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base: Add an asymmetrical Coroutine class

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This patch is providing gem5 a Coroutine class to be used for
instantiating asymmetrical coroutines. Coroutines are built on top of
gem5 fibers, which makes them ucontext based.

Change-Id: I7bb673a954d4a456997afd45b696933534f3e239
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/11195
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Gabe Black <gabeblack@google.com>
This commit is contained in:
Giacomo Travaglini
2018-06-14 11:37:20 +01:00
parent 90d448080e
commit a77222f8d0
3 changed files with 529 additions and 0 deletions
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1
src/base/SConscript
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@@ -48,6 +48,7 @@ if env['USE_PNG']:
Source('pngwriter.cc')
Source('fiber.cc')
GTest('fibertest', 'fibertest.cc', 'fiber.cc')
GTest('coroutinetest', 'coroutinetest.cc', 'fiber.cc')
Source('framebuffer.cc')
Source('hostinfo.cc')
Source('inet.cc')

266
src/base/coroutine.hh Normal file
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@@ -0,0 +1,266 @@
/*
* Copyright (c) 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Giacomo Travaglini
*/
#ifndef __BASE_COROUTINE_HH__
#define __BASE_COROUTINE_HH__
#include <functional>
#include <stack>
#include "base/fiber.hh"
namespace m5
{
/**
* This template defines a Coroutine wrapper type with a Boost-like
* interface. It is built on top of the gem5 fiber class.
* The two template parameters (Arg and Ret) are the coroutine
* argument and coroutine return types which are passed between
* the coroutine and the caller via operator() and get() method.
* This implementation doesn't support passing multiple values,
* so a tuple must be used in that scenario.
*
* Most methods are templatized since it is relevant to distinguish
* the cases where one or both of the template parameters are void
*/
template <typename Arg, typename Ret>
class Coroutine : public Fiber
{
// This empty struct type is meant to replace coroutine channels
// in case the channel should be void (Coroutine template parameters
// are void. (See following ArgChannel, RetChannel typedef)
struct Empty {};
using ArgChannel = typename std::conditional<
std::is_same<Arg, void>::value, Empty, std::stack<Arg>>::type;
using RetChannel = typename std::conditional<
std::is_same<Ret, void>::value, Empty, std::stack<Ret>>::type;
public:
/**
* CallerType:
* A reference to an object of this class will be passed
* to the coroutine task. This is the way it is possible
* for the coroutine to interface (e.g. switch back)
* to the coroutine caller.
*/
class CallerType
{
friend class Coroutine;
protected:
CallerType(Coroutine& _coro) : coro(_coro), callerFiber(nullptr) {}
public:
/**
* operator() is the way we can jump outside the coroutine
* and return a value to the caller.
*
* This method is generated only if the coroutine returns
* a value (Ret != void)
*/
template <typename T = Ret>
CallerType&
operator()(typename std::enable_if<
!std::is_same<T, void>::value, T>::type param)
{
retChannel.push(param);
callerFiber->run();
return *this;
}
/**
* operator() is the way we can jump outside the coroutine
*
* This method is generated only if the coroutine doesn't
* return a value (Ret = void)
*/
template <typename T = Ret>
typename std::enable_if<std::is_same<T, void>::value,
CallerType>::type&
operator()()
{
callerFiber->run();
return *this;
}
/**
* get() is the way we can extrapolate arguments from the
* coroutine caller.
* The coroutine blocks, waiting for the value, unless it is already
* available; otherwise caller execution is resumed,
* and coroutine won't execute until a value is pushed
* from the caller.
*
* @return arg coroutine argument
*/
template <typename T = Arg>
typename std::enable_if<!std::is_same<T, void>::value, T>::type
get()
{
auto& args_channel = coro.argsChannel;
while (args_channel.empty()) {
callerFiber->run();
}
auto ret = args_channel.top();
args_channel.pop();
return ret;
}
private:
Coroutine& coro;
Fiber* callerFiber;
RetChannel retChannel;
};
Coroutine() = delete;
Coroutine(const Coroutine& rhs) = delete;
Coroutine& operator=(const Coroutine& rhs) = delete;
/**
* Coroutine constructor.
