Implement the rivatimer and cyclical logging from my main NV3 branch so that we can get it reviewed and merged.

src/86box.c

@@ -103,6 +103,7 @@
 #include <86box/machine_status.h>
 #include <86box/apm.h>
 #include <86box/acpi.h>
+#include <86box/nv/vid_nv_rivatimer.h>
 
 // Disable c99-designator to avoid the warnings about int ng
 #ifdef __clang__
@@ -252,12 +253,37 @@ static volatile atomic_int do_pause_ack = 0;
 static volatile atomic_int pause_ack = 0;
 
 #ifndef RELEASE_BUILD
-static char buff[1024];
-static int  seen = 0;
+
+#define LOG_SIZE_BUFFER                 1024            /* Log size buffer */
+#define LOG_SIZE_BUFFER_CYCLIC_LINES    32              /* Cyclic log size buffer (number of lines that should be cehcked) */
+#define LOG_MINIMUM_REPEAT_ORDER        4               /* Minimum repeat size */
+
+static char buff[LOG_SIZE_BUFFER];
+static char cyclic_buff[LOG_SIZE_BUFFER_CYCLIC_LINES][LOG_SIZE_BUFFER];
+static int32_t cyclic_last_line = 0;
+static int32_t log_cycles = 0;
+
+static int seen = 0;
 
 static int suppr_seen = 1;
 #endif
 
+/* 
+    Ensures STDLOG is open for pclog_ex and pclog_ex_cyclic
+*/
+void
+pclog_ensure_stdlog_open()
+{
+    if (stdlog == NULL) {
+        if (log_path[0] != '\0') {
+            stdlog = plat_fopen(log_path, "w");
+            if (stdlog == NULL)
+                stdlog = stdout;
+        } else
+            stdlog = stdout;
+    }
+}
+
 /*
  * Log something to the logfile or stdout.
  *
@@ -269,19 +295,12 @@ void
 pclog_ex(const char *fmt, va_list ap)
 {
 #ifndef RELEASE_BUILD
-    char temp[1024];
+    char temp[LOG_SIZE_BUFFER];
 
     if (strcmp(fmt, "") == 0)
         return;
 
-    if (stdlog == NULL) {
-        if (log_path[0] != '\0') {
-            stdlog = plat_fopen(log_path, "w");
-            if (stdlog == NULL)
-                stdlog = stdout;
-        } else
-            stdlog = stdout;
-    }
+    pclog_ensure_stdlog_open();
 
     vsprintf(temp, fmt, ap);
     if (suppr_seen && !strcmp(buff, temp))
@@ -298,6 +317,114 @@ pclog_ex(const char *fmt, va_list ap)
 #endif
 }
 
