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-rw-r--r--src/core/ext/transport/chttp2/transport/flow_control.cc23
-rw-r--r--src/core/ext/transport/chttp2/transport/internal.h2
-rw-r--r--src/core/lib/transport/pid_controller.cc53
-rw-r--r--src/core/lib/transport/pid_controller.h110
4 files changed, 107 insertions, 81 deletions
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.cc b/src/core/ext/transport/chttp2/transport/flow_control.cc
index d0e80c4bd5..716cd71490 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.cc
+++ b/src/core/ext/transport/chttp2/transport/flow_control.cc
@@ -399,22 +399,19 @@ static double get_pid_controller_guess(grpc_exec_ctx* exec_ctx,
if (!tfc->pid_controller_initialized) {
tfc->last_pid_update = now;
tfc->pid_controller_initialized = true;
- grpc_pid_controller_args args;
- memset(&args, 0, sizeof(args));
- args.gain_p = 4;
- args.gain_i = 8;
- args.gain_d = 0;
- args.initial_control_value = target;
- args.min_control_value = -1;
- args.max_control_value = 25;
- args.integral_range = 10;
- grpc_pid_controller_init(&tfc->pid_controller, args);
+ tfc->pid_controller.Init(grpc_core::PidController::Args()
+ .set_gain_p(4)
+ .set_gain_i(8)
+ .set_gain_d(0)
+ .set_initial_control_value(target)
+ .set_min_control_value(-1)
+ .set_max_control_value(25)
+ .set_integral_range(10));
return pow(2, target);
}
- double bdp_error = target - grpc_pid_controller_last(&tfc->pid_controller);
+ double bdp_error = target - tfc->pid_controller->last_control_value();
double dt = (double)(now - tfc->last_pid_update) * 1e-3;
- double log2_bdp_guess =
- grpc_pid_controller_update(&tfc->pid_controller, bdp_error, dt);
+ double log2_bdp_guess = tfc->pid_controller->Update(bdp_error, dt);
tfc->last_pid_update = now;
return pow(2, log2_bdp_guess);
}
diff --git a/src/core/ext/transport/chttp2/transport/internal.h b/src/core/ext/transport/chttp2/transport/internal.h
index 703f3ba348..c75f813393 100644
--- a/src/core/ext/transport/chttp2/transport/internal.h
+++ b/src/core/ext/transport/chttp2/transport/internal.h
@@ -273,7 +273,7 @@ typedef struct {
/* pid controller */
bool pid_controller_initialized;
- grpc_pid_controller pid_controller;
+ grpc_core::ManualConstructor<grpc_core::PidController> pid_controller;
grpc_millis last_pid_update;
// pointer back to transport for tracing
diff --git a/src/core/lib/transport/pid_controller.cc b/src/core/lib/transport/pid_controller.cc
index 4b304f17b2..9f7750d693 100644
--- a/src/core/lib/transport/pid_controller.cc
+++ b/src/core/lib/transport/pid_controller.cc
@@ -19,45 +19,30 @@
#include "src/core/lib/transport/pid_controller.h"
#include <grpc/support/useful.h>
-void grpc_pid_controller_init(grpc_pid_controller *pid_controller,
- grpc_pid_controller_args args) {
- pid_controller->args = args;
- pid_controller->last_control_value = args.initial_control_value;
- grpc_pid_controller_reset(pid_controller);
-}
+namespace grpc_core {
-void grpc_pid_controller_reset(grpc_pid_controller *pid_controller) {
- pid_controller->last_error = 0.0;
- pid_controller->last_dc_dt = 0.0;
- pid_controller->error_integral = 0.0;
-}
+PidController::PidController(const Args &args)
+ : last_control_value_(args.initial_control_value()), args_(args) {}
-double grpc_pid_controller_update(grpc_pid_controller *pid_controller,
- double error, double dt) {
- if (dt == 0) return pid_controller->last_control_value;
+double PidController::Update(double error, double dt) {
+ if (dt <= 0) return last_control_value_;
/* integrate error using the trapezoid rule */
- pid_controller->error_integral +=
- dt * (pid_controller->last_error + error) * 0.5;
- pid_controller->error_integral = GPR_CLAMP(
- pid_controller->error_integral, -pid_controller->args.integral_range,
- pid_controller->args.integral_range);
- double diff_error = (error - pid_controller->last_error) / dt;
+ error_integral_ += dt * (last_error_ + error) * 0.5;
+ error_integral_ = GPR_CLAMP(error_integral_, -args_.integral_range(),
+ args_.integral_range());
+ double diff_error = (error - last_error_) / dt;
/* calculate derivative of control value vs time */
- double dc_dt = pid_controller->args.gain_p * error +
- pid_controller->args.gain_i * pid_controller->error_integral +
- pid_controller->args.gain_d * diff_error;
+ double dc_dt = args_.gain_p() * error + args_.gain_i() * error_integral_ +
+ args_.gain_d() * diff_error;
/* and perform trapezoidal integration */
- double new_control_value = pid_controller->last_control_value +
- dt * (pid_controller->last_dc_dt + dc_dt) * 0.5;
- new_control_value =
- GPR_CLAMP(new_control_value, pid_controller->args.min_control_value,
- pid_controller->args.max_control_value);
- pid_controller->last_error = error;
- pid_controller->last_dc_dt = dc_dt;
- pid_controller->last_control_value = new_control_value;
+ double new_control_value =
+ last_control_value_ + dt * (last_dc_dt_ + dc_dt) * 0.5;
+ new_control_value = GPR_CLAMP(new_control_value, args_.min_control_value(),
+ args_.max_control_value());
+ last_error_ = error;
+ last_dc_dt_ = dc_dt;
+ last_control_value_ = new_control_value;
return new_control_value;
}
-double grpc_pid_controller_last(grpc_pid_controller *pid_controller) {
- return pid_controller->last_control_value;
-}
+} // namespace grpc_core
diff --git a/src/core/lib/transport/pid_controller.h b/src/core/lib/transport/pid_controller.h
index 80899e9a20..87e59a1a90 100644
--- a/src/core/lib/transport/pid_controller.h
+++ b/src/core/lib/transport/pid_controller.h
@@ -19,9 +19,7 @@
#ifndef GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H
#define GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include <limits>
/* \file Simple PID controller.
