JIT: Initialize jitstdout lazily

src/coreclr/jit/codegencommon.cpp

@@ -2011,7 +2011,7 @@ void CodeGen::genEmitMachineCode()
 #if TRACK_LSRA_STATS
         if (JitConfig.DisplayLsraStats() == 3)
         {
-            compiler->m_pLinearScan->dumpLsraStatsSummary(jitstdout);
+            compiler->m_pLinearScan->dumpLsraStatsSummary(jitstdout());
         }
 #endif // TRACK_LSRA_STATS
 
@@ -2104,7 +2104,7 @@ void CodeGen::genEmitUnwindDebugGCandEH()
         genCreateAndStoreGCInfo(codeSize, prologSize, epilogSize DEBUGARG(codePtr));
 
 #ifdef DEBUG
-    FILE* dmpf = jitstdout;
+    FILE* dmpf = jitstdout();
 
     compiler->opts.dmpHex = false;
     if (!strcmp(compiler->info.compMethodName, "<name of method you want the hex dump for"))
@@ -2157,7 +2157,7 @@ void CodeGen::genEmitUnwindDebugGCandEH()
         fflush(dmpf);
     }
 
-    if (dmpf != jitstdout)
+    if (dmpf != jitstdout())
     {
         fclose(dmpf);
     }

src/coreclr/jit/compiler.cpp

@@ -154,7 +154,7 @@ void Compiler::JitLogEE(unsigned level, const char* fmt, ...)
     if (verbose)
     {
         va_start(args, fmt);
-        vflogf(jitstdout, fmt, args);
+        vflogf(jitstdout(), fmt, args);
         va_end(args);
     }
 
@@ -1229,13 +1229,14 @@ void DisplayNowayAssertMap()
             fout = _wfopen(strJitMeasureNowayAssertFile, W("a"));
             if (fout == nullptr)
             {
-                fprintf(jitstdout, "Failed to open JitMeasureNowayAssertFile \"%ws\"\n", strJitMeasureNowayAssertFile);
+                fprintf(jitstdout(), "Failed to open JitMeasureNowayAssertFile \"%ws\"\n",
+                        strJitMeasureNowayAssertFile);
                 return;
             }
         }
         else
         {
-            fout = jitstdout;
+            fout = jitstdout();
         }
 
         // Iterate noway assert map, create sorted table by occurrence, dump it.
@@ -1252,7 +1253,7 @@ void DisplayNowayAssertMap()
 
         jitstd::sort(nacp, nacp + count, NowayAssertCountMap::compare());
 
-        if (fout == jitstdout)
+        if (fout == jitstdout())
         {
             // Don't output the header if writing to a file, since we'll be appending to existing dumps in that case.
             fprintf(fout, "\nnoway_assert counts:\n");
@@ -1265,7 +1266,7 @@ void DisplayNowayAssertMap()
                     nacp[i].fl.m_condStr);
         }
 
-        if (fout != jitstdout)
+        if (fout != jitstdout())
         {
             fclose(fout);
             fout = nullptr;
@@ -1330,7 +1331,7 @@ void Compiler::compStartup()
     // Static vars of ValueNumStore
     ValueNumStore::ValidateValueNumStoreStatics();
 
-    compDisplayStaticSizes(jitstdout);
+    compDisplayStaticSizes(jitstdout());
 }
 
 /*****************************************************************************
@@ -1388,11 +1389,11 @@ void Compiler::compShutdown()
 #endif
 
 #if NODEBASH_STATS
-    GenTree::ReportOperBashing(jitstdout);
+    GenTree::ReportOperBashing(jitstdout());
 #endif
 
     // Where should we write our statistics output?
-    FILE* fout = jitstdout;
+    FILE* fout = jitstdout();
 
 #ifdef FEATURE_JIT_METHOD_PERF
     if (compJitTimeLogFilename != nullptr)
@@ -1661,10 +1662,10 @@ void Compiler::compShutdown()
     if (s_dspMemStats)
     {
         fprintf(fout, "\nAll allocations:\n");
-        ArenaAllocator::dumpAggregateMemStats(jitstdout);
+        ArenaAllocator::dumpAggregateMemStats(jitstdout());
 
         fprintf(fout, "\nLargest method:\n");
-        ArenaAllocator::dumpMaxMemStats(jitstdout);
+        ArenaAllocator::dumpMaxMemStats(jitstdout());
 
         fprintf(fout, "\n");
         fprintf(fout, "---------------------------------------------------\n");
@@ -1684,7 +1685,7 @@ void Compiler::compShutdown()
     if (JitConfig.DisplayLoopHoistStats() != 0)
 #endif // DEBUG
     {
-        PrintAggregateLoopHoistStats(jitstdout);
+        PrintAggregateLoopHoistStats(jitstdout());
     }
 #endif // LOOP_HOIST_STATS
 
