[tsan] First commit of ThreadSanitizer (TSan) run-time library.

Algorithm description: http://code.google.com/p/thread-sanitizer/wiki/ThreadSanitizerAlgorithm

Status:
The tool is known to work on large real-life applications, but still has quite a few rough edges.
Nothing is guaranteed yet.

The tool works on x86_64 Linux.
Support for 64-bit MacOS 10.7+ is planned for late 2012.
Support for 32-bit OSes is doable, but problematic and not yet planed.

Further commits coming:
  - tests
  - makefiles
  - documentation
  - clang driver patch

The code was previously developed at http://code.google.com/p/data-race-test/source/browse/trunk/v2/
by Dmitry Vyukov and Kostya Serebryany with contributions from
Timur Iskhodzhanov, Alexander Potapenko, Alexey Samsonov and Evgeniy Stepanov.

llvm-svn: 156542
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
new file mode 100644
index 0000000..b874826
--- /dev/null
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cc
@@ -0,0 +1,368 @@
+//===-- tsan_rtl_thread.cc --------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer (TSan), a race detector.
+//
+//===----------------------------------------------------------------------===//
+
+#include "tsan_rtl.h"
+#include "tsan_mman.h"
+#include "tsan_placement_new.h"
+#include "tsan_platform.h"
+#include "tsan_report.h"
+#include "tsan_sync.h"
+
+namespace __tsan {
+
+const int kThreadQuarantineSize = 100;
+
+static void MaybeReportThreadLeak(ThreadContext *tctx) {
+  if (tctx->detached)
+    return;
+  if (tctx->status != ThreadStatusCreated
+      && tctx->status != ThreadStatusRunning
+      && tctx->status != ThreadStatusFinished)
+    return;
+  ScopedReport rep(ReportTypeThreadLeak);
+  rep.AddThread(tctx);
+  OutputReport(rep);
+}
+
+void ThreadFinalize(ThreadState *thr) {
+  CHECK_GT(thr->in_rtl, 0);
+  if (!flags()->report_thread_leaks)
+    return;
+  Context *ctx = CTX();
+  Lock l(&ctx->thread_mtx);
+  for (int i = 0; i < kMaxTid; i++) {
+    ThreadContext *tctx = ctx->threads[i];
+    if (tctx == 0)
+      continue;
+    MaybeReportThreadLeak(tctx);
+    DestroyAndFree(tctx);
+    ctx->threads[i] = 0;
+  }
+}
+
+static void ThreadDead(ThreadState *thr, ThreadContext *tctx) {
+  Context *ctx = CTX();
+  CHECK_GT(thr->in_rtl, 0);
+  CHECK(tctx->status == ThreadStatusRunning
+      || tctx->status == ThreadStatusFinished);
+  DPrintf("#%d: ThreadDead uid=%lu\n", thr->tid, tctx->user_id);
+  tctx->status = ThreadStatusDead;
+  tctx->user_id = 0;
+  tctx->sync.Reset();
+
+  // Put to dead list.
+  tctx->dead_next = 0;
+  if (ctx->dead_list_size == 0)
+    ctx->dead_list_head = tctx;
+  else
+    ctx->dead_list_tail->dead_next = tctx;
+  ctx->dead_list_tail = tctx;
+  ctx->dead_list_size++;
+}
+
+int ThreadCreate(ThreadState *thr, uptr pc, uptr uid, bool detached) {
+  CHECK_GT(thr->in_rtl, 0);
+  Context *ctx = CTX();
+  Lock l(&ctx->thread_mtx);
+  StatInc(thr, StatThreadCreate);
+  int tid = -1;
+  ThreadContext *tctx = 0;
+  if (ctx->dead_list_size > kThreadQuarantineSize
+      || ctx->thread_seq >= kMaxTid) {
+    if (ctx->dead_list_size == 0) {
+      Printf("ThreadSanitizer: %d thread limit exceeded. Dying.\n", kMaxTid);
+      Die();
+    }
+    StatInc(thr, StatThreadReuse);
+    tctx = ctx->dead_list_head;
+    ctx->dead_list_head = tctx->dead_next;
+    ctx->dead_list_size--;
+    if (ctx->dead_list_size == 0) {
+      CHECK_EQ(tctx->dead_next, 0);
+      ctx->dead_list_head = 0;
+    }
+    CHECK_EQ(tctx->status, ThreadStatusDead);
+    tctx->status = ThreadStatusInvalid;
+    tctx->reuse_count++;
+    tid = tctx->tid;
+    // The point to reclain dead_info.
