[profile] Eliminate dynamic memory allocation for buffered writer

With this change, dynamic memory allocation is only used
for testing purpose. This change is one of the many steps to
make instrument profiler dynamic allocation free.



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@269453 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 35 insertions, 28 deletions

diff --git a/lib/profile/InstrProfilingFile.c b/lib/profile/InstrProfilingFile.c
index 14f7517b6..e2f68002e 100644
--- a/lib/profile/InstrProfilingFile.c
+++ b/lib/profile/InstrProfilingFile.c
@@ -32,18 +32,24 @@ static uint32_t fileWriter(ProfDataIOVec *IOVecs, uint32_t NumIOVecs,
 
 COMPILER_RT_VISIBILITY ProfBufferIO *
 lprofCreateBufferIOInternal(void *File, uint32_t BufferSz) {
-  CallocHook = calloc;
-  FreeHook = free;
-  return lprofCreateBufferIO(fileWriter, File, BufferSz);
+  FreeHook = &free;
+  DynamicBufferIOBuffer = (uint8_t *)calloc(BufferSz, 1);
+  VPBufferSize = BufferSz;
+  return lprofCreateBufferIO(fileWriter, File);
 }
 
-static int writeFile(FILE *File) {
+static void setupIOBuffer() {
   const char *BufferSzStr = 0;
-  FreeHook = &free;
-  CallocHook = &calloc;
   BufferSzStr = getenv("LLVM_VP_BUFFER_SIZE");
-  if (BufferSzStr && BufferSzStr[0])
+  if (BufferSzStr && BufferSzStr[0]) {
     VPBufferSize = atoi(BufferSzStr);
+    DynamicBufferIOBuffer = (uint8_t *)calloc(VPBufferSize, 1);
+  }
+}
+
+static int writeFile(FILE *File) {
+  FreeHook = &free;
+  setupIOBuffer();
   return lprofWriteData(fileWriter, File, lprofGatherValueProfData);
 }
 
diff --git a/lib/profile/InstrProfilingInternal.h b/lib/profile/InstrProfilingInternal.h
index a349244c5..5f75baa3a 100644
--- a/lib/profile/InstrProfilingInternal.h
+++ b/lib/profile/InstrProfilingInternal.h
@@ -68,12 +68,13 @@ typedef struct ProfBufferIO {
 } ProfBufferIO;
 
 /* The creator interface used by testing.  */
-ProfBufferIO *lprofCreateBufferIOInternal(void *File, uint32_t DefaultBufferSz);
+ProfBufferIO *lprofCreateBufferIOInternal(void *File, uint32_t BufferSz);
+
 /*!
  * This is the interface to create a handle for buffered IO.
  */
-ProfBufferIO *lprofCreateBufferIO(WriterCallback FileWriter, void *File,
-                                  uint32_t DefaultBufferSz);
+ProfBufferIO *lprofCreateBufferIO(WriterCallback FileWriter, void *File);
+
 /*!
  * The interface to destroy the bufferIO handle and reclaim
  * the memory.
@@ -119,8 +120,8 @@ void lprofMergeValueProfData(struct ValueProfData *SrcValueProfData,
 
 COMPILER_RT_VISIBILITY extern char *(*GetEnvHook)(const char *);
 COMPILER_RT_VISIBILITY extern void (*FreeHook)(void *);
-COMPILER_RT_VISIBILITY extern void *(*CallocHook)(size_t, size_t);
+COMPILER_RT_VISIBILITY extern uint8_t *DynamicBufferIOBuffer;
+COMPILER_RT_VISIBILITY extern uint32_t VPBufferSize;
 extern void (*VPMergeHook)(struct ValueProfData *, __llvm_profile_data *);
-extern uint32_t VPBufferSize;
 