* The only way to construct a coroutine is to pass it the routine
* it needs to run. The first argument of the function should be a
* reference to the Coroutine<Arg,Ret>::caller_type which the
* routine will use as a way for yielding to the caller.
*
* @param f task run by the coroutine
*/
Coroutine(std::function<void(CallerType&)> f)
: Fiber(), task(f), caller(*this)
{
// Create and Run the Coroutine
this->call();
}
virtual ~Coroutine() {}
public:
/** Coroutine interface */
/**
* operator() is the way we can jump inside the coroutine
* and passing arguments.
*
* This method is generated only if the coroutine takes
* arguments (Arg != void)
*/
template <typename T = Arg>
Coroutine&
operator()(typename std::enable_if<
!std::is_same<T, void>::value, T>::type param)
{
argsChannel.push(param);
this->call();
return *this;
}
/**
* operator() is the way we can jump inside the coroutine.
*
* This method is generated only if the coroutine takes
* no arguments. (Arg = void)
*/
template <typename T = Arg>
typename std::enable_if<std::is_same<T, void>::value, Coroutine>::type&
operator()()
{
this->call();
return *this;
}
/**
* get() is the way we can extrapolate return values
* (yielded) from the coroutine.
* The caller blocks, waiting for the value, unless it is already
* available; otherwise coroutine execution is resumed,
* and caller won't execute until a value is yielded back
* from the coroutine.
*
* @return ret yielded value
*/
template <typename T = Ret>
typename std::enable_if<!std::is_same<T, void>::value, T>::type
get()
{
auto& ret_channel = caller.retChannel;
while (ret_channel.empty()) {
this->call();
}
auto ret = ret_channel.top();
ret_channel.pop();
return ret;
}
/** Check if coroutine is still running */
operator bool() const { return !this->finished(); }
private:
/**
* Overriding base (Fiber) main.
* This method will be automatically called by the Fiber
* running engine and it is a simple wrapper for the task
* that the coroutine is supposed to run.
*/
void main() override { this->task(caller); }
void
call()
{
caller.callerFiber = currentFiber();
run();
}
private:
/** Arguments for the coroutine */
ArgChannel argsChannel;
/** Coroutine task */
std::function<void(CallerType&)> task;
/** Coroutine caller */
CallerType caller;
};
} //namespace m5
#endif // __BASE_COROUTINE_HH__

262
src/base/coroutinetest.cc Normal file
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@@ -0,0 +1,262 @@
/*
* Copyright (c) 2018 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Giacomo Travaglini
*/
#include <gtest/gtest.h>
#include "base/coroutine.hh"
using namespace m5;
/**
* This test is checking if the Coroutine, once it yields
* back to the caller, it is still marked as not finished.
*/
TEST(Coroutine, Unfinished)
{
auto yielding_task =
[] (Coroutine<void, void>::CallerType& yield)
{
yield();
};
Coroutine<void, void> coro(yielding_task);
ASSERT_TRUE(coro);
}
/**
* This test is checking the parameter passing interface of a
* coroutine which takes an integer as an argument.
* Coroutine::operator() and CallerType::get() are the tested
* APIS.
*/
TEST(Coroutine, Passing)
{
const std::vector<int> input{ 1, 2, 3 };
const std::vector<int> expected_values = input;
auto passing_task =
[&expected_values] (Coroutine<int, void>::CallerType& yield)
{
int argument;
for (const auto expected : expected_values) {
argument = yield.get();
ASSERT_EQ(argument, expected);
}
};
Coroutine<int, void> coro(passing_task);
ASSERT_TRUE(coro);
for (const auto val : input) {
coro(val);
}
}
/**
* This test is checking the yielding interface of a coroutine
* which takes no argument and returns integers.
* Coroutine::get() and CallerType::operator() are the tested
* APIS.