+    // delete tctx->dead_info;
+  } else {
+    StatInc(thr, StatThreadMaxTid);
+    tid = ctx->thread_seq++;
+    void *mem = internal_alloc(MBlockThreadContex, sizeof(ThreadContext));
+    tctx = new(mem) ThreadContext(tid);
+    ctx->threads[tid] = tctx;
+  }
+  CHECK_NE(tctx, 0);
+  CHECK_GE(tid, 0);
+  CHECK_LT(tid, kMaxTid);
+  DPrintf("#%d: ThreadCreate tid=%d uid=%lu\n", thr->tid, tid, uid);
+  CHECK_EQ(tctx->status, ThreadStatusInvalid);
+  ctx->alive_threads++;
+  if (ctx->max_alive_threads < ctx->alive_threads) {
+    ctx->max_alive_threads++;
+    CHECK_EQ(ctx->max_alive_threads, ctx->alive_threads);
+    StatInc(thr, StatThreadMaxAlive);
+  }
+  tctx->status = ThreadStatusCreated;
+  tctx->thr = 0;
+  tctx->user_id = uid;
+  tctx->unique_id = ctx->unique_thread_seq++;
+  tctx->detached = detached;
+  if (tid) {
+    thr->fast_state.IncrementEpoch();
+    // Can't increment epoch w/o writing to the trace as well.
+    TraceAddEvent(thr, thr->fast_state.epoch(), EventTypeMop, 0);
+    thr->clock.set(thr->tid, thr->fast_state.epoch());
+    thr->fast_synch_epoch = thr->fast_state.epoch();
+    thr->clock.release(&tctx->sync);
+    StatInc(thr, StatSyncRelease);
+
+    tctx->creation_stack.ObtainCurrent(thr, pc);
+  }
+  return tid;
+}
+
+void ThreadStart(ThreadState *thr, int tid) {
+  CHECK_GT(thr->in_rtl, 0);
+  uptr stk_addr = 0;
+  uptr stk_size = 0;
+  uptr tls_addr = 0;
+  uptr tls_size = 0;
+  GetThreadStackAndTls(&stk_addr, &stk_size, &tls_addr, &tls_size);
+
+  MemoryResetRange(thr, /*pc=*/ 1, stk_addr, stk_size);
+
+  // Check that the thr object is in tls;
+  const uptr thr_beg = (uptr)thr;
+  const uptr thr_end = (uptr)thr + sizeof(*thr);
+  CHECK_GE(thr_beg, tls_addr);
+  CHECK_LE(thr_beg, tls_addr + tls_size);
+  CHECK_GE(thr_end, tls_addr);
+  CHECK_LE(thr_end, tls_addr + tls_size);
+  // Since the thr object is huge, skip it.
+  MemoryResetRange(thr, /*pc=*/ 2, tls_addr, thr_beg - tls_addr);
+  MemoryResetRange(thr, /*pc=*/ 2, thr_end, tls_addr + tls_size - thr_end);
+
+  Lock l(&CTX()->thread_mtx);
+  ThreadContext *tctx = CTX()->threads[tid];
+  CHECK_NE(tctx, 0);
+  CHECK_EQ(tctx->status, ThreadStatusCreated);
+  tctx->status = ThreadStatusRunning;
+  tctx->epoch0 = tctx->epoch1 + 1;
+  tctx->epoch1 = (u64)-1;
+  new(thr) ThreadState(CTX(), tid, tctx->epoch0, stk_addr, stk_size,
+                       tls_addr, tls_size);
+  tctx->thr = thr;
+  thr->fast_synch_epoch = tctx->epoch0;
+  thr->clock.set(tid, tctx->epoch0);
+  thr->clock.acquire(&tctx->sync);
+  StatInc(thr, StatSyncAcquire);
+  DPrintf("#%d: ThreadStart epoch=%llu stk_addr=%lx stk_size=%lx "
+      "tls_addr=%lx tls_size=%lx\n",
+      tid, tctx->epoch0, stk_addr, stk_size, tls_addr, tls_size);
+}
+
+void ThreadFinish(ThreadState *thr) {
+  CHECK_GT(thr->in_rtl, 0);
+  StatInc(thr, StatThreadFinish);
+  // FIXME: Treat it as write.
