Check for containerized Posix when locating hsperfdata dir

Author: Matt

internal-api/build.gradle

@@ -246,6 +246,7 @@ dependencies {
   api project(':components:yaml')
   api project(':components:cli')
   api project(":utils:time-utils")
+  api project(":utils:container-utils")
 
   // has to be loaded by system classloader:
   // it contains annotations that are also present in the instrumented application classes

internal-api/src/main/java/datadog/trace/util/PidHelper.java

@@ -1,5 +1,6 @@
 package datadog.trace.util;
 
+import datadog.common.container.ContainerInfo;
 import datadog.trace.api.Platform;
 import datadog.trace.bootstrap.instrumentation.api.AgentTracer;
 import datadog.trace.context.TraceScope;
@@ -76,6 +77,11 @@ private static String getOSTempDir() {
     // the JDK OS-specific implementations of os::get_temp_directory(), i.e.
     // https://github.com/openjdk/jdk/blob/f50bd0d9ec65a6b9596805d0131aaefc1bb913f3/src/hotspot/os/bsd/os_bsd.cpp#L886-L904
     if (Platform.isLinux()) {
+      if (ContainerInfo.isRunningInContainer()) {
+        // See
+        // https://github.com/openjdk/jdk/blob/39a28ffe4e23274dba34317d8960bfb7e6d203ed/src/hotspot/os/posix/perfMemory_posix.cpp#L136-L146
+        return "/proc/" + getPid() + "/root/tmp/hsperfdata_" + System.getProperty("user.name");
+      }
       return "/tmp/";
     } else if (Platform.isWindows()) {
       return Stream.of(System.getenv("TMP"), System.getenv("TEMP"), System.getenv("USERPROFILE"))