+
+/*
+Starfrost, 7-8 January 2025: 
+
+For RIVA 128 emulation I needed a way to suppress logging if a repeated pattern of the same set of lines were found. 
+
+Implements a version of the Rabin-Karp algorithm https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm
+*/
+void 
+pclog_ex_cyclic(const char* fmt, va_list ap)
+{
+#ifndef RELEASE_BUILD
+    char temp[LOG_SIZE_BUFFER];
+
+    cyclic_last_line %= LOG_SIZE_BUFFER_CYCLIC_LINES;
+
+    vsprintf(temp, fmt, ap);
+
+    pclog_ensure_stdlog_open();
+
+    strncpy(cyclic_buff[cyclic_last_line], temp, LOG_SIZE_BUFFER);
+
+    uint32_t hashes[LOG_SIZE_BUFFER_CYCLIC_LINES] = {0};
+
+    // Random numbers
+    uint32_t base = 257;
+    uint32_t mod = 1000000007;
+
+    uint32_t repeat_order = 0;
+    bool is_cycle = false;
+
+    // compute the set of hashes for the current log buffer
+    for (int32_t log_line = 0; log_line < LOG_SIZE_BUFFER_CYCLIC_LINES; log_line++)
+    {
+        if (cyclic_buff[log_line][0] == '\0')
+            continue; // skip
+
+        for (int32_t log_line_char = 0; log_line_char < LOG_SIZE_BUFFER; log_line_char++)
+        {
+            hashes[log_line] = hashes[log_line] * base + cyclic_buff[log_line][log_line_char] % mod;
+        }
+    }
+
+
+    // Now see if there are real cycles...
+    // We implement a minimum repeat size.
+    for (int32_t check_size = LOG_MINIMUM_REPEAT_ORDER; check_size < LOG_SIZE_BUFFER_CYCLIC_LINES / 2; check_size++)
+    {
+        //TODO: Log what we need for cycle 1.
+        //TODO: Command line option that lets us turn off this behaviour.
+        for (int32_t log_line_to_check = 0; log_line_to_check < check_size; log_line_to_check++)
+        {
+            if (hashes[log_line_to_check] == hashes[(log_line_to_check + check_size) % LOG_SIZE_BUFFER_CYCLIC_LINES])
+            {
+                repeat_order = check_size;
+                break;
+            }
+        }
+
+        is_cycle = (repeat_order != 0);
+
+        // if there still is a cycle..
+        if (is_cycle)
+            break;
+            
+    }
+
+    if (is_cycle)
+    {
+        if (cyclic_last_line % repeat_order == 0)
+        {
+            log_cycles++;
+
+            if (log_cycles == 1)
+            {
+                // 'Replay' the last few log entries so they actually show up
+                // Todo: is this right?
+
+                for (uint32_t index = cyclic_last_line - 1; index > (cyclic_last_line - repeat_order); index--)
+                {
+                    // *very important* to prevent out of bounds index
+                    uint32_t real_index = index % LOG_SIZE_BUFFER_CYCLIC_LINES;
+                    fprintf(stdlog, "%s", temp);
+
+                }
+
+                fprintf(stdlog, "%s", temp); // allow normal logging
+            }
+                
+
+            if (log_cycles > 1 && log_cycles < 100)
+                fprintf(stdlog, "***** Cyclical Log Repeat of Order %d #%d *****\n", repeat_order, log_cycles);
+            else if (log_cycles == 100)
+                fprintf(stdlog, "Logged the same cycle 100 times...shutting up until something interesting happens\n");
+        }
+    }
+    else
+    {
+        log_cycles = 0;
+        fprintf(stdlog, "%s", temp);
+    }
+
+    cyclic_last_line++;
+    
+#endif
+
+}
+
 void
 pclog_toggle_suppr(void)
 {
@@ -1427,6 +1554,9 @@ pc_run(void)
         pc_reset_hard_init();
     }
 
+    /* Update the guest-CPU independent timer for devices with independent clock speed */
+    rivatimer_update_all();
+
     /* Run a block of code. */
     startblit();
     cpu_exec((int32_t) cpu_s->rspeed / 100);

src/include/86box/86box.h

@@ -187,8 +187,9 @@ extern int config_changed; /* config has changed */
 
 /* Function prototypes. */
 #ifdef HAVE_STDARG_H
-extern void pclog_ex(const char *fmt, va_list);
-extern void fatal_ex(const char *fmt, va_list);
+extern void pclog_ex(const char *fmt, va_list ap);
+extern void fatal_ex(const char *fmt, va_list ap);
+extern void pclog_ex_cyclic(const char* fmt, va_list ap);
 #endif
 extern void pclog_toggle_suppr(void);
 #ifdef _MSC_VER