+  if (thr->stk_addr && thr->stk_size)
+    MemoryResetRange(thr, /*pc=*/ 3, thr->stk_addr, thr->stk_size);
+  if (thr->tls_addr && thr->tls_size) {
+    const uptr thr_beg = (uptr)thr;
+    const uptr thr_end = (uptr)thr + sizeof(*thr);
+    // Since the thr object is huge, skip it.
+    MemoryResetRange(thr, /*pc=*/ 4, thr->tls_addr, thr_beg - thr->tls_addr);
+    MemoryResetRange(thr, /*pc=*/ 5,
+        thr_end, thr->tls_addr + thr->tls_size - thr_end);
+  }
+  Context *ctx = CTX();
+  Lock l(&ctx->thread_mtx);
+  ThreadContext *tctx = ctx->threads[thr->tid];
+  CHECK_NE(tctx, 0);
+  CHECK_EQ(tctx->status, ThreadStatusRunning);
+  CHECK_GT(ctx->alive_threads, 0);
+  ctx->alive_threads--;
+  if (tctx->detached) {
+    ThreadDead(thr, tctx);
+  } else {
+    thr->fast_state.IncrementEpoch();
+    // Can't increment epoch w/o writing to the trace as well.
+    TraceAddEvent(thr, thr->fast_state.epoch(), EventTypeMop, 0);
+    thr->clock.set(thr->tid, thr->fast_state.epoch());
+    thr->fast_synch_epoch = thr->fast_state.epoch();
+    thr->clock.release(&tctx->sync);
+    StatInc(thr, StatSyncRelease);
+    tctx->status = ThreadStatusFinished;
+  }
+
+  // Save from info about the thread.
+  // If dead_info will become dynamically allocated again,
+  // it is the point to allocate it.
+  // tctx->dead_info = new ThreadDeadInfo;
+  internal_memcpy(&tctx->dead_info.trace.events[0],
+      &thr->trace.events[0], sizeof(thr->trace.events));
+  for (int i = 0; i < kTraceParts; i++) {
+    tctx->dead_info.trace.headers[i].stack0.CopyFrom(
+        thr->trace.headers[i].stack0);
+  }
+  tctx->epoch1 = thr->clock.get(tctx->tid);
+
+  thr->~ThreadState();
+  StatAggregate(ctx->stat, thr->stat);
+  InternalAllocStatAggregate(ctx, thr);
+  tctx->thr = 0;
+}
+
+int ThreadTid(ThreadState *thr, uptr pc, uptr uid) {
+  CHECK_GT(thr->in_rtl, 0);
+  DPrintf("#%d: ThreadTid uid=%lu\n", thr->tid, uid);
+  Lock l(&CTX()->thread_mtx);
+  for (int tid = 0; tid < kMaxTid; tid++) {
+    if (CTX()->threads[tid] != 0
+        && CTX()->threads[tid]->user_id == uid
+        && CTX()->threads[tid]->status != ThreadStatusInvalid)
+      return tid;
+  }
+  return -1;
+}
+
+void ThreadJoin(ThreadState *thr, uptr pc, int tid) {
+  CHECK_GT(thr->in_rtl, 0);
+  CHECK_GT(tid, 0);
+  CHECK_LT(tid, kMaxTid);
+  DPrintf("#%d: ThreadJoin tid=%d\n", thr->tid, tid);
+  Context *ctx = CTX();
+  Lock l(&ctx->thread_mtx);
+  ThreadContext *tctx = ctx->threads[tid];
+  if (tctx->status == ThreadStatusInvalid) {
+    Printf("ThreadSanitizer: join of non-existent thread\n");
+    return;
+  }
+  CHECK_EQ(tctx->detached, false);
+  CHECK_EQ(tctx->status, ThreadStatusFinished);
+  thr->clock.acquire(&tctx->sync);
+  StatInc(thr, StatSyncAcquire);
+  ThreadDead(thr, tctx);
+}
+
+void ThreadDetach(ThreadState *thr, uptr pc, int tid) {
+  CHECK_GT(thr->in_rtl, 0);
+  CHECK_GT(tid, 0);
+  CHECK_LT(tid, kMaxTid);
+  Context *ctx = CTX();
+  Lock l(&ctx->thread_mtx);
+  ThreadContext *tctx = ctx->threads[tid];
+  if (tctx->status == ThreadStatusInvalid) {