@@ -5149,7 +5150,7 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
 #if TRACK_LSRA_STATS
     if (JitConfig.DisplayLsraStats() == 2)
     {
-        m_pLinearScan->dumpLsraStatsCsv(jitstdout);
+        m_pLinearScan->dumpLsraStatsCsv(jitstdout());
     }
 #endif // TRACK_LSRA_STATS
 
@@ -5875,7 +5876,7 @@ int Compiler::compCompile(CORINFO_MODULE_HANDLE classPtr,
     }
 #endif // FUNC_INFO_LOGGING
 
-    // if (s_compMethodsCount==0) setvbuf(jitstdout, NULL, _IONBF, 0);
+    // if (s_compMethodsCount==0) setvbuf(jitstdout(), NULL, _IONBF, 0);
 
     if (compIsForInlining())
     {
@@ -6359,7 +6360,7 @@ void Compiler::compCompileFinish()
     if (s_dspMemStats || verbose)
     {
         printf("\nAllocations for %s (MethodHash=%08x)\n", info.compFullName, info.compMethodHash());
-        compArenaAllocator->dumpMemStats(jitstdout);
+        compArenaAllocator->dumpMemStats(jitstdout());
     }
 #endif // DEBUG
 #endif // MEASURE_MEM_ALLOC

src/coreclr/jit/disasm.cpp

@@ -1478,12 +1478,12 @@ void DisAssembler::disAsmCode(BYTE* hotCodePtr, size_t hotCodeSize, BYTE* coldCo
     }
 #else  // !DEBUG
     // NOTE: non-DEBUG builds always use jitstdout currently!
-    disAsmFile = jitstdout;
+    disAsmFile = jitstdout();
 #endif // !DEBUG
 
     if (disAsmFile == nullptr)
     {
-        disAsmFile = jitstdout;
+        disAsmFile = jitstdout();
     }
 
     // As this writes to a common file, this is not reentrant.
@@ -1519,7 +1519,7 @@ void DisAssembler::disAsmCode(BYTE* hotCodePtr, size_t hotCodeSize, BYTE* coldCo
     DisasmBuffer(disAsmFile, /* printIt */ true);
     fprintf(disAsmFile, "\n");
 
-    if (disAsmFile != jitstdout)
+    if (disAsmFile != jitstdout())
     {
         fclose(disAsmFile);
     }

src/coreclr/jit/ee_il_dll.cpp

@@ -31,8 +31,6 @@ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
 
 /*****************************************************************************/
 
-FILE* jitstdout = nullptr;
-
 ICorJitHost* g_jitHost        = nullptr;
 bool         g_jitInitialized = false;
 
@@ -71,16 +69,25 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* jitHost)
 
     assert(!JitConfig.isInitialized());
     JitConfig.initialize(jitHost);
+    Compiler::compStartup();
+
+    g_jitInitialized = true;
+}
+
+static FILE* s_jitstdout;
 
+static FILE* jitstdoutInit()
+{
     const WCHAR* jitStdOutFile = JitConfig.JitStdOutFile();
+    FILE*        file          = nullptr;
     if (jitStdOutFile != nullptr)
     {
-        jitstdout = _wfopen(jitStdOutFile, W("a"));
-        assert(jitstdout != nullptr);
+        file = _wfopen(jitStdOutFile, W("a"));
+        assert(file != nullptr);
     }
 
 #if !defined(HOST_UNIX)
-    if (jitstdout == nullptr)
+    if (file == nullptr)
     {
         int stdoutFd = _fileno(procstdout());
         // Check fileno error output(s) -1 may overlap with errno result
@@ -89,40 +96,58 @@ extern "C" DLLEXPORT void jitStartup(ICorJitHost* jitHost)
         // or bogus and avoid making further calls.
         if ((stdoutFd != -1) && (stdoutFd != -2) && (errno != EINVAL))
         {
-            int jitstdoutFd = _dup(_fileno(procstdout()));
+            int jitstdoutFd = _dup(stdoutFd);
             // Check the error status returned by dup.
             if (jitstdoutFd != -1)
             {
                 _setmode(jitstdoutFd, _O_TEXT);
-                jitstdout = _fdopen(jitstdoutFd, "w");
-                assert(jitstdout != nullptr);
+                file = _fdopen(jitstdoutFd, "w");
+                assert(file != nullptr);
 
