Support java compilation sharding for target side.
Add "LOCAL_JAVAC_SHARD_SIZE" to represent the number of java
source path entries in each shard.
Sharding is not allowed when "LOCAL_JAVAC_SHARD_SIZE" and
"LOCAL_JAR_PROCESSORS" are both enabled.
Limitation:
1. 0 <= LOCAL_JAVAC_SHARD_SIZE <= 8192
1. 0 < NUM(java_sources) <= 8192
2. 0 <= NUM(shards) <= 100
Performance Compare:
<Unsharded Build------------------------------------------------>
1. Build from clean state
rm -r -f out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/
&& time m
out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar
real 1m2.720s user 5m26.604s sys 0m39.552s
2. Incremental build
m out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar &&
touch frameworks/base/core/java/android/net/http/HttpResponseCache.java && time m
out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar
real 0m37.586s user 5m47.804s sys 0m50.388s
<Sharded Build-------------------------------------------------->
1. Build from clean state
rm -r -f out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/
&& time m
out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar
Javac Shard Size: 50----real 1m10.163s user 25m59.008s sys 1m58.460s
Javac Shard Size: 100---real 1m2.115s user 21m3.600s sys 1m15.964s
Javac Shard Size: 150---real 0m59.520s user 18m10.544s sys 1m12.628s
Javac Shard Size: 200---real 0m56.894s user 15m39.244s sys 1m11.608s
Javac Shard Size: 250---real 0m55.991s user 14m38.716s sys 1m2.292s
Javac Shard Size: 300---real 0m55.114s user 13m6.568s sys 1m8.200s
Javac Shard Size: 350---real 0m53.144s user 12m7.740s sys 1m3.836s
Javac Shard Size: 400---real 0m54.929s user 12m9.324s sys 1m4.340s
Javac Shard Size: 450---real 1m30.194s user 25m31.468s sys 1m52.416s
Javac Shard Size: 500---real 0m53.976s user 10m35.500s sys 0m55.160s
2. Incremental build
m out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar &&
touch frameworks/base/core/java/android/net/http/HttpResponseCache.java && time m
out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar
Javac Shard Size: 50-----real 0m16.322s user 1m8.648s sys 0m31.700s
Javac Shard Size: 100----real 0m16.163s user 1m22.932s sys 0m29.440s
Javac Shard Size: 150----real 0m16.611s user 1m37.828s sys 0m21.168s
Javac Shard Size: 200----real 0m16.936s user 1m49.248s sys 0m28.636s
Javac Shard Size: 250----real 0m17.509s user 1m54.944s sys 0m32.768s
Javac Shard Size: 300----real 0m18.868s user 1m54.088s sys 0m28.824s
Javac Shard Size: 350----real 0m17.629s user 1m54.108s sys 0m31.056s
Javac Shard Size: 400----real 0m18.658s user 2m7.712s sys 0m30.636s
Javac Shard Size: 450----real 0m18.874s user 2m8.808s sys 0m33.540s
Javac Shard Size: 500----real 0m19.432s user 2m24.400s sys 0m30.368s
time m nothing:
real 0m5.799s user 0m7.236s sys 0m3.068s
Test: m clean && m -j checkbuild
Bug: b/67424047
Change-Id: Id0766d2b7de7c4546d29bbc7f8a0dd0e4b9ad45b
6 files changed