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author | Ethan Heilman <ethan.r.heilman@gmail.com> | 2020-10-04 21:07:51 -0400 |
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committer | Ethan Heilman <ethan.r.heilman@gmail.com> | 2020-10-07 20:46:49 -0400 |
commit | bd5215103eb3985c1622eddea45a040e6173829c (patch) | |
tree | 6563c6c006ebb5033b4ed0f37346da1c0b94fdd5 | |
parent | cce151317909ab8eb56d3e5da522f43c7d7db077 (diff) | |
download | bitcoin-bd5215103eb3985c1622eddea45a040e6173829c.tar.xz |
random: fixes read buffer resizing in RandAddSeedPerfmon
+ Replaces std::max with std::min to resize buffer in RandAddSeedPerfmon
+ Documents behavior of RandAddSeedPerfmon
-rw-r--r-- | src/randomenv.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/randomenv.cpp b/src/randomenv.cpp index 073d82b491..07122b7f6d 100644 --- a/src/randomenv.cpp +++ b/src/randomenv.cpp @@ -67,7 +67,8 @@ void RandAddSeedPerfmon(CSHA512& hasher) #ifdef WIN32 // Seed with the entire set of perfmon data - // This can take up to 2 seconds, so only do it every 10 minutes + // This can take up to 2 seconds, so only do it every 10 minutes. + // Initialize last_perfmon to 0 seconds, we don't skip the first call. static std::atomic<std::chrono::seconds> last_perfmon{std::chrono::seconds{0}}; auto last_time = last_perfmon.load(); auto current_time = GetTime<std::chrono::seconds>(); @@ -83,7 +84,7 @@ void RandAddSeedPerfmon(CSHA512& hasher) ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize); if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize) break; - vData.resize(std::max((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially + vData.resize(std::min((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially } RegCloseKey(HKEY_PERFORMANCE_DATA); if (ret == ERROR_SUCCESS) { |