Implements a proportional-integral-derivative controller.
@@ -30,41 +28,87 @@ extern "C" {
Gains can be set to adjust sensitivity to current error (p), the integral
of error (i), and the derivative of error (d). */
-typedef struct {
- double gain_p;
- double gain_i;
- double gain_d;
- double initial_control_value;
- double min_control_value;
- double max_control_value;
- double integral_range;
-} grpc_pid_controller_args;
+namespace grpc_core {
-typedef struct {
- double last_error;
- double error_integral;
- double last_control_value;
- double last_dc_dt;
- grpc_pid_controller_args args;
-} grpc_pid_controller;
+class PidController {
+ public:
+ class Args {
+ public:
+ double gain_p() const { return gain_p_; }
+ double gain_i() const { return gain_i_; }
+ double gain_d() const { return gain_d_; }
+ double initial_control_value() const { return initial_control_value_; }
+ double min_control_value() const { return min_control_value_; }
+ double max_control_value() const { return max_control_value_; }
+ double integral_range() const { return integral_range_; }
-/** Initialize the controller */
-void grpc_pid_controller_init(grpc_pid_controller *pid_controller,
- grpc_pid_controller_args args);
+ Args& set_gain_p(double gain_p) {
+ gain_p_ = gain_p;
+ return *this;
+ }
+ Args& set_gain_i(double gain_i) {
+ gain_i_ = gain_i;
+ return *this;
+ }
+ Args& set_gain_d(double gain_d) {
+ gain_d_ = gain_d;
+ return *this;
+ }
+ Args& set_initial_control_value(double initial_control_value) {
+ initial_control_value_ = initial_control_value;
+ return *this;
+ }
+ Args& set_min_control_value(double min_control_value) {
+ min_control_value_ = min_control_value;
+ return *this;
+ }
+ Args& set_max_control_value(double max_control_value) {
+ max_control_value_ = max_control_value;
+ return *this;
+ }
+ Args& set_integral_range(double integral_range) {
+ integral_range_ = integral_range;
+ return *this;
+ }
-/** Reset the controller: useful when things have changed significantly */
-void grpc_pid_controller_reset(grpc_pid_controller *pid_controller);
+ private:
+ double gain_p_ = 0.0;
+ double gain_i_ = 0.0;
+ double gain_d_ = 0.0;
+ double initial_control_value_ = 0.0;
+ double min_control_value_ = std::numeric_limits<double>::min();
+ double max_control_value_ = std::numeric_limits<double>::max();
+ double integral_range_ = std::numeric_limits<double>::max();
+ };
-/** Update the controller: given a current error estimate, and the time since
- the last update, returns a new control value */
-double grpc_pid_controller_update(grpc_pid_controller *pid_controller,
- double error, double dt);
+ explicit PidController(const Args& args);
-/** Returns the last control value calculated */
-double grpc_pid_controller_last(grpc_pid_controller *pid_controller);
+ /// Reset the controller internal state: useful when the environment has
+ /// changed significantly
+ void Reset() {
+ last_error_ = 0.0;
+ last_dc_dt_ = 0.0;
+ error_integral_ = 0.0;
+ }
-#ifdef __cplusplus
-}
-#endif
+ /// Update the controller: given a current error estimate, and the time since
+ /// the last update, returns a new control value
+ double Update(double error, double dt);
+
+ /// Returns the last control value calculated
+ double last_control_value() const { return last_control_value_; }
+
+ /// Returns the current error integral (mostly for testing)
+ double error_integral() const { return error_integral_; }
+
+ private:
+ double last_error_ = 0.0;
+ double error_integral_ = 0.0;
+ double last_control_value_;
+ double last_dc_dt_ = 0.0;
+ const Args args_;
+};
+
+} // namespace grpc_core
#endif /* GRPC_CORE_LIB_TRANSPORT_PID_CONTROLLER_H */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-28 10:51:24 +0000