[gem5-dev] Change in gem5/gem5[master]: systemc: Add a class which encapsulates Fibers.
Gabe Black has uploaded this change for review. (
https://gem5-review.googlesource.com/10935
Change subject: systemc: Add a class which encapsulates Fibers.
..
systemc: Add a class which encapsulates Fibers.
This class encapsulates the idea of a Fiber in such a way that other
implementations can be substituted in in the future. This
implementation uses the ucontext family of functions.
This change also adds a new unit test which exercises the new class. It
creates three new fibers which accept a sequence of other fibers to
switch to, one after the other. The main test function switches to
the these fibers which switch with each other and occasionally back to
the main fiber. Each time a test fiber is activated, it checks against
a list which shows the correct order for the fibers to run in. When the
main fiber gets control, it makes sure that list has been progressed
through by the correct amount.
Change-Id: I1fc2afa414b51baaa91e350a4ebc791d989f0b8a
---
M src/base/SConscript
A src/base/fiber.cc
A src/base/fiber.hh
A src/base/fibertest.cc
4 files changed, 359 insertions(+), 0 deletions(-)
diff --git a/src/base/SConscript b/src/base/SConscript
index a90b784..b3205a6 100644
--- a/src/base/SConscript
+++ b/src/base/SConscript
@@ -46,6 +46,8 @@
Source('fenv.c')
if env['USE_PNG']:
Source('pngwriter.cc')
+Source('fiber.cc')
+GTest('fibertest', 'fibertest.cc', 'fiber.cc')
Source('framebuffer.cc')
Source('hostinfo.cc')
Source('inet.cc')
diff --git a/src/base/fiber.cc b/src/base/fiber.cc
new file mode 100644
index 000..377c2b4
--- /dev/null
+++ b/src/base/fiber.cc
@@ -0,0 +1,144 @@
+/*
+ * Copyright 2018 Google, Inc.
+ *
+ * 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: Gabe Black
+ */
+
+#include "base/fiber.hh"
+
+#include "base/logging.hh"
+
+using namespace std;
+
+namespace
+{
+
+/*
+ * The Gem5Fiber class is a special case that attaches to the currently
+ * executing context. That makes handling the "gem5" fiber, aka the one
which
+ * most of gem5 is running under, no different than other Fibers.
+ */
+class Gem5Fiber : public Fiber
+{
+ public:
+Gem5Fiber() : Fiber(nullptr, 0) { started = true; }
+void main() { panic("Gem5Fiber main executed.\n"); }
+};
+
+Gem5Fiber _gem5Fiber;
+
+// A pointer to whatever the currently executing Fiber is.
+Fiber *_currentFiber = &_gem5Fiber;
+
+// A pointer to the Fiber which is currently being started/initialized.
+Fiber *startingFiber = nullptr;
+
+} // anonymous namespace
+
+// A trampoline which calls a Fiber's enterMain() as it starts up.
+void
+Fiber::startingFiberEnterMain()
+{
+startingFiber->enterMain();
+}
+
+Fiber::Fiber(size_t stack_size) :
+link(gem5Fiber()), stack(stack_size ? new uint8_t[stack_size] :
nullptr),
+stackSize(stack_size), started(false), _finished(false)
+{}
+
+Fiber::Fiber(Fiber *link, size_t stack_size) :
+link(link), stack(stack_size ? new uint8_t[stack_size] : nullptr),
+stackSize(stack_size), started(false), _finished(false)
+{}
+
+Fiber::~Fiber()
+{
+panic_if(stack && _currentFiber == this, "Fiber stack is in use.");
+delete [] stack;
+}
+
+void
+Fiber::startFiber()
+{
+// Set up a context for the new fiber, starting it in the trampoline.
+getcontext();
+ctx.uc_stack.ss_sp = stack;
+ctx.uc_stack.ss_size = stackSize;
+ctx.uc_link = nullptr;
+makecontext(, , 0);
+
+// Swap to the new context so it can enter its enterMain() function. It
+
[gem5-dev] Change in gem5/gem5[master]: systemc: Add a class which encapsulates Fibers.
