1 files changed, 134 insertions, 0 deletions
diff --git a/third_party/libwebrtc/build/toolchain/get_concurrent_links.py b/third_party/libwebrtc/build/toolchain/get_concurrent_links.py
new file mode 100755
index 0000000000..d77bb4375e
--- /dev/null
+++ b/third_party/libwebrtc/build/toolchain/get_concurrent_links.py
@@ -0,0 +1,134 @@
+#!/usr/bin/env python
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script computs the number of concurrent links we want to run in the build
+# as a function of machine spec. It's based on GetDefaultConcurrentLinks in GYP.
+
+from __future__ import print_function
+
+import argparse
+import multiprocessing
+import os
+import re
+import subprocess
+import sys
+
+sys.path.insert(1, os.path.join(os.path.dirname(__file__), '..'))
+import gn_helpers
+
+
+def _GetTotalMemoryInBytes():
+  if sys.platform in ('win32', 'cygwin'):
+    import ctypes
+
+    class MEMORYSTATUSEX(ctypes.Structure):
+      _fields_ = [
+          ("dwLength", ctypes.c_ulong),
+          ("dwMemoryLoad", ctypes.c_ulong),
+          ("ullTotalPhys", ctypes.c_ulonglong),
+          ("ullAvailPhys", ctypes.c_ulonglong),
+          ("ullTotalPageFile", ctypes.c_ulonglong),
+          ("ullAvailPageFile", ctypes.c_ulonglong),
+          ("ullTotalVirtual", ctypes.c_ulonglong),
+          ("ullAvailVirtual", ctypes.c_ulonglong),
+          ("sullAvailExtendedVirtual", ctypes.c_ulonglong),
+      ]
+
+    stat = MEMORYSTATUSEX(dwLength=ctypes.sizeof(MEMORYSTATUSEX))
+    ctypes.windll.kernel32.GlobalMemoryStatusEx(ctypes.byref(stat))
+    return stat.ullTotalPhys
+  elif sys.platform.startswith('linux'):
+    if os.path.exists("/proc/meminfo"):
+      with open("/proc/meminfo") as meminfo:
+        memtotal_re = re.compile(r'^MemTotal:\s*(\d*)\s*kB')
+        for line in meminfo:
+          match = memtotal_re.match(line)
+          if not match:
+            continue
+          return float(match.group(1)) * 2**10
+  elif sys.platform == 'darwin':
+    try:
+      return int(subprocess.check_output(['sysctl', '-n', 'hw.memsize']))
+    except Exception:
+      return 0
+  # TODO(scottmg): Implement this for other platforms.
+  return 0
+
+
+def _GetDefaultConcurrentLinks(per_link_gb, reserve_gb, thin_lto_type,
+                               secondary_per_link_gb):
+  explanation = []
+  explanation.append(
+      'per_link_gb={} reserve_gb={} secondary_per_link_gb={}'.format(
+          per_link_gb, reserve_gb, secondary_per_link_gb))
+  mem_total_gb = float(_GetTotalMemoryInBytes()) / 2**30
+  mem_total_gb = max(0, mem_total_gb - reserve_gb)
+  mem_cap = int(max(1, mem_total_gb / per_link_gb))
+
+  try:
+    cpu_count = multiprocessing.cpu_count()
+  except:
+    cpu_count = 1
+
+  # A local LTO links saturate all cores, but only for some amount of the link.
+  # Goma LTO runs LTO codegen on goma, only run one of these tasks at once.
+  cpu_cap = cpu_count
+  if thin_lto_type is not None:
+    if thin_lto_type == 'goma':
+      cpu_cap = 1
+    else:
+      assert thin_lto_type == 'local'
+      cpu_cap = min(cpu_count, 6)
+
+  explanation.append('cpu_count={} cpu_cap={} mem_total_gb={:.1f}GiB'.format(
+      cpu_count, cpu_cap, mem_total_gb))
+
+  num_links = min(mem_cap, cpu_cap)
+  if num_links == cpu_cap:
+    if cpu_cap == cpu_count:
+      reason = 'cpu_count'
+    else:
+      reason = 'cpu_cap (thinlto)'
+  else:
+    reason = 'RAM'
+
+  explanation.append('concurrent_links={}  (reason: {})'.format(
+      num_links, reason))
+
+  # See if there is RAM leftover for a secondary pool.
+  if secondary_per_link_gb and num_links == mem_cap:
+    mem_remaining = mem_total_gb - mem_cap * per_link_gb
+    secondary_size = int(max(0, mem_remaining / secondary_per_link_gb))
+    explanation.append('secondary_size={} (mem_remaining={:.1f}GiB)'.format(
+        secondary_size, mem_remaining))
+  else:
+    secondary_size = 0
+
+  return num_links, secondary_size, explanation
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--mem_per_link_gb', type=int, default=8)
+  parser.add_argument('--reserve_mem_gb', type=int, default=0)
+  parser.add_argument('--secondary_mem_per_link', type=int, default=0)
+  parser.add_argument('--thin-lto')
+  options = parser.parse_args()
+
+  primary_pool_size, secondary_pool_size, explanation = (
+      _GetDefaultConcurrentLinks(options.mem_per_link_gb,
+                                 options.reserve_mem_gb, options.thin_lto,
+                                 options.secondary_mem_per_link))
+  sys.stdout.write(
+      gn_helpers.ToGNString({
+          'primary_pool_size': primary_pool_size,
+          'secondary_pool_size': secondary_pool_size,
+          'explanation': explanation,
+      }))
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())