gpu_fdinfo: replace c code with c++ and minor fixes

Author: 17314642

src/gpu_fdinfo.cpp

@@ -1,107 +1,70 @@
 #include "gpu_fdinfo.h"
 namespace fs = ghc::filesystem;
 
-std::string GPU_fdinfo::get_drm_engine_type() {
-    std::string drm_type = "drm-engine-";
-
-    if (strstr(module, "amdgpu"))
-        drm_type += "gfx";
-    else if (strstr(module, "i915"))
-        drm_type += "render";
-    else if (strstr(module, "msm"))
-        drm_type += "gpu";
-    else
-        drm_type += "none";
-
-    return drm_type;
-}
-
-std::string GPU_fdinfo::get_drm_memory_type() {
-    std::string drm_type = "drm-";
-
-    // msm driver does not report vram usage
-
-    if (strstr(module, "amdgpu"))
-        drm_type += "memory-vram";
-    else if (strstr(module, "i915"))
-        drm_type += "total-local0";
-    else
-        drm_type += "memory-none";
-
-    return drm_type;
-}
-
 void GPU_fdinfo::find_fd() {
-#ifdef __linux__
-    DIR* dir = opendir("/proc/self/fdinfo");
-    if (!dir) {
-        perror("Failed to open directory");
+    auto path = fs::path("/proc/self/fdinfo");
+
+    if (!fs::exists(path)) {
+        SPDLOG_DEBUG("{} does not exist", path.string());
+        return;
     }
 
-    for (const auto& entry : fs::directory_iterator("/proc/self/fdinfo")){
-        FILE* file = fopen(entry.path().string().c_str(), "r");
+    std::vector<std::string> fds_to_open;
+    for (const auto& entry : fs::directory_iterator(path)) {
+        auto fd_path = entry.path().string();
+        auto file = std::ifstream(fd_path);
 
-        if (!file) continue;
+        if (!file.is_open())
+            continue;
 
-        char line[256];
         bool found_driver = false;
-        while (fgets(line, sizeof(line), file)) {
-            if (strstr(line, module) != NULL)
+        for (std::string line; std::getline(file, line);) {
+            if (line.find(module) != std::string::npos)
                 found_driver = true;
 
-            if (found_driver) {
-                if(strstr(line, get_drm_engine_type().c_str())) {
-                    fdinfo.push_back(file);
-                    break;
-                }
+            if (found_driver && line.find(drm_engine_type) != std::string::npos) {
+                fds_to_open.push_back(fd_path);
+                break;
             }
         }
-
-        if (!found_driver)
-            fclose(file);
     }
 
-    closedir(dir);
-#endif
+    for (const auto& fd : fds_to_open)
+        fdinfo.push_back(std::ifstream(fd));
 }
 
 uint64_t GPU_fdinfo::get_gpu_time() {
-    char line[256];
     uint64_t total_val = 0;
-    for (auto fd : fdinfo) {
-        rewind(fd);
-        fflush(fd);
-        uint64_t val = 0;
-        while (fgets(line, sizeof(line), fd)){
-            std::string scan_str = get_drm_engine_type() + ": %" SCNu64 " ns";
-
-            if (sscanf(line, scan_str.c_str(), &val) == 1) {
-                total_val += val;
-                break;
-            }
+
+    for (auto& fd : fdinfo) {
+        fd.clear();
+        fd.seekg(0);
+
+        for (std::string line; std::getline(fd, line);) {
+            if (line.find(drm_engine_type) == std::string::npos)
+                continue;
+
+            auto start = (drm_engine_type + ": ").length();
+            total_val += std::stoull(line.substr(start));
         }
     }
 
     return total_val;
 }
 
 float GPU_fdinfo::get_vram_usage() {
-    char line[256];
     uint64_t total_val = 0;
 
-    for (auto fd : fdinfo) {
-        rewind(fd);
-        fflush(fd);
-
-        uint64_t val = 0;
+    for (auto& fd : fdinfo) {
+        fd.clear();
+        fd.seekg(0);
 
-        while (fgets(line, sizeof(line), fd)) {
-            std::string scan_str = get_drm_memory_type() + ": %llu KiB";
+        for (std::string line; std::getline(fd, line);) {
+            if (line.find(drm_memory_type) == std::string::npos)
+                continue;
 
-            if (sscanf(line, scan_str.c_str(), &val) == 1) {
-                total_val += val;
-                break;
-            }
+            auto start = (drm_memory_type + ": ").length();
+            total_val += std::stoull(line.substr(start));
         }
     }
 
@@ -188,7 +151,6 @@ void GPU_fdinfo::get_load() {
             metrics.powerUsage = power_usage_since_last;
 
             previous_gpu_time = gpu_time_now;
-            previous_time = now;
             previous_power_usage = power_usage_now;
         }
 

src/gpu_fdinfo.h

@@ -16,9 +16,9 @@ class GPU_fdinfo {
     private:
         bool init = false;
         struct gpu_metrics metrics;
-        std::vector<FILE*> fdinfo;
-        const char* module;
-        const char* pci_dev;
+        std::vector<std::ifstream> fdinfo;
+        const std::string module;
+        const std::string pci_dev;
         void find_fd();
         void find_intel_hwmon();
         std::ifstream energy_stream;
@@ -30,17 +30,26 @@ class GPU_fdinfo {
 
         uint64_t get_gpu_time();
         void get_load();
-        std::string get_drm_engine_type();
-        std::string get_drm_memory_type();
+        std::string drm_engine_type = "EMPTY";
+        std::string drm_memory_type = "EMPTY";
         float get_vram_usage();
         float get_power_usage();
 
     public:
-        GPU_fdinfo(const char* module, const char* pci_dev) : module(module), pci_dev(pci_dev) {
+        GPU_fdinfo(const std::string module, const std::string pci_dev) : module(module), pci_dev(pci_dev) {
             find_fd();
 
-            if (strstr(module, "i915"))
+            if (module == "i915") {
+                drm_engine_type = "drm-engine-render";
+                drm_memory_type = "drm-total-local0";
                 find_intel_hwmon();
+            } else if (module == "amdgpu") {
+                drm_engine_type = "drm-engine-gfx";
+                drm_memory_type = "drm-memory-vram";
+            } else if (module == "msm") {
+                // msm driver does not report vram usage
+                drm_engine_type = "drm-engine-gpu";
+            }
 
             std::thread thread(&GPU_fdinfo::get_load, this);
             thread.detach();
@@ -59,11 +68,4 @@ class GPU_fdinfo {
             paused = false;
             cond_var.notify_one();
         }
-
-        ~GPU_fdinfo() {
-            for (size_t i = 0; i < fdinfo.size(); i++) {
-                fclose(fdinfo[i]);
-            }
-            fdinfo.clear();
-        }
 };