+    Printf("ThreadSanitizer: detach of non-existent thread\n");
+    return;
+  }
+  if (tctx->status == ThreadStatusFinished) {
+    ThreadDead(thr, tctx);
+  } else {
+    tctx->detached = true;
+  }
+}
+
+void MemoryAccessRange(ThreadState *thr, uptr pc, uptr addr,
+                       uptr size, bool is_write) {
+  if (size == 0)
+    return;
+
+  u64 *shadow_mem = (u64*)MemToShadow(addr);
+  DPrintf2("#%d: MemoryAccessRange: @%p %p size=%d is_write=%d\n",
+      thr->tid, (void*)pc, (void*)addr,
+      (int)size, is_write);
+
+#if TSAN_DEBUG
+  if (!IsAppMem(addr)) {
+    Printf("Access to non app mem %lx\n", addr);
+    DCHECK(IsAppMem(addr));
+  }
+  if (!IsAppMem(addr + size - 1)) {
+    Printf("Access to non app mem %lx\n", addr + size - 1);
+    DCHECK(IsAppMem(addr + size - 1));
+  }
+  if (!IsShadowMem((uptr)shadow_mem)) {
+    Printf("Bad shadow addr %p (%lx)\n", shadow_mem, addr);
+    DCHECK(IsShadowMem((uptr)shadow_mem));
+  }
+  if (!IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1))) {
+    Printf("Bad shadow addr %p (%lx)\n",
+        shadow_mem + size * kShadowCnt / 8 - 1, addr + size - 1);
+    DCHECK(IsShadowMem((uptr)(shadow_mem + size * kShadowCnt / 8 - 1)));
+  }
+#endif
+
+  StatInc(thr, StatMopRange);
+
+  FastState fast_state = thr->fast_state;
+  if (fast_state.GetIgnoreBit())
+    return;
+
+  fast_state.IncrementEpoch();
+  thr->fast_state = fast_state;
+  TraceAddEvent(thr, fast_state.epoch(), EventTypeMop, pc);
+
+  bool unaligned = (addr % kShadowCell) != 0;
+
+  // Handle unaligned beginning, if any.
+  for (; addr % kShadowCell && size; addr++, size--) {
+    int const kAccessSizeLog = 0;
+    Shadow cur(fast_state);
+    cur.SetWrite(is_write);
+    cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
+    MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, fast_state,
+        shadow_mem, cur);
+  }
+  if (unaligned)
+    shadow_mem += kShadowCnt;
+  // Handle middle part, if any.
+  for (; size >= kShadowCell; addr += kShadowCell, size -= kShadowCell) {
+    int const kAccessSizeLog = 3;
+    Shadow cur(fast_state);
+    cur.SetWrite(is_write);
+    cur.SetAddr0AndSizeLog(0, kAccessSizeLog);
+    MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, fast_state,
+        shadow_mem, cur);
+    shadow_mem += kShadowCnt;
+  }
+  // Handle ending, if any.
+  for (; size; addr++, size--) {
+    int const kAccessSizeLog = 0;
+    Shadow cur(fast_state);
+    cur.SetWrite(is_write);
+    cur.SetAddr0AndSizeLog(addr & (kShadowCell - 1), kAccessSizeLog);
+    MemoryAccessImpl(thr, addr, kAccessSizeLog, is_write, fast_state,
+        shadow_mem, cur);
+  }
+}
+
+void MemoryRead1Byte(ThreadState *thr, uptr pc, uptr addr) {
+  MemoryAccess(thr, pc, addr, 0, 0);
+}
+
+void MemoryWrite1Byte(ThreadState *thr, uptr pc, uptr addr) {
+  MemoryAccess(thr, pc, addr, 0, 1);
+}
+
+void MemoryRead8Byte(ThreadState *thr, uptr pc, uptr addr) {
+  MemoryAccess(thr, pc, addr, 3, 0);
+}
+
+void MemoryWrite8Byte(ThreadState *thr, uptr pc, uptr addr) {
+  MemoryAccess(thr, pc, addr, 3, 1);
+}
+}  // namespace __tsan