Merge pull request #14945 from ara-ayvazyan/improve_log_perf

Avoid low severity log message construction

grpc.def

@@ -185,6 +185,7 @@ EXPORTS
     gpr_cpu_current_cpu
     gpr_log_severity_string
     gpr_log
+    gpr_should_log
     gpr_log_message
     gpr_set_log_verbosity
     gpr_log_verbosity_init

include/grpc/support/log.h

@@ -61,6 +61,8 @@ GPRAPI const char* gpr_log_severity_string(gpr_log_severity severity);
 GPRAPI void gpr_log(const char* file, int line, gpr_log_severity severity,
                     const char* format, ...) GPR_PRINT_FORMAT_CHECK(4, 5);
 
+GPRAPI int gpr_should_log(gpr_log_severity severity);
+
 GPRAPI void gpr_log_message(const char* file, int line,
                             gpr_log_severity severity, const char* message);
 

src/core/lib/gpr/log.cc

@@ -44,10 +44,16 @@ const char* gpr_log_severity_string(gpr_log_severity severity) {
   GPR_UNREACHABLE_CODE(return "UNKNOWN");
 }
 
+int gpr_should_log(gpr_log_severity severity) {
+  return static_cast<gpr_atm>(severity) >=
+                 gpr_atm_no_barrier_load(&g_min_severity_to_print)
+             ? 1
+             : 0;
+}
+
 void gpr_log_message(const char* file, int line, gpr_log_severity severity,
                      const char* message) {
-  if (static_cast<gpr_atm>(severity) <
-      gpr_atm_no_barrier_load(&g_min_severity_to_print)) {
+  if (gpr_should_log(severity) == 0) {
     return;
   }
 

src/core/lib/gpr/log_android.cc

@@ -41,6 +41,10 @@ static android_LogPriority severity_to_log_priority(gpr_log_severity severity) {
 
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
+  /* Avoid message construction if gpr_log_message won't log */
+  if (gpr_should_log(severity) == 0) {
+    return;
+  }
   char* message = NULL;
   va_list args;
   va_start(args, format);

src/core/lib/gpr/log_linux.cc

@@ -44,6 +44,10 @@ static long gettid(void) { return syscall(__NR_gettid); }
 
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
+  /* Avoid message construction if gpr_log_message won't log */
+  if (gpr_should_log(severity) == 0) {
+    return;
+  }
   char* message = nullptr;
   va_list args;
   va_start(args, format);

src/core/lib/gpr/log_posix.cc

@@ -34,6 +34,10 @@ static intptr_t gettid(void) { return (intptr_t)pthread_self(); }
 
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
+  /* Avoid message construction if gpr_log_message won't log */
+  if (gpr_should_log(severity) == 0) {
+    return;
+  }
   char buf[64];
   char* allocated = nullptr;
   char* message = nullptr;

src/core/lib/gpr/log_windows.cc

@@ -34,6 +34,11 @@
 
 void gpr_log(const char* file, int line, gpr_log_severity severity,
              const char* format, ...) {
+  /* Avoid message construction if gpr_log_message won't log */
+  if (gpr_should_log(severity) == 0) {
+    return;
+  }
+
   char* message = NULL;
   va_list args;
   int ret;

src/ruby/ext/grpc/rb_grpc_imports.generated.c

@@ -208,6 +208,7 @@ gpr_cpu_num_cores_type gpr_cpu_num_cores_import;
 gpr_cpu_current_cpu_type gpr_cpu_current_cpu_import;
 gpr_log_severity_string_type gpr_log_severity_string_import;
 gpr_log_type gpr_log_import;
+gpr_should_log_type gpr_should_log_import;
 gpr_log_message_type gpr_log_message_import;
 gpr_set_log_verbosity_type gpr_set_log_verbosity_import;
 gpr_log_verbosity_init_type gpr_log_verbosity_init_import;
@@ -449,6 +450,7 @@ void grpc_rb_load_imports(HMODULE library) {
   gpr_cpu_current_cpu_import = (gpr_cpu_current_cpu_type) GetProcAddress(library, "gpr_cpu_current_cpu");
   gpr_log_severity_string_import = (gpr_log_severity_string_type) GetProcAddress(library, "gpr_log_severity_string");
   gpr_log_import = (gpr_log_type) GetProcAddress(library, "gpr_log");
+  gpr_should_log_import = (gpr_should_log_type) GetProcAddress(library, "gpr_should_log");
   gpr_log_message_import = (gpr_log_message_type) GetProcAddress(library, "gpr_log_message");
   gpr_set_log_verbosity_import = (gpr_set_log_verbosity_type) GetProcAddress(library, "gpr_set_log_verbosity");
   gpr_log_verbosity_init_import = (gpr_log_verbosity_init_type) GetProcAddress(library, "gpr_log_verbosity_init");

src/ruby/ext/grpc/rb_grpc_imports.generated.h

@@ -599,6 +599,9 @@ extern gpr_log_severity_string_type gpr_log_severity_string_import;
 typedef void(*gpr_log_type)(const char* file, int line, gpr_log_severity severity, const char* format, ...) GPR_PRINT_FORMAT_CHECK(4, 5);
 extern gpr_log_type gpr_log_import;
 #define gpr_log gpr_log_import
+typedef int(*gpr_should_log_type)(gpr_log_severity severity);
+extern gpr_should_log_type gpr_should_log_import;
+#define gpr_should_log gpr_should_log_import
 typedef void(*gpr_log_message_type)(const char* file, int line, gpr_log_severity severity, const char* message);
 extern gpr_log_message_type gpr_log_message_import;
 #define gpr_log_message gpr_log_message_import

test/core/surface/public_headers_must_be_c89.c

@@ -243,6 +243,7 @@ int main(int argc, char **argv) {
   printf("%lx", (unsigned long) gpr_cpu_current_cpu);
   printf("%lx", (unsigned long) gpr_log_severity_string);
   printf("%lx", (unsigned long) gpr_log);
+  printf("%lx", (unsigned long) gpr_should_log);
   printf("%lx", (unsigned long) gpr_log_message);
   printf("%lx", (unsigned long) gpr_set_log_verbosity);
   printf("%lx", (unsigned long) gpr_log_verbosity_init);