*/
TEST(Coroutine, Returning)
{
const std::vector<int> output{ 1, 2, 3 };
const std::vector<int> expected_values = output;
auto returning_task =
[&output] (Coroutine<void, int>::CallerType& yield)
{
for (const auto ret : output) {
yield(ret);
}
};
Coroutine<void, int> coro(returning_task);
ASSERT_TRUE(coro);
for (const auto expected : expected_values) {
int returned = coro.get();
ASSERT_EQ(returned, expected);
}
}
/**
* This test is still supposed to test the returning interface
* of the the Coroutine, proving how coroutine can be used
* for generators.
* The coroutine is computing the first #steps of the fibonacci
* sequence and it is yielding back results one number per time.
*/
TEST(Coroutine, Fibonacci)
{
const std::vector<int> expected_values{
1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233 };
const int steps = expected_values.size();
auto fibonacci_task =
[steps] (Coroutine<void, int>::CallerType& yield)
{
int prev = 0;
int current = 1;
for (auto iter = 0; iter < steps; iter++) {
int sum = prev + current;
yield(sum);
prev = current;
current = sum;
}
};
Coroutine<void, int> coro(fibonacci_task);
ASSERT_TRUE(coro);
for (const auto expected : expected_values) {
ASSERT_TRUE(coro);
int returned = coro.get();
ASSERT_EQ(returned, expected);
}
}
/**
* This test is using a bi-channel coroutine (accepting and
* yielding values) for testing a cooperative task.
* The caller and the coroutine have a string each; they are
* composing a new string by merging the strings together one
* character per time.
* The result string is hence passed back and forth between the
* coroutine and the caller.
*/
TEST(Coroutine, Cooperative)
{
const std::string caller_str("HloWrd");
const std::string coro_str("el ol!");
const std::string expected("Hello World!");
auto cooperative_task =
[&coro_str] (Coroutine<std::string, std::string>::CallerType& yield)
{
for (auto& appended_c : coro_str) {
auto old_str = yield.get();
yield(old_str + appended_c);
}
};
Coroutine<std::string, std::string> coro(cooperative_task);
std::string result;
for (auto& c : caller_str) {
ASSERT_TRUE(coro);
result += c;
result = coro(result).get();
}
ASSERT_EQ(result, expected);
}
/**
* This test is testing nested coroutines by using one inner and one
* outer coroutine. It basically ensures that yielding from the inner
* coroutine returns to the outer coroutine (mid-layer of execution) and
* not to the outer caller.
*/
TEST(Coroutine, Nested)
{
const std::string wrong("Inner");
const std::string expected("Inner + Outer");
auto inner_task =
[] (Coroutine<void, std::string>::CallerType& yield)
{
std::string inner_string("Inner");
yield(inner_string);
};
auto outer_task =
[&inner_task] (Coroutine<void, std::string>::CallerType& yield)
{
Coroutine<void, std::string> coro(inner_task);
std::string inner_string = coro.get();
std::string outer_string("Outer");
yield(inner_string + " + " + outer_string);
};
Coroutine<void, std::string> coro(outer_task);
ASSERT_TRUE(coro);
std::string result = coro.get();
ASSERT_NE(result, wrong);
ASSERT_EQ(result, expected);
}
/**
* This test is stressing the scenario where two distinct fibers are
* calling the same coroutine. First the test instantiates (and runs) a
* coroutine, then spawns another one and it passes it a reference to
* the first coroutine. Once the new coroutine calls the first coroutine
* and the first coroutine yields, we are expecting execution flow to
* be yielded to the second caller (the second coroutine) and not the
* original caller (the test itself)
*/
TEST(Coroutine, TwoCallers)
{
bool valid_return = false;
Coroutine<void, void> callee{[]
(Coroutine<void, void>::CallerType& yield)
{
yield();
yield();
}};
Coroutine<void, void> other_caller{[&callee, &valid_return]
(Coroutine<void, void>::CallerType& yield)
{
callee();
valid_return = true;
yield();
}};
ASSERT_TRUE(valid_return);
}