src/include/86box/nv/vid_nv_rivatimer.h

@@ -0,0 +1,84 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Fast, high-frequency, guest CPU-independent timer for Riva emulation.
+ *
+ *
+ * Authors: Connor Hyde, <mario64crashed@gmail.com> I need a better email address ;^)
+ *
+ *          Copyright 2024-2025 starfrost
+ */
+
+/*
+RivaTimer
+
+This is a fast, high-frequency, guest CPU-independent timer.
+
+The main 86box timer is dependent on the TSC (time-stamp counter) register of the emulated CPU core.
+This is fine for most purposes and has advantages in the fields of synchronisation and integrates neatly with 
+the clock dividers of the PC architecture, but in the case of the RIVA 128 it does not particularly suffice 
+(although it can be made to work with various techniques) since the clock source on the RIVA 128 is on the board itself
+and the GPU has several different clocks that control different parts of the GPU (e.g., PTIMER runs on the memory clock but the core gpu is using the pixel clock).
+
+As faster graphics cards that offload more and more of the 3D graphics pipeline are emulated in the future, more and more work needs to be done by the emulator and 
+issues of synchronisation with a host CPU will simply make that work harder. Some features that are required for 
+
+Architecture    Brand Name      3D Features
+NV1 (1995)      NV1             Some weird URBS rectangle crap but feature set generally similar to nv3 but a bit worse
+NV3 (1997)      RIVA 128 (ZX)   Triangle setup, edge-slope calculations, edge interpolation, span-slope calculations, span interpolation (Color-buffer, z-buffer, texture mapping, filtering)
+NV4 (1998)      RIVA TNT        NV3 + 2x1 pixel pipelines + 32-bit colour + larger textures + trilinear + more ram (16mb)
+NV5 (1999)      RIVA TNT2       NV4 + higher clock speed
+NV10 (1999)     GeForce 256     NV5 + initial geometry transformation + lighting (8x lights) + MPEG-2 motion compensation + 4x1 pixel pipelines
+NV15 (2000)     GeForce 2       NV10 + First attempt at programmability + 4x2 pixel pipelines
+NV20 (2001)     GeForce 3       Programmable shaders!
+
+As you can see, the performance basically exponentially increases over a period of only 4 years. 
+
+So I decided to create this timer that is completely separate from the CPU Core.
+*/
+
+#pragma once
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <86Box\86box.h>
+
+#ifdef _WIN32     
+#include <Windows.h>
+// Linux & MacOS should have the same API since OSX 10.12 
+#else
+#include <time.h>
+#endif
+
+typedef struct rivatimer_s
+{
+    struct rivatimer_s*     prev;           // Previous Rivatimer
+    double                  period;         // Period in uS before firing
+    double                  value;          // The current value of the rivatimer
+    bool                    running;        // Is this RivaTimer running?
+    struct rivatimer_s*     next;           // Next RivaTimer
+    void                    (*callback)();  // Callback to call on fire
+    #ifdef _WIN32
+    LARGE_INTEGER           starting_time;  // Starting time.
+    #else
+    struct timespec         starting_time;  // Starting time.
+    #endif
+    double                  time;           // Accumulated time in uS.
+} rivatimer_t;
+
+void rivatimer_init();                                              // Initialise the Rivatimer.
+rivatimer_t* rivatimer_create(double period, void (*callback)(double real_time));
+void rivatimer_destroy(rivatimer_t* rivatimer_ptr);
+
+void rivatimer_update_all();
+void rivatimer_start(rivatimer_t* rivatimer_ptr);
+void rivatimer_stop(rivatimer_t* rivatimer_ptr);
+double rivatimer_get_time(rivatimer_t* rivatimer_ptr);
+void rivatimer_set_callback(rivatimer_t* rivatimer_ptr, void (*callback)(double real_time));
+void rivatimer_set_period(rivatimer_t* rivatimer_ptr, double period);