Gabe Black has uploaded this change for review. (
https://gem5-review.googlesource.com/10848
Change subject: systemc: Add a class which encapsulates Fibers.
..
systemc: Add a class which encapsulates Fibers.
This class encapsulates the idea of a Fiber in such a way that other
implementations can be substituted in in the future. This
implementation uses the ucontext family of functions.
This change also adds a new unit test which exercises the new class. It
creates three new fibers which accept a sequence of other fibers to
switch to, one after the other. The main test function switches to
the these fibers which switch with each other and occasionally back to
the main fiber. Each time a test fiber is activated, it checks against
a list which shows the correct order for the fibers to run in. When the
main fiber gets control, it makes sure that list has been progressed
through by the correct amount.
Change-Id: I5a42c913fa90d3fc07b9684ab30ad811695bc962
---
M src/systemc/core/SConscript
A src/systemc/core/fiber.cc
A src/systemc/core/fiber.hh
A src/systemc/core/fibertest.cc
4 files changed, 331 insertions(+), 0 deletions(-)
diff --git a/src/systemc/core/SConscript b/src/systemc/core/SConscript
index e12ed59..65c00bd 100644
--- a/src/systemc/core/SConscript
+++ b/src/systemc/core/SConscript
@@ -30,6 +30,8 @@
if env['USE_SYSTEMC']:
SimObject('SystemC.py')
+Source('fiber.cc')
+GTest('fibertest', 'fibertest.cc', 'fiber.cc')
Source('kernel.cc')
Source('sc_attr.cc')
diff --git a/src/systemc/core/fiber.cc b/src/systemc/core/fiber.cc
new file mode 100644
index 000..387eae9
--- /dev/null
+++ b/src/systemc/core/fiber.cc
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2018 Google, Inc.
+ *
+ * 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: Gabe Black
+ */
+
+#include "systemc/core/fiber.hh"
+
+#include "base/logging.hh"
+
+using namespace std;
+
+namespace SystemC
+{
+
+namespace
+{
+
+/*
+ * The Gem5Fiber class is a special case that attaches to the currently
+ * executing context. That makes handling the "gem5" fiber, aka the one
which
+ * most of gem5 is running under, no different than other Fibers.
+ */
+class Gem5Fiber : public Fiber
+{
+ public:
+Gem5Fiber() : Fiber(0) { started = true; }
+void main() { panic("Gem5Fiber main executed.\n"); }
+};
+
+Gem5Fiber _gem5Fiber;
+
+// A pointer to whatever the currently executing Fiber is.
+Fiber *_currentFiber = &_gem5Fiber;
+
+// A pointer to the Fiber which is currently being started/initialized.
+Fiber *startingFiber = nullptr;
+
+} // anonymous namespace
+
+// A trampoline which calls a Fiber's enterMain() as it starts up.
+void
+Fiber::startingFiberEnterMain()
+{
+startingFiber->enterMain();
+}
+
+Fiber::Fiber(size_t stack_size) :
+stack(stack_size ? new uint8_t[stack_size] : nullptr),
+stackSize(stack_size), started(false), _finished(false)
+{}
+
+Fiber::~Fiber()
+{
+panic_if(stack && _currentFiber == this, "Fiber stack is in use.");
+delete [] stack;
+}
+
+void
+Fiber::startFiber()
+{
+// Set up a context for the new fiber, starting it in the trampoline.
+getcontext();
+ctx.uc_stack.ss_sp = stack;
+ctx.uc_stack.ss_size = stackSize;
+ctx.uc_link = nullptr;
+makecontext(, , 0);
+
+// Swap to the new context so it can enter its enterMain() function. It
+// will then swap itself back out and return here.
+startingFiber = this;
+panic_if(!_currentFiber, "No active
