 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceSelect(PetscOptionItems *PetscOptionsObject, PetscInt *id, PetscBool *flag) noexcept {
170   PetscFunctionBegin;
171   PetscCall(PetscOptionDeviceSelect(PetscOptionsObject, "Which device to use. Pass " PetscStringize(PETSC_DECIDE) " to have PETSc decide or (given they exist) [0-" PetscStringize(PETSC_DEVICE_MAX_DEVICES) ") for a specific device", "PetscDeviceCreate()", *id, id, flag, PETSC_DECIDE, PETSC_DEVICE_MAX_DEVICES));
172   PetscFunctionReturn(0);
173 }
174 
175 template <typename D>
176 template <typename... T, util::enable_if_t<sizeof...(T) >= 3, int>>
177 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceView(PetscOptionItems *PetscOptionsObject, T &&...args) noexcept {
178   PetscFunctionBegin;
179   PetscCall(PetscOptionDevice(PetscOptionsBool_Private, PetscOptionsObject, "-device_view_", std::forward<T>(args)...));
180   PetscFunctionReturn(0);
181 }
182 
183 template <typename D>
184 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceView(PetscOptionItems *PetscOptionsObject, PetscBool *view, PetscBool *flag) noexcept {
185   PetscFunctionBegin;
186   PetscCall(PetscOptionDeviceView(PetscOptionsObject, "Display device information and assignments (forces eager initialization)", "PetscDeviceView()", *view, view, flag));
187   PetscFunctionReturn(0);
188 }
189 
190 template <typename D>
191 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceBasic(PetscOptionItems *PetscOptionsObject, std::pair<PetscDeviceInitType, PetscBool> &initType, std::pair<PetscInt, PetscBool> &initId, std::pair<PetscBool, PetscBool> &initView) noexcept {
192   PetscFunctionBegin;
193   PetscCall(PetscOptionDeviceInitialize(PetscOptionsObject, &initType.first, &initType.second));
194   PetscCall(PetscOptionDeviceSelect(PetscOptionsObject, &initId.first, &initId.second));
195   PetscCall(PetscOptionDeviceView(PetscOptionsObject, &initView.first, &initView.second));
196   PetscFunctionReturn(0);
197 }
198 
199 template <typename D>
200 inline PetscErrorCode DeviceBase<D>::PetscOptionDeviceAll(MPI_Comm comm, std::pair<PetscDeviceInitType, PetscBool> &initType, std::pair<PetscInt, PetscBool> &initId, std::pair<PetscBool, PetscBool> &initView) noexcept {
201   constexpr char optname[] = "PetscDevice %s Options";
202   constexpr auto dtype     = PETSC_DEVICE_IMPL();
203   const auto     implname  = PetscDeviceTypes[dtype];
204   auto           buf       = std::array<char, 128>{};
205   constexpr auto buflen    = buf.size() - 1; // -1 to leave room for null
206 
207   PetscFunctionBegin;
208   if (PetscDefined(USE_DEBUG)) {
209     // -3 since '%s' is replaced and dont count null char for optname
210     const auto len = std::strlen(implname) + PETSC_STATIC_ARRAY_LENGTH(optname) - 3;
211 
212     PetscCheck(len < buflen, comm, PETSC_ERR_PLIB, "char buffer is not large enough to hold 'PetscDevice %s Options'; have %zu need %zu", implname, buflen, len);
213   }
214   PetscCall(PetscSNPrintf(buf.data(), buflen, optname, implname));
215   PetscOptionsBegin(comm, nullptr, buf.data(), "Sys");
216   PetscCall(PetscOptionDeviceBasic(PetscOptionsObject, initType, initId, initView));
217   PetscOptionsEnd();
218   PetscFunctionReturn(0);
219 }
220 
221 } // namespace impl
222 
223 } // namespace device
224 
225 } // namespace Petsc
226 
227 #define PETSC_DEVICE_IMPL_BASE_CLASS_HEADER(base_name, T) \
228   using base_name = ::Petsc::device::impl::DeviceBase<T>; \
229   friend base_name; \
230   using base_name::base_name
231 
232 #endif // __cplusplus
233 
234 #endif // IMPLDEVICEBASE_HPP
235