src/video/nv/nv_rivatimer.c

@@ -0,0 +1,274 @@
+/*
+ * 86Box    A hypervisor and IBM PC system emulator that specializes in
+ *          running old operating systems and software designed for IBM
+ *          PC systems and compatibles from 1981 through fairly recent
+ *          system designs based on the PCI bus.
+ *
+ *          This file is part of the 86Box distribution.
+ *
+ *          Fast, high-frequency, CPU-independent timer.
+ *
+ *
+ *
+ * Authors: Connor Hyde, <mario64crashed@gmail.com> I need a better email address ;^)
+ *
+ *          Copyright 2024-2025 starfrost
+ */
+
+/* See vid_nv_rivatimer.h comments for rationale behind not using the regular timer system 
+
+Notes applicable to this file:
+Since Windows XP, QueryPerformanceCounter and QueryPerformanceFrequency cannot fail so they are not checked.
+
+*/
+
+#include <86Box/nv/vid_nv_rivatimer.h>
+
+#ifdef _WIN32
+LARGE_INTEGER performance_frequency;
+#endif
+
+rivatimer_t* rivatimer_head;        // The head of the rivatimer list. 
+rivatimer_t* rivatimer_tail;        // The tail of the rivatimer list.
+
+/* Functions only used in this translation unit */
+bool rivatimer_really_exists(rivatimer_t* rivatimer);   // Determine if a rivatimer really exists in the linked list.
+
+void rivatimer_init()
+{
+    // Destroy all the rivatimers.
+    rivatimer_t* rivatimer_ptr = rivatimer_head;
+
+    if (!rivatimer_ptr)
+        return;
+
+    while (rivatimer_ptr)
+    {
+        // since we are destroing it
+        rivatimer_t* old_next = rivatimer_ptr->next;
+        rivatimer_destroy(rivatimer_ptr);
+        
+        rivatimer_ptr = old_next;
+    }
+        
+
+    #ifdef _WIN32
+    // Query the performance frequency.
+    QueryPerformanceFrequency(&performance_frequency);
+    #endif
+}
+
+// Creates a rivatimer.
+rivatimer_t* rivatimer_create(double period, void (*callback)(double real_time))
+{
+    rivatimer_t* new_rivatimer = NULL;
+
+    // See i
+    if (period <= 0 
+    || !callback)
+    {
+        fatal("Invalid rivatimer_create call: period <= 0 or no callback");
+    }
+
+    // If there are no rivatimers, create one
+    if (!rivatimer_head)
+    {
+        rivatimer_head = calloc(1, sizeof(rivatimer_t));
+        rivatimer_head->prev = NULL; // indicate this is the first in the list even if we don't strictly need to
+        rivatimer_tail = rivatimer_head; 
+        new_rivatimer = rivatimer_head;
+    }
+    else // Otherwise add a new one to the list
+    {
+        rivatimer_tail->next = calloc(1, sizeof(rivatimer_t));
+        rivatimer_tail = rivatimer_tail->next;
+        new_rivatimer = rivatimer_tail;
+    }
+    
+    // sanity check
+    if (new_rivatimer)
+    {
+        new_rivatimer->running = false;
+        new_rivatimer->period = period;
+        new_rivatimer->next = NULL; // indicate this is the last in the list
+        new_rivatimer->callback = callback;
+    }
+
+    return new_rivatimer;
+}
+
+// Determines if a rivatimer really exists.
+bool rivatimer_really_exists(rivatimer_t* rivatimer)
+{
+    rivatimer_t* current = rivatimer_head;
+
+    if (!current)
+        return false;
+
+    while (current)
+    {
+        if (current == rivatimer)
+            return true;
+
+        current = current->next;
+    }
+
+    return false;
+}
+
+// Destroy a rivatimer.
+void rivatimer_destroy(rivatimer_t* rivatimer_ptr)
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+        fatal("rivatimer_destroy: The timer was already destroyed, or never existed in the first place. Punch starfrost in the face");
+    
+    // Case: We are destroying the head
+    if (rivatimer_ptr == rivatimer_head)
+    {
+        // This is the only rivatimer
+        if (rivatimer_ptr->next == NULL)
+        {
+            rivatimer_head = NULL;
+            rivatimer_tail = NULL;
+        }
+        // This is not the only rivatimer
+        else 
+        {
+            rivatimer_head = rivatimer_ptr->next;
+            rivatimer_head->prev = NULL; 
+            // This is the only rivatimer and now there is only one
+            if (!rivatimer_head->next)
+                rivatimer_tail = rivatimer_head;
+        }
+    }