 #endif
diff --git a/lib/profile/InstrProfilingWriter.c b/lib/profile/InstrProfilingWriter.c
index aebe30468..db944e20f 100644
--- a/lib/profile/InstrProfilingWriter.c
+++ b/lib/profile/InstrProfilingWriter.c
@@ -13,9 +13,13 @@
 
 #define INSTR_PROF_VALUE_PROF_DATA
 #include "InstrProfData.inc"
+
 COMPILER_RT_VISIBILITY void (*FreeHook)(void *) = NULL;
-COMPILER_RT_VISIBILITY void *(*CallocHook)(size_t, size_t) = NULL;
-uint32_t VPBufferSize = 0;
+static ProfBufferIO TheBufferIO;
+#define VP_BUFFER_SIZE 8 * 1024
+static uint8_t BufferIOBuffer[VP_BUFFER_SIZE];
+COMPILER_RT_VISIBILITY uint8_t *DynamicBufferIOBuffer = 0;
+COMPILER_RT_VISIBILITY uint32_t VPBufferSize = 0;
 
 /* The buffer writer is reponsponsible in keeping writer state
  * across the call.
@@ -43,20 +47,20 @@ static void llvmInitBufferIO(ProfBufferIO *BufferIO, WriterCallback FileWriter,
 }
 
 COMPILER_RT_VISIBILITY ProfBufferIO *
-lprofCreateBufferIO(WriterCallback FileWriter, void *File, uint32_t BufferSz) {
-  ProfBufferIO *BufferIO = (ProfBufferIO *)CallocHook(1, sizeof(ProfBufferIO));
-  uint8_t *Buffer = (uint8_t *)CallocHook(1, BufferSz);
+lprofCreateBufferIO(WriterCallback FileWriter, void *File) {
+  uint8_t *Buffer = DynamicBufferIOBuffer;
+  uint32_t BufferSize = VPBufferSize;
   if (!Buffer) {
-    FreeHook(BufferIO);
-    return 0;
+    Buffer = &BufferIOBuffer[0];
+    BufferSize = sizeof(BufferIOBuffer);
   }
-  llvmInitBufferIO(BufferIO, FileWriter, File, Buffer, BufferSz);
-  return BufferIO;
+  llvmInitBufferIO(&TheBufferIO, FileWriter, File, Buffer, BufferSize);
+  return &TheBufferIO;
 }
 
 COMPILER_RT_VISIBILITY void lprofDeleteBufferIO(ProfBufferIO *BufferIO) {
-  FreeHook(BufferIO->BufferStart);
-  FreeHook(BufferIO);
+  if (DynamicBufferIOBuffer)
+    FreeHook(DynamicBufferIOBuffer);
 }
 
 COMPILER_RT_VISIBILITY int
@@ -91,8 +95,6 @@ COMPILER_RT_VISIBILITY int lprofBufferIOFlush(ProfBufferIO *BufferIO) {
   return 0;
 }
 
-#define VP_BUFFER_SIZE 8 * 1024
-
 static int writeOneValueProfData(ProfBufferIO *BufferIO,
                                  VPGatherHookType VPDataGatherer,
                                  const __llvm_profile_data *Data) {
@@ -111,14 +113,12 @@ static int writeValueProfData(WriterCallback Writer, void *WriterCtx,
                               const __llvm_profile_data *DataBegin,
                               const __llvm_profile_data *DataEnd) {
   ProfBufferIO *BufferIO;
-  uint32_t BufferSz;
   const __llvm_profile_data *DI = 0;
 
   if (!VPDataGatherer)
     return 0;
 
-  BufferSz = VPBufferSize ? VPBufferSize : VP_BUFFER_SIZE;
-  BufferIO = lprofCreateBufferIO(Writer, WriterCtx, BufferSz);
+  BufferIO = lprofCreateBufferIO(Writer, WriterCtx);
 
   for (DI = DataBegin; DI < DataEnd; DI++) {
     if (writeOneValueProfData(BufferIO, VPDataGatherer, DI))