                 // Prevent the FILE* from buffering its output in order to avoid calls to
                 // `fflush()` throughout the code.
-                setvbuf(jitstdout, nullptr, _IONBF, 0);
+                setvbuf(file, nullptr, _IONBF, 0);
             }
         }
     }
 #endif // !HOST_UNIX
 
-    // If jitstdout is still null, fallback to whatever procstdout() was
-    // initially set to.
-    if (jitstdout == nullptr)
+    if (file == nullptr)
     {
-        jitstdout = procstdout();
+        file = procstdout();
     }
 
-    Compiler::compStartup();
+    FILE* observed = InterlockedCompareExchangeT(&s_jitstdout, file, nullptr);
 
-    g_jitInitialized = true;
+    if (observed != nullptr)
+    {
+        if (file != procstdout())
+        {
+            fclose(file);
+        }
+
+        return observed;
+    }
+
+    return file;
+}
+
+FILE* jitstdout()
+{
+    if (s_jitstdout != nullptr)
+    {
+        return s_jitstdout;
+    }
+
+    return jitstdoutInit();
 }
 
 #ifndef DEBUG
 void jitprintf(const char* fmt, ...)
 {
     va_list vl;
     va_start(vl, fmt);
-    vfprintf(jitstdout, fmt, vl);
+    vfprintf(jitstdout(), fmt, vl);
     va_end(vl);
 }
 #endif
@@ -136,14 +161,14 @@ void jitShutdown(bool processIsTerminating)
 
     Compiler::compShutdown();
 
-    if (jitstdout != procstdout())
+    if ((s_jitstdout != nullptr) && (s_jitstdout != procstdout()))
     {
         // When the process is terminating, the fclose call is unnecessary and is also prone to
         // crashing since the UCRT itself often frees the backing memory earlier on in the
         // termination sequence.
         if (!processIsTerminating)
         {
-            fclose(jitstdout);
+            fclose(s_jitstdout);
         }
     }
 

src/coreclr/jit/error.cpp

@@ -370,7 +370,7 @@ int logf(const char* fmt, ...)
     {
         // if the EE refuses to log it, we try to send it to stdout
         va_start(args, fmt);
-        written = vflogf(jitstdout, fmt, args);
+        written = vflogf(jitstdout(), fmt, args);
         va_end(args);
     }
 #if 0  // Enable this only when you need it
@@ -431,7 +431,7 @@ void gcDump_logf(const char* fmt, ...)
     {
         // if the EE refuses to log it, we try to send it to stdout
         va_start(args, fmt);
-        vflogf(jitstdout, fmt, args);
+        vflogf(jitstdout(), fmt, args);
         va_end(args);
     }
 #if 0  // Enable this only when you need it

src/coreclr/jit/fgdiagnostic.cpp

@@ -674,7 +674,7 @@ FILE* Compiler::fgOpenFlowGraphFile(bool* wbDontClose, Phases phase, PhasePositi
     }
     else if (strcmp(filename, "stdout") == 0)
     {
-        fgxFile      = jitstdout;
+        fgxFile      = jitstdout();
         *wbDontClose = true;
     }
     else if (strcmp(filename, "stderr") == 0)

src/coreclr/jit/host.h

@@ -55,7 +55,7 @@ void jitprintf(const char* fmt, ...);
 #define _HOST_H_
 /*****************************************************************************/
 
-extern FILE* jitstdout;
+FILE* jitstdout();
 
 inline FILE* procstdout()
 {

src/coreclr/jit/inline.cpp

@@ -480,7 +480,7 @@ void InlineContext::DumpData(unsigned indent)
     {
         const char* inlineReason = InlGetObservationString(m_Observation);
         printf("%*s%u,\"%s\",\"%s\",", indent, "", GetOrdinal(), inlineReason, calleeName);
-        m_Policy->DumpData(jitstdout);
+        m_Policy->DumpData(jitstdout());
         printf("\n");
     }
 

src/coreclr/jit/lsra.cpp

@@ -1421,7 +1421,7 @@ PhaseStatus LinearScan::doLinearScan()
 #endif
         )
     {
-        dumpLsraStats(jitstdout);
+        dumpLsraStats(jitstdout());
     }
 #endif // TRACK_LSRA_STATS