+    // Case: We are destroying the tail
+    else if (rivatimer_ptr == rivatimer_tail)
+    {
+        // We already covered the case where there is only one item above
+        rivatimer_tail = rivatimer_ptr->prev;
+        rivatimer_tail->next = NULL;
+    }
+    // Case: This is not the first or last rivatimer, so we don't need to set the head or tail
+    else
+    {
+        // Fix the break in the chain that this 
+        if (rivatimer_ptr->next)
+            rivatimer_ptr->prev->next = rivatimer_ptr->next;
+        if (rivatimer_ptr->prev)
+            rivatimer_ptr->next->prev = rivatimer_ptr->prev;
+    }
+
+    free(rivatimer_ptr);
+    rivatimer_ptr = NULL; //explicitly set to null
+}
+
+void rivatimer_update_all()
+{
+    rivatimer_t* rivatimer_ptr = rivatimer_head;
+
+    if (!rivatimer_ptr)
+        return;
+
+    while (rivatimer_ptr)
+    {
+        // if it's not running skip it
+        if (!rivatimer_ptr->running)
+        {
+            rivatimer_ptr = rivatimer_ptr->next;
+            continue;
+        }
+
+        #ifdef _WIN32
+            LARGE_INTEGER current_time;
+
+            QueryPerformanceCounter(&current_time);
+
+            double microseconds = ((double)current_time.QuadPart / 1000000.0) - (rivatimer_ptr->starting_time.QuadPart / 1000000.0);
+        #else
+            struct timespec current_time; 
+
+            clock_gettime(CLOCK_REALTIME, &current_time);
+
+            double microseconds = ((double)current_time.tv_sec * 1000000.0) + ((double)current_time.tv_nsec / 1000.0);
+        #endif
+
+        rivatimer_ptr->time += microseconds; 
+
+        // Reset the current time so we can actually restart
+        #ifdef _WIN32
+            QueryPerformanceCounter(&rivatimer_ptr->starting_time);
+        #else
+            clock_gettime(CLOCK_REALTIME, &rivatimer_ptr->starting_time);
+        #endif 
+
+        // Time to fire
+        if (microseconds > rivatimer_ptr->period)
+        {
+            if (!rivatimer_ptr->callback)
+            {
+                pclog("Eh? No callback in RivaTimer?");
+                continue;
+            }
+                    
+            rivatimer_ptr->callback(microseconds);
+        }
+
+        rivatimer_ptr = rivatimer_ptr->next;
+    }
+
+}
+
+void rivatimer_start(rivatimer_t* rivatimer_ptr)
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+        fatal("rivatimer_start: The timer has been destroyed, or never existed in the first place. Punch starfrost in the face");
+
+    if (rivatimer_ptr->period <= 0)
+        fatal("rivatimer_start: Zero period!");
+
+    rivatimer_ptr->running = true;
+
+    // Start off so rivatimer_update_all can actually update.
+    #ifdef _WIN32
+        QueryPerformanceCounter(&rivatimer_ptr->starting_time);
+    #else
+        clock_gettime(CLOCK_REALTIME, &rivatimer_ptr->starting_time);
+    #endif 
+}
+
+void rivatimer_stop(rivatimer_t* rivatimer_ptr)
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+        fatal("rivatimer_stop: The timer has been destroyed, or never existed in the first place. Punch starfrost in the face");
+
+    rivatimer_ptr->running = false;
+    rivatimer_ptr->time = 0;
+}
+
+// Get the current time value of a rivatimer
+double rivatimer_get_time(rivatimer_t* rivatimer_ptr)
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+        fatal("rivatimer_get_time: The timer has been destroyed, or never existed in the first place. Punch starfrost in the face");
+
+    return rivatimer_ptr->time;
+}
+
+void rivatimer_set_callback(rivatimer_t* rivatimer_ptr, void (*callback)(double real_time))
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+        fatal("rivatimer_set_callback: The timer has been destroyed, or never existed in the first place. Punch starfrost in the face");
+
+    if (!callback)
+        fatal("rivatimer_set_callback: No callback!");
+
+    rivatimer_ptr->callback = callback;
+}
+
+void rivatimer_set_period(rivatimer_t* rivatimer_ptr, double period)
+{
+    if (!rivatimer_really_exists(rivatimer_ptr))
+       fatal("rivatimer_set_period: The timer has been destroyed, or never existed in the first place. Punch starfrost in the face");
+
+    rivatimer_ptr->period = period;
+}