tcp_echo.c

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//==========================================================================
//
//      tests/tcp_echo.c
//
//      Simple TCP throughput test - echo component
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD or other sources,
// and are covered by the appropriate copyright disclaimers included herein.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    gthomas
// Contributors: gthomas
// Date:         2000-01-10
// Purpose:      
// Description:  This is the middle part of a three part test.  The idea is
//   to test the throughput of box in a configuration like this:
//
//      +------+   port   +----+     port    +----+
//      |SOURCE|=========>|ECHO|============>|SINK|
//      +------+   9990   +----+     9991    +----+
// 
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <pkgconf/system.h>
#include <pkgconf/net.h>

#ifdef CYGBLD_DEVS_ETH_DEVICE_H    // Get the device config if it exists
#include CYGBLD_DEVS_ETH_DEVICE_H  // May provide CYGTST_DEVS_ETH_TEST_NET_REALTIME
#endif

#ifdef CYGPKG_NET_TESTS_USE_RT_TEST_HARNESS // do we use the rt test?
# ifdef CYGTST_DEVS_ETH_TEST_NET_REALTIME // Get the test ancilla if it exists
#  include CYGTST_DEVS_ETH_TEST_NET_REALTIME
# endif
#endif


// Fill in the blanks if necessary
#ifndef TNR_OFF
# define TNR_OFF()
#endif
#ifndef TNR_ON
# define TNR_ON()
#endif
#ifndef TNR_INIT
# define TNR_INIT()
#endif
#ifndef TNR_PRINT_ACTIVITY
# define TNR_PRINT_ACTIVITY()
#endif


// Network throughput test code

#include <network.h>

static __inline__ unsigned int
max(unsigned int m, unsigned int n)
{
    return m > n ? m : n;
}

#define SOURCE_PORT 9990
#define SINK_PORT   9991

#define MAX_BUF 8192
static unsigned char data_buf[MAX_BUF];

struct test_params {
    long nbufs;
    long bufsize;
    long load;
};

struct test_status {
    long ok;
};

#ifndef CYGPKG_LIBC_STDIO
#define perror(s) diag_printf(#s ": %s\n", strerror(errno))
#endif

#define STACK_SIZE (CYGNUM_HAL_STACK_SIZE_TYPICAL + 0x1000)
static char stack[STACK_SIZE];
static cyg_thread thread_data;
static cyg_handle_t thread_handle;

// Background load stuff
#define NUM_LOAD_THREADS         20 // Get 5% granularity
#define IDLE_THREAD_PRIORITY     CYGPKG_NET_THREAD_PRIORITY+3
#define LOAD_THREAD_PRIORITY     CYGPKG_NET_THREAD_PRIORITY-3
#define MAIN_THREAD_PRIORITY     CYGPKG_NET_THREAD_PRIORITY-4
#define DESIRED_BACKGROUND_LOAD  50 // should be accurate enough over range

// starting points for load calculation
#define MAX_LOAD_THREAD_LEVEL    100
#define MIN_LOAD_THREAD_LEVEL    0

static char         idle_thread_stack[STACK_SIZE];
static cyg_thread   idle_thread_data;
static cyg_handle_t idle_thread_handle;
static cyg_sem_t    idle_thread_sem;
volatile static long long    idle_thread_count;
static char         load_thread_stack[NUM_LOAD_THREADS][STACK_SIZE];
static cyg_thread   load_thread_data[NUM_LOAD_THREADS];
static cyg_handle_t load_thread_handle[NUM_LOAD_THREADS];
static cyg_sem_t    load_thread_sem[NUM_LOAD_THREADS];
static long         load_thread_level;
static void calibrate_load(int load);
static void start_load(int load);
static void do_some_random_computation(int p,int id);
#define abs(n) ((n) < 0 ? -(n) : (n))

static long long no_load_idle_count_1_second;

extern void
cyg_test_exit(void);

void
pexit(char *s)
{
    TNR_OFF();
    perror(s);
    cyg_test_exit();
}

int
do_read(int s, void *_buf, int len)
{
    int total, slen, rlen;
    unsigned char *buf = (unsigned char *)_buf;
    total = 0;
    rlen = len;
    while (total < len) {
        slen = read(s, buf, rlen);
        if (slen != rlen) {
            if (slen < 0) {
                diag_printf("Error after reading %d bytes\n", total);
                return -1;
            }
            rlen -= slen;
            buf += slen;
        }
        total += slen;
    }
    return total;
}

int
do_write(int s, void *_buf, int len)
{
    int total, slen, rlen;
    unsigned char *buf = (unsigned char *)_buf;
    total = 0;
    rlen = len;
    while (total < len) {
        slen = write(s, buf, rlen);
        if (slen != rlen) {
            if (slen < 0) {
                diag_printf("Error after writing %d bytes\n", total);
                return -1;
            }
            rlen -= slen;
            buf += slen;
        }
        total += slen;
    }
    return total;
}

//
// This function is called to calibrate the "background load" which can be
// applied during testing.  It will be called before any commands from the
// host are managed.
//
static void
calibrate_load(int desired_load)
{
    long long no_load_idle, load_idle;
    int percent_load;
    int high, low;

    // Set limits
    high = MAX_LOAD_THREAD_LEVEL;
    low = MIN_LOAD_THREAD_LEVEL;

    // Compute the "no load" idle value
    idle_thread_count = 0;
    cyg_semaphore_post(&idle_thread_sem);  // Start idle thread
    cyg_thread_delay(1*100);               // Pause for one second
    cyg_semaphore_wait(&idle_thread_sem);  // Stop idle thread
    no_load_idle = idle_thread_count;
    diag_printf("No load = %d\n", (int)idle_thread_count);

    // First ensure that the HIGH level is indeed higher
    while (true) {
        load_thread_level = high;
        start_load(desired_load);              // Start up a given load
        idle_thread_count = 0;
        cyg_semaphore_post(&idle_thread_sem);  // Start idle thread
        cyg_thread_delay(1*100);               // Pause for one second
        cyg_semaphore_wait(&idle_thread_sem);  // Stop idle thread
        load_idle = idle_thread_count;
        start_load(0);                         // Shut down background load
        percent_load = 100 - ((load_idle * 100) / no_load_idle);
        diag_printf("High Load[%d] = %d => %d%%\n", load_thread_level, 
                    (int)idle_thread_count, percent_load);
        if ( percent_load > desired_load )
            break; // HIGH level is indeed higher
        low = load_thread_level; // known to be lower
        high *= 2; // else double it and try again
    }

    // Now chop down to the level required
    while (true) {
        load_thread_level = (high + low) / 2;
        start_load(desired_load);              // Start up a given load
        idle_thread_count = 0;
        cyg_semaphore_post(&idle_thread_sem);  // Start idle thread
        cyg_thread_delay(1*100);               // Pause for one second
        cyg_semaphore_wait(&idle_thread_sem);  // Stop idle thread
        load_idle = idle_thread_count;
        start_load(0);                         // Shut down background load
        percent_load = 100 - ((load_idle * 100) / no_load_idle);
        diag_printf("Load[%d] = %d => %d%%\n", load_thread_level, 
                    (int)idle_thread_count, percent_load);
        if (((high-low) <= 1) || (abs(desired_load-percent_load) <= 2)) break;
        if (percent_load < desired_load) {
            low = load_thread_level;
        } else {            
            high = load_thread_level;
        }
    }

    // Now we are within a few percent of the target; scale the load
    // factor to get a better fit, and test it, print the answer.
    load_thread_level *= desired_load;
    load_thread_level /= percent_load;
    start_load(desired_load);              // Start up a given load
    idle_thread_count = 0;
    cyg_semaphore_post(&idle_thread_sem);  // Start idle thread
    cyg_thread_delay(1*100);               // Pause for one second
    cyg_semaphore_wait(&idle_thread_sem);  // Stop idle thread
    load_idle = idle_thread_count;
    start_load(0);                         // Shut down background load
    percent_load = 100 - ((load_idle * 100) / no_load_idle);
    diag_printf("Final load[%d] = %d => %d%%\n", load_thread_level, 
                (int)idle_thread_count, percent_load);
    no_load_idle_count_1_second = no_load_idle;
}

//
// This function is called to set up a load level of 'load' percent (given
// as a whole number, e.g. start_load(20) would mean initiate a background
// load of 20%, leaving the cpu 80% idle).
//
static void
start_load(int load)
{
    static int prev_load = 0;
    int i;
    if (load == 0) {
        diag_printf("Set no background load\n");
        if (prev_load == 0) return;  // Nothing out there to stop
        for (i = 0;  i < prev_load * NUM_LOAD_THREADS/100;  i++) {
            cyg_semaphore_wait(&load_thread_sem[i]);
        }
        prev_load = 0;
    } else {
        diag_printf("Set background load = %d%% starting %d threads\n",
                    load, load * NUM_LOAD_THREADS/100 );
        for (i = 0;  i < load * NUM_LOAD_THREADS/100;  i++) {
            cyg_semaphore_post(&load_thread_sem[i]);
        }
        prev_load = load;
    }
}

//
// These thread(s) do some amount of "background" computing.  This is used
// to simulate a given load level.  They need to be run at a higher priority 
// than the network code itself.
//
// Like the "idle" thread, they run as long as their "switch" (aka semaphore)
// is enabled.